Neurosurgery
dear
d34r123@yahoo.co.id
KOMUNITAS BLOGGER UNIVERSITAS SRIWIJAYA
1. Which of the following are true about the history of neurosurgery? A. The history of
trepanation dates back to the Neolithic period. B. The earliest known writing dealing with
surgical topics is the Ebers papyrus. C. The writings of Hippocrates contain the first recorded
descriptions of trepanation. D. The three key developments that were necessary to permit
successful intracranial and intraspinal surgery were anesthesia, asepsis, and the concept of
localization of different functions in different areas of the nervous system. E. Victor Horsely of
London was the first surgeon to specialize in neurosurgery. Answer: ACDE DISCUSSION:
Many skulls from the Neolithic period have been found, some of which contain cranial
defects with evidence of bone healing, indicating that these individuals underwent
trepanation during life and survived the operation. The earliest known writing dealing with
surgical topics is the Edwin Smith papyrus. In the works of Hippocrates is the first written
account of trepanation. During the second half of the nineteenth century, general anesthesia
was introduced and the principles of asepsis were developed. These steps were important
for all areas of surgery, including neurosurgery. In addition, it became recognized that certain
areas of the nervous system were especially important for certain neurologic functions and
that intracranial and intraspinal abnormalities might be localized by the history and neurologic
examination findings, thus providing a more specific target for neurosurgical exploration
through the small bony openings to which surgeons were restricted at the time. Victor
Horsley of London was the first surgeon to prepare himself specifically for surgery of the
nervous system and to concentrate his efforts in that area. 2. The neurosurgeon who has
had the most profound influence on the development of neurosurgery is: A. Fedor Krause of
Germany. B. William Macewen of Scotland. C. Harvey Cushing of the United States. D. Egas
Moniz of Portugal. E. Goeffrey Jefferson of England. Answer: C DISCUSSION: Harvey
Cushing (1869–1939) laid the groundwork for much of what is done in neurosurgery.
For example, he standardized operative procedures and introduced many techniques and
instruments that are still in use. He also made careful and detailed studies of intracranial
tumors and established their classification. By his own multifaceted career and through his
many students from around the world he influenced the development of neurosurgery to a
degree not equaled before or since. 3. Which of the following conditions can be evaluated by
magnetic resonance imaging (MRI)? A. Stroke is suspected in a patient with a cardiac
pacemaker. B. Computed tomography (CT) shows a skull base tumor. C. A coma patient
with CT-demonstrated subarachnoid hemorrhage and an aneurysmal clip. D. A patient with
intractable complex partial seizure. E. A lung cancer patient whose plain film of the lumbar
spine shows a compression fracture of the L2 vertebral body. Answer: BDE DISCUSSION:
MRI has proved to be a better modality than CT for evaluation of disease of the central
nervous system (CNS), such as diseases at the base of the skull (particularly the sellar and
cerebellopontine angle cistern regions) and for most tumors, white matter disease (e.g.,
multiple sclerosis), early stroke, congenital abnormalities, vascular malformations, and spinal
disease. New techniques of MRI such as fast spin echo (FSE) pulse sequence have been
developed to detect mesial temporal sclerosis, which is the most common cause of
intractable complex partial seizure. Differentiating pure compression fracture from metastatic
disease of the vertebral bodies in a patient with known primary cancer is also possible by
new MRI technique; however, for patients with certain types of metal (pacemaker, surgical
clip, or foreign body, which may move in the magnetic field and cause injury to the patient or
significant artifacts) within the bodies, MRI is contraindicated. 4. Which of the following
statements about neuroradiologic imaging modalities is/are correct? A. Diffusion-weighted
MRI can differentiate tumor from edema and identify the nonenhancing part of the tumor. B.
For evaluating the stenosis of the carotid bifurcation, MR angiography (MRA) is the most
accurate imaging modality. C. Myelography is still useful in detecting some diffuse spinal
disease such as cerebrospinal fluid (CSF) seeding. D. For evaluating the bony detail of
patients with facial trauma, CT is a better imaging modality than MRI. E. Decreased amount
of N-acetyl aspartate (NAA) and increased amount of lactate can be shown in the MR
spectroscopy (MRS) of a patient with acute stroke. Answer: ACDE DISCUSSION: Diffusionweighted MR is a new development in MR applications and is sensitive to microscopic
motion of water protons (Brownian motion). Initial applications have involved imaging of early
stroke and neoplasia. Early evidence also suggests that diffusion-weighted imaging can
differentiate tumoral edema from tumor and identify the nonenhancing part of the tumor.
Doppler sonography, MRA, and CT angiography (CTA) are all useful for evaluating the
stenotic condition of carotid bifurcation noninvasively. However, sonography is very operator
dependent, and MRA commonly overestimates the degree of carotid stenosis resulting from
the turbulence, dephasing at points of stenosis or irregularity. CTA obtained by spiral or
helical CT has a good correlation rate with carotid angiography (92%). Conventional carotid
angiography remains the most accurate imaging modality for evaluation of the stenosis of
carotid bifurcation. Although CT and MRI have taken the place of myelography in evaluating
neurologic diseases, it is still useful in detecting diffuse subarachnoid seeding, which may be
difficult to identify on MRI. The bone detail and calcification are poorly identified on MR, so in
a patient with facial trauma, CT is a better modality than MR. With MRS, metabolites within a
selected region of interest (ROI) can be investigated, and spectral peaks that reflect the
concentrations of the metabolite within the ROI can be obtained. The metabolites include
lactate, neuronal marker (NAA), phosphorus metabolites, creatine, and choline. Reduction in
the NAA level and elevation in lactate level could be noted in acute stroke. 5. Which of the
following are true about intracranial tumors? A. The most common location of brain tumors of
childhood is the posterior cranial fossa. B. With few exceptions, examination of the CSF is of
no value in the diagnosis of an intracranial tumor. C. Even the most malignant of primary
brain tumors seldom spread outside the confines of the central nervous system (CNS). D.
The majority of astrocytomas can be cured surgically. E. Primary neoplasms of astrocytic,
oligodendroglial, or ependymal origin represent gradations of a spectrum from slowly growing
to rapidly growing neoplasms. Answer: ABCD DISCUSSION: In children, brain tumors are
more commonly situated below the tentorium than above it. In adults, the reverse is true.
Cytologic examination of CSF may provide critical diagnostic information in a patient with
meningeal carcinomatosis or subarachnoid spread of a primary brain tumor such as a
medulloblastoma, but in most instances CSF examination is not of significant value.
Furthermore, in a patient with a brain tumor lumbar puncture may be dangerous; it may
promote brain herniation. If there has not been a surgical breach of the dura mater, primary
brain tumors seldom spread to areas outside the intracranial and intraspinal compartments.
Most gliomas, including astrocytomas, cannot be cured by surgical resection. The pilocytic
astrocytoma of the cerebellum and the optic nerve glioma are exceptions to that rule.
Neoplasms of astrocytic, oligodendroglial, or ependymal origin vary histologically along a
spectrum from benign to malignant, with no sharp dividing line. Furthermore, even the most
benign-looking ones tend to recur after surgical resection. 6. The intracranial tumor most
likely to be encountered in a middle-aged man with the acquired immunodeficiency
syndrome (AIDS) is: A. Glioblastoma multiforme. B. Ependymoma. C. Meningioma. D.
Oligodendroglioma. E. Lymphoma. Answer: E DISCUSSION: Primary intracranial
lymphomas occur with increased frequency in patients who are immunocompromised, such
as recipients of organ transplants and patients with AIDS. 7. Patients who have survived a
subarachnoid hemorrhage from a ruptured intracranial aneurysm are at risk for: A.
Rehemorrhage. B. Cerebral artery vasospasm. C. Ischemic stroke. D. Hydrocephalus.
Answer: ABCD DISCUSSION: Twenty percent of patients who suffer a subarachnoid
hemorrhage from a ruptured intracranial aneurysm experience a second hemorrhage in the
ensuing 2 weeks. Following subarachnoid hemorrhage, the patient is at risk for developing
vasospasm, an idiopathic narrowing of the intracranial arteries that reside in the
subarachnoid space. Vasospasm manifests clinically as cerebral ischemia or stroke. Blood
within the subarachnoid space hinders normal flow and absorption of spinal fluid, frequently
resulting in mild hydrocephalus. Although this hydrocephalus usually resolves in the days or
weeks following the hemorrhage, in some cases it persists, necessitating a ventricular shunt.
8. Intracranial hemorrhages resulting from chronic arterial hypertension: A. Most often
originate in the basal ganglia. B. Most often originate in the subarachnoid space. C. Can
present as an enlarging cerebellar mass. D. Should not be treated surgically when they occur
in the cerebellum. Answer: AC DISCUSSION: The most frequent site of a hypertensive
hemorrhage is the basal ganglia. Blood may appear in the spinal fluid after the hemorrhage
has dissected through the brain parenchyma into the cerebral ventricles. Approximately 10%
of hypertensive hemorrhages originate in the cerebellum. Rapid removal of a cerebellar
hemorrhage can be life saving. 9. The physician is most effective in treating: A. Cerebral
contusions. B. Epidural hematomas. C. Cerebral lacerations. D. Hypoxia. Answer: BD
DISCUSSION: The physician can do very little to repair damage incurred at the time of the
head trauma such as cerebral contusions and lacerations. The physician\'s job is to thwart
secondary injuries to the brain. Enlarging intracranial mass lesions, especially hematomas,
are a common cause of secondary brain injury. Evacuation of an epidural, subdural, or
intracranial hematoma can be life saving. Metabolic insults are another cause of secondary
neurologic injury. Hypoxia, hypotension, and hypocapnia are avoidable secondary insults
that should be treated at the scene of the accident. Unfortunately, a large percentage of
trauma patients still arrive at the emergency room with metabolic abnormalities. 10. The
evaluation of a comatose patient with a head injury begins with: A. The cardiovascular
system. B. Pupillary reflexes. C. Establishment of an airway. D. Computed tomography (CT)
of the brain. Answer: C DISCUSSION: The treatment of every comatose patient begins with
an assessment of the patient\'s respiratory system, followed shortly thereafter with an
assessment of the patient\'s cardiovascular system. The unconscious patient\'s normal
protective pharyngeal reflexes are compromised, making mechanical airway obstruction and
aspiration pneumonia common events. Hypotension, secondary to intra- or extracorporal
hemorrhage, is deleterious to the patient\'s cerebral injury. Neurologic assessment is
undertaken only after the patient\'s respiratory and cardiovascular status are secured. 11. An
epidural hematoma: A. Is usually arterial in origin. B. Is usually accompanied by a skull
fracture. C. Should be suspected only in comatose patients. D. Can be diagnosed from a
brain CT scan. Answer: AB DISCUSSION: An epidural hematoma is a blood clot situated
between the skull and the dura. Epidural hematomas are usually arterial in origin and most
often are secondary to hemorrhage from the middle meningeal artery. Approximately 90% of
adult patients with an epidural hematoma have a concomitant skull fracture. Such skull
fractures are much less common in children under the age of 2 years. The epidural
hematoma is best diagnosed before transtentorial herniation and the development of third
cranial nerve palsy (“blown pupil”). The outcome of therapy is directly related to
the patient\'s level of consciousness before surgery. The clinical diagnosis of an epidural
hematoma is rarely confirmed by brain CT. 12. Which of the following statements is/are true?
A. Cranial osteomyelitis most frequently arises from the spread of bacteria through the
bloodstream from an infection elsewhere in the body. B. Subdural empyema is ordinarily
treated by administration of antibiotics without the need for surgical drainage. C. Bacterial
meningitis may lead to the development of hydrocephalus. D. A bacterial brain abscess
commonly presents as a mass lesion of the brain, without systemic signs of infection such as
fever or leukocytosis. E. Bacterial brain abscesses are difficult to visualize by CT. Answer:
CD DISCUSSION: Cranial osteomyelitis can arise from hematogenous spread, but more
often it results from direct spread from an infected paranasal sinus, inoculation by a
penetrating object, or operative infection of a craniotomy bone flap. Subdural empyema
ordinarily cannot be brought under control with antibiotics alone, and it does require surgical
drainage. One of the sequelae that can follow bacterial meningitis is hydrocephalus, which is
usually due to the obliteration of subarachnoid spaces and interference with CSF
reabsorption. A brain abscess, per se, is not ordinarily accompanied by systemic signs of
infection; these can be present if the patient also has meningitis or an active infection
elsewhere. CT, especially after intravenous administration of a contrast agent, is an excellent
way to demonstrate a brain abscess. 13. Complete excision of a brain abscess used to be
the preferred method of treatment, and it is still performed occasionally today. Most
commonly, now, a brain abscess is treated by: A. Systemic antibiotic administration. B.
Aspiration and drainage of the abscess through a small opening in the skull. C. Injection of
antibiotics into the abscess. D. Aspiration and drainage of the abscess plus systemic
antibiotic administration. E. Marsupialization of the abscess. Answer: D DISCUSSION: In the
past, the preferred treatment of a brain abscess was total surgical excision. Now that such
abscesses can be followed closely by CT, aspiration and drainage is usually employed, at
least initially, to reduce the mass effect, provide information about the pathogens, and lower
the risk of intraventricular rupture while the abscess is treated by systemic administration of
antibiotics. 14. Which of the following statements are true? A. Extradural neoplasms are
usually benign. B. A typical type of intramedullary tumor is a meningioma. C. An intradural
extramedullary neoplasm is ordinarily treated by a combination of surgical resection and
radiotherapy. D. Extradural neoplasms are usually malignant. E. A hemangioblastoma is a
benign intramedullary tumor that has the potential for surgical cure. Answer: DE
DISCUSSION: Extradural neoplasms are usually malignant, the most common type being a
metastasis to a vertebra from a primary carcinoma elsewhere in the body. A meningioma is
an extramedullary tumor arising from the meninges surrounding the spinal cord rather from
within the cord itself. Most intradural extramedullary neoplasms are benign tumors
(meningiomas, neurofibromas, schwannomas) that are treated by surgical excision without
postoperative radiotherapy. Despite its name, the hemangioblastoma is a benign tumor. It
typically arises within the spinal cord and can be cured if it is completely removed surgically.
15. Which of the following statements about intraspinal dermoid and epidermoid tumors and
lipomas are true? A. They are benign lesions. B. They can be found within the spinal
subarachnoid space. C. They can be found within the spinal cord. D. They are most common
in the lumbosacral area. E. They are at times associated with spinal dysraphism. Answer:
ABCDE DISCUSSION: Intraspinal dermoid and epidermoid tumors and lipomas are benign
lesions that can be found within the subarachnoid space or the spinal cord, or both. They are
most common in the lumbosacral area. Dermoid and epidermoid tumors can be associated
with spinal dysraphism and in particular with a dermal sinus tract that opens onto the back,
usually in the lumbosacral region. Lipomas are also associated with spinal dysraphism, at
times in the form of a lipomyelomeningocele with a tethered spinal cord. 16. Which of the
following statements are true? A. The usual symptomatic lumbar disc herniation occurs in a
posterolateral direction. B. Approximately 95% of lumbar disc herniations occur at the
L5–S1 or L4–L5 level. C. Sciatica is a term used to denote pain felt along the
distribution of the sciatic nerve. D. Weakness of dorsiflexion of the foot is a mechanical sign
of a lumbar disc herniation. E. X-ray films of the lumbosacral spine are obtained to
demonstrate the presence and location of a lumbar disc herniation. Answer: ABC
DISCUSSION: Most symptomatic lumbar disc herniations do occur in a posterolateral
direction, impinging on the overlying nerve root. About 95% of lumbar disc herniations occur
at the L5–S1 or L4–L5 level. Approximately 4% occur at the L3–L4
level, and less than 1% at the L2–L3 or L1–L2 level. Sciatica is a term used to
refer to pain along the course of the sciatic nerve. A ruptured lumbar disc typically causes
low back pain and ipsilateral sciatica. The mechanical signs of a lumbar disc herniation
include paravertebral muscle spasm, lumbar scoliosis, tenderness over one or more of the
lower lumbar spines, limitation of low back motion, limitation of straight leg raising, and a
positive popliteal compression test. Weakness of dorsiflexion of the foot is a neurologic sign,
not a mechanical sign. Plain x-ray films of the spine do not demonstrate the presence and
location of a lumbar disc herniation except in the rare instance of a calcified disc herniation.
Myelography, CT, or MRI is needed to visualize the herniated disc. 17. A right-sided disc
herniation at the L5–S1 level typically may cause: A. Low back pain and right sciatica.
B. Weakness of dorsiflexion of the right foot. C. A diminished or absent right ankle jerk. D.
Diminution of sensation over the medial aspect of the right foot, including the great toe. E.
Weakness of dorsiflexion of the left foot. Answer: AC DISCUSSION: A lumbar disc herniation
at the L5–S1 or L4–L5 level typically causes low back pain and ipsilateral
sciatica. If a ruptured L5–S1 disc causes weakness, it ordinarily involves plantar
flexion of the ipsilateral foot. Although a diminished or absent ankle jerk can be caused by
either an L5–S1 or an L4–L5 disc herniation, it is more common with the
former. The L5–S1 disc herniation ordinarily affects the S1 nerve root, which supplies
the lateral aspect of the foot, including the small toe. 18. Which of the following statements
are true? A. A symptomatic cervical disc herniation usually occurs in an anterolateral or
anterior direction and can be removed by a surgical approach through the front of the neck.
B. Cervical spondylosis represents a combination of degenerative disc disease and
osteoarthritis in the cervical spine. C. The joints of Luschka are the main spinal facet joints.
D. The term cervical myelopathy refers to pain and/or neurologic dysfunction in the
distribution of one or more cervical nerve roots. E. Full neck extension frequently
accentuates the neck and arm pain of a patient with a cervical disc herniation. Answer: BE
DISCUSSION: A symptomatic cervical disc herniation usually occurs in a posterolateral
direction, although a directly posterior (central) herniation may occasionally occur. The
posterolateral herniated disc can be removed by either a posterior or an anterior approach,
but the anterior approach is preferred for the central herniation because the surgeon can
remove the ruptured disc without manipulating (and possibly injuring) an already
compromised spinal cord. Cervical spondylosis represents a combination in the cervical
spine of degenerative disc disease and osteophyte formation (including that from
osteoarthritis of the apophyseal joints and the joints of Luschka). The cervical spine contains
the joints of Luschka, which are not present elsewhere in the spine. These joints, one on
each side of the disc, are separate from the more posteriorly situated facet joints
(apophyseal or interpedicular joints). The term cervical myelopathy refers to dysfunction of
the cervical portion of the spinal cord. Pain and/or neurologic dysfunction in the distribution of
one or more cervical nerve roots is termed cervical radiculopathy. Neck movement,
especially extension, often intensifies the neck and arm pain of a patient with a cervical disc
herniation. 19. A 36-year-old man developed neck and left arm pain. He noted paresthesias
in the left index and long fingers. He was found to have weakness of the left triceps muscle
and a diminished left triceps jerk. His left-sided disc herniation is most likely to be at: A.
C3–C4. B. C4–C5. C. C5–C6. D. C6–C7. E. C7–T1.
Answer: D DISCUSSION: This patient has all of the neurologic components of the most
common cervical disc syndrome, that caused by a herniation at the C6–C7 level with
compression of the C7 nerve root. 20. Which of the following statements are true? A. The
fascicles in a peripheral nerve divide and recombine along their course. B. Neurapraxia is a
type of nerve injury in which the nerve is still in continuity but individual axons are disrupted.
C. Recovery from neurotmesis requires surgical repair. D. Axonal sprouting begins 1 to 2
months after transection of a peripheral nerve. E. The patient\'s age influences the rate and
success of nerve regeneration. Answer: ACE DISCUSSION: Fascicles within a peripheral
nerve do divide and recombine along their course, forming funicular plexuses. If a segment
of a nerve is removed and the remaining ends are reapproximated, the fascicles will not
match exactly. In neurapraxia (first-degree nerve injury) anatomic continuity of the axons is
preserved, but there is selective demyelination. Surgical repair is not necessary. Recovery
does not depend on regeneration and occurs within days or weeks. With neurotmesis there
is significant disorganization in the nerve or actual disruption of its continuity, which
precludes recovery without surgical repair. Axonal sprouting ordinarily begins 10 to 20 days
after transection of a peripheral nerve. The patient\'s age affects the rate and success of
nerve regeneration: the younger the patient is, the faster and more complete is the recovery.
21. Which of the following statements are true? A. The Hoffmann-Tinel sign localizes the
level of a nerve injury. B. Causalgia is a term used to denote the etiology of pain. C.
Secondary repair of a lacerated nerve 3 to 8 weeks after injury has several advantages. D. A
surgeon who finds at delayed (3 to 8 weeks) exploration that a clinically nonfunctioning nerve
is in continuity should resect the injured portion of the nerve and suture together the ends. E.
If a nerve is found to be disrupted at delayed (3 to 8 weeks) exploration, the surgeon should
find the two ends of the nerve and suture them together. Answer: C DISCUSSION: The
Hoffmann-Tinel sign identifies the most distal point of small nerve fiber regeneration. As
nerve regeneration progresses, this point moves farther away from the level of the nerve
injury. Causalgia is a specific severe pain syndrome that may accompany a partial injury to a
mixed peripheral nerve. As compared with primary repair, the extent of damage to a nerve
can be better assessed and the correct amount trimmed off, with a secondary repair 3 to 8
weeks after the injury; the epineurium and perineurium are stronger and can be sutured more
easily; optimal operating room conditions can be arranged; and there is no time for wallerian
degeneration (i.e., the involved neurons are capable immediately of regenerating new distal
segments, and the regenerating axons can penetrate the repair site before a significant
amount of scar forms). If a clinically nonfunctioning nerve is in continuity when it is explored
some weeks after the initial injury the surgeon may find it helpful to stimulate the nerve
electrically proximal to the injury and to look distally for evidence of muscle contraction or
transmission of nerve action potentials. If there is no evidence of transmission across the
area of injury, the injured portion of the nerve should be excised and the cut ends sutured
together. If there is transmission across the area of injury, surgical treatment should be
limited to external neurolysis. A disrupted nerve should be reapproximated surgically, but
only after each end has been trimmed back to healthy fascicles. The trimmed nerve ends
must not be under tension when they are sewn together. 22. Which of the following lesions is
not one of the cutaneous stigmata of occult spinal dysraphism? A. Midline lumbar capillary
hemangioma. B. Focal hairy patch over the thoracolumbar spine. C. Dermal sinus located
above the midsacrum. D. Midline subcutaneous lipoma. E. Café-au-lait spot over the
thoracolumbar spine. Answer: E DISCUSSION: Café-au-lait spots are not a feature of
spina bifida occulta. The other four skin features all may be associated with significant
intradural pathology and warrant further investigation, most commonly with magnetic
resonance imaging (MRI). A dermal sinus tract that overlies the coccyx is a pilonidal sinus
and is not likely to be associated with intradural pathology. 23. Myelomeningoceles are
congenital malformations of the spinal cord. Which of the following findings are not
commonly associated? A. Hydrocephalus. B. Chiari II malformation. C. A midline dorsal
spinal mass easily noted at birth. D. Skin, bone, and dural defects superficial to the neural
placode. E. Mandatory urinary incontinence. Answer: E DISCUSSION: Myelomeningoceles
are usually associated with hydrocephalus and the Chiari II malformation. The
myelomeningocele sac is a midline dorsal spinal mass associated with defects in the skin,
bone, and dura overlying the neural placode, and the sac is readily apparent at birth.
Although the innervation of the bladder is dysmorphic, the majority of patients can achieve
social urinary continence through the use of clean intermittent bladder catherization. 24.
Which of the following signs does Horner\'s syndrome include? A. Ptosis. B. Facial
hyperhidrosis. C. Miosis. D. Exophthalmos. E. Mydriasis. Answer: AC DISCUSSION:
Horner\'s syndrome is due to loss of sympathetic innervation to the head and neck and
includes ptosis, anhidrosis, miosis, and the appearance of enophthalmos. The pupil is small
owing to loss of the tonic dilating effect of the sympathetics in the presence of continued
parasympathetic activity. There is sympathetic innervation to Muller\'s muscle in the upper
lid. Sympathetic nerves supply the sweat glands. It commonly follows stellate ganglion
resection and involves removal of the T1 cord level sympathetic outflow. 25. Cordotomy
results in which of the following? A. Contralateral loss of pin appreciation. B. Vagal instability.
C. Contralateral loss of temperature appreciation. D. Ipsilateral loss of pin and temperature
appreciation. E. Contralateral loss of two-point discrimination. Answer: AC DISCUSSION:
Cordotomy results in a lesion of the spinothalamic tract, which is a crossed pathway carrying
signals for pain and temperature. 26. Surgical therapy for epilepsy should be considered in
patients with: A. Seizures poorly controlled with antiepileptic medications. B. A single
epileptic focus. C. Seizures arising from multiple areas of cerebral cortex. D. Seizures arising
within the cortical motor strip. Answer: AB DISCUSSION: Because seizure surgical
procedures can never be guaranteed to alleviate seizures, it is only undertaken when
medical therapy fails to control the patient\'s seizures at doses that do not produce
intolerable side effects. Most surgical procedures are aimed at removing a single
epileptogenic area of cerebral cortex and are rarely employed in patients with multiple areas
of epileptogenic cortex. Eloquent areas of cerebral cortex such as those subserving speech
or hand functions generally are not intentionally resected in an attempt to achieve seizure
control. 27. The epileptogenic area of cerebral cortex is localized by: A. Direct identification.
B. Observing the patient\'s seizures. C. Electroencephalography. D. Visualizing cortical
abnormalities on cerebral imaging studies. Answer: BCD DISCUSSION: Since the exact
anatomy of an epileptogenic focus remains obscure, the focus of the patient\'s seizures is
determined by concordance of the clinical manifestations of the seizures, abnormalities
demonstrated by cerebral imaging, and abnormalities demonstrated by
electroencephalography. 28. Which of the following stereotactic procedures would be
performed primarily to alter the function of the brain? A. Stereotactic biopsy of a brain tumor
in the right posterior thalamus. B. Stereotactic radiotherapy of an arteriovenous malformation
in the right ventrolateral thalamus. C. Stereotactic radiofrequency lesion of the right
ventrolateral thalamus for Parkinson\'s disease. D. Stereotactic craniotomy for excision of
arteriovenous malformation in the right posterior thalamus. Answer: C DISCUSSION: The
biopsy of a lesion, radiotherapy treatment of an arteriovenous malformation, and excision of
an arteriovenous malformation are all procedures for structural lesions of the brain that can
be imaged by either CT or MRI. These structural lesions may or may not cause neurologic
changes, but the treatment directed at them is intended principally to keep lesion-induced
damage from increasing (for example, with the development of hemorrhage). On the other
hand, the thalamus is expected to have a normal structural appearance and function in
Parkinson\'s disease, when the neurochemical abnormality is located in the substantia nigra
and the striatum (caudate and putamen). Thus, a lesion is made in the thalamus principally
to affect the function of the brain, altering a normal component of one of the motor circuits to
compensate for the changes in the other parts (i.e., the basal ganglia). 29. What is the critical
difference between frame-based and frameless stereotactic procedures? A. The use of
digitized imaging studies such as CT and MRI. B. The use of rendered three-dimensional
images and a three-dimensional digitizer. C. Rigid fixation of the patient\'s head to the
operating room table. D. The presence of a lesion in the brain on digitized imaging studies.
E. The absence of a lesion in the brain on digitized imaging studies. Answer: B
DISCUSSION: Frame-based and frameless procedures both use digitized imaging studies as
the basis for converting the scan coordinate system into a treatment coordinate system. Both
types of procedures also require rigid fixation of the patient\'s head to the operating room
table and can be performed in the presence or absence of a lesion. The critical difference is
the use of a rendered, three-dimensional image and the three-dimensional digitizer, which
together allow the alignment to be generated between the patient\'s imaging studies and the
patient; this alignment occurs in frame-based stereotactic procedures because of the imaging
study performed after the frame is applied. 30. A 54-year-old patient with a history of
successful renal transplantation is hospitalized with a diverticular abscess. Surgical
exploration and drainage of the abscess with a Hartmann’s procedure is eventually
required. Although the patient’s septic appearance resolves, the patient complains of
severe headache and altered mental status is observed. A grand mal seizure follows. Which
of the following statement(s) is/are true concerning this patient’s management? a. An
intracranial epidural abscess is the likely diagnosis b. A bacterial brain abscess secondary to
hematogenous spread from the pericolonic infection is the likely diagnosis c. The abscess
expected in this case is usually solitary d. Appropriate parenteral antibiotic treatment should
be sufficient in this high risk patient. e. Despite aggressive surgical and medical
management, mortality rates associated in this patient may exceed 30% Answer: b, d, e A
brain abscess is a purulent lesion of brain tissue, beginning as a focal infection, usually in the
white matter surrounded by a typical inflammatory response. Brain abscesses usually are
secondary to focal infection elsewhere. Abscesses that develop by direct intracranial
extension are usually solitary and are typically found in the frontal and temporal lobes.
Multiple brain abscesses that develop in the septic patient are often related to bacterial
endocarditis, pneumonia, and diverticulitis. Abscess formation is frequent among patients
with compromised immunity either from an underlying illness or during pharmacologic
immunosuppression (i.e., during organ transplantation). Signs and symptoms of brain
abscess are related to its mass effect. Headache, focal neurologic deficits, and impaired
mentation are often noted. There may be little or no evidence of infection and the patient may
be afebrile. Seizures may occur. Intracranial epidural abscesses are quite uncommon and
are usually caused by a local extension of osteomyelitis or by hematogenous spread from a
distant suppurative focus. In cases of early abscess formation or high surgical risk, medical
therapy alone with the appropriate parenteral antibiotic may be sufficient. The most effective
therapy is drainage of the purulent material with simultaneous administration of appropriate
intravenous antibiotics. Although needle aspiration may be successful, craniotomy with
evacuation and removal of the abscess wall may be necessary. Surgical drainage reduces
the mass effect, thereby reducing the most critical and dangerous aspect of the infection. It
also allows accurate bacteriologic analysis. Despite aggressive surgical and medical
management, mortality rates associated with brain abscess approach 40%, especially in the
malnourished, chronically debilitated, or immunosuppressed patient. 31. All intracranial
nervous system tumors can be malignant in behavior due to their location. Which of the
following tumor(s) is/are usually considered to be histologically benign? a. Astrocytoma b.
Meningioma c. Schwannoma d. Medulloblastoma e. Craniopharyngioma Answer: b, c, e
Astrocytomas arise from the glial (stromal or supporting) cells of the brain. These tumors are
infiltrative and rarely can be totally excised. High-grade astrocytomas (grades III and IV) are
the most common primary intracranial tumor constituting 25% of all intracranial tumors and
50% of all gliomas. For the most part meningiomas are benign tumors that arise from the
arachnoid layer of the meninges occurring in the fourth through sixth decades of life.
Meningiomas can occur in a variety of sites and together constitute about 17% of intracranial
tumors. The treatment for meningiomas is surgical, however, total resection is uncommon,
frequently resulting in recurrence. Malignant histologic appearance of meningiomas is far
less common than a benign appearance. Schwannomas are benign tumors that arise from
the Schwann cells that surround axons as they leave the CNS by way of the cranial nerves.
Schwannomas constitute 8% of all intracranial tumors and are almost twice as common in
females as males. Medulloblastomas are part of the primitive neuroectodermal classification
of brain tumors. They are thought to arise from primitive cells of the cerebellum, most likely
the external granular layer. They constitute 8% of all gliomas. Two-thirds of
medulloblastomas occur in children, with the average age of onset being 14 years. They
commonly metastasize throughout the subarachnoid space by way of the CSF and are rarely
found outside the CNS. Treatment involves aggressive surgical removal of the tumor
followed by radiation of the brain. Chemotherapy is commonly used as well.
Craniopharyngiomas are histologically benign and arise from nests of squamous cells within
the pituitary gland. They may be found in the intrasellar or suprasellar locations but are
always along the craniopharyngeal canal. Over 50% occur in the first two decades of life.
Although craniopharyngiomas can be cured with surgical removal or controlled with radiation,
many of these histologically-benign tumors cannot be removed safely. 32. A 54-year-old
physician with a history of lung cancer presents after a grand mal seizure with a several
month history of increasing headaches. Which of the following statement(s) is/are true
concerning this patient? a. Lung cancer as well as breast, kidney, testicular and colon cancer
are the most common primary sites to metastasize to the brain b. A symptomatic, solitary
metastatic brain lesion should be removed if surgically accessible c. If excision is complete,
no further chemo-or radiation therapy is indicated d. Symptoms of cranial nerve palsies,
radiculopathies and nuchal rigidity are suggestive of meningeal carcinomatosis e. Cytologic
examination of CSF is almost always positive with meningeal metastasis Answer: a, b, d The
percentage of intracranial tumors representing metastases approach 25%. Malignant cells
invade the CNS hematogenously and tend to lodge at the grey and white matter junction.
Although any malignancy has the potential to metastasize to the brain, the most common
primary sites are the lung, breast, kidney, testes, colon, and skin. The presenting symptoms
are determined by the site or sites of the metastases. Symptoms commonly include
headache, mental status changes, seizures and hemiparesis. In general, a symptomatic
solitary lesion that is surgically accessible should be removed if the patient has at least a sixmonth life expectancy. Surgery should not be undertaken for multiple lesions or in patients
who are severely afflicted by their primary disease. Whole brain irradiation is almost always
indicated after surgical resection. There is little evidence that chemotherapy plays a
significant role. Tumor metastasis to the leptomeninges (meningiocarcinomatosis) is also
common particularly in adults with lymphoma, breast, and lung cancer. Patients may present
with cranial nerve palsies, radiculopathies, obstructive hydrocephalus. They often have signs
and symptoms suggestive of meningitis. Analysis of the CSF is usually critical, often
revealing increased opening pressure, elevated white blood cell count and protein levels, and
a decreased glucose. Cytology should always be obtained, however it is not universally
positive for malignant cells. 33. The management of a skull fracture is highly dependent on
the type and location of the fracture. Which of the following statement(s) is/are true
concerning skull fractures? a. A simple nondepressed linear skull fracture is of no significant
consequence b. Most depressed skull fractures require surgery to elevate the depressed
bone fragment regardless of neurologic status c. Basal skull fractures involve the base of the
calvarium and may be suggested by bruising about the eye or behind the ear d. CSF
rhinorrhea associated with a basal skull fracture requires prompt surgical exploration and
repair of the defect e. Prophylactic antibiotics are indicated in all basal skull fractures
associated with CSF rhinorrhea or otorrhea Answer: b, c Skull fractures are classified
according to whether the skin overlying the fracture is intact (closed) or disrupted (open or
compound), whether there is a single fracture line (linear), several fractures radiating from a
central point (stellate), or fragmentation of the bone (comminuted), and whether the edges of
the fracture line had been driven below the level of the surrounding bone (depressed) or not.
Simple skull fractures (linear, stellate, or comminuted nondepressed) require no specific
treatment. They are, however, potentially serious and can be fatal if they cross major
vascular channels in the skull, such as the groove of the middle meningeal artery or the dural
venous sinuses. Depressed skull fractures often require surgery to elevate the depressed
bone fragments. If there are no adverse neurologic signs and the fracture is closed, repair
may be done electively. Basal skull fractures involve the floor of the calvarium. Bruising may
occur about the eye (raccoon sign) or behind the ear (Battle sign), suggesting a fracture
involving either the anterior or middle fossa, respectively. Any associated cerebrospinal fluid
(CSF), rhinorrhea, or otorrhea should be treated expectantly. Traumatic CSF leaks typically
stop within the first 7 to 10 days. Should a leak persist, lumbar CSF drainage can be
implemented to seal the leak by lowering CSF volume and intracranial pressure. If this
therapy fails, surgical exploration and oversewing of the defect with a facial patch graft is
indicated. Less than 5% of patients actually require surgical repair. Prophylactic antibiotics
are no longer used since prospective studies have failed to demonstrate any significant
benefit from their use. 34. Which one or more of the following statement(s) is/are true
concerning spinal cord injuries? a. Incomplete spinal cord lesions may result in the BrownSequard syndrome which is manifest by contralateral loss of motor function and positionvibratory sensation with ipsilateral loss of pain and temperature sensation below the level of
the injury b. The presence of hypotension associated with a cervical spine injury following
blunt trauma would suggest invariably the presence of blood loss in association with the
neurologic injury c. Cervical spine malalignment can almost always be reduced by skeletal
traction d. An indication for early operation following spinal cord injury is neurologic
deterioration in a patient with initially incomplete cord lesion e. The natural history of a cord
injury in which some function is preserved immediately after the injury is progressive loss of
function despite appropriate treatment Answer: c, d, e Injuries to the spinal cord can be either
complete, resulting in total loss of function below the level of the injury or incomplete which
may be manifest in the Brown-Sequard syndrome. This syndrome is manifested by ipsilateral
loss of motor function and position-vibratory sensation with contralateral loss of pain and
temperature sensation below the level of the injury. Anatomically, this presentation is
explained by hemisection of the cord. In addition to the neurologic deficit, acute spinal cord
injury is accompanied by many systemic responses. Blood pressure is generally low if the
cord injury is above the T-5 level. Such an injury effectively denervates the sympathetic
nervous system, which leads to increased venous capacitance and decreased venous return.
The resulting hypotension is controlled by the administration of intravenous fluids. The goals
of treatment of a spinal injury are to correct spinal alignment, to protect undamaged neural
tissue, to restore function to irreversibly damaged neural tissue, and ultimately to achieve
permanent spinal stability. Reduction and immobilization of any fracture or dislocation must
receive top priority to meet these objectives. Cervical spine malalignment can almost always
be reduced by skeletal traction. Traction may be applied using skull tongs or halo apparatus.
Both are seated percutaneously through the outer table of the skull while the patient is kept
supine and immobilized. The indications for early operation on patients with spinal cord injury
include the inability to close the fracture or dislocation satisfactorily by closed methods,
neurologic deterioration in a patient with initially incomplete cord lesion, and severe
compression of the spinal cord by an intraspinal mass shown on myelography or MRI. Either
the anterior or posterior approach may be used, depending on the nature of the spine injury
and the degree of instability. If cord function is preserved immediately after injury, additional
function usually returns if the cord and spine are protected from secondary injury. Patients
with complete injuries rarely recover function below the level of the lesion. 35. A 48-year-old
man presents with chronic back pain with radiation into the buttock, posterior thigh, and calf.
Which of the following statement(s) is/are true? a. In the lumbar spine, more than half of
clinical problems arise from L-2 to L-3 and L-3 to L-4 intervertebral discs b. Imaging studies
with CT or MRI followed by myelography is necessary for the diagnosis in most patients c.
Initially, medical management is indicated in all patients who do not have neurologic
deterioration d. Surgical treatment is reserved for the patient with acute or progressive
neurologic deficit, chronic disabling back pain, or both e. Anal sphincter muscle disturbances
can be expected in most patients and are of no clinical significance Answer: c, d Herniated
lumbar intervertebral discs often produce some degree of nerve compression. The severity of
the syndrome depends on the degree of root compression. In the lumbar spine, more than
90% of clinical problems arise from the L-4 to L-5 and L-5 to S-1 intervertebral discs.
Diagnosis is based on history of back pain usually with radiation into the buttock, posterior
thigh, and calf at both levels. Pain may be exacerbated by coughing, sneezing, or straining.
Bending and sitting accentuate the discomfort, whereas lying down characteristically relieves
it. Thorough evaluation of back pain is necessary because of the multitude of causes for
such symptoms. Plane films of the lumbosacral spine can identify congenital or bony
changes. Disc space narrowing is an unreliable sign, however, of symptomatic disease since
narrowing of the disc space can occur without clinical symptoms. Myelography can be
diagnostic in symptomatic lumbar disc disease, but CT alone delineates the lesion in most
cases. MRI has replaced myelography and CT at some centers in the workup of lumbar
radiculopathy. With contrast, it can be extremely helpful in previously-operated cases.
Initially, medical treatment is indicated in all patients who do not have neurologic
deterioration. Bed rest, local heat, analgesics, and skeletal muscle relaxants are usually
effective within a few days. Physical therapy and limited exercise often help when the acute
episode passes. With an aggressive conservative management, most patients improve
sufficiently to return to full activity. Recurrent symptoms may be treated in a similar fashion,
often successfully. Surgical treatment is reserved for a patient with acute or progressive
neurologic function, chronic disabling pain, or both. The acute onset of weakness or
sphincter disturbances constitute an emergency, demanding prompt diagnosis and early
operation. 36. Which of the following statement(s) is/are true concerning intracranial
aneurysms? a. Over 85% of cerebral aneurysms occur in the carotid or anterior circulation b.
Most intracranial aneurysms are congenital c. Up to 20% of patients with cerebral aneurysms
have multiple aneurysms d. Most patients with intracranial aneurysms present with signs and
symptoms of subarachnoid hemorrhage with severe headache followed by neck stiffness and
photophobia e. Once the diagnosis of aneurysmal rupture is confirmed, surgery should be
performed immediately Answer: a, b, c, d Most intracranial aneurysms are congenital,
evolving and developing during life. They are typically found at the bifurcation of major
vessels of the circle of Willis with over 85% occurring in the carotid or anterior circulation. Up
to 20% of patients with aneurysms will have multiple aneurysms. Patients with intracranial
aneurysms most commonly present with signs and symptoms of subarachnoid hemorrhage.
In fact, 80% of nontraumatic subarachnoid hemorrhages are caused by aneurysm rupture.
The patient notes a sudden severe headache commonly followed by neck stiffness and
photophobia due to associated meningeal irritation caused by subarachnoid blood. Transient
loss of consciousness may occur. Some patients may develop a focal neurologic deficit or
become comatose due to acute rise in ICP. The diagnosis of subarachnoid hemorrhage is
usually made clinically and confirmed either by noting blood within the subarachnoid spaces
on CT scan or finding bloody CSF with xanthochromia on a lumbar puncture. The CT scan
should be obtained first since it spares the patient an LP and also eliminates the potential
risk of brain-stem compression from herniation if an unsuspected mass lesion is present.
Complete cerebral angiography is then used to identify and delineate the aneurysm and, at
the same time, rule out multiple aneurysms or an associated arterial venous malformation.
Once the diagnosis of aneurysmal rupture is confirmed, the patient is placed on a medical
regimen to reduce the risk of rebleeding. This includes strict bed rest with the head elevated.
Blood pressure is tightly controlled below 150 mm Hg systolic. Careful observation is
necessary to watch for signs of raised ICP which may be attributable to delayed
hydrocephalus. Anticonvulsants are started for seizure prophylaxis. The ultimate treatment of
aneurysms is microsurgical dissection and obliteration, usually by placing a metallic clip on
the aneurysm’s neck by way of a craniotomy. The timing of surgery depends on the
clinical grade of the patient. Good grade (I and II) patients should undergo operation within
72 hours of rupture. Poor grade (III and IV) should continue intensive medical management
until they improve to a lower grade because mortality is higher with higher grades. Surgically
accessible unruptured aneurysms should be operated on electively to prevent rupture. 37.
The severity of a brain injury reflects the result of both the primary injury and resulting
complications constituting the secondary injury. Which of the following statement(s)
concerning brain injury is/are true? a. Increased intracranial pressure (ICP) contributes to
secondary brain injury by reducing cerebral perfusion pressure producing cerebral ischemia
b. Intracranial hypertension is one of the most important factors affecting outcome for brain
injury c. In using the Glasgow Coma Scale (GCS), the higher the score, the poorer the
neurologic status d. Comatose patients who require emergent surgery for other injuries
should have their ICP monitored e. Corticosteroids are the first line treatment for elevation of
ICP Answer: a, b, d Elevated intracranial pressure (ICP) contributes to secondary brain injury
by reducing cerebral perfusion pressure which, by definition, is the difference between the
mean arterial blood pressure and the cerebral venous pressure. For all clinically-relevant
purposes, the cerebrovenous pressure is identical to ICP. Thus, when ICP increases and the
mean arterial blood pressure remains stable, cerebral perfusion pressure decreases. When
cerebral perfusion pressure falls below 70 mm Hg, cerebral blood flow is compromised,
producing cerebral ischemia and compounding the primary injury with secondary insult. In
studies of head injury mortality, intracranial hypertension appears to be one of the most
important factors affecting outcome. For this reason, aggressive management to circumvent
cerebral blood flow reduction and secondary injury is imperative. Initial clinical assessment is
essential. Although extensive neurologic testing is limited in uncooperative or unresponsive
patients, certain features of examination are crucial. The Glasgow Coma Scale (GSC) uses a
numerically scored elevated eye-opening and motor behavior, both spontaneously and in
response to stimulation. The higher the score generated in assessment, the better the
patient’s neurologic status. This scale also provides useful information regarding the
ultimate outcome of the head-injured patient. ICP monitoring may be indicated especially in
patients with marked depression or deterioration in neurologic function. Comatose patients
who require emergent surgery for other injuries should also be monitored, since frequent
neurologic assessment is not possible during general anesthesia. The steps in management
to prevent ICP elevation include elevation of the head to facilitate venous return. Sedation
reduces posturing and reflexively combative activity which both worsen ICP. Hyperventilation
keeps arterial carbon dioxide levels between 25 and 28 mm Hg and lowers cerebral blood
volume and ICP. Mild dehydration with judicious sodium replacement and prompt treatment
of inappropriate secretion of the antidiuretic hormone (SIADH) protects the brain from insult
secondary to fluid overload. If ICP remains elevated despite these measures, mannitol, 0.5 to
1 g/kg and furosemide, 0.1 mg/kg can be used to reduce cerebral edema. Deep sedation
with narcotics and even the use of paralyzing agents may be helpful. Corticosteroids are
occasionally used, but have no proven benefit. 38. A 15-year-old boy is struck by a baseball
in the side of the head. He briefly looses consciousness but quickly returns to a lucid state.
Which of the following statement(s) is/are true concerning his subsequent course. a. The
initial neurologic finding may be dilatation of the ipsilateral pupil b. If the patient has a normal
neurologic examination at the time of emergency room assessment, he can be discharged
safely to home c. A head computed tomography (CT) scan should be performed regardless
of the current neurologic examination d. The likely mechanism of injury arises from a tear of
a branch of the middle meningeal artery as it courses through a grove in the skull at the area
of impact e. If, after an initial lucid interval, a rapid progression to coma with fixed and dilated
pupils and decerebration occurs, the most likely CT finding would be a subdural hematoma
Answer: a, c, d Hemorrhage between the inner table of the skull and the dura mater most
commonly arises from a tear of the middle meningeal artery or one of its branches that
course through a grove in the lateral skull. Arterial bleeding strips the dura from the
undersurface of the bone and produces still more bleeding because the small bridging veins
from the dura to the skull are torn. The result is an epidural hematoma which may rapidly
increase in size and compress the cerebral cortex. An epidural hematoma classically follows
a blow to the head which causes a brief period of unconsciousness. After the patient regains
consciousness, there may be a lucid interval during which there are no abnormal neurologic
symptoms or signs. As the hematoma enlarges, hemispheric compression occurs. With time
the medial portion of the temporal lobe is forced over the edge of the tentorium causing
compression of the oculomotor nerve and subsequent dilatation of the ipsilateral pupil.
Similarly, compression of the ipsilateral cerebral peduncle causes contralateral hemiparesis,
which progresses to decerebrate posturing. Coma, fixed and dilated pupils, and
decerebration is the classic triad suggestive of transtentorial herniation. Epidural hematomas
are curable lesions, but the mortality rate remains high because the severity of the injury is
often not recognized early. A patient may be seen during a lucid interval and discharged.
Later, the patient becomes unconscious because of progressive brain compression by the
expanding hematoma. Because of the danger of misdiagnosis, any patient with a history of a
blow to the head leading to a period of unconsciousness should have a CT scan. 39. Which
of the following statement(s) is/are true regarding peripheral nerve injuries? a. Neuropraxia is
temporary loss of function without axonal injury; structure damage does not occur b.
Axonotmesis is disruption of the axon and axon sheath associated with traumatic injury c.
Neurotmesis is disruption of the axon with preservation of the axon sheath which usually
preserves sensory and motor function d. Electromyography (EMG) is useful in the early
assessment of nerve injuries e. Regeneration in a peripheral nerve occurs at a rate of 1
mm/day, so improvement may not be obvious for many months Answer: a, e Peripheral
nerve injuries may be categorized functionally. Neuropraxia is a temporary loss of function
without axonal injury and structural damage does not occur. Axonotmesis is a disruption of
the axon with presentation of the axon sheath. Wallerian degeneration of the distal axon
fragment occurs. Stretched or prolonged compression causes this functional and structural
loss. Regeneration of the proximal axon occurs, but functional recovery depends on the
associated injuries, the amount of healthy proximal axon remaining after injury, and the age
of the patient. Neurotmesis is disruption of both the axon and axon sheath with
corresponding loss of function and is caused by transection of a nerve. Regeneration occurs,
but function rarely returns to normal. Clinically, sensory motor changes correspond with the
peripheral nerve involved. Detailed history and a precise neurologic examination can localize
the site of injury with accuracy. EMG is not useful within the first three weeks of injury but is
highly effective for monitoring the status of the degeneration and regeneration process that
occurs later. Regeneration in a peripheral nerve occurs at 1 mm/day (roughly 1 inch each
month), so improvement may not be obvious for months. Factors that adversely affect the
return of function include advanced age of the patient, proximal nerve injury, extensive nerve
tissue loss, associated soft tissue injury, and mixed sensory motor function. Unfortunately,
incomplete neurologic recovery is often the rule. DOWNLOAD