UWorld Notes Neurology:
Spontaneous ​cerebellar​ hemorrhage is typically
caused by poorly controlled hypertension and
presents with ​occipital headache​, neck stiffness,
nausea/vomiting, nystagmus, and ​ipsilateral
hemiataxia​. Usually no hemiparesis or sensory loss.
Patients who develop serious bleeding (eg,
intracerebral hemorrhage) due to excess
anticoagulation with warfarin should have their
anticoagulation immediately reversed with
intravenous vitamin K and prothrombin complex
concentrate
Prothrombin complex concentrate (PCC) should also
be provided as it contains vitamin K-dependent clotting factors (eg, II, VII, IX, X) that offer
rapid (minutes) and short-term (hours) reversal of warfarin. Fresh frozen plasma can be
considered if PCC is not available; however, it takes longer to prepare/administer and
requires more volume infusion compared to PCC.
A MMSE score of less than ​24 points​ is suggestive of dementia (total maximum is
30).
Alzheimer's Disease
Neuroimaging may demonstrate atrophy which is more prominent in the temporal and parietal
lobes in patients. CT scan shows​ ​generalized/diffuse cortical atrophy​. ​The typical first
symptoms are subtle memory loss, language difficulties and apraxia, followed by impaired
judgment and personality changes.
There is selective loss of cholinergic neurons.
Tx: ​cholinesterase inhibitor​ (donepezil (Aricept), galantamine (Razadyne), galantamine ER
(Razadyne ER), and rivastigmine).
Frontotemporal Dementia
Similar to Alzheimer's, however he age of onset is earlier (usually at 40-60 years).
Initially less disorientation and memory loss, but more personality changes and loss of social
restraints.
Central retinal artery occlusion​ Is a monocular painless acute vision loss. “Curtain falling”
Funduscopic examination is often normal but may show embolic plaques and retinal whitening
(due to ischemia).
Painless, sudden (sometimes subacute) vision loss (or haze) can be seen In
central retinal vein occlusion, likely from venous thrombosis. It can progress to an
ischemic form that can be painful. Funduscopy usually reveals dilated and tortuous veins
leading to scattered and diffuse hemorrhages ("blood and thunder"), disk swelling, and/or
cotton wool spots.
Detached retina typically have light flashes, floaters, or a curtain across their visual field.
Parkinson’s​: Amantadine is a dopamine agonist used in the treatment of Parkinson's
Disease. DO NOT confuse with memantine which is used for moderate - severe dementia in
Alzheimer’s.
NPH:
Gait impairment is the most prominent clinical feature of NPH and ​appears early in its course.
The gait is broad-based and shuffling.
Gait impairment is the most prominent early clinical feature of
normal-pressure hydrocephalus but is a later finding in Alzheimer's dementia.
Optic neuritis usually presents in women age <50 with monocular
vision loss and pain on eye movement. Patients also typically have an afferent pupillary
defect with optic disc swelling on fundoscopy.
Aminoglycosides can cause ototoxicity (hearing loss) by damaging the
cochlear cells. In addition, some aminoglycosides (especially gentamicin) can also
damage the motion-sensitive hair cells in the inner ear to cause selective vestibular injury
(vestibulopathy) with or without significant ototoxicity.
An abnormal head thrust test can
help detect vestibular dysfunction due to gentamicin. The patient is asked to look at a
fixed target. Rapid head movement away from the target normally causes the eyes to
remain fixed on the target. However, patients with vestibulopathy are unable to maintain
their eyes on the target. The eyes move away and then return back to the target with a
horizontal saccade.
Infarction of the medial vermis of the cerebellum can cause severe vertigo
and nystagmus. Lateral cerebellar infarction causes dizziness, ataxia, weakness, and a
tendency to sway toward the side off the lesion.
Meniere disease is due to excess endolymphatic fluid pressure in the inner
ear that presents with the triad of episodic dizziness, low-frequency hearing loss, and
tinnitus.
can develop significant vertigo that lasts for days and is associated
with nausea, vomiting, and horizontal-torsional nystagmus during an episode.
Spasticity, bulbar symptoms, and exaggerated
deep tendon reflexes are signs of upper motor neuron damage, while fasciculations
indicate a lower motor neuron damage. Weakness and wasting of the muscles may be
due to both upper and lower motor neuron lesions.
Riluzole is a glutamate inhibitor that is currently approved for use in patients with
amyotrophic lateral sclerosis.
plasmapheresis and intravenous immunoglobulins are the main treatment modalities of
Guillain-Barre syndrome.
Phenytoin is a known teratogen capable of causing fetal hydantoin syndrome (eg,
orofacial clefts, microcephaly, nail/digit hypoplasia, cardiac defects, dysmorphic facial
features). Valproic acid is an antiepileptic drug that has been linked to
an increased risk of congenital anomalies such as neural tube defects (eg, spina bifida)
and dysmorphic facial features.
Anterior cord syndrome is commonly associated with burst fracture of the vertebra and is
characterized by total loss of motor function below the level of lesion with loss of pain and
temperature on both sides below the lesion with ​intact proprioception.
Central cord syndrome is characterized by burning pain and paralysis in
upper extremities with relative sparing of lower extremities. It is commonly seen in elderly
secondary to forced hyperextension type of injury to the neck.
Acute disk prolapse will be characterized by severe radicular pain
Lesions in the ​central nervous system ​occurring above the facial nucleus will typically cause a
contralateral​ lower facial weakness that spares the forehead.
It typically presents as bilateral leg weakness that ascends to the
arms, respiratory muscles, and face to generalized ​flaccid paralysis. ​Distal
paresthesias are common, but other sensory symptoms are uncommon or mild.
Reflexes are diminished or absent​. A
​ utonomic disturbances ​are common and include
tachycardia, bradycardia, hypertens.ion, orthostatic hypotension, and urinary retention.
Cerebral spinal fluid (CSF) analysis shows a high protein concentration with normal white
blood cell (WBC) counts (albuminocytologic dissociation).Guillain-Barre syndrome (GBS) is
characterized by ascending weakness, bulbar
symptoms (eg, dysarthria, dysphasia) and respiratory compromise
Gold standard treatment includes
intravenous immunoglobulin or plasmapheresis.
GBS
patients are at risk of developing dysautonomia (eg, arrhythmias, orthostatic hypotension,
urinary retention, ileus, lack of sweating) due to autonomic nervous system involvement.
About two-thirds of patients also complain of severe pain in the back or extremities.
Both IVIG and
plasmapheresis are equally beneficial and the choice of treatment depends on
patient-specific risk factors and availability.
Deep-tendon reflexes are also
normal in MG.
The CT/MRI findings of a butterfly appearance with central
necrosis is classic for GBM, and the heterogenous, serpiginous contrast enhancement is
typical of high-grade astrocytoma.
low-grade astrocytoma usually present with seizures, and have
a longer duration of symptoms. Furthermore, contrast enhancement is less likely.
Patients typically develop rapid onset of severe
eye pain and may see halos around lights. The affected eye will appear injected and
the pupil will be dilated and poorly responsive to light. Patients can also develop
tearing and headache with subsequent nausea and vomiting as the intraocular
pressure increases. Untreated acute ACG can lead to severe and permanent vision
loss within 2-5 hours of symptom onset.Acute angle-closure glaucoma commonly occurs as a
response to pupillary dilation from
medications (eg, anticholinergics, sympathomimetics) or another stimulus (eg, dim light).
Patients typically develop unilateral orbitofrontal headache associated with
nausea/vomiting, unilateral eye pain with conjunctival injection, and a dilated pupil with
poor light response.
Optic neuritis (acute vision loss, pain, afferent pupillary defect) most
commonly occurs in women age <50 and is often an initial presentation of multiple
sclerosis. Optic neuritis is ​rarely associated with nausea/vomiting.
In temporal arteritis, the erythrocyte sedimentation rate (ESR) is usually >50 mm/h. This
patient's
mildly elevated ESR may be due to her urinary tract infection.
Seizures (UWorld):
Evaluation of a first-time seizure:
Metabolic (eg, hypoglycemia, electrolyte disturbances) and toxic (eg, ​amphetamine use,
benzodiazepine/alcohol withdrawal) causes.
Basic laboratory tests typically include serum electrolytes, glucose, calcium, magnesium,
complete blood count, renal function tests, liver function tests, and a toxicology screen.
***If any of these are missing in the question, then this is the next step. THEN do CT &
EEG.
-
Unprovoked, first seizure (CBC, electrolytes, EKG all normal): Get ​Computed
tomography (CT) ​scan of the brain without contrast is as initial imaging study.
**Important: get neuroimaging before you do EEG (which is next step)
Helps to exclude acute neurologic problems (eg, intracranial or subarachnoid bleed) that might
require urgent intervention.
**MRI is more sensitive than CT in identifying most structural causes of epilepsy and is the
neuroimaging modality of choice in ​elective​ situations.
EEG is useful for risk-stratifying patients after a first-time seizure once metabolic and toxic
etiologies have been excluded.
The presence of ​epileptiform activity on an EEG indicates a higher risk of seizure
recurrence ​and therefore may justify the need to start anti-epileptic therapy.
Brain that has seized for >5 minutes is at increased risk of developing permanent injury due to
excitatory cytotoxicity.
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Cortical laminar necrosis ​is the hallmark of prolonged seizures and can lead to
persistent neurologic deficits and recurrent seizures.
Phenytoin and alcohol abuse can cause cerebellar atrophy.
Status epilepticus: any single seizure lasting >5 minutes or a cluster of seizures with the patient
not recovering a normal mental status in between.
Woman of reproductive age: NEVER give valproic acid.
Q60: