Orr Exam 2 Review
Vertigo:
1. Know the basic pathophysiology of vertigo:
- Sensory mis-match from any point in the vestibulo-cerebellar network projecting to
the integrative cortex.
2. Differentiate central vs. peripheral vertigo:
- Central has brainstem/ other neuro signs
o Ex. MS, TIA, stroke- classic “neighborhood signs”
- Peripheral will often have ear symptoms
o Ex. Tinnitus or hearing issues
3. Duration of symptoms is key history
- Sec-min= BPPV
- 1-2 hour per episode= Meniere’s Dz
- Days= labyrinthitis
- Sudden onset + other signs= stroke
- Subacute progression from tinnitus vertigo + worse w/ supine positioning=
Acoustic Neuroma
4. Dx & mechanism/Mx and Tx of BPV
- Dix-Hallpike maneuver used for dx of BPPV
- Most common in middle/ older adults
- Can be precipitated by movement
o Lying down, rolling in bed
- N/V/ blurred vision common NO complaints of hearing loss or tinnitus
- Latency of 5-15 seconds after maneuver before sx
- Habituation occurs= will stop triggering vertigo if repeated multiple times
- Nothing else wrong with pt
- Unilateral= one ear affected
- Mx= Calcium carbonate crystals fallen out of the utricle into the posterior
semicircular canal  irritate the hair cells  send bad volley of sensory signals=
asymmetric sensory vestibular input
- Tx w/ Epley maneuver
o Tilt head towards side of problem= look at where ceiling meets the wall
o Lay down keeping head position, wait for vertigo to stop
o Look towards other side of head at where ceiling meets the wall, wait for
vertigo to stop
o Have pt lay lateral recumbent on the same side they were just looking
o Tuck the chin to the chest and have pt look where wall meets floor, wait for
vertigo to subside
o Have pt sit up with chin still tucked to chest and wait for vertigo to subside
- Tx could also include antihistamine w/ anticholinergic effects such as meclizine
5. Dx of brainstem stroke/TIA with vertigo
- Older adults w/ multiple vascular risk factors
- Sudden onset
-
Event in the vestibular nucleus of the pons will show brainstem signs
o UMN weakness
o Sensory disturbance
o CN dysfunction
6. Wallenberg stroke syndrome and “neighborhood signs”
- Caused by infarction in the lateral medulla
o Usually due to PICA
- Affects Horner’s tract= Horner’s syndrome= double vision, decreased pupil size,
drooped eyelid, less sweating
- Affects vestibular nucleus= vertigo/ dizziness
- Affects spinothalamic tract= CT loss pain/temp
- Affects trigeminal nuc= IPSI loss facial pain/temp
- Affects nucleus ambiguous= dysphagia
- Affects inferior cerebellar peduncle= IPSI intention tremor
7. Dx labyrinthitis
- Duration of attack is measured in days
o 2/3 monophasic, 1/3 recurrent  warn pts
- Acute onset
- Usually following a URI
o Aural sx will occur on the inflamed/ infected side
- May have mild hearing disturbance
- Affects any age, gender
- Aggravated by movement.
- Jerk nystagmus present
- May have gait disorder during attack
- Hallpike will be negative for BPPV
8. Dx acoustic neuroma
- Hearing loss, tinnitus, facial weakness often precede the vertigo
- Nystagmus, worse w/ movement
- Most common in adults
- Sx will get progressive as the neoplasm grows
o Most often found at the cerebello-pontine angle or in internal auditory canal
- NO latency, adaptation, fatigue
- Will find mass on MRI
- Surgery is curative, can also tx w/ meclizine
9. Why does nystagmus occur w/ vertigo
- Medial longitudinal fasciculus (MLF) directly attaches to the vestibular nuclei in
brainstem.
- Issue w/ vestibular nuclei in (ex. Wallenberg syndrome) will also affect MLF which
controls CN 3 + 6
- Vertigo and nystagmus will occur together
10. Mx of vertigo in MS
- Young woman
- Issue with seeing, weakness, or sensory loss (temporary loss)
-
Vertigo due to demyelination of cerebellar tracts/ peduncles
Myelin stripped from outside vestibular nuclei but attacks oligodendrocytes b/c CNS
issue
Sensory Disorders:
1. Understand “sensory ataxia” and Romberg
- Sensory complaints
o Numbness
o Tingling
o Pain in feet
- Frequent tripping or stumbling on irregular surfaces
- ALWAYS worse in the dark
o Proprioception knocked out
o Balance relies on sight
- Subacute or chronic onset
- NO complaint of dysarthria or nystagmus
- Sensory deficits in LE
o Decreased vibratory sense in feet
o Decreased joint position sense in feet
- Romberg sign is +
- Underlying cause
o DM neuropathy
o B12 deficiency
o Tabes dorsalis Argyll-Robertson pupil (not react to light but will to
accommodation)
2. Know the anatomy of spinothalamic tract (STT) and Dorsal Columns (DC)- memorize
diagram in DSA and be able to reproduce.
- STT  Lateral: pain/temp, Anterior: crude touch/ pressure
o 1st order neuron: A-delta/ pain enters the spinal cord
o Synapse in ipsilateral gray matter
o 2nd order neuron: Decussates in spinal cord as the anterior white commissure
 ascends contralaterally
o Synapse in VLP (thalamus)  sensory cortex
- DC  Pressure, vibration, fine touch, conscious proprioception
o 1st order neuron: Sensory nerve ending enters the spinal cord, ascends
ipsilaterally in the dorsal column
o Synapse in ipsilateral medulla
o 2nd order neuron: Decussates in medulla  ascends contralaterally as the
medial lemniscus
o Synapse in VLP (thalamus)  sensory cortex
3. Dx thalamic stroke
- Older adult w/ multiple vascular risk factors
- Sudden neurological event
-
4.
5.
6.
7.
Distribution will be complete numbness of sensory modality down the middle of the
body
o Ex. R side of body numb= stroke on L side
Dx cervical/lumbar/ sacral radiculopathy
- Pain in area of radiculopathy is common
- Weakness presents in the distribution of a single nerve root
- Pain or numbness may radiate into a limb
- C6
o Outside of the arm down to and around the thumb
- T10
o At the level of the belly button
- L2-3
o Below inguinal ligament
o Wraps from outer hip medially
- L5
o Down the center on the top and bottom of the foot
o Does not include the kneecap
- S1
o Lateral side of the leg
o Goes up and behind the entire leg
o Continues around the top of the buttock area
Mx of Romberg sign
- Loss of vibration and proprioception due to sensory ataxia
- Don’t know where they are standing in the dark
- If they close eyes they will begin to fall b/c no vision is available to help compensate
for lost proprioception
Dx syringomyelia
- Middle/ older adults
- Hx trauma, especially to cervical spine is common
- Onset may be insidious or gradual
- Decreased pain and temperature sensation in UE
- Shawl like distribution over the shoulders
- Light touch and position sense are NOT affected
- Possible LMN weakness and atrophy in the hands
- MRI is most sensitive and specific test for Dx
Dx parietal lesion by cortical sensory signs
- CT sensory disturbance to any/all modalities
- Language disturbance if dominant hemisphere is affected
- Cortical sensory disturbances (agnosia’s)
o Astereognosis= loss of recognition of object by feeling
o Agraphesthesia= loss of recognition of writing on hand
o Extinction with bilateral simultaneous stimulation
o Diminished 2 point discrimination
o CT pinprick, temp, vibration diminished
o Spatial disturbance in the non-dominant hemisphere is affected
- Brain MRI/CT is usually diagnostic
8. Dx Subacute-Combined Degeneration
- Due to vitamin B12 deficiency
- Subacute/ gradual onset
- Older patient
- Gait disturbance due to sensory ataxia (+ Romberg)
- Decreased vibration/ position sense in feet
- UMN weakness in legs
9. Mx diabetic polyneuropathy
- Chronic high blood sugar levels damage the small arteries supplying peripheral
nerves
- Bilateral, stocking glove pattern (feet and hands)
- Affects LMN circuit causing flaccid weakness and other LMN signs
Traumatic Brain Injuries:
1. Be able to ID imaging with EDH and SDH
- EDH
o Biconvex shape
o Hyperdense
- SDH
o Crescentic
o Hyperdense
o Can cross suture lines
2. Dx pathologic anatomy for EDH
- Usually due to fracture of temporal bone
- Fracture causes tearing in middle meningeal artery (MMA)= epidural location
- High pressure of artery results in mass effect, see above for ID
3. Dx traumatic lesion to cauda equina
- Crushing injury at L4-5
- Weakness below cord ending at L1-2
- LMN findings
4. Know management strategy for sports concussion:
- Remove from play that day
- Need to be cleared by physician via graduated exercise
- Happens over several days
- Can’t have recurrent sx in that period
5. Dx cervical spine trauma
- Traumatic event such as a car wreck or falling down stairs
- UMN, spasticity, weakness, pathologic reflexes, sensory loss below the lesion
- C2
o Posterior half of skull dermatome
- C3
o High turtle neck dermatome
o Keeps the diaphragm alive= respiratory compromise is likely
-
C4
o Low collar shirt dermatome
o Keep diaphragm alive, resp compromise
-
C5
o Lateral middle of the arm
o Keeps diaphragm alive, resp compromise
o Loss of Biceps/ brachioradialis reflex
-
C6
o Lateral arm including thumb dermatome
o Biceps/brachioradialis/triceps reflex lost
-
C7
o Middle back of arm & 2nd and 3rd fingers dorsally dermatome
o Loss of triceps reflex
-
C8
o Medial surface of arm on front and back & 4th and 5th fingers
o Loss of triceps reflex
6. Dx/definitions of concussion/ TBIm
- Hx acute head trauma, witnessed, LOC= mild TBI
- LOC NOT required to dx concussion
- Degree of amnesia following injury is common
- Dizziness, HA/N/V, confusion are all common sx
- May say they are dazed, confused, saw stars
- Sx have to match the head injury
- Imaging is normal for concussion, if not then another problem
7. Know imaging characteristics of concussion
- CT/MRI are normal
Neuroembryology:
1. Know the whole DSA
- Made a mind-map to trace the origins of things
2. Dx NTD: be able to ID anterior/rostral vs. posterior/ caudal NTDs
- Anterior/rostral NTDs
o Anencephaly= no closure to the cranial vault, no complete brain
development
o Holoprosencephaly= failure to separate hemispheres along the midline,
spectrum of deficits from cleft palate to cyclopia.
- Posterior/caudal NTDs
o Spinal bifida occulta= most common, no neurodeficits, tuft of hair or dimple
at the level of defect on the back
o Meningocele= meninges herniate through the opening, can have deficits
below the defect level
o Meningomyelocele= neural elements herniate too, severe deficits below the
level
o Rachishisis= open defect, complete failure to close
3. Know the derivatives of the neural tube and neural crest
- Use flow chart
4. Dx meningomyelocele by diagram/pic
- Outpouching on the back with meninges and neural elements. Usually see
involvement of cord/ nerves entrapped.
5. Know the developmental origin of main structures in the brain
- Use the flow chart