Neuro Flashcards
___-flow, ___ fistulas most commonly occur after severe head trauma and produce a cranial bruit.
High-flow, direct fistulas most commonly occur after severe head trauma and produce a cranial bruit.
Genetic mutation associated with oculopharyngeal muscular dystrophy
PABPN1
In general, damage to a ___ (medial or lateral) region of the brainstem disrupts the ___ (sensory or motor) pathways.
In general, damage to a lateral region of the brainstem disrupts the sensory pathways.
Therefore, Wallenberg syndrome is a type of “stroke without paralysis.”
Wallenberg syndrome
Lateral medullary infarct
Occlusion of the posterior inferior cerebellar artery or proximal vertebral artery
**Ipsilateral loss of facial P/T (descending tract of CN V)
**Contralateral loss of hemibody P/T (lateral spinothalamic tract)
- Ipsilateral cerebellar ataxia (spinocerebellar tracts)
- Ipsilateral first-order Horner syndrome (descending hypothalamic tracts)
- Ipsilateral ocular tilt reaction (head tilt toward the side of the lesion)
Also:
- Ipsilateral hearing loss (cochlear nuclei)
- Vertigo, nystagmus (vestibular nuclei)
- Dysphagia, dysarthria, dysphonia (nucleus ambiguus)
- Hiccups!
Weber syndrome
“Weak Weber”
Ipsilateral CNIII palsy
+
contralateral hemiparesis (damage to the ventral midbrain and the cerebral peduncle)
Benedikt syndrome
Ipsilateral CNIII palsy
+
contralateral ataxia or tremor (involvement of the red nucleus and substantia nigra)
Claude syndrome
Ipsilateral CNIII palsy
+
contralateral ataxia (damage to the dorsal midbrain may involve the superior cerebellar peduncle)
Nothnagel syndrome
Ipsilateral CNIII palsy (nuclear lesion)
+
contralateral ataxia, supranuclear eye movement dysfunction
(Dorsal lesion with a slightly different configuration)
Causes of skew deviation
Demyelinating lesion (young) Stroke (old)
Locations of multiple simultaneous cranial nerve palsies (4)
Orbital apex (II, III, IV, V, VI) Brainstem, e.g. midbrain (III, IV) Cavernous sinus (III, IV, V1-2, VI) Cerebellopontine angle (V, VI, VII, VIII)
The ___ system holds the image of an object on the fovea during brief head movement. The ___ system holds the image of an object on the fovea during sustained head movement.
The vestibular-ocular system holds the image of an object on the fovea during brief head movement. The optokinetic system holds the image of an object on the fovea during sustained head movement.
Anisocoria greater in light than dark
Dilated pupil = 3rd nerve palsy, Adie tonic pupil, pharmacologic dilation
Anisocoria greater in dark than light
Miosed pupil = Horner’s syndrome
Unilateral painful ophthalmoparesis without a change in visual function or orbital signs such as proptosis is most likely to occur from a ___ ___ process.
Unilateral painful ophthalmoparesis without a change in visual function or orbital signs such as proptosis is most likely to occur from a cavernous sinus process.
Differential for light-near dissociation / tonic pupil (5)
Neurosyphilis, diabetes, dorsal midbrain syndrome, chronic alcoholism, and dysautonomias, Adie tonic pupil
VF defects respecting midline correlate with lesions ___ (anterior or posterior) to the chiasm.
VF defects respecting midline correlate with lesions posterior to the chiasm.
What kind of MRI is helpful in patients with acute stroke?
Diffusion-weighted imaging (usually T1, better for anatomy)
What kind of MRI is helpful in patients with optic neuropathy?
MRI with fat suppression
How do you distinguish between autoimmune or paraneoplastic retinopathy, and optic neuropathy by history?
Presence of photopsias and nyctalopia
What kind of MRI is helpful in patients with suspected demyelinating disease?
FLAIR (always T2-weighted): attenuates bright CSF signal, which obscures periventricular white matter lesions
The ___ ___ ___ of the MLF and the ___ ___ of Cajal are located in the ___ and are involved in the generation of torsional and vertical saccades.
The rostral interstitial nucleus of the MLF and the interstitial nucleus of Cajal are located in the midbrain and are involved in the generation of torsional and vertical saccades.
The excitatory burst neurons for generating horizontal saccades are located in the ___ ___ ___ ___.
The excitatory burst neurons for generating horizontal saccades are located in the paramedian pontine reticular formation.
What are atypical features of optic neuritis that should prompt further work-up? (7)
Older age, lack of pain, peripapillary hemorrhages, ocular inflammation (uveitis or choroiditis), retinal changes, involvement of other cranial nerves, and lack of any improvement in vision after 1 month
How does a nuclear versus infranuclear CN III palsy present?
Nuclear: unilateral or bilateral ptosis, contralateral superior rectus palsy
Infranuclear: unilateral ptosis, ipsilateral superior rectus palsy