3rd, 4th, 5th, 6th, 7th Nerve Syndromes Flashcards
What are the 6 syndromes of the 6th nerve?
- Brainstem syndrome
- Subarachnoid space syndrome (pseudotumor - tethering in Dorello’s canal)
- Petrous apex syndrome
- Cavernous sinus syndrome
- Orbital syndrome
- isolated 6th nerve palsy
What are the 3 brainstem syndromes of CN6?
- Millard-Gubler syndrome (6,7,contralateral hemiparesis)
- Raymonds syndrome (6+contralateral hemiparesis)
- Foville’s syndrome (5-8 palsy + Ipsilateral Horner’s syndrome)
What are the 3 Petrous Apex Syndrome?
- Gradenigo’s - 6th nerve palsy + ipsilateral decreased hearing, facial pain, facial paralysis)
- Petrous skull fracture - 5-8 CN involvement
- Pseudo-Gradenigo - nasopharyngeal carcinoma or CPA tumor
What innervates the SR muscle?
The CONTRALATERAL 3rd nerve nucleus
What innervates the levator muscle?
Both levators are innervated by ONE subnuclear structure - central caudal nucleus–> there fore a nuclear 3rd requires b/l ptosis
What are the 4 fascicle 3rd nerve syndromes?
- Nothnagel - Ipsilateral 3rd nerve + cerebellar ataxia (lesion in area of the superior cerebellar peduncle)
- Benedikt’s syndrome - lesion of the red nucleus (ipsi 3rd nerve with contralateral hemitremor)
- Weber’s syndrome - (lesion of cerebral peduncle) - ipsi 3rd with contra hemiparesis
- Claude - both benedikt + Nothnagel
Fascicular lesions always ischemic, infiltrative, or rarely inflm
What are the 2 vessels that the 3rd + 4th nerve courses betwn in the midbrain?
- Posterior Cerebral Artery (top)
2. Superior Cerebellar Artery (bottom)
When does abberant regeneration of 3rd nerve occur?
- Tumor
- Trauma
(never to ISCHEMIA)
Whart are the 2 clinical phenomenon of abberant regeneration?
- Lid-Gaze dyskinesis
2. Pupil-gaze dyskinesis
What CN is the only one to exit the dorsal aspect of the brainstem?
CN 4
Which CN has the longest intracranial nerve?
CN 4 (75mm)
The left nerve fascicle innervates what muscle?
R SO
What are the 5 syndromes of CN 4?
- Nuclear-Fascicular syndrome
- Subarachnoid space syndrome
- Cavernous sinus syndrome
- Orbital syndrome
- Isolated CN 5 palsy
In Brown’s syndrome what adaptations occur?
- Chin up position ( affected eye usually hypotropic)
2. Face turn (AWAY from Brown’s eye)
What causes paroxysmal, rapid, vertical, and torsional movements of one eye that are usually small, necessitating slit-lamp exam?
SO myokymia (tx with carbamazepine)
In double maddox rod test which line is one top?
White
Greater than how many degrees of torsion suggestive b/l 4th nerve palsy?
10 degrees (also large V pattern stab >25D)
How do you differentiate 4th nerve palsy from skew deviation?
Skew - increased vertical strabismus on up gaze
4th nerve - increased on down gaze
What type of inflm do you see in Tolosa-Hunt?
Granulomatous
In Botulism what happens with pupils?
Dilated, poorly reactive pupils, ptosis
What is the bulbar variant of Guillain-Barre syndrome?
Miller Fisher syndrome - pupils involved with loss of accomadation.
What are the 2 functions of CN5?
- Ipsilateral sensory
2. Ipsilateral motor - muscles of mastication (masseter, temporalis, pterygoids)
Concentric periporal numbness has the lesion where?
Central (nuclear) origin - ischemic, demylination
What is CN5 nerve distribution pain with ipsilateral Horner’s syndrome?
Raeder’s paratrigeminal neuralgia
- middle aged or elderly males
