Cranial nerve examination Flashcards
What are generalised causes of cranial nerve palsy?
- Diabetes
- Stroke
- MS
- Tumour
- Sarcoid
- SLE
- Vasculitis
Specific causes of olfactory palsy
- Trauma
- Frontal lobe tumour
- Meningitis
- Early signs of parkinsons
Cause of monocular blindness
- MS
- GCA
Causes of bitemporal Hemianopia
- pituitary adenoma
- Internal carotid artery aneurysm
Causes of a homonymous hemianopia?
- anything behind the chiasm
- stroke tumour abscess
Causes of a partial occulomotor palsy
Diabetes pupils spared
Causes of a complete occulomotor palsy
- PCA aneurysm
- Raised intracranial pressure with tentorial herniation
Causes of a single trochlea palsy
- Single palsy is rare
- Usualy due to orbit trauma
Causes of a trigeminal palsy
- Idiopathic (trigeminal neuralgia which is neuropathic pain due to nerve lesion or dysfunction)
- Accoustic neuroma
- Herpes zoster
Causes of an abducens nerve palsy
- Skull fracture involving petrous temporal bone
- Nasopharyngeal carcinoma
- Raised intracranial pressure
Causes of a facial nerve palsy
- LMN (forehead affected)
- Bell’s palsy
- Malignant parotid tumour
- Herpes zoster (ramsay hunt)
- UMN (forehead spared)
- Stroke / Tumour
Vestibularcochlear nerve lesion.
- excessive noise level
- Menieres disease
- Frosemide
- Aminoglycoside antibiotics (gentamycin)
palsies to CN 9, 10, 12 Lower Motor Neuron.
LMN (bulbar palsy)
- Motor neuron disease
- Dipthermia
- Polio
- Gullian - Barre syndrome
- Syringobulbia
Palsies to CN 9, 10, 12 Upper Motor Neuron.
UMN
- Motor neuron disease
- Bilateral strokes
- MS
Causes of grouped cranial nerve palsy
e.g cerebellopontine angle tumour (accoustic neuroma or meningioma). Which cranial nerve is affected?
- Corneal reflex lost first
- Then VII & VIII
- Then the rest of V
- sometimes IX & X
Causes of a grouped cranial nerve lesion e.g. paget’s disease of bone - impingment of nerves as they pass through a bony foramen. Which cranial nerve is affected
CN V, VII & VIII.
Gradenigos syndrome (Complication of otitis media) affects which cranial nerve?
CN V & VI
Syringobulbia causes palsy to which CN?
- Bulbar palsy IX, X & XII
- VIII vertigo and nystagmus
- V facial pain and sensory lost
- VII sparing
- may also have Horners syndrome and features of syringomyelia
What are upper motor neuron cranial nerve signs
- Facial nerve palsy with forehead sparing (due to bilateral cortical representaion of the forehead
- Brisk jaw jerk
- Pseudobulbar palsy
Causes of Opthalmoplegia
- Myasthenia gravis
- Cranial nerve palsy
- Graves disease
- Wernickes encephalopathy (particular failure of upward gaze)
- Progressive supranuclear palsy (particularly failure of downward gaze)
Features of internuclear opthalmoplegia
- disorder of conjugate gaze caused by lesion of the medial longitudinal fissure
- Causes failure of adduction of the affected side
- in a left sided INO
- Lateral gaze to left is normal
- On attempting to look right
- the right eye abducts
- The left eye fails to Adduct and remains looking straight ahead
- Right eye consequently displays nystagmus as it attempts to compensate
- Convergence is perserved (the left eye can adduct normally as long as the goal is to not lateral gaze
What are causes of internuclear opthalmoplegia
- MS (almost always the cause in a young patinet)
- Stroke
- Lyme disease and tricyclic antidepressent overdose are rare causes
Causes of a bulbar palsy (LMN lesion)
- MND
- Diptheria
- Polio
- Gullian-Barre syndrome
- Syringobulbia
Causes of a pseudobulbar palsy (UMN Lesion)
- MND
- Bilateral strokes (e.g. internal capsule)
- MS
