Bells Palsy and Cranial Nerves

hrhodes's version from 2015-10-13 02:20

Bells Palsy

Question Answer
What is virus most likely to cause BP?HSV1 (Ramsay Hunt = VZV - must Rx aciclovir)
Who gets BP?M=W but more common in pregnancy, 15-45 years, 1/60 lifetime risk
What is the onset of BP?sudden (hours)
What are the signs and symptoms of BP?upper AND lower 1⁄2 face affected, numbness/paraesthesia, paralysis (incomplete - better prognosis; or complete) - loss of taste ant 2⁄3 tongue, pre-auricular pain, dry eyes
What is “Bell phenomenon”?eye rolling up when trying to close
What investigations do you do?MRI Brain
Management of BPEye lubricant 2/24, ointment and patch at night, Incomplete: no Rx; Complete- prednisone alone = best outcome. (eTG): pred alone or no Rx; unless VZV
Differential diagnosis of BPStroke, GBS, lyme disease, sarcoid, polio, HIV

Trigeminal neuralgia

Question Answer
What is trigeminal neuralgia?Chronic, debilitating condition of trigeminal nerve CN V (maxillary or mandibular divisions) → episodes of sev facial pain ("electric shock") lasting secs to mins. Happens for days-months
Who gets TN?>40 years, F>M 2-4% patients have MS
What causes TN?Compression - blood vessels may press on CN V as exits brainstem, Degeneration, Myelin sheath infiltration eg tumour or amyloid, Idiopathic
What triggers TN?vibration, skin contact, brushing teeth, oral intake, exposure to wind. Sometimes may be preceeding symptoms eg tingling/numbness
What investigations in TN?clinical diagnosis, MRI - may show compression or other causes eg MS
How do you manage TN?Support and education, Anticonvulsants, tricyclics, Surgery - 75% success rate (decompression)

Cranial nerves

Question Answer Column 3 Column 4
CN IOlfactoryanosmiameningioma, ethmoid tumour, BSF, pituitary OT
CN IIOpticVAs, visual fields, pupilsmultiple causes
CN IIIOculomotorptosis, down and out (can’t looks up and in), mydriasis, no light/accommodation reflexDM and HTN most common causes, but spare pupil as ischaemic to central fibres first Ca (eg brain, nasopharyngeal), aneurysm, arteritis, MS, GBS (MFS), incr ICP, diptheria, botulism
CN IVTrochlearup and out - can’t look down and in, head tilted to opposite sidemononeuritis multiplex; MS, GBS, incr ICP, diptheria, botulism, DM, HTN
CN VIIIVestibulo-cochlearWhispering test, Rinnes (behind ear, air should be > bone, if not = conductive deafness), Webers (forehead; conductive localises to affected side, sensory to opposite), Hallpikeacoustic neuroma, TORCH, # petrous temporal bone, aspirin, gent, brainstem disease, vascular, conductive
CN IXGlosso-pharyngealTympanic (MM of middle ear and auditory tube, parotid), stylopharyngeus, pharyngeal sesnation, carotid sinus; taste and sensation to post 1/3 of tongue, tonsils, post 1/3 palate, ant epiglottis
CN XVagusUvula deviation away, absent gag, hoarseness, bovine cough
CN XIAccessoryDrooping of shoulder, downward rotation and protraction of scapula, wasting of traps
CN XIIHypoglossalTo all except palatoglossus; tongue deviates to side of lesion