Aetiology of neurogenic palsies 2 Flashcards
The pupil in third nerve
Rule: when aneurysm compresses 3rd nerve, the iris sphincter will be impaired
Do not apply rule where palsy is incomplete
Great caution in the under 50 year age group unless glaring vasculopathic risk factors
Third nerve palsy- aberrant regeneration
Tends to occur where trauma or space occupying lesion is cause
Features occur six weeks or more after
onset. Include (alone or in combination):
Retraction of upper lid on down gaze
Elevation of upper lid on adduction
Constriction of the pupil on elevation, depression or adduction
Adduction on attempted elevation (and occasionally on depression)
Herpes Zoster Ophthalmicus findings
Virus affects dorsal root ganglia - trigemminal ganglia affected - unilateral painful rash
Muscle palsies may be ipsilateral, contralateral or bilateral, and may affect one or more nerves
Can affect any age, but more common in elderly or immuno-compromised
Treated with anti-viral therapy (e.g acyclovir)
Demyelination and MS
MultipleSclerosisDemyelination of nerve sheathSuspected in young adults with isolated nerve palsy(most common age for presentation 20 – 40 years; but can be younger or older)
May have other symptoms or history of previous episode
Other inflammatory conditions
Meningitis
Encephalitis
Poliomyelitis
Tertiary syphilis (late stage)
Tolosa-Hunt syndrome
Tolosa Hunt syndrome
Non-specific granulomatous inflammation
in anterior part cavernous sinus / SOF area
Possible involvement 3rd, 4th, 6th nerves with severe constant pain
Visual loss if ON involved
Proptosis
Sluggish Pupil
Diagnosis: CT scan, ESR may be raised
Treatment: Systemic steroids (e.g prednisolone)
Systemic lupus erythematosus (SLE)
Immunological disorder affecting connective tissue and nervous system
Nerve palsy may be due to vaso-occlusion of small vessels
No cure, pain relief used, if severe immunosuppressives
Sarcoidosis
Granulomatous disease
Isolated or multiple nerve palsies reported, may be accompanied by pain
No cure, but treated with steroids
Guillian Barre syndrome
Acute inflammatory demyelinating polyradiculoneuropathy – Aetiology not fully understood. May occur after viral infection.
Slightly more common in males than females, can affect any age but most common 20-50 yrs age
Sudden, acute motor paresis peaking within 4 weaks
Ocular involvement to varying extent: ophthlmoplegia, fixed dilated pupils, optic neuritis, facial nerve palsy
Guillian Barre syndrome treatment
Intravenous immunoglobulin treatment, steroids, plasma exchange (treatment removes antibodies from blood)
Miller- Fisher syndrome
Possibly a variant of Guillan-Barre
May occur after upper respiratory tract infection
Ophthalmoplegia – usually symmetrical (divergence paralysis, impaired smooth pursuit have also been reported)
Ataxia
Hyporeflexia or areflexia
Diagnosis: Increased protein in CSF from lumbar puncture.
Management: As for Guillan-Barre. Good prognosis
Gradenigos syndrome
Infection of middle ear leading to petrositis and affecting 6th nerve as it crosses petrous part of temporal bone
Ipsilateral pain of trigeminal nerve distribution
Constant ottorhea
AIDS
Complications may involve cranial nerves:
Infections e.g. Parasitic e.g toxoplasmosis and Fungal e.g cryptococcosis
Neoplasms
Vascular (high risk of infarct or haemorrhage)
Multiple cranial nerve palsies causes
Most common- neoplasms (abnormal growth of tissue) and trauma
Least common- cavernous sinus lesions, aneurysms, herpes zoster, meningitis, encephalitis, tolosa hunt, miller fisher
Cause of congenital neurogenic palsies
Congenital conditions
-Hydrocephalus
-Cerebral palsy
-Inherited SO palsy
Intoxications from mother
e.g. lead poisoning, drugs, alcohol
Birth trauma
