Swollen optic disk

 

Papilledema - only from inc ICP

 

Congenital

anomalous elevation, disc drusen

Inflammatory

idiopathic demyelinating optic neuritis, infection-syphillis, sarcoid

Infiltrative

glioma, lymphoma

Compressive

vascular

ion, htn retinopathy

elevated retinal venous pressure

CRVO, carotid-cavernous fistula

 

if have shunt vessel - disc edema is chronic

 

elevated pressure in perineural subarachnoid sapce imedes slow and rapid orthograde axoplasmic transport at level of lamina cribrosa.  in several days the obstructed axons swell, producing papilledema.  papilledema is caused by axonal swelling and not extracellular edema.  vision is preserved because the cell membrane is uninjured and axoplasmic flow is not completely blocked.

 

papilledema and differentiation from other causes -

bilateral, preservation of Va until late

etiology:

intracranial mass lesions, cerebral venous thrombosis, meningitis, hydrocephalus, HTN encephalopathy, pseudotumor cerebri

 

w/u for maybe papilledema -

neuro-image, lp, ophthalmologic eval.  must have visual fields - chronical inc ICP will lead to constricting vf and blindness

 

Pseudotumor cerebri:

dx criteria

- elevated icp (>200-250 mm H2O)

- nl CSF

- nl neuroimaging (no mass or hydrocephalus)

 

minor sx of pseudotumor cerebri, round & keane, neurology, 1988

 

Signs of IIH

papilledema, VF inc blind spot, VF other, dec Va, VI nerve palsy

 

VF defects in IIH

- enlarged blind spot from pulling up of retina around optic nerve

- nasal loss, constricting visual field, should respect horizontal

 

similar vf defects

aion, intrapapillary drusen, glc, optic neuritis, optic nerve compression, on hypoplasia

 

ICH from:

arachnoid granulation scarring, venous sinus thrombososi, svc syndrome, hypercoag states, contig mastoid or ear infections, av malformations, hyper vit a, addison's disease, hypo parathyroid, steroid withdrawal, exogenous growth hormone

 

assoc conditions:  head trauma, iron def anemia, lithium, diphenylhydantoin, norplant implants, nalidixic acid, amiodarone, sulfa abx, steroids, tetracycline, mvi,

 

theories on pathophys

inc intracranial blood volume, inc csf prod, dec csf absorption, brain parenchymal edema, sustained inc intracranial venous pressure

 

management:

medical - serial lp, carbonic anhydrase inhibitors (diamox), diuretics, steroids

 

surgical - lumboperitoneal shunt, optic nerve sheath fenestration

 

LP shunt - generally effective, may not protect visual fx, but need frequent revisions in 50% people

 

ONSF - window or mult incisions in dura, medial vs. lateral approach, stabilize/improve in 85%, impr papilledema in 50%, imp HA in 63%

complications - minor include motility, tonic pupils in 40%.  major are CRAO, hemorrhage, 5%