Friday, April 12, 2013

Papilledema and obstructive sleep apnea syndrome.



To characterize the pathogenesis and clinical features of optic disc edema associated with obstructive sleep apnea syndrome (SAS).


A series of 4 patients with SAS and papilledema (PE) underwent complete neuro-ophthalmologic evaluation and lumbar puncture. In 1 patient, continuous 24-hour intracranial pressure (ICP) monitoring was also performed.


All 4 patients had bilateral PE that was asymmetric in 2. Three patients had optic nerve dysfunction, asymmetric in 1, unilateral in 2. Daytime cerebrospinal fluid pressure measurements were within normal range. Nocturnal monitoring performed in one patient, however, demonstrated repeated episodes of marked ICP elevation associated with apnea and arterial oxygen desaturation.


We propose that PE in SAS is due to episodic nocturnal hypoxemia and hypercarbia resulting in increased ICP secondary to cerebral vasodilation. In these individuals, intermittent ICP elevation is sufficient to cause persistent disc edema. These patients may be at increased risk for developing visual loss secondary to PE compared with patients with obesity-related pseudotumor cerebri because of associated hypoxemia. The diagnosis of SAS PE may not be appreciated because daytime cerebrospinal fluid pressure measurements are normal and because patients tend to present with visual loss rather than with symptoms of increased ICP.

Monday, April 08, 2013

Common pitfalls in management IIH

Management Errors:
missing venous sinus thrombosis
failure to address other secondary causes (e.g., anemia, hypoxia)
relying on optic disc appearance without monitoring visual fields
being too slow to proceed to surgical intervention

Papilledema pearls

1. Cotton wool spots OFF disk may suggest hypertensive syndrome
2.  Hemorrhages off disc suggest central retinal vein occlusion
3.  New onset pulsatile tinnitus is significant finding indicating need to look for increased ICP, as well as transient obscurations, graying of vision for twenty seconds, with postural change and headache.  Field before acuity is affected, disc edema usually affected.
4.  MRI findings  may include disc enhancement, occassionally, enhanced perioptic space (40 %), flattening of posterior globe (80 %), empty sella  Get MRI/MRV
5.  Check blood pressure
6.  Blood:  CBC, electrolytes for Addison's, Ca for HPT, ANA for lupus that is it..  Lumbar puncture always.
7.  Must check visual fields  since acuity is preserved. That is affected early.
8.  Protect optic nerve function and appearance: the two goals of management of pappilledema, not normal pressure, that is not a goal.
9.  Therapy:  diamox 500 bid to start, add Lasix 40  mg q am with Kcl 20 meq.
10. Fenestration protects eye, but does not lower headache or pressure.  Consider fenestrating patients with progressive visual loss, severe loss early, patients with severe papilledema at risk for hypotension (dialysis) or patients unable to comply with monitoring vision.  Shunt is a better treatment for headache of IIH.
h't Valerie Purvin AAN 2013

Causes of pappilledema (bilateral) with good optic nerve function

increased intracranial pressure
malignant hypertension
toxins (amiodarone,cyclosporine)
sleep apnea syndrome
uveitis, eg. sarcoidosis