Papilledema and obstructive sleep apnea syndrome

Objectives: To characterize the pathogenesis and clinical features of optic disc edema associated with obstructive sleep apnea syndrome (SAS). Methods: A series of 4 patients with SAS and papilledema (PE) underwent com plete neuro-ophthalmologic evaluation and lumbar puncture. In 1 patient, co ntinuous 24-hour intracranial pressure (ICF) monitoring was also performed. Results: All 4 patients had bilateral PE that was asymmetric in 2. Three pa tients had optic nerve dysfunction, asymmetric in 1, unilateral in 2. Dayti me cerebrospinal fluid pressure measurements were within normal range. Noct urnal monitoring performed in one patient, however, demonstrated repeated e pisodes of marked ICP elevation associated with apnea and arterial oxygen d esaturation. Conclusions: We propose that PE: in SAS is due to episodic nocturnal hypoxe mia and hypercarbia resulting in increased ICP secondary to cerebral vasodi lation. In these individuals, intermittent ICP elevation is sufficient to c ause persistent disc edema. These patients may be at increased risk for dev eloping visual loss secondary to PE compared with patients with obesity-rel ated 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 lo ss rather than with symptoms of increased ICP.