Two female children, ages 9 and 2 years, who presented with pseudotumor cerebri and within 2 to 3 days, were diagnosed with Miller Fisher syndrome are reported from the Hopital Universitaire des Enfants Reine Fabiola, Brussels, Belgium. The 9-year old had sudden onset of frontal headaches associated with nausea, diplopia, and convergent stabismus. Two weeks previously she had developed an acute febrile illness with diarrhea. Neurologic examination on admission was normal except for a left VIth nerve palsy. CT was normal, but opening pressure on lumbar puncture was 300 mm water. Headache and nausea improved initially after removal of 15 ml CSF, but then recurred, with vomiting. Following treatment with acetazolamide, symptoms again improved, but 3 days later, she developed Miller Fisher syndrome, presenting with bilateral III and VI nerve palsies, ataxia, and areflexia. EMG and NCS were normal, and H reflexes were absent, indicating impaired nerve conduction in proximal fibers and acute demyelinating polyneuropathy. Plasma serology was positive for Campylobacter jejuni and anti-GQ1b antiganglioside antibodies. Treatment with a 2-day course of iv immunoglobulin resulted in lessening of ataxia in 1 week, and recovery of reflexes and eye movements in one month and at 3 month follow-up. The 2-year old patient had a similar history and diagnoses. Plasma serology was negative for C jejuni, but positive for antimyelin antibodies. EMG and NCS were abnormal, with widespread fibrillations, reduced motor and sensory nerve conduction velocities, conduction blocks, and increased F wave latencies, indicative of demyelination and also signs of axonal neuropathy. Following iv immunoglobulin and corticosteroids, dysarthria and dysphagia had resolved and ataxia was mild at 4-week follow-up. 
COMMENT. The syndrome first described by Dr Miller Fisher, neurologist at the Massachusetts General Hospital, is “An unusual variant of acute idiopathic polyneuritis (syndrome of ophthalmoplegia, ataxia and areflexia) .” The immune-mediated, acute demyelinating Guillain-Barre variant involves anti-GQ1b antiganglioside antibodies in 90% of cases, and is preceded by a respiratory or gastrointestinal infection in two thirds, Campylobacter jejuni being a common isolate in the cases that present with diarrhea. The cases in the present report are particularly rare since they occur in children, and the MF syndrome is preceded by symptoms of pseudotumor cerebri. The co-occurrence of papilledema and Guillain-Barre syndrome is reported in 4% of childhood cases . The authors cite only one previous case of MF syndrome, in a 5-year-old male, presenting with pseudotumor . CSF opening pressure and funduscopic examination should be included in the evaluation of patients with Guillain-Barre syndrome.