Isolated external ophthalmoplegia associated with IgG anti-GQ1b antibody (P2.434)

Objective: We present a case with isolated external ophthalmoplegia with high anti-GQ1b IgG titer effectively treated by intravenous immunoglobulin (IVIg).

Background: Atypical Miller Fisher syndrome (MFS) or acute ophthalmoplegia (AO) is defined by ophthalmoplegia without ataxia, areflexia, or both. Although controversial, there are several reports on AO with positive anti-GQ1b IgG antibodies.

Design/Methods: 54-year-old right-handed Caucasian male with no known past medical history except a recent upper respiratory tract infection 2 weeks prior to admission presented with complains of horizontal diplopia on waking up. He denied weakness, imbalance, numbness, dyspnea, dysarthria, dysphagia, or incontinence/retention. Exam showed bilateral abducens nerve palsies with horizontal diplopia and no nystagmus. There was a mild right ptosis without pupillary abnormalities. Motor strength, sensory testing, deep tendon reflexes, cerebellar testing, and gait were normal. The CT and CTA head, and MRI brain exam were unremarkable. A detailed serological workup for causes of neuropathy and myasthenia was unremarkable. CSF only revealed minimally increased protein of 47mg/dl (<45) (with normal cell count?). The anti-GQ1b antibody was strongly positive with a titre of 1:3200. The patient received a course of IVIg 2 g/kg. At a 10-months follow-up appointment, the patient had near complete recovery of diplopia without requiring further treatment.

Results: This case illustrates the importance of clinical suspicion for AO in cases of isolated ophthalmoplegia following an acute illness.

Conclusions: It also suggests the need for ganglioside antibody testing in such situations, and the effectiveness of IVIg even for isolated cranial nerve abnormalities.

Disclosure: Dr. Kim has nothing to disclose. Dr. Husain has nothing to disclose. Dr. Zeidman has nothing to disclose.