Serum and CSF GQ1b antibodies in isolated ophthalmologic syndromes.

OBJECTIVE

To establish the sensitivity and specificity of serum and CSF antibodies targeting the gangliosides GQ1b (GQ1bAb) in isolated ophthalmologic syndromes, such as acute ophthalmoplegia (AO) and optic neuritis (ON), caused by disorders other than Miller-Fisher syndrome (MFS).

METHODS

We measured serum and CSF GQ1bAb in patients with MFS and with AO or ON caused by other disorders than MFS.

RESULTS

Twenty-one patients with AO (21 serum, 9 CSF), 13 with ON (13 serum, 13 CSF), and 12 with MFS (12 serum, 10 CSF) were included in the study. There were no significant differences in age, sex, and CSF findings between the AO and MFS groups. Elevated serum GQ1b titers occurred in 11 of 12 patients with MFS but in only 1 of the 34 patients without MFS. Sensitivity was 92% (95% confidence interval [CI] 62%-100%) and specificity 97% (95% CI 85%-100%). In CSF, GQ1bAb were identified in 2 of 10 patients with MFS but in none with other disorders. Sensitivity was 20% (95% CI 2%-56%) and specificity 100% (95% CI 85%-100%).

CONCLUSIONS

Increased serum GQ1bAb are highly specific for MFS. Measurement of GQ1bAb in CSF does not improve diagnosis.

CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that serum GQ1bAb accurately distinguish MFS from other disorders (sensitivity 92%, 95% CI 62%-100%; specificity 97%, 95% CI 85%-100%).