Transient Isolated Lower Bulbar Palsy With Elevated Serum Anti-GM1 and Anti-GD1b Antibodies During Aripiprazole Treatment.

Background: Transient bulbar palsy without involvement of the facial or extraocular muscles is a rare presentation. It is considered a form of cranial polyneuropathy, a variant of Guillain-Barré syndrome that is related to the autoimmune mechanisms induced by preceding infections or vaccinations. However, drug-induced cranial polyneuropathy has not previously been reported. We describe a boy with isolated bulbar palsy and positive serum antiganglioside antibodies during aripiprazole treatment.

Patient Description: This 12-year-old boy was admitted with a seven-day history of dysarthria, tongue discomfort, and tinnitus. Three weeks before symptom onset, aripiprazole was added to the patient's medications for attention-deficit hyperactivity disorder. On examination, he showed curtaining of the pharyngeal wall, tongue fasciculation and deviation, and a weak gag reflex. Cranial magnetic resonance imaging suggested lower cranial nerve involvement. Serum anti-GM1 IgG and anti-GD1b IgG antibodies were positive. After stopping aripiprazole, his bulbar symptoms improved. However, on readministration of aripiprazole seven weeks later, dysarthria recurred and again resolved after stopping the drug.

Conclusion: We describe the first patient with anti-GM1 IgG and anti-GD1b IgG antibodies-associated transient cranial polyneuropathy presenting as isolated bulbar palsy. These findings could be an adverse effect of aripiprazole treatment.