Pathologic laughing and intractable hiccups can occur early in multiple sclerosis.

Pathologic laughing occurs in approximately 10% of patients with multiple sclerosis (MS), especially when patients have entered the chronic stage. We describe four patients with MS who, at an early stage, developed pathologic laughing associated, in two cases, with intractable hiccups. In two patients, MRI showed an enhanced lesion in the medulla oblongata and the mesencephalon, two regions suspected of being involved in pathologic laughing and intractable hiccups.