Pathological Laughter: The First Manifestation of Intracerebral Haemorrhage Linked to Phenylephrine Overuse.

A 42-year-old woman presented to the emergency department with sudden-onset uncontrollable laughter, 'fou rire prodromique' (prodrome of crazy laughter), and left leg weakness. Imaging revealed a right cerebral haemorrhage of the premotor cortex corresponding to the leg cortical representation. A history of excess phenylephrine use for sinusitis and migraine was subsequently obtained. The patient's neurological recovery was good, enabling a return to her pre-stroke employment. The neurological causes of pathological laughter and the brain networks involved are discussed in this report. The role of sympathomimetics in the causation of cerebral haemorrhage potentially via the initiation of a reversible cerebral vasoconstriction syndrome is highlighted. The use of over-the-counter substances should be part of medication history in such cases.