Clival chordoma associated with pathological laughter. Case report.

The case of a 40-year-old man with a clival chordoma who presented with symptoms of pathological laughter and left sixth cranial nerve paresis is reported. Laughing and talking during sleep were noted on polygraphic and videotape recordings of nocturnal sleep. Selective disorganization of sleep was observed, with laughing facial expressions and a lack of muscular atonia. The tumor developed in the prepontine cistern, compressing the pontomesencephalic structures backward and involving the upper clivus and the left cavernous sinus. No recurrence of laughter attacks were noted after total removal of the tumor. The sleep patterns observed were similar to those of experimental animals with lesions of the peri-alpha locus ceruleus. The importance of uncontrolled laughter as a sign of a ventral brain-stem mass is emphasized.