[Harlequin syndrome].

Harlequin syndrome is an autonomic syndrome of heat, emotion and exercise induced flushing and sweating limited to one side of the face in combination with impairment of sweating and flushing on the contralateral side, Two women aged 32 and 39 years displayed this syndrome. In one patient no other neurological symptoms were found; MRI of cervicothoracic spine failed to disclose a structural lesion. The second patient had four years before presented with a Horner's syndrome on the contralateral side, where MRI now disclosed a tumour located in the paravertebral thoracic region at the apex of the lung.