harlequin syndrome is characterized by unilateral facial flushing and sweating , which are predominantly induced by heat or exercise ( 1 ) . harlequin syndrome is mostly idiopathic ( 1 ) , but may occur in association with brainstem infarction , superior mediastinal neurinoma , internal jugular vein catheterization ( 1 - 3 ) . the sympathetic deficit is in the non - flushing side and the healthy side shows normal or excessive flushing and sweating . rarely , the autonomic deficit involves the arm or the parasympathetic neurons in the ciliary ganglia ( 4 , 5 ) . we report a patient with unilateral facial flushing and sweating , and ipsilateral arm coldness , which were mainly induced by exertion . a 43-yr - old woman presented with a 3-yr - history of facial flushing and sweating in the right side , which were mainly induced by exercise . the symptoms were more prominent in the winter , but did not aggravate during the preceding three years . however , after a 30-min - running , she showed flushing and sweating only on the right side of the face ( fig . blood pressure , pulse rate , and skin color did not differ among the four extremities during the episode . using a digital skin thermometer , skin temperature measured 2 colder on the right arm than on the left arm , and 2.9 colder on the left face than on the right face . the immersion of one hand in ice water for 1 min ( cold pressure test ) revealed a normal response in both arms . the pupils did not constrict with 0.125% pilocarpine eyedrops . computed tomography of the chest was normal . the name harlequin syndrome was first coined by lance and drummond in 1988 when they described five cases of unilateral facial flushing and sweating , which were induced by exercise in four ( 1 ) . they proposed that the torsional occlusion of the anterior radicular artery at the third thoracic segment caused the syndrome , and that the lesion might involve both pre- or postganglionic cervical sympathetic fibers and parasympathetic neurons of the ciliary ganglion . the preganglionic neurons of the sympathetic division originate in the intermediolateral cell column of the spinal gray matter , from the eighth cervical to the second lumbar segments . the preganglionic fibers synapse with the cell bodies of postganglionic neurons , which are collected in two large ganglionated chains or cords , one on each side of the vertebral column ( paravertebral ganglia ) , and in several single prevertebral ganglia . there are three cervical ( superior , middle , and inferior or stellate ) , eleven thoracic , and four to six lumbar sympathetic ganglia . the head receives its sympathetic innervation from the eighth cervical and the first two thoracic cord segments , the fibers of which passing through the inferior and middle cervical ganglia , and synapsing at the superior cervical ganglia . postganglionic fibers from the cells of the superior cervical ganglion follow the internal and external carotid arteries and innervate the blood vessels and smooth muscle as well as the sweat , lacrimal , and salivary glands of the head . the arm receives its postganglionic innervation from the inferior cervical and uppermost thoracic ganglia , which are fused to form the stellate ganglion . our patient showed crossed sympathetic deficits in the left face and right arm , which suggested that the lesions were multifocal . previously , crossed sympathetic deficits involving the face , arm , and leg has been described only once , in a 37-yr - old woman ( 6 ) . ( 7 ) reported another patient with unilateral loss of facial flushing and sweating , and with contralateral anhidrosis , which were induced by exercise . however , she also had tonic pupils and areflexia , and was considered to have ross syndrome ( adie syndrome with anhidrosis ) . the spectrum of pre- and postganglionic autonomic dysfunction in patients with harlequin syndrome indicates a relation with holmes - adie and ross syndromes , and the persisting autonomic deficit in guillain - barre syndrome ( 8 - 10 ) . the clinical course of partial dysautonomias , such as ross syndrome or holmes - adie syndrome , seems to be benign but may progress slowly . each of these entities has a more widespread dysfunction than previously believed , with considerable overlap . there is increasing evidence that classic partial autonomic disorders may lie on a spectrum of generalized injury to the autonomic and dorsal root ganglia ( 11 , 12 ) . because the sympathetic , parasympathetic , and dorsal root ganglia are all neural crest cell derivatives , it is conceivable that some property of these related tissues makes them more susceptible to injury , although the mechanism of ganglionic damage or degeneration remains unknown .
harlequin syndrome is characterized by unilateral hyperhidrosis and flushing , which are predominantly induced by heat or exercise . 
 usually , the sympathetic deficits confine to the face . 
 rarely , the autonomic deficits involve the arm or the parasympathetic neurons in the ciliary ganglia . 
 we report a 43-yr - old woman who presented with facial flushing and sweating in the right side , which were mainly induced by exercise . the facial flushing accompanied relative coldness in the right arm . 
 valsalva maneuver , cold pressure and 0.125% pilocarpine test , and computed tomography of the chest were normal . 
 the crossed sympathetic deficit in the left face and right arm suggested that the lesions were multifocal . 
 the sympathetic impairment in our patient may lie on a spectrum of pre- and postganglionic autonomic dysfunction , which was observed in holmes - adie , ross , and guillain - barr syndrome .