Unilateral loss of facial flushing and sweating with contralateral anhidrosis: harlequin syndrome or Adie's syndrome?

A 45-year-old woman presented with a 10 year history of asymmetrical facial flushing and sweating after exertion or in hot weather. During these episodes the right side of her face remained dry and white, while the left side normally flushed. Sweating was impaired on the left side in the limbs and trunk. She also had areflexia in the lower limbs and slow pupillary reactions to light and darkness, as seen in Adie's syndrome. The topography of the sweating disorder suggested that the lesion involved the sympathetic pathways at the level of spinal cord. The relationship with the harlequin syndrome and related disorders is discussed.