From Horner sydrome to Multiple sclerosis; a case report

A 29 year-old male presented with vision blurred of superior quadrant in right eye. He had 2 mm left upper lid pitozis. He had anisocoria. Right pupil diameter was 3 mm, left pupil diameter was 1.5 mm. Apraclonidine test was performed and confirmed Horner syndrome in left side. At the level of centrum semiovale, in the periventricular white matter, perpendicular to the ventricular system, demyelinating plaques were observed in cranial MRI. Patient was consultated to neurology, LP and radiological evaluation were diagnosed with MS. This patient was diagnosed with MS with Horner syndrome. Anisocoria is an important finding and differential diagnosis should be done carefully