A case of disequilibrium due to central nervous disorders with a good response to acetazolamide

Abstract

We report herein on a case of disequilibrium due to central nervous disorders with a good response to acetazolamide. A 51-year-old woman presented with episodic disequilibrium and vertigo. Her symptoms began when she was a child. Her symptoms were worsened by positional change or physical exercise, lasting for several hours. She also had migraine-like headaches. Her family history was unremarkable. On examination, she showed gaze-evoked nystagmus, direction-fixed right beating positional nystagmus with down-beating nystagmus. Electronystagmography revealed saccadic pursuit, impaired optokinetic nystagmus, and disorders of visual suppression in caloric tests, suggesting central nervous disorders. MRI showed slight cerebellar atrophy without downward displacement of the cerebellar tonsil through the foramen magnum. Although she did not have family history, we clinically diagnosed her as having episodic ataxia type 2 (EA-2). She took acetazolamide (250 mg) per day. The frequency and intensity of her symptoms dramatically decreased. When we see a patient with episodic disequilibrium due to central nervous disorders, we should take EA-2 into account.