[Paroxysmal dystonic choreoathetosis with chronic hemolytic anemia and morphologically abnormal erythrocytes]

A 38-year-old man was admitted to our hospital because of paroxysmal involuntary movement. He had a normal birth and normal development. No other members of his family had similar symptoms. He had attacks of choreoathetoic involuntary movement without loss of consciousness since about 11 years of age. Paroxysmal choreic movement occurred once or twice a month and lasted for 30 minutes to 4 hours. The attacks were intractable with phenytoin, phenobarbital, valproic acid, etc. He had slight disturbance of visual acuity due to toxoplasmosis and low intelligence (IQ 59, WAIS-R test). There were no other abnormal findings on general and neurological examinations. He was diagnosed as paroxysmal dystonic choreoathetosis (PDC) because of the typical attacks of paroxysmal choreic movement. He had macrocytic anemia with elliptocytes (13%) and stomatocytes (12%) but no acanthocytosis. There were increased reticulocytosis and low level of haptoglobin. Bone marrow aspiration showed increased erythroblasts. However, other hemolytic findings including bilirubin levels, Coombs test, osmolality tolerance test were normal. Biochemical analyses of erythrocyte membrane proteins and lipids, glycolytic enzymes activities and intermetabolites contents showed no abnormality. EEG revealed slow waves without abnormal paroxysmal discharges, and CT revealed no abnormal calcification. T2 weighted MRI showed bilateral multiple high intensity spots in the subcortical area, but no atrophy of the caudate nucleus. The pathogenesis of PDC is still unknown. In the present case, we suspect that a biochemical defect which had not been disclosed might result in abnormal erythrocyte membrane and PDC.