Clinical and neuropsychological correlates in two brothers with pantothenate kinase-associated neurodegeneration.

Adult-onset focal dystonia was the presenting sign of pantothenate kinase-associated neurodegeneration (PKAN) in a patient with a novel homozygous missense mutation (C856T). His brother shared the same mutation and showed similar, albeit minor, motor signs, but a different behavioral profile. Both brothers had an atypical form of PKAN. The neuropsychological assessment showed that, despite a normal Mini-Mental State Examination, both patients presented a deficit of executive functions and of attention. The profile of cognitive impairment in these cases was typically that of a subcortical dementia. Both patients fulfilled Diagnostic and Statistical Manual for Mental Disorders criteria for obsessive-compulsive disorder; however, paranoia was associated with depression and aggressive behavior in Patient 1, whereas Patient 2 had hyperactivity, disinhibition, and euphoria. Our findings suggest that these two brothers had a different pattern of involvement of motor and nonmotor basal ganglia-thalamocortical circuits. Copyright 2004 Movement Disorder Society.