APRAXIA IN PARKINSONS-DISEASE, PROGRESSIVE SUPRANUCLEAR PALSY, MULTIPLE SYSTEM ATROPHY AND NEUROLEPTIC-INDUCED PARKINSONISM

We studied 45 non-demented patients with Parkinson's disease (PD), 12 with progressive supranuclear palsy (PSP), 10 with multiple system atr ophy (MSA) and 12 with neuroleptic-induced parkinsonism (NIP) for the presence of apraxia. Our aim was to determine whether a standard compr ehensive assessment of different praxic functions would demonstrate sp ecific types of errors not attributable to bradykinesia, rigidity trem or or any other abnormal elementary motor deficit. PD patients on chro nic levodopa treatment were examined in the 'on' and 'off' (treatment) states. Based on apraxia assessment scores, bilateral ideomotor aprax ia for transitive movements was found in eight (75%) and 12 (27%) of P SP and PD patients, respectively. Ideomotor apraxia was mainly charact erized by spatial errors (i.e. external and internal configuration bod y-part-as-object and trajectory). Four PSP but no PD patients exhibite d ideomotor apraxia for intransitive movements. PSP as well as PD pati ents with ideomotor apraxia also had difficulties in imitating hand an d finger postures, but none of them failed on pantomime comprehension and pantomime recognition/discrimination. Some PSP patients exhibited in addition, a limbkinetic type of apraxia and a minority of them disp layed deficits on tasks involving multiple steps. Neither MSA nor NIP patients showed arty disturbance of praxic functions. There were no di fferences in age, disease duration, Mini Mental State Examination (MMS E), Unified Parkinson's Disease Racing Scale and Hoehn-Yahr scores bet ween apraxic and non-apraxic PD patients, and ideomotor apraxia scores were similar in the 'on' and 'off' states. A correlation was found be tween ideomotor apraxia scores in PD patients and deficits in frontal lobe-related neuropsychological tasks such as the Tower of Hanoi, verb al fluency and the Trail Making Test. Furthermore, PD patients with ap raxia showed higher Hamilton depression scores than non-apraxic PD pat ients. In PSP patients, ideomotor apraxia scores correlated significan tly with cognitive deficit as measured with MMSE. The presence or abse nce of cortical involvement, and its severity and distribution might d etermine the presence and type of apraxia in PD and PSP Apraxia in the se conditions would therefore reflect combined cortico-striatal dysfun ction.