Parkinsonian axial signs in schizophrenia

INTRODUCTION: We have recently demonstrated evidence of nigro-striatal denervation, disease progression and response to levodopa in a subgroup of patients with schizophrenia who developed parkinsonism. OBJECTIVE: In the present study, we investigated whether axial parkinsonian signs might be an early manifestation of parkinsonism in schizophrenia not necessarily related to chronic administration of antipsychotic drugs (AP) drugs. METHODS: From a baseline cohort of 299 schizophrenic patients who did not satisfy the diagnostic criteria for parkinsonism (presence of at least two of the following appendicular signs: bradykinesia, tremor, rigidity), we identified a group of patients who manifested two out of three axial parkinsonian signs (abnormality of trunk posture, hypomimia and short-step gait). Accordingly, we obtained two sub-groups of patients with schizophrenia, with (Schiz-Axial, N = 26), and without parkinsonian axial signs (Schiz-NO-Axial, N = 273). Clinical and demographical variables were compared between groups. The motor section of the Unified Parkinson's disease rating scale (UPDRS) was employed to measure motor disability. RESULTS: Schiz-Axial patients were significantly older (p = 0.007) and had longer disease duration (p = 0.04) compared to Schiz-NO-Axial. The two groups did not differ for variables related to AP treatment. Total UPDRS motor score (p < 0.0001) as well as limb (p < 0.0001) and axial (p < 0.0001) UPDRS sub-scores were increased in Schiz-Axial patients compared to Schiz-NO-Axial. CONCLUSIONS: Our findings provide evidence that axial parkinsonian signs might be an early manifestation of parkinsonism in schizophrenia associated to older age and longer disease duration.