Parkinsonian axial signs in schizophrenia

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.

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.

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.

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.

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.