Detection, Assessment, and Management of Schizophrenia in an Andean Population of South America: Parkinsonism Testing and Transcranial Ultrasound as Preventive Tools

Parkinsonian motor impairment predicts personality domains related to genetic risk and treatment outcomes in schizophrenia

Identifying endophenotypes of schizophrenia is of critical importance and has profound implications on clinical practice. Here we propose an innovative approach to clarify the mechanims through which temperament and character deviance relates to risk for schizophrenia and predict long-term treatment outcomes. We recruited 61 antipsychotic naïve subjects with chronic schizophrenia, 99 unaffected relatives, and 68 healthy controls from rural communities in the Central Andes. Diagnosis was ascertained with the Schedules of Clinical Assessment in Neuropsychiatry; parkinsonian motor impairment was measured with the Unified Parkinson’s Disease Rating Scale; mesencephalic parenchyma was evaluated with transcranial ultrasound; and personality traits were assessed using the Temperament and Character Inventory. Ten-year outcome data was available for ~40% of the index cases. Patients with schizophrenia had higher harm avoidance and self-transcendence (ST), and lower reward dependence (RD), cooperativeness (CO), and self-directedness (SD). Unaffected relatives had higher ST and lower CO and SD. Parkinsonism reliably predicted RD, CO, and SD after correcting for age and sex. The average duration of untreated psychosis (DUP) was over 5 years. Further, SD was anticorrelated with DUP and antipsychotic dosing at follow-up. Baseline DUP was related to antipsychotic dose-years. Further, ‘explosive/borderline’, ‘methodical/obsessive’, and ‘disorganized/schizotypal’ personality profiles were associated with increased risk of schizophrenia. Parkinsonism predicts core personality features and treatment outcomes in schizophrenia. Our study suggests that RD, CO, and SD are endophenotypes of the disease that may, in part, be mediated by dopaminergic function. Further, SD is an important determinant of treatment course and outcome.

Prediction of Neurocognitive Deficits by Parkinsonian Motor Impairment in Schizophrenia: A Study in Neuroleptic-Naïve Subjects, Unaffected First-Degree Relatives and Healthy Controls From an Indigenous Population

BACKGROUND

Neurocognitive deficits are among the most debilitating and pervasive symptoms of schizophrenia, and are present also in unaffected first-degree relatives. Also, multiple reports reveal parkisonian motor deficits in untreated subjects with schizophrenia and in first-degree relatives of affected subjects. Yet, the relation between motor and cognitive impairment and its value as a classifier of endophenotypes has not been studied.

AIMS

To test the efficacy of midbrain hyperechogenicity (MHE) and parkinsonian motor impairment (PKM) as predictors of neurocognitive impairment in subjects with or at risk for schizophrenia, that could be used to segregate them from first-degree relatives and healthy controls.

METHOD

Seventy-six subjects with chronic schizophrenia never exposed to antipsychotic medication, 106 unaffected first-degree relatives, and 62 healthy controls were blindly assessed for cognitive and motor function, and transcranial ultrasound.

RESULTS

Executive function, fluid intelligence, motor planning, and hand coordination showed group differences. PKM and MHE were significantly higher in untreated schizophrenia and unaffected relatives. Unaffected relatives showed milder impairment, but were different from controls.

CONCLUSIONS

PKM and MHE predict cognitive impairment in neuroleptic-naive patients with schizophrenia and their unaffected first-degree relatives and may be used to segregate them from first-degree relatives and healthy controls.