Neurological soft signs and prepulse inhibition of the startle reflex in psychosis: A pilot study

Abstract

Objective. Prepulse inhibition (PPI) of the startle reflex deficit and neurological soft signs (NSS) are two markers of vulnerability to psychosis. This study investigated the possibility of a PPI–NSS relation due to a putative common biological substrate, hypothesizing that patients with higher NSS scores also show higher PPI deficits. Moreover, we examined the possibility of an association of PPI deficits and NSS with negative symptoms. Methods. Fifteen subjects with psychosis and fifteen healthy controls underwent PPI and NSS evaluations. Results. Patients did not exhibit higher PPI deficits but only higher NSS rates (p < 0.01), as compared with healthy controls. Higher NSS rates were not associated with PPI deficits, and NSS sensory integration signs correlated positively with negative symptoms (p < 0.01). Conclusion. Our study supported the hypothesis that NSS are trait markers whereas PPI deficits state markers and that their putative common biological substrate is not sufficient to determinate an association between them. The study hypothesis, however, needs further investigation.

Key words::

• PPI
• NSS
• sensory integration signs
• motor sequencing signs
• schizophrenia

Acknowledgements

We are grateful to all participants who contributed to the study. We also thank Mr. Agostino Scaglia for his technical support. The project was supported by the grant “Promoting research to improve quality of care: The Verona WHO Centre for mental health research’’ from Fondazione Cariverona to Professor Tansella and Professor Ruggeri. Dr. Ira was funded by the FSE grant “Acquisizione nuove tecniche automatizzate di studio di immagini di risonanza magnetica nucleare cerebrali” from the Veneto Region.

Statement of interest

None to declare.