Frontal release signs and cognition in people with schizophrenia, their siblings and healthy controls.
BACKGROUND
Frontal release signs, a subset of neurological soft signs, are common in schizophrenia.


OBJECTIVE
To explore the relationship between frontal release signs and neuropsychological tests of frontal lobe function in people with schizophrenia, their siblings and healthy controls.


METHODS
Neuropsychological tests and frontal release signs were measured in a cohort of index cases (n=302), their siblings (n=240) and healthy controls (n=346).


RESULTS
The mean total score of frontal release signs was 1.5 (s.d.=1.58) in the schizophrenia group, 0.54 (s.d.=0.92) for siblings and 0.42 (s.d.=0.77) for controls. Schizophrenia group scores were greater than healthy control or sibling cohort scores (P < 0.0001), which did not differ. In all three cohorts, right grasp reflex scores positively correlated with number of perseverative errors on the Wisconsin Card Sort Task (P < 0.05). In the schizophrenia group, frontal release signs scores showed an inverse correlation with IQ (R=-0.199, P < 0.0005).


CONCLUSIONS
Our findings of relationships between frontal release signs and cognitive assays of cortical dysfunction and the increased frequency of these signs in people with schizophrenia implicate a cortical origin for these clinical signs and evidence of frontal lobe dysfunction in this disorder.
Hyde
Thomas M
TM
Clinical Brain Disorders Branch, Intramural Research Program, National Institutes of Health, 10 Center Drive, Bethesda, Maryland 20892, USA. HydeT@mail.nih.gov
Goldberg
Terry E
TE
Egan
Michael F
MF
Lener
Marc C
MC
Weinberger
Daniel R
DR
D000328:Adult; D001927:Brain Diseases / Q000453:epidemiology / Q000503:physiopathology*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000453:epidemiology / Q000503:physiopathology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D015588:Observer Variation; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology / Q000503:physiopathology*; D035781:Siblings