Schizophrenia Research, 6 (1992) 25-30 $3 1992 Elsevier Science Publishers B.V. All rights reserved

SCHIZO

25 0920-9964/92/$05.00

00192

Neurological Johannes

soft signs in schizophrenia

Schriider, Rainer Niethammer, Michael Binkert, Marek

Department of Psychiatry. University (Received

Franz-Josef Geider, Christoph Jauss and Heinrich Sauer

Reitz,

of Heidelberg, VowStrasse 4. D-6900 Heidelberg. lTR.G.

5 August

1990, accepted

14 April

1991)

A new scale for neurological soft signs (NSS) was constructed and consists of 17 items compiled from the literature. The scale was found to have a high internal reliability (Cronbach’s cr 0.83) and a high interrater reliability (0.88). According to the results of a factor analysis, NSS are covered by five factors: ‘motor coordination’, ‘integrative functions’, ‘complex motor tasks ’ , ‘right/left and spatial orientation’ and ‘hard signs’. Using this scale, the associations of NSS with clinical course and brain alterations were investigated. NSS varied with the clinical course and were significantly correlated with some BPRS subscales, in particular ‘thought disorder’. In addition, the ‘motor coordination’ soft signs were found to correlate with morphological alterations in the basal ganglia. Key words: Neurological

soft sign; Motor

coordination;

Brain alteration;

INTRODUCTION

Previous studies have shown that minor neurological abnormalities-also called neurological soft signs (NSS)-are more frequent in schizophrenics than in non-psychiatric controls (Heinrichs and Buchanan, 1988). It is generally agreed that NSS mainly reflect areas of integrative sensory function, motor coordination and sequencing of complex motor acts. The significance of these signs, however, remains largely unknown, despite increased scientific efforts in recent years. Some of the available studies (Rossi et al., 1990) seem to suggest that NSS represent a trait characteristic of the illness, based on finding NSS in untreated and non-psychotic relatives of schizophrenics. In contrast, other studies have presented some evidence which may indicate that the impairment is tied to fluctuations in the clinical state (Torrey, 1980). The aim of our study was to determine whether Correspondence to: J. Schrdder, Department of Psychiatry, University of Heidelberg, Voss-Strasse 4, D-6900 Heidelberg, F.R.G.

Basal ganglia;

(Schizophrenia)

or not neurological soft signs vary with the course of illness. If so, this would indicate that the signs are state-dependent phenomena. Additionally, we wanted to clarify whether these impairments are associated with brain alterations on computed tomography (CT) scans.

SUBJECTS

AND

METHODS

50 consecutively admitted patients with a DSMIII schizophreniform disorder or schizophrenia participated in the study. According to the DSMIII classification of clinical course, 27 patients (mean age 36.04, f 12.12 years) met the criteria for a chronic or subchronic schizophrenia with an acute exacerbation; 23 (mean age 28.94, &8.8X years) were diagnosed as having a remitting schizophrenia (n = 16) or schizophreniform disorder (n = 7). 17 of the 50 schizophrenic patients were drugnaive. Particular care was taken to exclude patients with a history of neurological disorders, drug abuse or alcoholism. 34 healthy volunteers (mean age:

26

25.74, + 3.1 S), recruited by public advertisement, served as a control group. As no validated NSS scale existed, 17 NSS items were compiled from the literature (Quitkin et al.. 1976; Cox and Ludwig, 1979; Manschreck and Ames, 1984; Rossi et al., 1990). Our scale included the following items: station and gait, tandem walkright/left orientation, speech articulation, ing, primitive reflexes, Ozeretzki’s test, pronation/supination, diadochokinesis, finger-to-thumb opposition, 2-point discrimination, fist-edge-palm test, finger-to-nose test, face hand sensory test, graphesthesia. stereognosis, mirror movements. armholding test. The examination procedures followed the instructions given in the literature. If instructions were not available or were conflicting, two widely recommended handbooks for neurological examination were consulted (Bates, 1983; Schenck, 1985)*. The NSS were examined blindly to the patient’s diagnosis and rated on a O-3 scale (absent, slight, present. marked). All items, with the exception of station and gait, tandem walking, right/left orientation. speech articulation, primitive reflexes and Ozeretzki’s test were rated separately on the right and left side. To test the interrater reliability of the NSS scale, 42 patients and healthy controls were simultaneously evaluated by two raters. The internal reliability of the scale was assessed by calculating Cronbach’s a. Our testing procedure was generally standardized, but we adjusted our explanations and the time required to complete the tasks to the condition of the patients. The psychopathological status and extrapyramidal side effects were assessed using the Brief Psychiatric Rating Scale/BPRS (Overall and Gorham, 1962) and the Rating Scale for Extrapyramidal Side Effects (Simpson and Angus, 1970). NSS and the other clinical ratings were performed on admission (T,), 7 days later (T,) and after remission (TR) of the acute illness. The CT scans were taken at IO” cranial to the orbitomeatal line. To quantify the size of the external and internal cerebral spinal fluid (CSF) spaces, the following CT parameters were measured: width of the frontal interhemispheric fissure, width of the three largest cortical sulci and of the *The detailed manual used for the examination will be sent on request.

of the NSS

third ventricle. Moreover, the frontal horn ratio, the ventricle brain ratio (VBR) and the ventricle ratio were determined. The ventricle ratio (Fig. I) is defined as the ratio of the distance between the frontal horns divided by the distance between the heads of the caudate nuclei (Vogel, 1986). Thus, if a loss of the caudate nuclei substance occurs, the distance between both heads becomes larger, leading to a smaller ventricle ratio. Each CT was examined by two independent investigators, blind to the patient’s diagnosis. In the case of divergent opinions, a consensus assessment was made. After admission (7’,) all patients received neuroleptic treatment. The psychiatrist in charge was responsible for the choice and dosage of the drug. All statistical computations were performed using the SAS and SPSS statistical packages.

RESULTS

The internal reliability of the NSS scale, as estimated by Cronbach’s c(, was 0.85 when applied to schizophrenics, and 0.89 when applied to healthy controls. The interrater reliability of the NSS scale was 0.88 (p< 0.005). The NSS item, primitive reflexes (Nasrallah et al., 1983) could not be identified in any of our patients and therefore was removed from the scale.

Fig. I The ventricle ratio is defined as the ratio of the distance between the frontal horns (A) divided by the distance between the heads of the caudate nuclei (B).

27

To investigate whether NSS are state dependent, their frequency was determined in the acute psychotic state and followed longitudinally during the course of the acute illness. The patient sample was subdivided into those with a remitting and those with a chronic condition. When contrasting both groups on admission, the remitting condition was associated with a non-significant lower total NSS score than the chronic disorders (Table 1). During the clinical course, both groups showed a significant decrease of the NSS. This decrease, however, was significantly (p

Neurological soft signs in schizophrenia.

A new scale for neurological soft signs (NSS) was constructed and consists of 17 items compiled from the literature. The scale was found to have a hig...
513KB Sizes 0 Downloads 0 Views