R. Schlenker

NEUROLOGICAL SOFT SIGNS IN SCHIZOPHRENIA : ASSESSMENT AND CORRELATES

A German version of the Neurological Evaluation Scale (NES) was administered to 143 schizophrenic patients, 45 of them being severly chronic and disabled. Seventy-eight alcohol-dependent inpatients and 57 healthy volunteers were tested as control groups. Neurological soft signs (NSS) were rated with convincing agreement. Schizophrenic patients are more impaired on all scales than healthy controls. The chronic, severly disabled schizophrenic patients are more impaired compared with the main group of schizophrenic patients and both control groups. A significant patients and alcohol-dependent patients was only found for the subscale “Motor Coordination”. Compared with healthy controls the alcohol-dependent patients show a higher NES total score. The NES total score was related to the relative width of the third ventricle. Total score and subscales were correlated consistently with the level of cognitive functioning as measured by the Raven Standard Progressive Matrices and various neuropsychological tests presumably sensitive to dysfunctions of the prefrontal cortex. The NSS were related to positive as well as to negative symptoms, the correlations with negative symptoms being confined to items of “Cognitive Disorganization”. This close association of psychomotor and cognitive dysfunctions may be seen as related to the frequently discussed dysfunctions of the prefrontal cortex or the neurointegrative deficit postulated by Meehl.

AFFECTIVE MODULATION OF THE STARTLE REFLEX IN SCHIZOPHRENIC PATIENTS

Startle-elicited blinks were measured during the presentation of affective slides in order to investigate emotional responsiveness in 24 male healthy subjects and 34 male schizophrenic patients. Although the two groups did not differ with regard to their subjective and autonomic responses to the slide stimuli, there was a significant difference between the groups in their responses to the startle probes. Patients rated low in affective expression showed a linear response pattern comparable to that of normal controls with largest amplitudes during unpleasant slides and smallest during pleasant slides. Patients without apparent deficit in affective expression showed a quadratic relationship with smaller blink amplitudes during both pleasant and unpleasant slides. Diminished affective expression rated on the basis of a clinical interview is not associated with a general attenuation of the blink reflex or of its modulation by exposure to emotional slides. Thus, we found no indication of an impairment in the perception of affective stimuli nor of reduced appreciation of pleasant stimuli (anhedonia) in these patients.

Motoric neurological soft signs and psychopathological symptoms in schizophrenic psychoses.

Motoric neurological soft signs (NSS) were investigated by means of the Brief Motor Scale (BMS) in 82 inpatients with DSM-III-R schizophrenic psychoses. To address potential fluctuations of psychopathological symptoms and extrapyramidal side effects, patients were examined in the subacute state, twice at an interval of 14 days on the average. NSS were significantly correlated with severity of illness, lower social functioning, and negative symptoms. Modest, but significant correlations were found between NSS and extrapyramidal side effects as assessed on the Simpson-Angus Scale. Neither the neuroleptic dose prescribed to the patient, nor scores for tardive dyskinesia and akathisia were significantly correlated with NSS. Moreover, NSS scores did not significantly differ between patients receiving clozapine and conventional neuroleptics. Patients in whom psychopathological symptoms remained stable or improved over the clinical course showed a significant reduction of NSS scores. This finding did not apply to those patients in whom psychopathological symptoms deteriorated. Our findings demonstrate that NSS in schizophrenic psychoses are relatively independent of neuroleptic side effects, but they are associated with the severity and persistence of psychopathological symptoms and with poor social functioning.

Smooth-pursuit eye movement dysfunction in schizophrenia: the role of attention and general psychomotor dysfunctions

Smooth-pursuit eye-tracking performance was examined in 100 schizophrenic patients and various control groups under both attention-enhancing and attentiondistracting conditions. The level of attentional demand was varied by introducing a secondary reaction time task that directed attention either toward or away from the visual-tracking target. Distraction from the target led to a significant deterioration of tracking performance in all subjects, which was most pronounced in the group of schizophrenic patients. Attention-enhancement, on the other hand, did not normalize performance in this group. In schizophrenic patients, mainly in the distraction condition, there was a moderate association between performance in tracking and tests presumably measuring prefrontal functions. Tracking accuracy from both conditions was related to general motor performance as measured by the Neurological Evaluation Scale. It was concluded that in schizophrenic patients attentional factors (distraction) may contribute to eye-tracking impairment, and that the impairment may be viewed as an aspect of general motor dysfunctions.

Smooth-pursuit eye-movement dysfunction and motor control in schizophrenia: A follow-up study

Smooth-pursuit eye-tracking data of 63 schizophrenic patients and 52 normal controls are presented and compared with data collected on the same subjects 2 years earlier. Despite considerable clinical stabilization of the patients the overall eye-tracking performance did not improve. Intrasubject stability over 2 years was moderate. Eye-tracking impairment was significantly correlated with number of psychomotor soft signs and with number of errors in an antisaccade task. The correlations indicate that impairment of smooth-purisuit eye movements is likely to be a consequence of deficient motor control.

Electrodermal and vascular orienting response in schizophrenic patients: Relationship to symptoms and medication

Peripheral indicators of autonomic nervous system activity, including electrodermal activity and finger-pulse volume, were investigated in 100 schizophrenic inpatients. Healthy siblings of the patients and healthy subjects matched for age and gender served as control groups. Acoustic stimuli (70 dB) were presented and orienting response (OR) parameters were determined independently for the two response systems. The relationship of both OR measures to negative symptoms and medication was studied. The two OR measures were found to be not interrelated, i.e. most of the subjects were discordant with regard to presence or absence of their OR in the two different response systems. The electrodermal, but not the vascular OR. differed between patients and control groups. Among patients receiving medication with anticholinergic effects there were significantly more electrodermal nonresponders than among patients without such medication. There was no indication that electrodermal nonresponders show more negative symptoms or generally more severe psychopathology than electrodermal responders.