Biomedical subjects

B Steinacher

Publications and source records attributed to B Steinacher.

4 recordsLinked to original sources

PubMed2001

Basic parameters of saccadic eye movements--differences between unmedicated schizophrenia and affective disorder patients.

BACKGROUND: Smooth pursuit eye movement (SPEM) dysfunctions are considered a biological marker for schizophrenia and have been studied widely. In contrast, saccadic eye movements have received less attention, although disturbances have been described previously. Basic neurophysiologic parameters of saccades in schizophrenics, especially in unmedicated patients, have not been studied extensively. METHODS: Saccadic eye movements of 38 unmedicated schizophrenic patients, 32 patients with major depression and 42 non-psychiatric controls were examined using high-resolution infrared oculography. Two large-amplitude saccadic tasks were presented. The groups were compared on peak velocity, reaction time and accuracy. RESULTS: Peak velocity was significantly increased in schizophrenic patients. Depressive patients had a significantly longer reaction time. Both patient groups needed more corrective saccades to reach the target than controls. CONCLUSIONS: Peak velocity distinguishes unmedicated schizophrenic patients from depressive patients and normal controls. This could be explained by deficits of the prefrontal cortex in the inhibitory control of saccades. Our findings suggest that schizophrenia affects not only SPEM but also saccadic eye movements.

Adult↗

PubMed1998

[Follow-up assessment of mood in depressive patients].

Three short, respectively promising self-rating scales used for the assessment of emotional states, especially depression, were examined: a visual analogue scale with only five items, a short version of the so-called "adjectives list" and a differentiated scale for recording current emotions, possible susceptibility to them and the ability to express them. We checked statistical parameters of item analysis, reliability, validity and time course measurement. This study was carried out with depressive inpatients (n = 35) at the time of admission and 4 weeks later in beginning remission. All three scales proved to be reliable (Cronbach-alpha between 0.48 and 0.97) and partially very valid instruments (concurrent validity between 0.04 and 0.87). In order to improve the documentation of a beginning response to therapeutic efforts, separate recordings of depressive subsyndromes such as "impetus" or "positive emotionality" seem to be quite promising approaches.

Adult↗

PubMed1997

Smooth pursuit eye movements in schizophrenia and affective disorder.

BACKGROUND: Smooth pursuit eye movement (SPEM) dysfunction is considered to be a promising candidate for a biological marker for genetic vulnerability to schizophrenia. There are conflicting findings regarding the question of what is exactly dysfunctional in SPEM dysfunction and what component of eye movements is really specific to schizophrenia. The purpose of the current study was to help to clarify the nature of (SPEM) dysfunction and its specificity to schizophrenia. METHODS: Smooth pursuit eye movements of 43 schizophrenic patients, 34 patients with major depression and 42 normal controls were examined using high resolution infrared oculography. These groups were compared on several indices of oculomotor functioning (gain, different saccadic categories). RESULTS: Schizophrenics had a significantly higher catch-up saccade rate than depressed patients and normals. The percentage of subjects with an abnormally high catch-up saccade rate defined as beyond the mean plus 2 S.D. of the normal control group was significantly higher in schizophrenics (27.9%) than in depressed patients (8.8%) and normal controls (0%). Low gain and higher numbers of intrusive saccades tended to be more prevalent in both patient groups but did not distinguish schizophrenics from depressed patients. CONCLUSIONS: Low gain and high rates of intrusive saccades contribute to SPEM dysfunction in major depression. Abnormally high rates of catch-up saccades seem to be the oculomotor component in smooth pursuit, that is specific to schizophrenia.

Adult↗

PubMedDate not supplied

Subthreshold symptoms and vulnerability indicators (e.g., eye tracking dysfunction) in schizophrenia.

Subthreshold symptoms in schizophrenia can be prodromal signs of a psychotic relapse. In people without schizophrenia, similar symptoms may indicate the presence of disorders termed schizophrenia spectrum disorders. Subthreshold schizophrenia-like symptoms may indicate a genetically transmitted higher proneness to schizophrenia. Such a higher liability to develop schizophrenia is ascertained on a symptom level. In genetic studies, asymptomatic members of a pedigree are therefore classified as unaffected although they may possess the genes in question. On a biological level, eye tracking dysfunction has been shown to fulfill certain criteria for a vulnerability indicator and therefore promises to offer more information on genetically transmitted proneness to schizophrenia even in people without psychopathological symptoms. Subthreshold symptoms may warrant treatment. The database for prophylactic treatment in populations at high risk, especially those without symptoms, is currently very small.

Genetic Predisposition to Disease↗