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.

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.

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.

[Suicide rates in a community psychiatric service system]. / Suizidraten in einem gemeindepsychiatrischen Versorgungssystem.

Reduction of the elevated suicide rates in psychiatric patients remains an important aim of psychiatric treatment. There has been an ongoing discussion on the question of whether the increased tendency to transfer long-term psychiatric patients from inpatient care to community psychiatric care might go along with increased suicide rates. In our community care system we found an age- and sex-adjusted suicide rate 40 times as high as in the general population in the period between 1973 and 1993. Within the first 4 years suicide rates were significantly elevated. All suicides had the diagnosis of chronic schizophrenia or schizoaffective psychosis. In the non-schizophrenic group no suicide occurred during treatment. Our study shows that in community psychiatric care suicide rates in schizophrenic patients are significantly increased whereas suicide rates is non-schizophrenic patients may be decreased.

The feasibility of suicide rates as an evaluation criterion in community psychiatry: methodological problems.

Over the last 30-40 years the reform of psychiatric care in many countries has led to deinstitutionalization and treatment of many patients in community psychiatric services. There is an ongoing discussion on whether this process may lead to a higher suicide rate. There are only a few studies addressing this issue, and empirical data are scarce. Several methodological problems make it difficult to use suicide rates as an evaluation criterion for community psychiatry. These problems are briefly discussed.

Mixed connective tissue disease: recurrent episodes of optic neuropathy and transverse myelopathy. Successful treatment with plasmapheresis.

Severe neuropsychiatric manifestations in mixed connective tissue disease (MCTD) are thought to be quite rare. We report an unusual case of MCTD with recurrent optic neuropathy and transverse myelopathy suggestive of a relapsing-remitting demyelinating disorder. Symptoms responded dramatically to a treatment with plasmapheresis and immunosuppressive medication.

Lithium effect on smooth pursuit eye movements of healthy volunteers.

Smooth pursuit eye movement (SPEM) dysfunctions in major affective disorder patients have been reported to be associated with lithium treatment. We report that SPEM of 13 healthy volunteers, either taking lithium (n = 7) or placebo (n = 6), were not significantly impaired by lithium. This could point to a pathophysiologic difference between affective disorder patients and a normal population.

Increased blink rates in schizophrenics. Influences of neuroleptics and psychopathology.

During a standardized visuomotor task, eye blinking, a possible parameter of central dopaminergic activity, was studied in 18 previously medicated and eight drug-naive schizophrenic in-patients in the acute state and during remission. Whereas schizophrenics executed the visuomotor task with the same precision as age- and sex-matched normal control subjects did, the mean blink rate was increased in both schizophrenic groups. During neuroleptic treatment, the mean blink rate was reduced only in the group of drug-naive patients, but not in the previously neuroleptic treated schizophrenics. This varying blinking activity is discussed with respect to the development of neuroleptic tolerance and influence of psychopathology.

Increased blink rate in drug-naive acute schizophrenic patients.

Eye blinks were investigated during a standardized visuomotor task in 15 drug-naive schizophrenic inpatients (8 men and 7 women) and 15 age- and gender-matched healthy volunteers. Whereas the schizophrenics demonstrated the same precision as normal controls in executing the visuomotor task, their mean blink rate was markedly increased (16.2 +/- 10.8 versus 9.3 +/- 6.4, p less than 0.05). Following neuroleptic treatment, the blink rate decreased, and was no longer statistically distinct from controls. The changes in blink rate correlated significantly with changes in several Brief Psychiatric Rating Scale (BPRS) items: "anxiety" (tau = 0.75; p less than 0.02), "hostility" (tau = 0.78; p less than 0.02), and "unusual thought content" (tau = 0.59, p less than or equal to 0.05), but not with the neuroleptic dose given between the first and second testing. These results underscore the influence of psychopathology on blink rates in schizophrenics.