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Biomedical subjects

G Oepen

Publications and source records attributed to G Oepen.

At least 37 records · Page 2Linked to original sources
PubMed1987

Schizophrenia--an emotional hypersensitivity of the right cerebral hemisphere.

While modern neuropsychological and electrophysiological studies claim a functional disturbance of the left hemisphere (LH) in schizophrenia, historical clinical and anatomical work rather points to the right hemisphere (RH) as the main site of psychosis. In the light of an interhemispheric functional balance of inhibition and release, LH-dysfunction in schizophrenia could be interpreted as a consequence of an overactive and inhibiting RH. Since the RH is especially activated by emotional stimuli, and exaggerated distractability and sensitivity to emotional stimuli are hallmarks of schizophrenia, we compared the emotional irritability of the RH and LH in 35 acute schizophrenics and 22 matched controls. Using tachistoscopic half-field presentation we found in acute schizophrenics a selective impairment of RH-function with simultaneous improvement of LH-performance induced by emotional distractors. We therefore suggest that a right hemispheric dysfunction and hypersensitivity to emotional material plays an essential catalytic role in acute schizophrenia.

Acute Disease↗
PubMed1987

Neuroleptic malignant syndrome: observations on altered consciousness.

A young man with a previously untreated schizophrenia developed a neuroleptic malignant syndrome (NMS) on the second day of neuroleptic treatment. The dominant symptom was deep coma. The NMS occurred on the second day of neuroleptic therapy with rapidly progressing mental deterioration, temperature elevation, and extrapyramidal signs. After anticholinergics were injected the patient regained consciousness. This suggests that a cholinergic hyperactivity in the central nervous system (rather than hyperthermia) is responsible for the disturbance of consciousness in NMS. The experimental evidence that central cholinergic systems are stimulated by neuroleptics is discussed. It is concluded that anticholinergics might be helpful in treating coma during NMS.

Adult↗
PubMed1987

[SPECT studies with 99mTc-HMPAO in Huntington's chorea patients].

Huntington's chorea is an autosomal dominant inherited disease with a chronic course and atrophy of the corpus striatum. PET examination shows reduced glucose metabolism in the caudate nucleus. We examined seven patients with Huntington's chorea by SPECT, using 99mTc-HMPAO. All patients had cortical defects of varying severity. In addition, five patients showed increased uptake in the region of the caudate nucleus. The specific tracer uptake due to the metabolic processes in the region of the caudate nucleus in Huntington's chorea is discussed.

Caudate Nucleus↗
PubMed1987

[Hemispheric laterality and early childhood autism. A case study of the etiologic and nosologic problem of the autistic syndrome in childhood].

Most studies on childhood autism emphasize a left hemispheric disturbance. In the presented case a primary right (and only secondary left) hemispheric dysfunction seems to be obvious. This seems to be true also for other reports in the literature. Supported by the hypermasculine aspect of our patient a pathological intrauterine testosterone level is suggested to be responsible for the observed altered cerebral asymmetry and consecutive hemispheric dysfunction. The advantage of such neuropsychologic findings and hypothesis should stimulate further studies on autism and other psychiatric disturbances.

Autistic Disorder↗
PubMed1986

[Differential diagnosis of acute life threatening catatonia and malignant neuroleptic syndrome--a case report].

This study reports the development of a severe life threatening catatonia in a 19 years old woman. Initially she displayed paranoia and hallucinations, which were complicated under neuroleptic treatment by extended rigor, temperature and autism. ECT led to a certain improvement of all symptoms, but complete recovery was only reached after neuroleptic drug withdrawal. The course of this case shows that the differential-diagnosis between genuine "pernicious" catatonia and the neuroleptica malignant syndrome is very difficult clinically. Therefore, before the application of ECT, an observation period without any neuroleptic drugs is recommended in similar cases with rigor, stupor and raised temperature, to avoid additional risks by narcosis and ECT itself. Diagnostic and therapeutic outlines are given.

Adult↗
PubMed1985

Foveal interocular time thresholds and latency differences in multiple sclerosis.

Nineteen patients with suspected multiple sclerosis (MS) and 28 control subjects were foveally stimulated by a small cross formed by rectangular red-light-emitting diodes. By means of crossed polarizers one eye was exposed only to the horizontal bar of the cross, the other to the vertical. Stimulus onset asynchrony ranged from 0 to +/- 300 ms (the horizontal bar preceding or following the vertical). The task was to indicate whether the horizontal or vertical bar had appeared first. Compared with normal subjects, MS patients exhibited much higher time thresholds (ranging from -150 to +130 ms) and had considerable interocular latency differences (up to 29 ms), indicating unilateral or asymmetrical impairment of the visual pathways. The psychophysical latency differences of the patients were compared to monocular latencies and interocular latency differences of the visually evoked cortical potential (VEP) obtained by foveal stimulation. Under the stimulus conditions chosen in this study, the diagnostic value of the psychophysical measurements was equal to or, for McAlpine's classes I and II of definite and probable MS patients, better than that based on VEP recordings.

Adult↗
PubMed1985

Long-term effects of partial callosal lesions. Preliminary report.

Ten patients with partial callosal lesions were investigated with a broad scale neuropsychological assessment. Nine patients with a variety of lesions affecting midline structures have been operated using a direct transcallosal approach, one patient with a callosal lipoma remained unoperated. Sophisticated studies of the interhemispheric transfer of somaesthetic and perceptual motor tasks, as well as psychometric testing related to parameters of memory and attention performance were applied. The results indicate that there is no clear correlation between the site of callosal lesion and clinical symptoms. Although special disconnecting symptoms due to callosal dissection could be found, they didn't reach clinical significance. The most severe symptoms of impairment were caused by the extracallosal pathology. The results indicate that the transcallosal approach is a safe and feasible alternative in the management of pathological lesions in the midline region.

Adolescent↗
PubMed1985

Piracetam improves visuomotor and cognitive deficits in early Parkinsonism--a pilot study.

The influence of Piracetam on Parkinsonism was studied in 18 patients and 18 matched controls. Clinical, visuomotor and psychometric variables were measured. Piracetam improved visuomotor reaction time (RT) and accuracy in 6 mildly affected and tracing time in 6 moderately affected patients, the clinical condition and the organic brain syndrome in all patients investigated. The improvement of the prolonged RT seems to be correlated with bradyphrenia. No drug influence could be observed in the prolonged interhemispheric transfer time. As the mildly affected patients displayed the clearest effect of Piracetam, its administration in early and mild stage of parkinsonism is recommended.

Aged↗
PubMed1985

Huntington's disease: visuomotor disturbance in patients and offspring.

In 15 patients with Huntington's disease, 17 offspring at risk and 63 healthy controls, visuomotor performances were assessed by quantitative (statistical) and qualitative analysis. The much enlarged error score of the nondominant left hand in patients with Huntington's disease was explained as callosal dyspraxia. Five of the 17 offspring revealed results similar to that of the patients.

Adolescent↗
PubMed1982

The effect of cervical and vestibular reflexes on eye movements in Huntington's chorea.

In 8 patients with manifest Huntington's Chorea vestibulo-ocular (VOR) and cervico-ocular (COR) reflexes were compared with eye movements during active head turnings. Seated patients were stimulated with their eyes closed by sinusoidal swings around the vertical axis at frequencies of 0.05, 0.1 and 0.2s-1 with amplitudes of 20, 40 and 60 degrees. 1) With all stimuli and in all patients a weak nystagmus was elicited in the direction of head movements, superimposed on larger slow eye deviations. 2) The averaged total saccadic amplitudes were smaller than in normals, increased with stimulus amplitudes and were smallest for COR, followed by VOR and active head movements. 3) The gain (peak velocity of slow phase of nystagmus to peak stimulus velocity) was only slightly below norm values and decreased with increasing stimulus frequency and amplitude. 4) The peak amplitudes of average slow eye deviations increased with stimulus amplitudes. In VOR they were comparable to norm values but were below them during COR and active head movements. 5) In normal subjects these slow eye deviations were compensatory to head movements in VOR but anticompensatory in COR and during active head movements. In choreic patients during COR and more often during active head movements these slow eye movements were compensatory for the head turning.

Adult↗
PubMed1982

Huntington's disease - imbalance of free amino acids in the cerebrospinal fluid of patients and offspring at-risk.

A total of 27 different amino acids were determined in the fasting, morning lumbar CSF of 12 patients with Huntington's Disease (HD), 8 at-risk offspring and 16 non-choreic control patients. A significant (P less than 0.001) decrease was observed for asparagine, isoleucine, leucine, phenylalanine, histidine, arginine, alpha-aminoadipic acid and homocarnosine in patients with HD compared to the non-choreic controls. Only tyrosine was increased in HD. These alterations were to an extent more pronounced in 5 neurophysiologically conspicuous offspring. The alterations suggest that amino acid imbalance is an early metabolic disturbance in HD.

Amino Acids↗
PubMed1982

Huntington's disease: alterations of visual and somatosensory cortical evoked potentials in patients and offspring.

In 13 patients suffering form Huntington's chorea (H.Ch.), VEPs and SEPs were investigated in comparison to 9 clinically inconspicuous offspring and normal adults. 1. The mean amplitude of VEP was reduced in choreatic patients and in four out of nine offspring. 2. Latencies of P100 in VEP were normal in all subjects. 3. The late components were reduced in amplitude and rather irregular in shape. 4. The latencies of SEPs were slightly prolonged, less marked in the early peaks and more pronounced in the later ones. 5. The late components after 70 to 100 msec were often attenuated or even absent. 6. The mean amplitude of the first two peaks was reduced. 7. Interhemispheric asymmetries were pronounced in three out of nine offspring.

Adult↗
PubMed1982

Visual evoked potentials by central foveal and checkerboard reversal stimulation in multiple sclerosis.

In 200 patients with suspected MS, the diagnostic value of VEP elicited by checkerboard reversal and central foveal stimulation was compared. No significant difference was evident, but both methods overlap. The more stable checkerboard reversal stimulation should be preferred as a diagnostic method. Only in suspected MS with normal checkerboard responses, additional foveal responses may give supplementary information. Normal VEPs cannot exclude a prior retrobulbar neuritis.

Diagnosis, Differential↗
PubMed1981

Huntington's chorea-- measurements of somatostatin, substance P and cyclic nucleotides in the cerebrospinal fluid.

Somatostatin, substance P, cyclic AMP and cyclic GMP were determined in the cerebrospinal fluid of patients with Huntington's disease, in first generation relatives of choreic patients and in neurological control patients. Substance P levels were not significantly altered, but somatostatin levels were markedly decreased both in affected patients and symptom-free offspring. Cyclic AMP was decreased only in patients with advanced stages of the disease while cyclic GMP was normal. Evidence is discussed which may support a role of somatostatin deficiency in the pathophysiology of chorea.

Adult↗
PubMed1981

Diagnostic value of CT in patients with Huntington's chorea and their offspring.

Striatal and cortical atrophy are significant features in the pathology of Huntington's chorea (HCh). A correlative study revealed that the CT findings of atrophy in HCh (8 patients) parallel the clinical and neurophysiological findings. In offspring (8 subjects) of HCh patients, however, the CT changes were insignificant although neurophysiological data were already suspicious in four of them. One patient with hereditary non-progressive chorea showed no CT changes at all. Perhaps with a more sensitive CT scanning technique minor morphological alterations may also be detected and used for a pre-clinical diagnosis.

Adult↗
PubMed1981

Disturbance of eye movements in Huntington's chorea.

Eye movements were investigated in 14 patients with manifest Huntington's Chorea, 10 offspring and 10 normal subjects with electronystagmography (ENG) and during REM sleep. In choretic patients the following abnormalities were found: 1. Voluntary saccades were slowed in 10 of 14 patients and were more disturbed in the vertical than the horizontal direction. 2. Also, the velocity of the fast phase of optokinetic nystagmus was clearly reduced, especially in the vertical plane. 3. Horizontal, pendular pursuit movements are often superimposed by square wave opposite jerks. 4. Vestibular nystagmus was disturbed, too, especially in the fast phase. 5. During paradoxical sleep, rapid eye movements are less frequent. 6. In ten offspring, eight showed similar oculomotor disturbances.

Adult↗
PubMed1981

Qualitative H-reflex testing in huntington's disease.

The occurrence of H-reflexes over both the anterior tibial muscle and the thenar muscle on both sides was investigated in 15 patients suffering from Huntington's disease, 8 clinically inconspicuous offspring, and 30 healthy normal controls. The following results were obtained: 1. An obvious H-reflex over the anterior tibial muscle was found in 12 of 15 patients; there was no H-reflex in only 3 patients. 2. After stimulation on the median nerve there was an H-reflex in 12 of 13 patients investigated. 3. In 5 of 8 clinically inconspicuous offspring there was an H-reflex after peroneal [4] or median [5] nerve stimulation. In 30 normal controls, 1 displayed a weak H-reflex over the anterior tibial muscle, 9 showed a weak H-reflex after median nerve stimulation. 5. The possibility is discussed that an abnormal H-reflex might be an early sign of central reflex disinhibition in otherwise asymptomatic offspring.

Adult↗