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Biomedical subjects

G Oepen

Publications and source records attributed to G Oepen.

49 records · Page 3Linked to original sources
PubMed1981

Visual evoked potentials (VEP) elicited by checkerboard versus foveal stimulation in multiple sclerosis. A clinical study in 235 patients.

In 235 patients with suspected multiple sclerosis (MS) the diagnostic value of visual evoked potentials (VEP) elicited by checkerboard and central foveal stimulation was compared. No significant difference was found. Both methods are supplementary in diagnostic value. Foveal stimulation may provide an additional diagnostic clue. Normal VEPs do not exclude a prior retrobulbar neuritis. Electronystagmography and examination of CSF are at least essential for the diagnosis of MS as VEPs. The combination of these methods increase the accuracy of diagnosis.

Adolescent↗
PubMed1981

Visual (VEP) and somatosensory (SSEP) evoked potentials in Huntington's chorea.

In 13 patients suffering from Huntington's chorea (H.Ch.) VEPs and SSEPs were investigated in comparison with 9 clinically unaffected offsprings and 40 normal adults. (1) The mean amplitude of VEPs was reduced in all patients and in 4 out of 9 offsprings. (2) Latencies of P100 in VEPs were normal in all subjects. (3) The late components were reduced in amplitude and rather irregular in shape. (4) The latencies of SSEPs were slightly prolonged, less marked in the early peaks and more pronounced in the later ones. (5) The late components after 70--100 msec were often attenuated or even absent. (6) The mean amplitude of P1/N2 was remarkably reduced. (7) Interhemispheric asymmetries were pronounced in 3 out of 9 offsprings.

Adult↗
PubMed1980

The late facilitation in H-reflex recovery cycles in different pyramidal lesions.

H-reflex amplitudes were recorded after stimulation of the tibial nerve and different electrical stimuli in 18 normal persons and 26 patients showing pyramidal spasticity (8 spastic spinal paralysis, 6 spastic hemiparesis, 12 spinal lesions). A just subthreshold stimulus of the tibial nerve facilitated the H-reflex in spastic patients slightly after about 300 ms (up to 113%), following an early strong facilitation (10 ms) and a longer lasting depression (20-200ms). Similar postinhibitory facilitation was obtained in spastic patients after ipsilateral stimulation of the plantar surface and after direct stimulation of the dorsal columns. Conditioning by contralateral stimuli of the posterior tibial nerve caused a slight late facilitation in both normal and spastic patients. This late facilitation did not correlate significantly with the severity of spasticity, but it was more pronounced in cerebral pyramidal lesions than in spinal ones. It is assumed that this postinhibitory facilitation is probably generated as a spinal rhythm, similar to the clonus, and that it is modulated from supraspinal structures.

Adolescent↗
PubMed1979

[Cauda equina syndrome with total myelographic block (author's transl)].

Twenty-seven cases of complete subarachnoid block discovered through myelography are analysed with regard to the causes of obstruction, the neurologic symptoms, and the cerebrospinal fluid. The neurologic signs in cases of cauda equina compression, most often caused by massive disc protrusions (20 patients), vary considerably and rarely correspond to the gross myelographic findings. Bilateral neurologic symptoms of any degree with or without sphincter disturbance were observed in 21 among 27 cases and are signs of cauda compression. In contrast to cases of sciatica with unilateral root compression and radicular symptoms neurological symptoms are not reliable in revealing the site of the lesion in cases of massive central disc protrusions. Therefore radiculography (myelography of the cauda equina) is necessary for diagnosis. In addition to the well-known elevation of the spinal fluid protein and pleocytosis, the presence of neutrophile granulocytes is frequently found (11 of 20 cases) in cytological analysis.

Cauda Equina↗
PubMed1979

[Heparin-induced changes in blood gas analysis (author's transl)].

In modern blood gas analysis heparin is used for preventing coagulation in the syringe and the analyzer. If the amount of heparin added is too large the pH of the blood sample falls and so an artificial metabolic acidosis is induced. Consequently the amount of heparin used should be just enough to prevent blood coagulation without changing appreciably the acid-base status of the sample. High concentrations of inspired oxygen have no additional effect on the ability of heparin to alter the pH values.

Acid-Base Equilibrium↗
PubMedDate not supplied

Disordered recognition and perception of human faces in acute schizophrenia and experimental psychosis.

Three disorders of facial recognition and perception in acute schizophrenia and mescaline-induced psychosis are described and illustrated using original clinical and experimental material: "affective prosopagnosia" or stress-related dysfunctional face recognition; "physiognomization" of the environment or persistent illusions and hallucinations of nonspecific faces; and the "mirror phenomenon" or the experience of inner alienation from one's reflected face, which is perceived as independently alive, sinister, and generally physically distorted. It is proposed that neuropsychology suggests relationships between these phenomena that might otherwise be less apparent. No final neurobiological solution to the problem of dysfunctional facial perception and recognition in psychosis is presented, but various insights and suggestive models from the neurosciences are discussed. Attention is also paid to the conditions under which one might need to combine neuropsychological approaches with hermeneutically oriented analyses.

Acute Disease↗
PubMedDate not supplied

A new identity for misidentification syndromes.

The systematic study of delusional misidentification syndromes has been hampered by the often confusing and imprecise eponymic nomenclature currently in use. We present a case report that demonstrates the inadequacies of the current system. We then propose a new classification system designed to improve research and understanding in this important area.

Aged↗
PubMedDate not supplied

A neuropsychological perspective on dual diagnosis.

The purpose of this study was to investigate whether patients experiencing both a major psychiatric disorder and a concurrent substance abuse problem (dual diagnosis) manifest greater neuropsychological dysfunctions than patients experiencing a major psychiatric disorder alone. Differences in diagnostic variability and fluidity between dual diagnosis and non-dual diagnosis patients and the occurrence of polysubstance abuse among the dual diagnosis patients were also investigated. The hypotheses were tested by retrospectively reviewing the psychiatric records of 50 dual diagnosis patients and comparing them to 36 chronically hospitalized non-dual diagnosis psychiatric patients. Results revealed that dual diagnosis patients manifested significantly greater neuropsychological impairments than non-dual diagnosis patients and that dual diagnosis patients showed a greater range of diagnoses and diagnostic fluidity than non-dual diagnosis patients. Results also revealed that over one-half of the dual diagnosis patients abused a variety of different substances. An etiological role of neuropsychological dysfunction in the development of the dual diagnosis syndrome in at least a subgroup of dual diagnosis patients is suggested. More specifically, it is suggested that the neuropsychological dysfunctional pattern that is described may represent an organic substrate of a nonspecific vulnerability to developing both (atypical) psychoses and (poly) substance abuse.

Adult↗
PubMedDate not supplied

Neurological comorbidity in treatment-resistant dual diagnosis patients.

This paper discusses the possible role of neurological dysfunction in the frequent treatment-resistance of dual diagnosis patients. Through case vignettes, the complex treatment process of three dual diagnosis patients is presented. Each case demonstrates how in addition to both psychiatric and substance abuse problems, the patients also experienced neurological difficulties that made treatment even more complicated. The authors suggest that treatment providers should carefully screen for neurological disorders among this patient population. Attending to such comorbid difficulties in addition to patients' psychiatric and substance abuse problems may sometimes play a pivotal role in enabling patients to attain abstinence. The authors also speculate concerning the role of neurological dysfunction in the etiology of the dual diagnosis syndrome in at least a subgroup of dual diagnosis patients.

Adult↗