Biomedical subjects

K Schmidtke

Publications and source records attributed to K Schmidtke.

18 recordsLinked to original sources

PubMed1998

Cognitive frontal lobe dysfunction in obsessive-compulsive disorder.

BACKGROUND: There is evidence that dysfunction within associative frontostriatal circuits represents a feature of obsessive-compulsive disorder (OCD). Previous neuropsychologic studies have yielded diverging results, which may in part be explained by differences in the selection of subjects and methods. The present study focused on the question of cognitive frontal lobe performance in OCD. METHODS: Twenty-nine unmedicated OCD patients were compared to a double-size control group of normal subjects matched individually for age, sex, and intelligence. A series of 12 neuropsychologic tests was applied, most of which are thought to be sensitive to different aspects of cognitive frontal lobe function. RESULTS: OCD patients were unimpaired at tests of abstraction, problem solving, set-shifting, response inhibition, active memory search, and choice reaction speed. Deficits of approximately one standard deviation were observed at timed tests of verbal and nonverbal fluency, attentional processing, and weight sorting. CONCLUSIONS: OCD patients exhibited selective deficits in tasks involving controlled attentional processing and self-guided, spontaneous behavior. We discuss a link between this neuropsychologic profile and dysfunctioning within the anterior cingulate, but not the dorsolateral prefrontal circuit.

Adolescent↗

PubMed1998

Early-onset Alzheimer's disease due to mutations of the presenilin-1 gene on chromosome 14: a 7-year follow-up of a patient with a mutation at codon 139.

Mutations in the presenilin-1 gene (PS-1 gene) on chromosome 14 have recently been identified as a cause of familial early-onset Alzheimer's disease (EOAD). To our knowledge, only two German EOAD patients with mutations in the PS-1 gene have been identified thus far. Herein we report the case of a German EOAD patient with a family history of dementia and a missense mutation at codon 139 (M139V) of the PS-1 gene. The patient came to our clinic for the first time when he was 44 years old. During the following 7 years, his Mini-Mental State Examination (MMSE) score dropped from 24 to 0. Myocloni were an early neurological symptom that was already present during the first consultation. We could demonstrate that myoclonic activity was of cortical origin using a back-averaging method. Magnetic resonance imaging (MRI) revealed only slight changes in the early stage of the disease. Follow-up MRI studies showed progression of bitemporal ventricular enlargement and progressive frontal and temporal cortical atrophy. Although the majority of EOAD patients belong to the sporadic (non-genetic) type of AD, early-onset dementia, early myocloni and a familial history of AD should direct attention to the possibility of a genetic form of AD.

Adult↗

PubMed1998

Transient global amnesia and migraine. A case control study.

This study examined the putative association of transient global amnesia (TGA) and migraine. 57 TGA patients were compared to a double-size control group of normal subjects. TGA patients who also had migraine were additionally compared to those without migraine and to a second control group of outpatients with migraine only. The prevalence of migraine, and also of episodic tension-type headache, was markedly increased among TGA patients. Precipitants and accompanying vegetative symptoms of TGA and migraine overlapped. However, there was no evidence of an interaction between TGA and migraine, in that the expression of key TGA features was not affected by comorbidity with migraine, and vice versa. The present findings argue against the hypothesis that TGA represents a type of migraine aura or migraine equivalent. They conform to the hypothesis that the two conditions are essentially independent and result from an inherited brain state that disposes to different types of paroxysmal dysregulation, presumably at the level of the brain stem.

Amnesia↗

PubMed1998

Cerebral perfusion during transient global amnesia: findings with HMPAO SPECT.

UNLABELLED: The aim of this study was to investigate the pattern of regional cerebral blood flow changes associated with transient global amnesia (TGA). METHODS: HMPAO SPECT was performed in six consecutive patients during the acute phase of TGA. A follow-up SPECT was performed 3-20 wk later in four of the six patients. Semiquantitative analysis of 14 regions of interest, including the basal ganglia and the basal section of the temporal lobes, was performed by comparing patient data with control data obtained from a matched group of healthy subjects. RESULTS: During TGA, unilateral or bilateral hypoperfusion of the temporo-basal region was observed in four patients. Variable hypoperfusion of further cortical areas was observed in five patients. Two patients who exhibited the most marked cortical hypoperfusion also showed striatal and thalamic hypoperfusion. These changes were normalized in the control studies obtained in four patients. CONCLUSION: It remains unclear whether hypoperfusion during TGA represents a primary feature or a sequel of regional brain hypometabolism. Because hypoperfusion is not confined to the temporo-basal region or to the territory of the posterior cerebral artery, it is suggested that the origin of TGA-related changes lies at the level of subcortical structures that project diffusely to the cerebral cortex.

Acute Disease↗

PubMed1997

[Follow-up and prognosis of early summer meningoencephalitis].

Sixty-three patients with tick-borne encephalitis were studied for sequelae up to 5 years after the acute illness (median: 12 months, range: 1-44 months). Patients were examined clinically, by neuropsychological testing and by electroencephalography. The clinical presentation during the acute stage was as follows: Meningitis (M,n = 12), Meningoencephalitis (Me,n = 27), Meningoencephalomyelitis (My,n = 15), and Meningoencephaloradiculitis (R,n = 9). A total of 59 patients reported a neurasthenic syndrome after discharge, which correlated with the severity of the acute illness. Twenty patients were not able to work because of reduced stress tolerance, fatigue or an elevated emotional sensitivity, which lasted for 3 months at most. In some patients hypacusis (n = 7), severe dysarthria and dysphagia (n = 4) remained essentially unimproved for years following the acute illness. While in 8/9 patients with radiculitis paresis of the extremities improved well over months to years, improvement was quite limited in all patients with myelitis. In 41/55 patients, investigations by electroencephalography revealed normal findings even within months after acute illness. Persistent cognitive deficits were present only in 7/11 patients with a severe course of disease.

Adolescent↗

PubMed1997

Retrograde amnesia: a study of its relation to anterograde amnesia and semantic memory deficits.

This group study of 24 amnesic patients and 40 control subjects examined the hypothesis that retrograde memory deficits result from a combination of two impairment mechanisms: (1) a deficit in the retrieval of contents that is related to dysfunctioning of the hippocampal anterograde memory system, and (2) a deficit in the storage and/or retrieval of contents that is related to concomitant neocortical lesions. Retrograde amnesia was evaluated with the use of new Famous Persons and Autobiographical Memory Tests. The postulated components of retrograde memory impairment were assessed using the Wechsler Memory Scale and a new Semantic Memory Test, respectively. Regression analyses showed that recent episodic autobiography was exclusively related to the hippocampal component, while memory for famous persons and childhood autobiography was related to the neocortical component. In the case of details concerning people of recent fame, both components were identified as independent determinants. The temporal gradient of patients' impairment at the Famous Persons Test was marked for detailed knowledge, but small for overlearned knowledge. The present results thus support the combination hypothesis. They conform to the view that the transition from a hippocampus-dependent to a neocortex-dependent mnemonic representation of new contents is mediated by reiteration, and occurs within 5-10 years.

Adult↗

PubMed1997

Progressive hemiparesis in frontal lobe degeneration.

Hemiparesis has rarely been observed in frontal lobe degeneration (FLD). We describe the clinical, neuropsychological and neuroimaging findings of a patient in whom a slowly evolving hemiparesis was the principal symptom of FLD, and of 2 demented patients in whom hemiparesis was an early and prominent symptom. The occurrence of central motor deficits in FLD is reviewed, and a synopsis of the differential diagnosis of hemiparesis in neurodegenerative diseases is given.

Adult↗

PubMed1996

Cognitive procedural learning in amnesia.

This group study examined the role of residual declarative memory and task-specific cognitive abilities for cognitive procedural learning in amnesia. 20 amnesic patients and 40 control subjects were studied, using four new cognitive tasks, as well as the Tower of Hanoi and a Mirror Reading task. On the cognitive tasks, but not on Mirror Reading, the learning of amnesic patients was significantly impaired relative to controls. Between- and within-group differences in learning were found to be statistically related to cognitive abilities that are involved in the processing of the procedural tasks. In amnesic patients, significant effects of residual declarative memory on learning scores were not observed, but there was indirect evidence for a role of memory in two tasks. The analysis of the correlative relationship between absolute procedural task performances and cognitive abilities indicated a prolonged dependence on nonspecific intellectual abilities in amnesic patients, suggesting a retarded transition to more advanced stages of skill acquisition.

Adult↗

PubMed1995

Characterization and chromosomal assignment of yeast artificial chromosomes containing human 3p13-p21-specific sequence tagged sites.

Human chromosomal region 3p12-p23 is proposed to harbor at least three tumor suppressor genes involved in the development of lung cancer, renal cell carcinoma, and other neoplasias. In order to identify one of these genes we defined sequence tagged sites (STSs) specific for 3p13-p24.2 by analyzing a chromosome 3p14 microdissection library. STSs were used for isolating yeast artificial chromosome (YAC) clones from the Centre d'Etude du Polymorphisme Humain (CEPH) YAC libraries. Thirty-eight YACs were assembled into a contig approximately 2.5 Mb in size spanning the t(3;8) and t(3;6) translocation breakpoints associated with hereditary renal cell carcinoma and hematologic malignancies, respectively. Chromosomal localization and chimeric status of 126 YACs was analyzed by fluorescence in situ hybridization (FISH). The order of 17 YACs determined by double-color FISH was in agreement with the STS-based arrangement of the YAC-contig.

Base Sequence↗

PubMed1995

[Functional memory disorders. A study of 25 patients].

Twenty-five patients without relevant organic disease were examined who complained of long-standing memory disturbance, but were free of relevant organic disease and exhibited a test performance that was normal, or reduced by not more than two standard deviations. Cases of amnesia in the context of dissociative reactions were not considered. Symptoms attributed to memory disturbance were differentiated into deficits of new learning, retrograde memory and attention. Typical complaints were forgetting plans on the way to executing them and temporary blockage of material that had been committed to memory. While sex and age were evenly distributed, there was a clear predominance of professionals compared to manual workers. Relevant psychiatric findings or psychiatric diagnoses were present in all cases. The most frequent diagnoses were chronic stress disorder and depressive syndromes. Accompanying psychosomatic symptoms were present in about half of the cases. Wordlist learning scores were in the normal range in the majority of cases, and psychomotor speed scores were in the normal range in nearly all cases. The discussion addresses symptoms, diagnosis, etiology and therapy of functional memory disturbances and examines the relationship to the syndrome of pseudodementia.

Adult↗

PubMed1993

Wernicke-Korsakoff syndrome following attempted hanging.

The case of an alcoholic man is reported who survived a suicidal hanging attempt, and subsequently suffered of amnesia, dementia, apathy and behavioural abnormalities. A clinical diagnosis of hypoxic brain damage was made, but upon autopsy six years later, extensive pseudosystematic thalamic degeneration and mammillary body atrophy were found, indicating a status post Wernicke encephalopathy. Precipitation of the disease is attributed to the synergetic effect of cerebral hypoxia/ischemia and thiamine deficiency.

Adult↗

PubMed1992

Hartnup syndrome, progressive encephalopathy and allo-albuminaemia. A clinico-pathological case study.

Clinical, biochemical, neuropathological and neurochemical findings in a case of Hartnup syndrome are reported. After initially normal development, the affected girl suffered progressive neuropsychiatric decline with statomotor and mental retardation and intractable seizures and died at the age of 2 years. Postmortem neuropathological and neurochemical investigations showed a combination of extensive neuronal degeneration and cerebral dysmyelination. Pathogenetic hypotheses and the relationship between neuropsychiatric disease and Hartnup syndrome are discussed. Additionally, a fast type bisalbuminaemia present in the girl and her mother is described.

Amino Acids↗

PubMed1992

Nervous control of eyelid function. A review of clinical, experimental and pathological data.

This review of the clinical and experimental literature on pre-motor eyelid control, including an analysis of available clinico-pathological reports, suggests support for the following hypotheses: (1) cortex, extrapyramidal motor systems and rostral brainstem structures contribute to the control of the levator palpebrae muscle (LP) in various eyelid functions; (2) though the LP motor nucleus is unpaired, the pre-motor control of LP is at least in part lateralized; (3) signals of the rostral interstitial nucleus of the medial longitudinal fasciculus (MLF) are involved in the control of coordinated lid movements with saccadic up- and downgaze movements; (4) lesions of the medial and/or principal portion of the nuclear complex of the posterior commissure are essential for the production of lid retraction. These structures are assumed to be involved in lid-eye coordination by providing inhibitory modulation of LP motor neuronal activity; (5) the ventral periaqueductal grey is assumed to play a role in the generation of tonic LP motor neuronal activity; (6) neurons of the caudal supraoculomotor area could play a role in the mediation of converging inhibitory inputs onto LP motor neurons.

Blepharoptosis↗

PubMed1990

[Striato-nigral degeneration (SND): a multisystem atrophy?].

Two cases of striato-nigral degeneration are reported. In case 1 the female patient showed a Parkinson syndrome, cardiac arrhythmias and vasomotor disturbances. Morphologically mainly the putamen and substantia nigra revealed severe atrophic changes according to the restricted form of striato-nigral degeneration (SND). In case 2 there was a disorder of the upper and lower motor neuron in a female patient. Morphologically this case was an example of a multisystem atrophy with changes in the striato-nigral, olivo-ponto-cerebellar systems and spinal motor and autonomic neurons. These cases demonstrate the variability of the striato-nigral degenerations which are met with in two forms: a "pure" form as in case one and as a part of multisystem atrophies. This is underlined in a review of 69 literature cases, which also shows that SND, Shy-Drager syndrome and olivo-ponto-cerebellar atrophy represent very probably different varieties of one and the same degenerative process.

Aged↗

PubMed1989

Pena-Shokeir phenotype with major CNS-malformations: clinicopathological report of two siblings.

Clinical and pathological features of two siblings of opposite sex with the Pena-Shokeir phenotype are reported. A detailed account of the prenatal and dysmorphological findings is given in one case. A broad range of deformations regarded as secondary to fetal hypokinesia was present, including a number of yet unreported findings. One case showed additional endocrine hyperplasia and left lung trilobation. Both siblings displayed extensive, highly similar CNS-abnormalities. The type and convergence of these malformations differ from previously reported cases and characterize a new familial subtype of the Pena-Shokeir phenotype.

Abnormalities, Multiple↗

PubMed1989

Cell groups of the medial longitudinal fasciculus and paramedian tracts.

The aim of this article is to introduce the reader to a continuum of cell clusters which may play an important role in the maintenance of eye position. They lie interspersed between the fascicles of the medial longitudinal fasciculus (MLF) and paramedian tracts in the caudal pons and medulla, and they also constitute the rostral part of the classical abducens nucleus. Previous workers showed that these 'cell groups of the paramedian tracts' (pmt cell groups) project to the flocculus, and receive afferents from several horizontal premotor cell groups. Results of neuroanatomical tracer experiments reported here demonstrate that they also receive a direct input from the vertical premotor gaze neurons in the mesencephalon (rostral iMLF and the interstitial nucleus of Cajal), as well as from some groups of oculomotor internuclear neurons. The projecting fibres descend to the cell groups of the paramedian tracts in the MLF. It is suggested that deficits in gaze-holding seen in internuclear ophthalmoplegia, for example, may result from damage to afferents of this paramedian cell continuum.

Abducens Nerve↗

PubMedDate not supplied

Evaluation of intracerebral lesions in patients with acquired immunodeficiency syndrome. Neuropathological findings and experimental data.

In this paper we present the results of post-mortem examinations of the central nervous system in 61 male patients who died with Acquired Immunodeficiency Syndrome (AIDS); it includes 23 patients with reported neurological abnormalities at the time of presentation. The analysis revealed central nervous system (CNS) neoplasms (lymphoma, Kaposi's sarcoma) and a variety of inflammatory lesions (bacterial, fungal, protozoal and viral) in 32 cases. A total of 11 patients without opportunistic infections showed significant brain abnormalities characterized by microglial nodules and/or multinucleated giant cells, changes which are probably related to infection by human immunodeficiency virus (HIV). In addition, we describes results from a series of experiments designed to define the target cell population of HIV in the brain. The expression of CD4 complex--putative receptor for HIV--was investigated using short-term cultured brain cells taken from embryonic brain anlage and from different regions of fetal brain; glioma cells were also used. Cells derived from normal embryonic and fetal brain, as well as glioma cells, were examined with respect to their susceptibility to HIV. CD4 antigen expression could be demonstrated only on glioma cells of the permanent glioma line 85HG-59 comprised of cells with properties characteristic of astrocytes. Nevertheless, normal embryonic and fetal brain cells as well as glioma cells could be infected by HIV as documented by immunocytochemical methods and southern blot analysis. HIV infected brain cells showed reduced growth rate and altered growth pattern. This study emphasizes the diversity of HIV conditioned CNS impairments, suggesting that genomic variability of HIV may result in varying cell type preference of the virus. The experimental data indicate that CD4 expression in brain cells is probably not 'conditio sine qua non' for HIV susceptibility. The alterations of HIV-infected brain cells demonstrated provide further evidence for a direct involvement of HIV in the pathogenesis of AIDS-related neurological syndromes.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Sarcoidosis of the spinal cord and medulla oblongata. A pathological and neuroradiological case report.

A case of 68-year-old woman with symptoms of slowly progressive diffuse myelopathy, is presented, which could only temporally be reversed by immunosuppression. Contrast enhanced magnetic resonance (MR) scan demonstrated multifocal patchy enhancing lesions from cervical to mild thoracic segment and a circumscribed lesion of the whole medulla oblongata. Postmorten examination disclosed a histological confirmed, multifocal sarcoidosis of the spinal cord and medulla oblongata, with few sarcoid granulomas in one hilar lymph node and skeletal muscle of the upper extremities. Only nine similar cases of intramedullary sarcoidosis confirmed by autopsy with symptoms solely attributable to the spinal cord have been reported. A review of the pathological manifestations, diagnostic and treatment of intramedullary sarcoidosis is given.

Aged↗