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Biomedical subjects

D Kömpf

Publications and source records attributed to D Kömpf.

At least 73 records · Page 4Linked to original sources
PubMed1993

Follow-up of neurophysiological tests and CT in late-onset cerebellar ataxia and multiple system atrophy.

The follow-up of neurophysiological tests (brain-stem auditory evoked potentials; blink reflex; sensory, motor and visual evoked potentials) and CT was investigated in 21 patients with late-onset cerebellar ataxia (CA) or multiple system atrophy. The study included an initial investigation and a follow-up examination on average 25.3 months later (minimum 8, maximum 36). Patients were divided into four groups: (1) those with pure CA after a minimum course of 5 years; (2) those with pure CA with pathological neurophysiological findings at the last examination; (3) those who at the first examination clinically presented with pure CA, but at the last examination were seen to have developed a multisystem disorder; (4) those with multiple system atrophy (mostly olivopontocerebellar atrophy) presenting additional non-cerebellar signs of involvement. Conforming to a strict interpretation of pure CA, group 1 patients invariably exhibited normal neurophysiological findings at all examinations. All patients in group 4, except for 2 only at the first examination, showed pathological changes in at least one of the neurophysiological tests. The main conclusion of this paper is that individuals who according to clinical criteria were initially classified as having CA but finally developed a multisystem disorder already had pathological neurophysiological findings at the initial examination (group 3). The increasing frequency of pathology in the several neurophysiological tests together with the progression of the disease is obviously of prognostic significance. CT revealed cerebellar atrophy without apparent involvement of brain-stem structures in all patients with CA; the majority of patients with multiple system atrophy also had atrophy of the brain-stem, pointing to olivopontocerebellar atrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Long-latency reflexes, somatosensory evoked potentials and transcranial magnetic stimulation: relation of the three methods in multiple sclerosis.

Afferent and efferent central pathways were tested by electrically elicited long-latency reflexes (LLRs), somatosensory evoked potentials (SEPs), and motor potentials (MEPs) evoked by transcranial magnetic stimulation (TMS) in 37 patients with multiple sclerosis. Of these 27 (72.9%) had abnormal results, with bilateral abnormalities in 17 (45.9%). MEPs were abnormal in 21 (56.8%), LLRs in 17 (45.9%) and SEPs in 16 (43.2%). Compared with TMS (MEPs) alone, additional testing of LLRs and SEPs revealed abnormalities in 6 additional patients (2 LLRs, 3 SEPs, 1 LLR and SEP). When the hands were analysed separately 32 (47.3%) showed abnormal results with TMS, 29 (39.2%) with LLRs and 22 (29.7%) with SEPs. All hands with absent or delayed N20 components of the SEP also had abnormal LLRs, supporting the hypothesis that LLRs and SEPs share the same afferent pathways. In contrast to this, 10 hands had normal LLRs but slightly delayed central motor conduction times. Calculating the sum of the latency of the N20 component of the SEP and the latency of the MEP, we found a mean cortical relay time for the LLR of 8.5 +/- 4.7 msec, which is compatible with a polysynaptic transcortical pathway. This is supported by our finding of a linear correlation between the LLR latency and the sum of N20 and MEP latencies.

Electroencephalography↗
PubMed1993

Carotid artery disease in vascular ocular syndromes.

We prospectively investigated 83 consecutive patients with vascular ocular syndromes: 19 suffered from amaurosis fugax attacks, 23 had occlusions of the central retinal artery or a branch retinal artery occlusion, 26 had a central retinal vein occlusion or a branch retinal vein occlusion, and another 15 exhibited an anterior ischemic optic neuropathy. In 5 patients bilateral symptoms occurred; thus a total of 88 eyes were affected. All patients underwent a neurological examination and ultrasound investigations of the carotid arteries, including continuous wave (cw)-Doppler-sonography and duplex ultrasound. Stenosis of more than 50% diameter reduction and occlusion of the internal carotid artery ipsilateral to the symptomatic eye were significantly more frequent in amaurosis fugax attacks and central or branch retinal artery occlusion than in central or branch retinal vein occlusion or anterior ischemic optic neuropathy (p < .025). Additionally, the analysis of plaque surface and echogenicity of the plaques on the affected side with a high-resolution duplex scan uncovered that ulcerated plaque surfaces and plaques with a heterogeneous echogenicity were found significantly more frequent in the internal carotid arteries of patients with amaurosis fugax attacks and central or branch retinal artery occlusions than in patients with anterior ischemic optic neuropathy (p < .04) or central and branch retinal vein occlusion (p < .025). We conclude that amaurosis fugax attacks and central retinal artery or branch retinal artery occlusions are due to arterio-arterial embolization from ulcerated and heterogeneous carotid artery plaques.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Low-tension glaucoma: a comparative study with retinal ischemic syndromes and anterior ischemic optic neuropathy.

In low-tension glaucoma (LTG), nerve-fiber-bundle defects are assumed to result from ischemia of the choroidal branches of the posterior ciliary arteries, due either to local vascular changes or, presumably, hemodynamically occlusive carotid artery disease. To study the possible hemodynamical origin of LTG, we examined and compared, clinically and by ultrasound (continuous-wave Doppler and duplex-scanning), the extracranial carotid arteries of (1) 21 patients (34 eyes) with LTG, (2) 48 patients (49 eyes) with retinal ischemic syndromes (RIS), and (3) 15 patients (17 eyes) with anterior ischemic optic neuropathy (AION). High-grade stenoses and occlusions of the internal carotid arteries ipsilateral to the affected eyes were significantly more frequent in the RIS patients (17 of 49) than in the LTG patients (2 of 34; P < .01) and the AION patients (0 of 17; P < .01). Among our relatively small group of LTG patients, we found no striking evidence supporting a hemodynamic origin of LTG.

Aged↗
PubMed1992

Late cognitive event-related potentials in adult Down's syndrome.

Event-related electroencephalogram (EEG) potentials (ERPs) using two different tasks were measured in 14 adults with Down's syndrome (DS; mean age 32 years) without clinically detectable cognitive decline. Two groups, young healthy (YH) and old healthy (OH) adults, served as controls. In the oddball task, DS had prolonged N1 and earlier P2 latencies than the control groups. P3 latency was delayed in comparison to YH. In the PushWait task, P3 latency was later in DS than in YH and OH. In both tasks, DS showed a marked amplitude shift towards positivity overlapping the N1-P2 complex and seemingly also P3: The P3 amplitude evoked by target tones and by "Push" was shifted towards anterior sites resulting in a Cz maximum. Changes of the N1 latency and amplitude in DS may be related to enhanced arousal during stimulus processing, indicating a possible defect of central inhibitory mechanisms. The study suggests that differentiated ERP procedures provide information on adult DS cognition exceeding those given by mere P3 latency measurements. Such procedures may be useful in the evaluation of the cognitive decline due to precocious aging or Alzheimer-type dementia in DS.

Adult↗
PubMed1992

Presence of methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinolines, derivatives of the neurotoxin isoquinoline, in parkinsonian lumbar CSF.

The TIQ derivatives 2-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (2-MDTIQ) and 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (1-MDTIQ, salsolinol) were identified the first time as possible endogenous neurotoxins in parkinsonian but not in normal human lumbar cerebrospinal fluid by high performance liquid chromatography with electrochemical detection. Additionally, MDTIQ analogues were incubated with a monoamine oxidase (MAO) assay. MAO was able to metabolize dose-dependently 2-MDTIQ, whereas 1-MDTIQ was not modified by the enzyme.

Aged↗
PubMed1992

[CO2 test with transcranial Doppler sonography in cerebral ischemia].

We evaluated the CO2-induced vasomotor reactivity of the cerebral vasculature in 48 patients with high degree stenosis or occlusion of the internal carotid artery by transcranial Doppler ultrasonography measuring changes of flow velocities in the middle cerebral artery. Further, the vasomotor reactivity of the basilar artery was measured in 48 patients with vertebro-basilar ischemia. These results were compared with the findings in normal individuals. The vasomotor reactivity was significantly reduced in patients with stenosis or occlusion of the internal carotid artery as compared to normal controls. In patients with high degree ICA stenoses, undergoing to carotid surgery, CO2-test showed a significant improvement of the pathological vasomotor reactivity 6 month after the operation. In the group of patients with vertebro-basilar ischemia, the vasomotor reactivity measured in the basilar artery, was significantly reduced in patients with completed brainstem infarctions but not in patients with transient brainstem ischemia or infarctions in the posterior cerebral artery territory. We conclude that evaluation of the cerebral vasomotor reactivity by transcranial Doppler ultrasound is able to identify an inadequate cerebral blood supply and may help to estimate the hemodynamic effect of stenosis or occlusion of the extracranial brain supplying arteries.

Adult↗
PubMed1992

[Musical pseudo-hallucination in acquired hearing loss].

Auditory hallucinations take various forms including the perception of tinnitus, voices, and, rarely, music. While formed hallucinations are usually ascribed to psychiatric illness, we describe a syndrome of musical hallucinations in mentally sane patients, who are hard of hearing or deaf. 26 cases from the literature are supplemented by 6 own observations, including the first description of two cases in a single family. The different modes of emergence, the spectrum of clinical features and their course are outlined. Differential diagnostic, pathogenetic and therapeutic aspects are discussed.

Aged↗
PubMed1992

[The importance of neurophysiology and computerized tomography for diagnosis of cerebellar ataxia with late onset].

Twenty patients diagnosed as suffering from autosomal dominant or idiopathic late onset cerebellar ataxia were investigated clinically, by means of neurophysiological tests (blink reflex, BAEP, SEP, MEP, VEP) and CT scan. Twelve patients presented with a pure cerebellar ataxia (CA) after a disease duration of at least five years (mean disease duration ten years). Eight patients presented with additional non-cerebellar signs of involvement; hence the disease was classified as olivo-ponto-cerebellar atrophy (OPCA). Eight of the twelve patients with CA already exhibited pathological results in at least one of the neurophysiological tests as subclinical evidence of a lesion beyond the cerebellum. Three of these patients showed an atrophy of brainstem structures in addition to the cerebellar atrophy. The ongoing prospective follow-up study will show whether these signs of subclinical involvement of non-cerebellar pathways are predictive for the development of a multi-system disorder in terms of OPCA. In cases of CA with subclinical signs of a lesion beyond the cerebellum there may be no clinical, non-cerebellar signs for a multisystem disorder even within a disease duration of up to fifteen years.

Adult↗
PubMed1991

Epidemiology and out-patient care in Parkinson's disease--results from a pilot-study in northern Germany (Schleswig-Holstein).

An attempt was made to estimate prevalence on Parkinsonism using consultation rates in physicians' practices in a two-step, one-phasic pilot study in a rural-urban area of Northern Germany. Though participation of physicians was low, reported rates for Parkinsonian patients (183/100,000) were in the range yielded in comparable areas, but by different methodology. Only 64% of a large subsample of patients used L-Dopa preparations for therapy. Confirming previous results the objective records of doctors and the subjective notices of patients regarding disease state showed considerable differences in several important items.

Adult↗
PubMed1991

Parkinsonian features in advanced Down's syndrome.

The results of a clinical study on extrapyramidal, frontal release, and other neurological signs in 54 demented and non-demented patients with Down's syndrome (DS) are presented. Fourteen patients were demented, five of them showed extrapyramidal signs, mainly of the rigid-hypokinetic spectrum and rather similar to Parkinsonian features in advanced Alzheimer's disease (AD). None of the non-demented patients had Parkinsonian signs. The mean ages of the demented DS patients with extrapyramidal signs was significantly higher than that of the patients without the respective signs. Frontal release signs were present in demented and nondemented patients. From a questionnaire neither a raised proportion of early- or senile-onset dementia nor of Parkinsonism among first- and second-degree relatives of DS patients could be traced. Parkinsonian signs seem to be present at a lower frequency in DS than in advanced AD. A speculative hypothesis about a gene dosage effect of Cu/Zn-superoxide dismutase in preventing toxic radical formation in the substantia nigra of DS patients is presented.

Adult↗
PubMed1991

Transcranial magnetic brain stimulation: lack of oculomotor response.

We have investigated whether eye movements can be evoked by transcranial magnetic brain stimulation (TMS) from frontal, precentral, posterior- and inferior- parietal, occipital and temporal positions of the stimulating coil. Our findings were negative, even for structures concerned with voluntary eye movements, such as the frontal eye field (FEF) and the inferior parietal lobe (IPL). The lack of oculomotor responses after stimulation of the cortex shall be discussed in the following context: (1) Low-threshhold intracortical stimulation experiments suggest that in functional terms, the FEF is confined to small areas which are extend to the floor of sulci. TMS does not reach these structures to a sufficient extent. Furthermore efferent connections of the cortex to the paramedian pontine reticular formation (PPRF) seem to be polysynaptic. (2) The function of the cortex in rapid eye movement is to analyze and process conditions with differing functional requirements, rather than to directly generate saccades. TMS does not elicit oculomotor responses, demonstrating again that the role played by the cortex in eye movement is not analogous to the role of the somatic motor cortex in controlling skeletal movements.

Adult↗
PubMed1991

Colour Doppler flow imaging of the carotid arteries.

53 patients with carotid artery atherosclerosis were examined by colour Doppler flow imaging. These results were compared with real time duplex sonography and continuous wave Doppler sonography. In 48 low degree stenoses (less than 50%) the B-mode showed 36 smooth and 12 ulcerated plaque surfaces. In 24 high degree stenoses (greater than 50%) 10 plaques were smooth and 14 ulcerated. In the low degree stenoses, which exhibited smooth surfaces in B-mode examination, colour flow Doppler showed nine additional cases with turbulences in the area of the stenotic site. This indicates that plaque ulcerations in low degree stenoses are underestimated. In contrast, in nearly all cases with high degree stenoses marked turbulences could be demonstrated by colour Doppler flow imaging independent of the B-mode, showing regular or ulcerated plaque surfaces. Additionally, the duplex ultrasound diagnosed a carotid artery occlusion in 11 cases, but the colour coded Doppler was able to assess a remaining blood flow in two out of these 11 cases. Our results suggest that the colour Doppler flow imaging as a noninvasive technique is an advantage in diagnosing plaque ulcerations and it is more precise in diagnosing carotid occlusions than duplex-sonography is.

Arteriosclerosis↗
PubMed1991

On the reasons for the delay of P3 latency in healthy elderly subjects.

The P3 component reaches its peak later in elderly subjects than in young subjects. The aim of this study was to repeat this finding in the usual auditory oddball task and to look for reasons for the delay by analysing other components and by applying another task, the visual Push/Wait task. It was found in the oddball that the age delay was present for mismatch negativity already but further increased until P3's peak. In the Push/Wait task, the size of the age delay was independent of another delay caused by reduced visual intensity of the stimuli. Further, the age delay had its onset after the occipital P140 component whereas the intensity delay was present before this component. Within the elderly, P3 latencies correlated between the auditory and the visual tasks, and the common factor extracted from both latencies correlated with a test of short-term memory span. It is concluded that the age delay of P3 is not due to a delay of perceptual encoding but perhaps due to delayed memory processes in the elderly. As usual, P3 amplitudes were larger and more parietally focussed in the young than in the elderly. Possible differences in motivation might account for this finding.

Acoustic Stimulation↗