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Biomedical subjects

H Hefter

Publications and source records attributed to H Hefter.

At least 55 records · Page 3Linked to original sources
PubMed1995

Focal brain lesions in patients with AIDS: aetiologies and corresponding radiological patterns in a prospective study.

We report the results of a hospital-based study of 188 consecutive patients seropositive for the human immune deficiency virus type 1 (HIV-1) who presented in a 4-year period (1988-1991) with possible signs or symptoms of first-ever central nervous system disease. Confirmed diagnoses were cerebral toxoplasmosis in 47 patients (25.0%), HIV-1 encephalopathy in 19 (10.1%), progressive multifocal leucoencephalopathy (PML) in 9 (4.8%), cerebral lymphoma in 1 (0.5%), and other conditions in 9 patients (4.8%). Seventy-three subjects (38.8%) showed focal brain lesions on initial computed tomography or magnetic resonance imaging, which were assessed prospectively. Positive predictivity for toxoplasmosis was 100% if multiple lesions occurred in combination with mass effect or contrast enhancement (23 patients), or if at least one space-occupying or enhancing lesion was located in the basal ganglia or the thalamus (26 patients). Solitary lesions with mass effect or contrast enhancement were seen in 26 patients and were caused by cerebral toxoplasmosis in 22 (84.6%). Eight of the 9 PML patients presented with one or more non-enhancing, non-mass lesions, although the predictive value of this pattern was low (47.1% for PML). Thus, in our epidemiological context, certain imaging findings in HIV-1-seropositive patients were highly predictive of cerebral toxoplasmosis. This may differ from findings from other parts of the world where cerebral toxoplasmosis may be less prevalent among HIV-1-infected individuals.

AIDS Dementia Complex↗
PubMed1995

Late diagnosis of Wilson's disease in a case without onset of symptoms.

Wilson's disease (WD) was diagnosed on the basis of a liver biopsy, blood investigations and a radio copper test in a 60-year-old, neurologically normal female with uncharacteristic gastrointestinal complaints. Since this patient never developed symptoms indicative for WD this case suggests the possibility of a subclinical course of untreated WD.

Biopsy↗
PubMed1995

Fast finger extensions are slower in stutterers than in nonstutterers.

10 adult stutterers and 10 nonstutterers were required to extend as fast as possible their right and left index fingers under isometric conditions in response to an auditory signal. Force developed during finger extension was measured continuously during each trial. From these force records reaction time, contraction time, and peak force were measured. For stutterers, contraction times were longer (about 36 msec.) than for nonstutterers. Possible reasons for this result are discussed.

Adult↗
PubMed1994

[A hemolytic crisis with liver failure as the first manifestation of Wilson's disease].

An 18-year-old woman developed an acute haemolytic anaemia, acute transient renal failure and progressive hepatic failure. Coeruloplasmin and serum copper concentration were normal; a Kayser-Fleischer ring and any neurological symptoms were absent initially. Liver biopsy was contraindicated because of increased bleeding tendency. Wilson's disease was diagnosed only after the acute renal failure had regressed, on the basis of the urinary copper excretion (2890 micrograms/d, rising to 7330 micrograms/d after D-penicillamine administration). Progressive liver failure required transplantation. After it the patient quickly recovered and is now, two years later, free of disease. -This case demonstrates that Wilson's disease may be difficult to diagnose at the time of initial acute manifestation. But it can be recognized early from the pathognomonic low alkaline phosphatase and by calculation of free serum copper.

Acute Disease↗
PubMed1994

HIV-specific changes in the motor performance of HIV-positive intravenous drug abusers.

Motor tests comprising the analysis of postural tremor, most rapid voluntary alternating index finger movements (MRAM) and the rise time of most rapid index finger extensions (CT) allow us to quantify HIV-associated minor motor deficits electrophysiologically. The electrophysiological results in 57 HIV-positive individuals who acquired HIV infection by intravenous drug abuse (IVDA) were compared with those of 57 matched HIV-positive homosexuals and 98 HIV-negative controls to evaluate a possible additional influence of IVDA on motor performance. Motor deficits showed no differences between HIV-positive i.v. drug abusers and homosexuals, revealing a highly significant slowing of MRAM and prolongation of CT to an almost identical extent. Thus, in HIV-infected individuals minor motor deficits are characteristic early signs of subclinical central nervous system involvement regardless of the mode of HIV infection.

Adult↗
PubMed1994

Dopamine D2 receptor binding and cerebral glucose metabolism recover after D-penicillamine-therapy in Wilson's disease.

Regional cerebral glucose metabolism (rCMRGlc) and dopamine D2 receptor binding were measured in a 31-year-old, severely affected, untreated patient with Wilson's disease of 3 years' duration using positron emission tomography and 18F-deoxyglucose and 18F-methylspiperone ([18F]MSP), respectively. There was a severe reduction of striatal and extrastriatal rCMRGlc as well as of striatal [18F]MSP accumulation rate. After 1 year of treatment with D-penicillamine, striatal and extrastriatal rCMRGlc and striatal [18F]MSP accumulation rate reached almost normal levels. It is hypothesized that recovery of motor functions due to copper trapping therapy was associated with an increase in basal ganglia activity and a re-expression or upregulation of dopamine D2 receptors.

Adult↗
PubMed1994

Motor analysis predicts progression in HIV-associated brain disease.

One hundred HIV-positive individuals without clinically evident central nervous system (CNS) deficits entered this follow-up study and were examined clinically and with a well-defined motor test battery every 3 months over 2 years or until they decreased. They underwent magnetic resonance tomography once a year. None received any form of therapy at onset of the study. Three groups were analyzed: (A) patients without electrophysiologically detectable motor impairment (n = 23), (B) patients with electrophysiologically detectable motor impairment but no virostatic medication (n = 33), and (C) patients with motor deficits undergoing AZT treatment (n = 44) after study onset. Group A patients, although slightly deteriorating over time, had the best clinical and electrophysiological outcome compared to the other groups, whereas group B patients deteriorated markedly in both clinical and electrophysiological tests, even though the majority did not develop cerebral complications during the observation period. Those group C patients belonging to early CDC stages (II and III) improved electrophysiologically under AZT therapy, while 76% of the patients in more advanced stages (CDC IVA-D) died of cerebral AIDS manifestations. Four patients of this group, being alive at the end of the study, were completely demented. It is suggested that early detectable motor impairment predicts future cerebral involvement in AIDS. Late onset of virostatic treatment did not influence the clinical outcome.

AIDS Dementia Complex↗
PubMed1994

Motor impairment in Wilson's disease. 3: The clinical impact of pyramidal tract involvement.

Magnetic brain stimulation was performed on 24 patients with Wilson's disease (WD). Responses to the right and left first dorsal interosseus muscle (FDI) and to the right and left tibialis anterior muscle (TA) were analysed. In 45% of the patients prolonged central motor conduction times (CCTs) to the FDIs were found, whereas only 12% of the patients presented with prolonged CCTs to the TA muscles. No consistent significant correlations between copper metabolism and pyramidal tract function tested by magnetic brain stimulation were found. An improvement of CCTs and response amplitudes with copper elimination therapy was observed only at early phases of therapy. There was no correlation with duration of therapy or neurological symptoms. Thus magnetic brain stimulation turns out to be sensitive to detect subclinical pyramidal tract impairment in WD but seems to test a too specific aspect of motor impairment in WD to reflect the overall neurological status of the patients. Therefore, it has to be combined with other tests to be used for therapy control.

Adolescent↗
PubMed1994

High frequency bursting during rapid finger movements in an unusual case of epilepsia partialis continua.

Myoclonic activity was analyzed in a 25-year-old male patient suffering from epilepsia partialis continua in his right finger and hand extensors and flexors. The involuntary tremorlike regular muscle jerks occurred at an average rate 7.7/s under resting conditions. Bursting frequency did not change during smooth ramp movements but increased up to 25/s during rapid extensions of the fingers. The EEG showed trains of sharp waves over the left temporoparietal and the midcentral regions but backaveraging did not yield reproducible jerk-related potentials. Somatosensory evoked potentials were not enhanced. It is suggested that the observed pattern of muscle jerks resulted from a spontaneous bursting behaviour of motor cortical neurones.

Adult↗
PubMed1993

Role of the cerebellum in visuomotor coordination. I. Delayed eye and arm initiation in patients with mild cerebellar ataxia.

The initiation of coupled eye and arm movements was studied in six patients with mild cerebellar dysfunction and in six age-matched control subjects. The experimental paradigm consisted of 40 deg step-tracking elbow movements made under different feedback conditions. During tracking with the eyes only, saccadic latencies in patients were within normal limits. When patients were required to make coordinated eye and arm movements, however, eye movement onset was significantly delayed. In addition, removal of visual information about arm versus target position had a pronounced differential effect on movement latencies. When the target was extinguished for 3 s immediately following a step change in target position, both eye and arm onset times were further prolonged compared to movements made to continuously visible targets. When visual information concerning arm position was removed, onset times were reduced. Eye and arm latencies in control subjects were unaffected by changes in visual feedback. The results of this study clearly demonstrate that, in contrast to earlier reports of normal saccadic latencies associated with cerebellar dysfunction, initiation of both eye and arm movements is prolonged during coordinated visuomotor tracking thus supporting a coordinative role for the cerebellum during oculo-manual tracking tasks.

Adult↗
PubMed1993

Electrophysiological motor testing, MRI findings and clinical course in AIDS patients with dementia.

Thirty-three HIV-positive patients with clinical signs of dementia according to the 1991 AAN criteria underwent psychometric, electrophysiological and radiological examination and were compared with a group of normal healthy subjects and a cohort of clinically asymptomatic HIV-1-positive individuals of comparable education and social environment. Compared with the other groups, test performance was severely impaired in the demented patients. Results of motor testing and MRI revealed that subcortical structures were not exclusively affected, but most severely and early, thus characterizing the clinical feature in HIV-1-associated dementia. In demented patients a rapid deterioration was observed, leading to death within about 12 months on average, which is a markedly shorter survival time than described in the literature for non-demented HIV-1-positive individuals.

AIDS Dementia Complex↗
PubMed1993

Relationship between striatal glucose consumption and copper excretion in patients with Wilson's disease treated with D-penicillamine.

In 12 patients with Wilson's disease treated with D-penicillamine (DPA), the regional cerebral metabolic rate of glucose consumption of the lentiform and caudate nucleus was analysed using the 18Fluorodeoxyglucose method and correlated with the clinical symptoms of the patients, the ceruloplasmin level, the serum level of free copper and the 24-h copper excretion. The more copper was eliminated, the higher was the basal ganglia glucose consumption. On the other hand, in seven patients who had been treated for more than 7 years a significant decline of the basal ganglia glucose consumption was observed, suggesting too low a maintenance dose of DPA.

Adolescent↗
PubMed1993

Acoustically evoked event-related potentials in HIV-associated dementia.

Cognitive event-related potentials (ERPs) were recorded in 33 HIV-positive individuals with clinical signs of dementia (group C) using an auditory oddball paradigm, in comparison to a healthy control group of comparable education and social environment (group A) and to a cohort of clinically asymptomatic HIV-positive individuals (group B). Parameters evaluated were: N1, P2, N2 and P3 latencies and N1-P2, P2-N2 and N2-P3 amplitudes. Results of group B and C were correlated with clinical findings, test psychometric performance and standard EEG records of both groups. The demented patients revealed significant prolongations of N2 and P3 peak latencies or complete abolition of these "endogenous," not stimulus-related, ERP peaks. Clinical bradykinetic symptoms and time-dependent psychometric abilities correlated with N2 and P3 latency prolongations and with the general slowing of the alpha rhythm, indicating an involvement of cortical and subcortical structures in HIV-related brain disease.

AIDS Dementia Complex↗
PubMed1993

Age-dependent decline in cognitive information processing of HIV-positive individuals detected by event-related potential recordings.

Cognitive event-related potentials (ERP) were recorded in 100 HIV-positive patients of all CDC stages without clinical CNS deficits with an auditory oddball paradigm. Four latency peaks and three amplitudes were evaluated (N1, P2, N2 and P3 latencies, N1-P2, P2-N2 and N2-P3 amplitudes). In contrast to an age-matched control group of comparable education and social environment, a statistically significant N2-P3 amplitude reduction was found in the patient group deteriorating with the CDC stages. The physiological N2-P3 amplitude reduction with age in normals was found to be twice as fast in HIV-positive individuals. No group-statistically relevant EEG abnormalities were found in the patient group. In psychometric testing, there was no marked depressive syndrome in the HIV-positive individuals, but a mild slowing of speed-dependent abilities.

Adult↗
PubMed1993

Motor impairment in Wilson's disease, I: Slowness of voluntary limb movements.

Twenty-three patients with Wilson's disease (WD) treated with D-penicillamine underwent clinical examination, as well as laboratory and motor testing. The clinical findings were scored. Laboratory tests included determination of the caeruloplasmin level, the free serum copper level, 24 h urinary copper excretion, liver enzymes and in 10 patients liver copper content of a liver biopsy. Laboratory tests and clinical scores were correlated. To quantify impairment of voluntary movements in WD fastest possible isometric index finger extensions and fastest alternating finger movements were analysed. Eleven patients presented with abnormally slow and 15 with abnormally irregular voluntary movements. Slowness of alternating movements correlated with the clinical score. The clinical score also correlated with the duration of symptoms prior to onset of therapy. Motor testing turned out to be sensitive enough to monitor improvement of neurological symptoms after onset of therapy. Comparison with motor testing in other basal ganglia diseases and cerebellar patients showed differences to patients with Parkinson's and Huntington's disease and similarities to patients suffering from AIDS-related dementia. In a small number of WD-patients similar results as in patients with a degenerative cerebellar disease were found.

Adolescent↗
PubMed1993

Motor impairment in Wilson's disease, II: Slowness of speech.

The maximal syllable production rate (MSPR) and the ability to reproduce a given target frequency in the 1 to 8 Hz range by repeating the short syllable "ta" was tested in 20 patients with Wilson's disease (WD) and 20 normal subjects. MSPR was significantly reduced in the WD-patients. In the 1 to 5 Hz range normal subjects as well as WD-patients tended to produce slightly higher frequencies than the target frequencies. This hastening was maximal in normals between 4 to 5 Hz whereas in the WD-patients hastening mainly occurred between 3 to 4 Hz. The test results showed a considerable variation across the patients. This variation can be interpreted on the basis of the theory of coupled oscillators. Comparison of speech and finger movements revealed a highly significant correlation between MSPR and the highest possible frequency of voluntary alternating index finger movements. As an application of the presented test treatment effects on speech movements were demonstrated.

Adolescent↗