Biomedical subjects

R Töpper

Publications and source records attributed to R Töpper.

At least 55 records · Page 3Linked to original sources

PubMed1996

[Sensory Jacksonian seizures as initial manifestation of sarcoidosis].

A 46-year old patient is reported presenting with somatosensory focal seizures of either arm as the only manifestation of an otherwise clinically inapparent sarcoidosis. MRI showed signs of a granulomatous leptomeningeal affection. Histological examination of a meningeal biopsy proved the diagnosis of sarcoidosis by demonstrating noncaseating granulomas. There was no other clinical manifestation of sarcoidosis. Chest X-ray was normal and the serum level of angiotensin-converting-enzyme was only slightly elevated. The CD4/CD8 ratio in the bronchoalveolar lavage cell population, however, was clearly abnormal, supporting the role of this diagnostic tool in the diagnosis of sarcoidosis.

Biopsy↗

PubMed1996

Stretch reflexes of the proximal arm in a patient with mirror movements: absence of bilateral long-latency components.

The stretch reflex responses evoked by unilateral limb displacement in distal (first dorsal interosseus (FDI)) and in proximal (biceps brachii (Bb)) arm muscles were studied during matched bilateral contractions in a patient with congenital mirror movements. In this patient unilateral transcortical magnetic stimulation (TMS) elicited not only the normal contralateral EMG response but also a clear ipsilateral component in the EMG of both proximal and distal arm muscles. As expected from previous studies, the ipsilateral FDI muscle responded to stretch of the index finger with short- (M1) and long-latency (M2) reflex components. In addition, the FDI contralateral to displacement exhibited an abnormal mirrored response corresponding to the M2 interval. In contrast, whereas the ipsilateral Bb responded to imposed elbow extension with a marked M1/M2 reflex response, no mirroring of either reflex component was apparent in the contralateral Bb EMG. If the mirroring of the M2 in the FDI is accepted as evidence for the transcortical nature of the M2 reflex response, then it follows that the absence of such mirroring in the Bb indicates that a transcortical mechanism cannot play a major role in the generation of long-latency stretch reflex responses in proximal arm muscles.

Adult↗

PubMed1995

Rapid appearance of beta-amyloid precursor protein immunoreactivity in glial cells following excitotoxic brain injury.

Clinical and experimental data have indicated an up-regulation of amyloid precursor protein (APP) after various types of CNS injury. In the present study the cellular source of lesion-induced APP has been investigated in a neurotoxic CNS model. Quinolinic acid injection into the striatum results in neuronal degeneration, while glial cells survive. APP immunoreactivity was detected in glial cells starting at postoperative day 3 and persisted until day 21, the last time point studied. Double immunocytochemistry identified the majority of APP-immunoreactive cells as glial fibrillary acidic protein-immunoreactive astrocytes. There was no evidence of amyloid fibril deposition during this time. It is concluded that following excitotoxic neuronal degneration APP is mainly produced by reactive astrocytes in the lesioned area.

Amyloid beta-Protein Precursor↗

PubMed1995

Volitional type of facial palsy associated with pontine ischaemia.

A dissociation between voluntary and emotional facial innervation is described in a patient with a pure motor stroke due to a unilateral ischaemic pontine infarction. Voluntary facial innervation of the contralateral orbicularis oris muscle was affected whereas emotionally induced innervation of the same muscle was spared. This report provides evidence that fibres conveying voluntary and emotional commands are still separated in the pons. Whereas corticobulbar tracts carry the information for voluntary facial innervation, efferents from the amygdala and the lateral hypothalamus are candidates for the somatomotor aspects of emotions.

Brain Ischemia↗

PubMed1995

Evidence for cardioembolic stroke in a case of Kearns-Sayre syndrome.

BACKGROUND: Cerebral infarction is a known complication in patients with mitochondrial encephalomyopathies (MELAS, MERRF, Kearns-Sayre syndrome), but the etiology in the different types remains uncertain. CASE DESCRIPTION: A 33-year-old woman who had suffered from ophthalmoplegia, bilateral ptosis, ataxia, retinitis pigmentosa, and epilepsy since childhood was diagnosed to have Kearns-Sayre syndrome. The diagnosis was confirmed by muscle biopsy when she was 17 years old. A pacemaker was implanted because of the occurrence of bradyarrhythmias when she was 24 years old. The patient was admitted to the hospital with left-sided hemiparesis of sudden onset due to right striatocapsular infarction. Results of Doppler sonography of the carotid arteries were normal; however, transesophageal echocardiography revealed a thrombus in the left atrial appendage. CONCLUSIONS: Stroke in Kearns-Sayre syndrome is likely to be due to cardiac embolism. Anticoagulant therapy should be considered even for mild forms of cardiomyopathies leading to left ventricular dysfunction.

Adolescent↗

PubMed1994

[Home ventilation in neurologic diseases. Survey of 62 patients].

Home ventilation has developed as a sufficient and safe method in many neurological diseases afflicting respiratory functions. To achieve an overview of the situation of these patients in Germany, a questionnaire was distributed by the manufacturer of the most commonly used ventilator in Germany. The patients were asked to send the form back, even anonymous, to the Department of Neurology, RWTH Aachen. 65 of 110 questionnaires were answered, most of patients with muscle dystrophy's (n = 14), Polio (n = 14) and spinal cord injuries (n = 11). Home ventilation in ALS was performed in 3 cases only. The majority of patients (n = 30) was aged between 20 and 49 years, but here were also 5 children younger than 10 years. Most patients were ventilated not more than 4 years, but there were also 5 patients ventilated for over 20 years, all of them Polio-patients. 70% of all lived at home with their relatives, who take care for them. Nevertheless, 13 were full- or part-time working.

Activities of Daily Living↗

PubMed1993

B-50 (GAP-43) in the spinal cord caudal to hemisection: indication for lack of intraspinal sprouting in dorsal root axons.

Sprouting of dorsal root axons has been suggested to occur in the mature cat spinal cord caudal to a hemisection at a low thoracic level sparing the dorsal columns. The lesion interrupts supraspinal descending projections, while leaving ascending collaterals of dorsal root axons intact. This hypothesis was re-evaluated by comparing the light and electron microscopic immunoreactivity of B-50 (GAP-43) on both sides of the postulated target regions for sprouting, the intermediate gray and the dorsal horn. The neural-specific phosphoprotein B-50 is involved in regenerative and developmental axonal outgrowth and synaptic plasticity. The light microscopic distribution pattern and density of B-50 immunostaining, measured by quantitative densitometry, were bilaterally symmetrical in all segments below the hemisection 3.5, 8, 14, 21, and 56 days postoperatively, as they were in the intact animal. Ultrastructurally, growth cone-like profiles were not detectable during putative periods of sprouting in regions of interest. After removal of degenerated axon terminals, vacated postsynaptic places appeared to be covered by astrocytic processes. These results indicate that, under the present experimental conditions, sprouting of primary afferents in adult cats is unlikely to be involved in functional plasticity after removal of descending pathways.

Animals↗

PubMed1993

B-50 (GAP-43) in Onuf's nucleus of the adult cat.

The nucleus of Onuf in the sacral spinal cord contains motoneurons that innervate the pelvic floor muscles and possess somatic and autonomic characteristics. We show in this study that in the intact adult cat, the immunocytochemical labelling of the nervous tissue-specific growth-associated protein, B-50 (GAP-43), which persists in Onuf's nucleus, differs markedly from that in the remaining 'purely somatic' motor nuclei of the sacral spinal cord. At the light microscopic level, an intense B-50 (GAP-43) immunoreactivity (B-50-IR) in the neuropil of Onuf's nucleus contrasts with a faint staining in the other spinal motor nuclei. Ultrastructurally, B-50-IR is found in Onuf's nucleus within some unmyelinated small diameter nerve fibres and numerous axon terminals on dendritic and somatic surfaces. Conversely, in all other motor nuclei only a few of these structures are stained. No other cellular profiles show B-50-IR in the tissue examined. According to the proposed functions of B-50 (GAP-43), its persistence in mature spinal axon terminals may indicate a latent capability of functional and structural remodeling, as well as an involvement in long-term enhancement in synaptic transmission. If so, these properties would be considerably more pronounced in Onuf's nucleus as compared to purely somatic motor nuclei.

Animals↗

PubMed1993

Comparison of somatosensory evoked potentials with striatal glucose consumption measured by positron emission tomography in the early diagnosis of Huntington's disease.

Both somatosensory evoked potentials (SEP) and striatal glucose consumption (rCMRGlc) measured by positron emission tomography (PET) have been reported to be abnormal early in the course of Huntington's disease (HD). To compare their diagnostic value, SEP and rCMRGlc were measured in a group of 18 first degree off-spring of HD families: 6 had manifest HD with chorea and the remaining 12 individuals were chorea-free subjects at risk for HD. In five patients with manifest disease, both SEP and striatal rCMRGlc were significantly abnormal, defined in SEP as having either a bilaterally absent frontal N30 amplitude or a reduction of the parietal N20/P25 amplitude below 1 microV on at least one side; in PET as exhibiting a reduction of the cerebellar ratio (CR) of both caudate and lentiform rCMRGlc below the 99% confidence limits of these variables determined in 20 normal volunteers. The remaining patient with manifest HD had questionably abnormal SEP and significantly reduced indices of striatal rCMRGlc. The five persons at risk for HD who had normal SEP also had normal striatal rCMRGlc; those three at-risk patients with abnormal SEP also had a reduction of the CR of both caudate and lentiform rCMRGlc. Of the remaining four individuals at risk for HD who had questionably abnormal SEP, three had CR values of striatal rCMRGlc in the normal range and one a reduction of the CR of lentiform rCMRGlc. In at-risk patients, the SEP diagnosis correlated significantly with caudate (r = -0.8; p < 0.002) and lentiform (r = -0.76; p < 0.005) rCMRGlc. These data indicate a parallel deterioration of SEP and striatal rCMRGlc early in the course of HD even before the development of chorea.

Adult↗

PubMed1993

Remote microglial activation in the quinolinic acid model of Huntington's disease.

Intrastriatal injection of quinolinic acid (QA) in the rat leads to several structural and biochemical events which resemble neuropathological changes seen in the striatum of Huntington's disease patients. In the present experiment the accompanying microglial response in striatal projection areas following QA injection was studied immunocytochemically using monoclonal macrophage/microglial markers. After injection of 240 nmol of QA a marked microglial reaction was observed in the entire striatum, whereas injection of the same amount of solvent resulted only in a local microglial reaction around the injection site. Activated microglia were also found in the globus pallidus (GP), the entopeduncular nucleus (EP), the substantia nigra (SN), and the ventroanterior/ventrolateral, the ventromedial, and, in some rats, the reticular thalamic nucleus. The remote microglial reaction started in the first-order projection areas at Day 1 (GP) or Day 3 (EP, SN) and was found in the second-order projection areas (thalamic nuclei) by Day 5. Areas projecting to the striatum such as the amygdala and intralaminar thalamic nuclei remained free of activated microglia. It is concluded that a microglial response in striatal projection areas accompanies excitotoxic striatal injury. Anterograde degeneration of striatal projection neurons can explain the microglial activation in first-order projection areas but other mechanisms such as neuronal hyperexcitation following removal of inhibitory striatal input must be responsible for the rapid transsynaptic microglial activation seen in the thalamus.

Animals↗

PubMed1993

Expression of transforming growth factor-beta 1 and interleukin-1 beta mRNA in rat brain following transient forebrain ischemia.

Transforming growth factor-beta 1 (TGF-beta 1) and interleukin-1 beta mRNA expression were studied in rat brains after 30 min of global ischemia by in situ hybridization. Ischemia was produced by four-vessel occlusion followed by different recirculation times ranging between 15 min and 7 days. TGF-beta 1 mRNA could first be detected 3 days after ischemia in the hippocampus, in layers II/III of cortex, in the striatum and in parts of the ventral thalamus. At 7 days after recirculation a prominent increase in TGF-beta 1 mRNA was observed in the CA1 sector of the hippocampus. Induction of interleukin-1 beta mRNA, however, was less marked and limited to the rostral striatum 3 and 7 days after ischemia. TGF-beta 1 expression 7 days after ischemia correlated well with the histological localization of regions where neuronal degeneration and subsequent astrocytic and microglial activation had occurred. In adjacent brain sections, the distribution of TGF-beta 1 mRNA after 7 days closely resembled that of the immunostaining pattern of activated microglia, indicating that at this time point TGF-beta 1 mRNA was mainly produced by microglial cells. The late induction of TGF-beta 1 mRNA after ischemia points to an involvement in the persistent glial response rather than the initial glial activation. The differential pattern of interleukin-1 beta mRNA induction indicates regional variations of cytokine production after ischemic brain lesions.

Animals↗

PubMed1993

Immunocytochemistry of B-50 (GAP-43) in the spinal cord and in dorsal root ganglia of the adult cat.

The distribution of the neural-specific growth associated protein B-50 (GAP-43), which persists in the mature spinal cord and dorsal root ganglia, has been studied by light and electron microscopic immunohistochemistry in the cat. Throughout the spinal cord, B-50 immunoreactivity was seen confined to the neuropil, whereas neuronal cell bodies were unreactive. The most conspicuous immunostaining was observed in the dorsal horn, where it gradually decreased from superficial laminae (I-II) toward more ventral laminae (III-V), and in the central portion of the intermediate gray (mainly lamina X). In these regions, the labelling was localized within unmyelinated, small diameter nerve fibres and axon terminals. In the rest of the intermediate zone (laminae VI-VIII), B-50 immunoreactivity was virtually absent. The intermediolateral nucleus in the thoracic and cranial lumbar cord showed a circumscribed intense B-50 immunoreactivity brought about by the labelling of many axon terminals on preganglionic sympathetic neurons. In motor nuclei of the ventral horn (lamina IX), low levels of B-50 immunoreactivity were present in a few axon terminals on dendritic and somal profiles of motoneurons. In dorsal root ganglia, B-50 immunoreactivity was mainly localized in the cell bodies of small and medium-sized sensory neurons. The selective distribution of persisting B-50 immunoreactivity in the mature cat throughout sensory, motor, and autonomic areas of the spinal cord and in dorsal root ganglia suggests that B-50-positive systems retain in adult life the capacity for structural and functional plasticity.

Animals↗

PubMed1993

Cell adhesion molecule expression in the regenerating rat facial nucleus.

Transection of the rat facial nerve leads to an intrinsic microglial reaction in the facial nucleus. In the present study, we have examined immunocytochemically the expression of cell adhesion molecules during this process. Resting microglia constitutively expressed the LFA-1 alpha and beta chain (CD11a and CD18) in the white matter, rather than in the intact, control facial nucleus. From 24 h after facial nerve transection onward, activated microglia showed an increased expression of LFA-1 alpha and beta. The immunoreactivity reached its peak around day 7 following axotomy, i.e. at a time when activated microglia are found in a close perineuronal position. In contrast, the expression of the principal ligand of LFA-1, i.e. ICAM-1, remained unchanged following axotomy; the immunoreactivity being constitutively found on cerebral blood vessels. Increased LFA-1 expression thus appears to be a general marker for microglial activation and might further be involved in the rearrangement of the microglial cytoskeleton upon activation of this cell.

Animals↗

PubMed1993

Absence of frontal somatosensory evoked potentials in Huntington's disease.

A fast route for transmission of deep and cutaneous afferent information to the frontal cortex is well established in non-human primates. Whether the incoming cortical information gives rise to early frontal somatosensory evoked potentials (SEPs) in humans is still a matter of contention. We attempted to solve this question by investigating the topography of SEP generators evoked by median nerve stimulation in 30 healthy subjects and in 30 patients suffering from Huntington's disease, who are known to have reduced SEP amplitudes. Using an earlobe reference, SEPs were recorded with an array of either five surface electrodes over the contralateral parietal cortex or 32 electrodes distributed over the whole scalp. In normal subjects analysis of frontal potentials revealed an early positive (P22) and negative (N30) component which could not be explained by generators located in the parietal cortex. Apart from the reduction of parietal components (N20, P25) frontal P22 and N30 were diminished or absent in Huntington's disease patients. Frontal potentials were even reduced in those patients who had parietal SEP amplitudes within the range of normal subjects. These frontal changes are similar to those reported in other basal ganglia disorders. Basal ganglia dysfunction might therefore be associated with changes of frontal SEP components.

Adult↗

PubMed1993

Changes in the short- and long-latency stretch reflex components of the triceps surae muscle during ischaemia in man.

1. In order to establish the afferent source responsible for the M1 and M2 stretch reflex components of the voluntarily activated human triceps surae muscle, mechanical reflex testing was applied before and during ischaemic blockade of the lower limb. This procedure is known to affect large, fast conducting afferent fibres earliest, specifically Ia afferents arising from muscle spindle afferents. 2. It was found that both the M1 and M2 components were eliminated at the same time, at a point when the P40 peak in the somatosensory evoked potential, produced from stimulation of fast conducting peripheral afferents, was also abolished. This evidence indicates that both reflex components are mediated by information carried by muscle spindle Ia afferents. 3. The M1 component was selectively increased in the early stages of ischaemia. The M2 response did not increase during this period, but showed a tendency to reduce in amplitude. This effect may arise as the result of increased recruitment of motor units in the M1 component reducing the number of units available for activation in the M2 response. 4. These results do not support the view that the M2 reflex component of the triceps surae muscle is mediated by secondary afferent information, but indicate, rather, that both the M1 and M2 components are mediated by Ia afferent information acting on spinal pathways.

Adult↗

PubMed1992

Abnormalities of somatosensory evoked potentials in the quinolinic acid model of Huntington's disease: evidence that basal ganglia modulate sensory cortical input.

Intrastriatal injection of quinolinic acid (QA) in rats provides an animal model that mimics some of the neuropathological and neurochemical alterations observed in the striatum of patients with Huntington's disease (HD). One of the very early neurophysiological signs in HD is a diminution of amplitude of early somatosensory evoked potentials (SEPs) recorded over the parietal cortex. The present study investigated whether the QA model exhibits similar neurophysiological abnormalities. Two weeks after unilateral intrastriatal injection of QA (240 nmol) or of the solvent, early SEPs were recorded with chronically implanted electrodes from the somatosensory cortex or from the ventrobasal nucleus of the thalamus of lightly pentobarbital-anesthetized rats, in response to single-shock electrical stimulation of the contralateral forepaw. Whereas intrastriatal injection of solvent did not influence SEPs, the striatal QA lesion significantly reduced the amplitude of early cortical SEPs by about 40% without affecting the latency. SEPs recorded from the ventrobasal nucleus were unchanged after QA lesion. Histological examination and glial fibrillary acid protein staining after intrastriatal injection of QA revealed no evidence for damage in the somatosensory system. It is concluded that (1) the QA animal model of HD mimics some of the SEP abnormalities of patients, and (2) a striatal lesion modulates somatosensory transmission to the cortex in rats.

Animals↗

PubMed1992

Contralateral early blink reflex in patients with facial nerve palsy: indication for synaptic reorganization in the facial nucleus during regeneration.

Fifty patients with Bell's palsy and 30 patients with etiologically different symptomatic peripheral facial nerve palsy were studied by means of electrically evoked blink reflexes 1-23 days after onset of paresis. Their results were compared with a normal control group of 30 healthy subjects. In a significant number of patients (64% in Bell's palsy and 53% in symptomatic facial nerve palsy) a contralateral early blink reflex response (R1) could be elicited upon stimulation of the normal side as compared to 13% in the control group. It is suggested that this result may be explained by synaptic reorganization of the facial nucleus leading to functional unmasking of pre-existing crossed trigemino-facial reflex pathways during regeneration. This view is in line with previous experimental data in animals on the time course of structural changes in the facial nucleus after lesioning of the ipsilateral facial nerve.

Adolescent↗

PubMed1991

[Recurrent aseptic meningitis (Mollaret meningitis)--spontaneous and drug-induced origin].

Since its initial description by Mollaret in 1944, the etiology of the chronic aseptic meningitis has remained unknown. This rare disease may cause diagnostic problems if bacterial or viral causes are suspected. A different form of aseptic meningitis may be seen following a variety of drug treatments, especially with non-steroidal anti-rheumatic drugs: In many reports since 1978, meningitic attacks following administration of ibuprofen have been reported. We describe two cases of Mollaret-Meningitis with certain specialities: one case shows clear encephalitic involvement with aphasia in all six attacks. In the other case, five meningitic attacks appeared spontaneously, while two were drug-induced: the first attack was seen after a lumbar myelography with lopamidol and one attack appeared two hours after oral administration of 400 mg ibuprofen. It is suggested that Mollaret-Meningitis is a special form of a drug-induced allergic reaction, the provoking agent of which remains unknown.

Aged↗