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Biomedical subjects

B Neundörfer

Publications and source records attributed to B Neundörfer.

At least 145 records · Page 8Linked to original sources
PubMed1999

Patterns of hyperalgesia in complex regional pain syndrome.

Complex regional pain syndrome (CRPS) is characterized by a triad of sensory, motor and autonomic dysfunctions, with long-standing pain and temperature differences of the affected and contralateral limb as predominant symptoms. The pathogenesis of the disorder still remains unclear. Among the main hypotheses of an underlying pathophysiology we find inflammatory processes and dysfunction of the sympathetic nervous system. Whether the main site of dysfunction is found centrally or peripherally is not known. With psychophysical methods we studied patterns of hyperalgesia to obtain a better understanding of the neuropathic pain component in CRPS. Forty patients in an acute phase of CRPS and a median duration of the disease of 10 weeks, were included in the study. Hyperalgesia to heat was tested with a thermode providing feedback-controlled temperature increases. Two forms of mechanical hyperalgesia were examined: phasic mechanical stimuli by using a custom-made impact stimulator for the determination of individual pain thresholds, tonic mechanical stimuli were applied using a pinch-device. Additionally a 'wind-up' paradigm was used to study a pain phenomenon of presumed central origin: a defined impact stimulus was given once and five times in repetition. A subpopulation of patients was reevaluated for mechanical hyperalgesia after i.v. injection of 500 mg acetyl-salicylic acid. Hyperalgesia to heat was insignificant. We found, however, a marked mechanical hyperalgesia to phasic impact stimuli (P < 0.005), whereas, static stimulation (squeezing skin folds) results were insignificant again. Wind-up related pain was also significantly enhanced in the affected limb (P < 0.02). The anti-inflammatory agent had no effect. These results indicate a non-inflammatory pathogenesis in CRPS presumably central in origin.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

The electrical and magnetical cerebral responses evoked by electrical stimulation of the esophagus and the location of their cerebral sources.

OBJECTIVES: After electrical stimulation of the esophagus cerebral responses are recordable, their cortical source is under discussion. Brain mapping using electroencephalography recordings demonstrated partially controversial results. Sources of evoked responses can be localized more easily using magnetoencephalography than electroencephalography. METHODS: We examined 22 volunteers by recording electrical somatosensory potentials after electrical stimulation of the esophagus. In 9 of these 22 subjects additional recording of magnetic fields was performed and the sources of the evoked magnetic fields were computed. RESULTS: The evoked potentials after electrical stimulation of the esophagus had a similar latency as the previously published data. The source localization done by magnetoencephalography suggest that first a region of the postcentral gyrus is activated which is temporo-lateral to the primary somatosensory cortex of the pharynx. This region is suggested to be the primary somatosensory region of the esophagus. This source was followed by a source in the parietal operculum thought being part of the secondary somatosensory cortex. Simultaneously the insular cortex was activated pointing to a parallel neuronal pathway to the central autonomic nervous system. CONCLUSION: After electrical stimulation of the esophagus somatosensory cortical areas of the temporal postcentral gyrus and the operculum are activated. In parallel activation of the insular cortex as part of the central autonomic network was found.

Adult↗
PubMed1999

[The reliability of stroke scales. The german version of NIHSS, ESS and Rankin scales].

Aim of the study was the translation of three frequently used stroke scales ("National Institutes of Health Stroke Scale" NIHSS, "European Stroke Scale" ESS and "Rankin Scale") into German and the analysis of the interrater reliability of the respective German versions. The translation process followed the protocol of the Medical Outcomes Trust (Boston) and included two independent forward, one backward translation and a consensus conference for the German versions. Interrater reliability was assessed using the weighted kappa statistic. For this study 43 patients with an ischemic stroke determined by computed tomography or magnetic resonance imaging were recruited from two university hospitals. Excluded were patients with an intracerebral hemorrhage or TIA. The interrater reliability of the three German versions was substantial to excellent. Mean Kappa for the NIHSS was 0.80, for the ESS 0.79 and 0.76 for the Rankin Scale using simple weights in the analysis. Additional analysis revealed the influence of preselected weights on the results of the kappa statistic. The use of German versions of frequently used stroke scales can reduce bias that is introduced by different levels of knowledge of the English language and thus improve the standardised assessment of neurological deficits in stroke.

Aged↗
PubMed1999

Quantitative thermal perception testing in adults.

In 225 adults aged 18 to 80 years, normative warm and cold perception thresholds were assessed at the volar distal forearm, thenar eminence, lower medial calf, and lateral dorsal foot using the method of limits and a Thermotest (Somedic, Stockholm, Sweden). A 1.5-cm x 2.5-cm thermode, a 1 degrees C/s stimulus change rate, and a 32 degrees C baseline temperature were applied. Thresholds of five consecutive stimuli were averaged. At the thenar eminence a 3 degrees C/s stimulation was applied in addition to the 1 degree C/s stimulation. Effects of spatial summation were studied at the calf and forearm by additional testing with a 2.5-cm x 5.0-cm thermode. To evaluate the influence of skin temperature, thresholds were correlated with the pretest skin temperature at the tested sites. Reproducibility of stimulus perception was determined by comparing the lowest to the highest response to five consecutive stimuli. Results showed sufficient accuracy of thermal perception thresholds. Thresholds were higher with the 3 degrees C/s stimulation than with the 1 degree C/s stimulation. Thresholds were lower with the large than with the small probe. Skin temperature had only minimal influence on thresholds. The use of a 32 degrees C baseline temperature and a 1 degree C/s stimulus change rate is recommended. The large probe should be used at body sites where the entire thermode surface adjusts planely to the skin. Warming up the tested skin area is not necessary before thermotesting.

Adolescent↗
PubMed1999

Cardiac sympathetic denervation in early stages of amyotrophic lateral sclerosis demonstrated by 123I-MIBG-SPECT.

Involvement of the autonomic cardiac nervous system in early stages of amyotrophic lateral sclerosis (ALS) was evaluated in 40 patients. I-123-metaiodobenzylguanidine-single photon emission computed tomography (MIBG-SPECT) and heart rate variability (HRV) yielded information about sympathetic and parasympathetic innervation of the heart. MIBG-SPECT is a sensitive diagnostic method for demonstration of early cardiac sympathetic denervation. Both sympathetic and parasympathetic dysfunction was observed in 16 (40%) out of 40 patients. Mean cardiac MIBG uptake as demonstrated by the heart/mediastinum ratio was significantly reduced in all ALS patients in comparison with controls (P<0.01). The global MIBG-SPECT score was clearly abnormal in 29% and slightly abnormal in 22% of patients. HRV was diminished in 6 of 38 patients, 4 of whom having an abnormal MIBG-SPECT score as well. The presented results indicate that ALS patients with mild to moderate impairment may have evidence of postganglionic sympathetic adrenergic cardiac or cardiovagal denervation. To our knowledge, this is the first study indicating possible postganglionic sympathetic denervation in ALS. The original concept of ALS as an isolated degeneration of motor neurons seems to extend to a more widespread understanding of the disease which possibly represents different entities.

3-Iodobenzylguanidine↗
PubMed1999

Vestibular evoked blood flow response in the basilar artery.

BACKGROUND AND PURPOSE: Monitoring of the basilar artery (BA) is difficult and has been sparsely performed. The aim of this study was to present physiological data of functional transcranial Doppler sonography (TCD) of the BA during caloric vestibular stimulation in healthy volunteers. METHODS: TCD of the BA was performed in 26 healthy volunteers (14 women, 12 men, age 25.1+/-3 years) during caloric vestibular stimulation. Vertigo was documented using electronystagmography (ENG) and a subjective vertigo scale ranging from 0 to 10 points. Simultaneously, capnogpraphy was performed. RESULTS: All subjects experienced vertigo, nausea and oszillopsia during vestibular irrigation. The average subjective vertigo was for a period of 106 s (+/-65.4); the average subjective estimated degree of vertigo was 6.7 points (+/-1.5). In all subjects, ENG demonstrated horizontal nystagm to the left non-irrigated side. In 14 subjects the subjective vertigo was rated by the individuals as extreme (point score > or =7) and in 12 subjects as low (point score <7). Mean flow velocity (MFV) in the BA increased significantly during vestibular irrigation, being more prominent in the initial irrigation and vertigo phase (5.8+/-5.9%, P<0.05) than in the second vertigo phase (2.2+/-8.8%, P<0.05). The calculated pulsatility index (PI), which indicates the condition of the small resistance vessels, decreased significantly (-4.9+/-8.1%; 4.3+/-8.9%, P<0.05) during both phases of vestibular activation. End tidal pCO2 did not change significantly (constant 5.4+/-0.4 Vol%), but respiration frequency was significantly increased during vestibular stimulation (12.3+/-3.8 min(-1) to 16.4+/-5.3 min(-1) and 16.3+/-4.8 min(-1), P<0.05) probably as a vegetative sign of vertigo. The observed MFV- and PI-changes were more prominent, although not quite significant, in the subgroup of subjects who experienced extreme subjective vertigo than in the subgroup who experienced low subjective vertigo. CONCLUSION: These observations indicate that MFV increase in the posterior circulation is due to activation of the vestibulocerebellum. In addition, it is possible that the previously elaborated MFV increase in the MCA might contribute to MFV increase in the BA via the posterior communicating artery. The difference in the 2 subgroups (extreme vertigo vs. low vertigo) may reflect the great variety of anatomical and physiological conditions of the peripheral vestibular organ, the brainstem anatomy and the corresponding blood supply. For clinical purposes this TCD-test may contribute to the investigation of the vasomotor reserve of the posterior circulation, e.g. in patients with vertebrobasilar ischemia, bilateral vestibular loss or local neurodegenerative disease.

Adult↗
PubMed1999

[Brain syndrome and home ventilation--diagnosis, therapy and consequences].

BACKGROUND: A growing number of patients with neuromuscular diseases has been treated with mechanical ventilatory support during the last years. In some of these patients acute or chronic organic brain syndromes complicate the situation. PATIENTS AND METHODS: We present case reports of 5 patients who have been ventilated at home with neuromuscular diseases but who also suffered from brain syndromes of different etiology. CASE REPORTS: (1) Multifactorial acute organic brain syndrome after intensive care therapy. (2) Recurrent paranoid psychosis correlating with hypercapnia. (3) Oneiroids (awake dreamings). (4) Refusal of the rejection of mechanical ventilation facing dyspnea. (5) Persistent vegetative state after polyradiculomyeloencephalitis. DISCUSSION: Patients with hypoventilation or mechanical ventilation often present with various types of brain syndromes. Careful history taking and the use of laboratory and imaging techniques allow the differentiation in primary and secondary (metabolic) brain syndromes. With respect to the fact that home ventilation has marked consequences for the patient and his carer organic disorders of brain function raise two questions: (1) Is the patient able to understand and critically reflect the consequences of long-term mechanical ventilation? (2) Is the patient able to understand and manage the practical aspects and skills of home-ventilation. e.g., does he have the mental capacity for a sufficient compliance? From our point of view patients with severe brain syndromes should not be selected for home-ventilation.

Adult↗
PubMed1999

Transcranial Doppler sonography during acute 80 degrees head-down tilt (HDT) for the assessment of cerebral autoregulation in humans.

Cerebrovascular hemodynamics during postural changes have been sparsely investigated despite the fact that abnormal responses may contribute to the risk of stroke. The aim of this study was to determine the effect of acute 80 degrees head-down tilt (HDT) on cerebrovascular hemodynamics in humans using transcranial Doppler sonography (TCD). In 13 healthy volunteers (2 female, 11 male, age 19-37 years, mean age 26.8 years) left midcerebral artery blood flow velocities (CBFVs) were continuously monitored using TCD during 180 sec in horizontal position and during 60 sec of 80 degrees HDT. Simultaneously, systolic, diastolic, mean CBFVs, pulsatility index (PI), heart rate, beat-to-beat blood pressure (BP) and transcutaneous pCO2 were measured. In five volunteers, the procedure was repeated the next day to test the repeatability of the results. Mean BP increased slightly, but not significantly during tilt (from 80.5 +/- 7.7 mmHg to 85.9 +/- 14.1 mmHg; p > 0.05). Heart rate decreased significantly during the first 20 sec of HDT (from 66.8 +/- 9.9 min-1 to 60 +/- 11 min-1; p < 0.05). Transcutaneous pCO2 was within physiological ranges during the whole procedure (mean pCO2 minimum 39.5 +/- 2.9 mmHg, mean pCO2 maximum 42.2 +/- 3.3 mmHg). Mean CBFV did not change significantly during tilt (from 70.1 +/- 19.1 cm sec-1 to 66.6 +/- 14.1 cm sec-1; p > 0.05). PI, however, increased significantly with a more pronounced increase during the first 20 sec than the last 40 sec of tilt (PIsupine 0.92 +/- 0.11; PItilt(0-20 sec) 1.15 +/- 0.18; PItilt(21-60 sec) 1.03 +/- 0.16; p = 0.001; p = 0.017). The HDT results were found to be reproducible in the five volunteers. During 80 degrees-HDT mean BP and pCO2 did not change significantly. This observation combined with the significant decrease in heart rate during the first 20 sec of HDT, suggests that there is no sympathetic activation. The significant PI increase during HDT indicates a vasoconstriction of the cerebral resistance vessels. We assume that this vasoconstriction is due to the myogenic mechanism of cerebrovascular autoregulation triggered by a rapid, passive intracranial blood volume influx during HDT.

Adult↗
PubMed1999

Herniated cervical intervertebral discs with radiculopathy: an outcome study of conservatively or surgically treated patients.

To study the functional outcomes of patients with cervical herniated intervertebral discs with radiculopathy but without signs of cervical myelopathy using a retrospective cohort study design. The patients were retrospectively identified by chart reviews. Inclusion criteria were (a) cervical radiculopathy with defined neurological disturbances (sensory disorder, reflex abnormalities, and motor weakness); (b) a spinal computed tomograph scan or magnetic resonance image demonstrating neuroradiologic abnormalities (soft or hard disc); and (c) completion of conservative physical and pharmacological treatment. Of 119 consecutive patients who were treated at the Departments of Neurology and Neurosurgery, University of Erlangen-Nuremberg, between January 1, 1985, and December 31, 1995, 60 patients met the inclusion criteria and were prospectively assessed, with an average follow-up time of 5.5 years. The patients were interviewed with regard to their daily activities, ability to work, and the surgical treatment they had undergone. A complete neurological examination also was performed. In 88.3%, the onset of disease was acute and in 11.7% subacute or chronic. The most common signs and symptoms were brachialgia (98.3%), neck pain (93.3%), sensory disorders (88.3%), reflex abnormalities (61.7%), and motor weakness (51.7%). The neuroimaging procedures demonstrated a disc prolapse (soft disc) in approximately 90% and spondylotic osteophytes (hard disc) in approximately 10%. During an average follow-up time of 5.5 years (range, 4.6 months-10.6 years) 39 (65%) patients had been treated using only conservative methods (COG = conservatively treated group), and 21 (35%) patients had undergone surgery (ventral discectomy) (SUG = surgically treated group). Brachialgia was completely or essentially improved in 100% of the COG and 95.1% of the SUG. Sensory disorders remitted completely or markedly in 97% of the COG and 75% of the SUG. The reflex abnormalities normalized or improved in 59.2% of the COG and in 53.3% of the SUG. Motor weakness improved in 94.1% of the COG and in 50% of the SUG. Neck pain was difficult to treat. It improved in only 36.1% of the COG and in 20% of the SUG. Occupational capacity was lost in 10% of the COG and in 38.9% of the SUG. In a self-rating scale, 89.7% of patients in the COG did not feel disabled in their everyday activities, compared with 66.7% of the patients in the SUG. Patients with a herniated cervical intervertebral disc with radiculopathy can be treated conservatively with good results, although a residual intermittent neck pain syndrome often persists. The patients in the SUG, who initially showed more severe and long-lasting neurological disturbances, were improved at the time of examination, although with more marked residual disorders. Surgery is indicated only when appropriate conservative treatment for a reasonable time has failed.

Adult↗
PubMed1998

Creutzfeldt-Jakob disease via dural and corneal transplants.

A review of all published cases of iatrogenic Creutzfeldt-Jakob disease (CJD) via dural (N=71) and corneal (N=4) transplants is given. All but three of the dural cases were obviously due to a commercial product recalled in 1996. Two of the corneal grafts were taken from patients who had died of sporadic CJD. These cases differed from CJD due to human growth hormone injections and the new variant. Instead. they were akin to sporadic cases, but memory loss, disorders of higher cerebral functions and extrapyramidal signs were fewer, while cerebellar abnormalities were more frequent. Progressive dysarthria and gait disorder/gait ataxia were prominent signs during the early stages, myocloni the most salient feature later. A nonperiodic EEG did not contradict the diagnosis. Using current diagnostic criteria the disease was underdiagnosed ante mortem. Utmost care is needed in selecting, harvesting and handling dural and corneal grafts to avoid inadvertent transmission of CJD.

Adolescent↗
PubMed1998

[Autonomic disorders in polyneuropathies].

BACKGROUND: Many polyneuropathies manifest autonomic disturbances. Diabetic neuropathy, the most frequent neuropathy in the western world, serves as model of the symptomatology of autonomic disturbances. DIABETIC NEUROPATHY: Clinical symptoms comprise pupillary and cardiovascular dysfunction such as orthostatic hypotonia and syncopes, thermoregulatory, gastrointestinal symptoms, disturbances in urogenital and respiratory function and unawareness of hypoglycemia. OTHER NEUROPATHIES: This article also describes autonomic symptoms in alcoholic neuropathy, in Guillain-Barré syndrome, in paraneoplastic polyneuropathies, in toxic neuropathies, in acute and subacute autonomic neuropathy, in amyloidosis, in porphyria, in familiar dysautonomia, in HIV infection and in botulism.

Autonomic Nervous System Diseases↗
PubMed1998

Normative values of vibratory perception in 530 children, juveniles and adults aged 3-79 years.

Impaired vibratory perception is an early and frequent finding in various neuropathies. Quantitative vibratory threshold assessment refines the diagnosis of neuropathies but is based on psychophysical techniques requiring patient cooperation. Large, age and sex matched normative data bases are needed to better identify abnormal vibratory perception. In this study vibratory perception was tested at the second metacarpal bone and above the first metatarsal bone of 530 children, juveniles and adults aged 3.3-79.2 years. Thresholds assessed with a 128 Hz graded Rydel-Seiffer tuning fork, TF, were compared to three Vibrameter values, the vibration perception thresholds, VPT, determined with increasing vibration stimuli, the vibration disappearance threshold, VDT, determined with decreasing supraliminal stimuli, and the vibration threshold VT which equals the mean of VPT and VDT. The influence of gender, age, body height, weight and skin temperature at the tested site on thresholds was studied. Retest reliability was tested in 73 children aged 3.3-6.9 years and in 20 volunteers aged 5.2-66.1 years who were also tested for the influence of pretest skin warming on thresholds and for differences between results of the left and right body side. TF, VPT, VDT, VT were closely correlated with each other (Spearman: -0.67<Rs<-0.47; P<0.01). The skin temperature, body side, weight and height did not influence thresholds. In adults, thresholds increased with age and were higher in men above the age of 50 than in women of the same age. Thresholds at the feet were higher than at the hands (Wilcoxon: P<0.001). Retest reliability was high and did not depend on the retest interval. The study provides important normative data for the widespread use of quantitative vibration testing.

Adolescent↗
PubMed1998

Spatial extension of sudomotor axon reflex sweating in human skin.

Acetylcholine (ACh) applied to human skin is known to elicit a sweat response, which consists of a direct muscarinergic (M3) activation of sweat glands and a nicotinic axon reflex response from sudomotor terminals. To visualize the extent of axon reflex sweating after ACh-iontophoresis, iodine starch staining was used. Iontophoresis was performed under occlusion at the peroneal aspects of the lower leg and the center of the foot dorsum of healthy volunteers (n = 10). Ten minutes after stimulation, the area of dark blue staining was recorded by a video camera. Control experiments were performed with saline, histamine, pilocarpine and nicotine iontophoresis. The stained area was measured and the maximum and minimum distance of its boundary from the edge of the iontophoresis probe was determined (maximum/minimum radius). Sizes of stained areas and maximum radii were significantly greater on the lower leg compared to the foot (P < 0.01). The median sizes of the stained areas on the leg were 14.6 cm2 and on the foot dorsum 8.0 cm2. The respective median maximum radii were 3.1 cm on the leg and 2.3 cm on the foot dorsum (median minimum, leg 1.1 cm, foot 0.8 cm). These results match microneurographic findings of innervation territories of sympathetic efferent units. Area sizes of stained skin showed a close correlation between both stimulation sites (R = 0.96, P < 0.01), i.e. the sizes of sweat responses on leg and foot show a constant relation (foot/leg = 0.57) in spite of their great interindividual variability. This novel technique of establishing sweat responses provides information on the size of sudomotor innervation territories and may be useful for clinical studies in patients with suspected impairment of sympathetic functions.

Acetylcholine↗
PubMed1998

[Invasive therapeutic strategies in the acute phase of ischemic arterial cerebral infarct].

BACKGROUND: Currently to an increasing extent aggressive therapeutic approaches in ischemic stroke are discussed. These approaches include intraarterial and systemic thrombolysis to reduce infarction size and also decompressive surgical measures to prevent from fatal consequences of elevated intracranial pressure. This report gives an overview over these strategies. Their specific values are discussed. STRATEGIES: In acute vertebrobasilar artery occlusion an attempt of intraarterial thrombolysis is indicated because of the mostly poor prognosis of large brainstem infarction. Acute artery occlusion in carotid territory has a better prognosis, so that the indication of intraarterial thrombolysis has to be regarded more critically. In view of recent reports systemic rt-PA-thrombolysis seems to be justified in well defined cases independently from site of occlusion. At present there is no longer doubt about the benefit of decompressive surgery in space occupying cerebellar stroke. The value of surgery in malignant brain infarction in carotid territory is not clear due to date. Further randomised studies are necessary to learn more about benefit, risks and required proceedings in space occupying supratentorial infarction. CONCLUSIONS: A well defined group of patients suffering from ischemic stroke seems to benefit from aggressive therapeutic approaches in ischemic stroke. Concerning the selection of patients and management of those approaches a close cooperation with an experienced center is required.

Cerebral Infarction↗