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Biomedical subjects

B Neundörfer

Publications and source records attributed to B Neundörfer.

At least 109 records · Page 6Linked to original sources

Oral mucosal blood flow following dry ice stimulation in humans.

The aim of the current pilot study was to establish a procedure that would allow the investigation of microcirculatory changes in the oral cavity. The authors studied the effects of painful stimulation using dry ice (CO2). To investigate potential regional differences in the change of blood flow, recordings were made for the tongue and at the mucosa of the hard palate, lip, and oral vestibule. The authors investigated 26 patients divided into groups of younger subjects (10 men, 3 women; age range 21-31 y) and older patients (2 men, 11 women; age range 54-74 y). Mucosal blood flow (mBF) was obtained at the hard palate, at the tip of the tongue, on the midline of the oral vestibule, and at the lip. Measurements were made during rest and for 2 minutes after application of dry ice for a 10-second duration, using a pencil-shaped apparatus. Blood pressure, heart rate, cutaneous blood flow, transcutaneous partial pressure of carbon dioxiode (PCO2) and partial pressure of oxygen (PO2) were recorded. Mucosal blood flow increased at all sites in response to application of dry ice (p <0.001), with peak flow at 0.5 minute to 1.5 minutes after onset of stimulation. During the 1.5 minutes to 2 minutes, blood flow decreased at all measurement sites with a tendency to return to baseline. Heart rate, blood pressure, pCO2, PO2, and cutaneous blood flow did not show significant changes. Overall, responses in older patients showed more variance when compared with younger patients. Stimulation by dry ice appears to be an effective, noninvasive, and tolerable means to investigate mucosal blood flow at different mucosal sites. Preliminary data indicate different levels of responsiveness to painful cold stimulation at different sites on the oral and perioral mucosa; particularly, mucosal blood flow response at the tongue was least pronounced. Therefore, assessment of stimulated mucosal blood flow appears to be a promising tool to investigate the pathophysiology of a number of neurologic symptoms, eg, the burning mouth syndrome.

Adult↗

[Generalized brain edema in non-purulent meningoencephalitis. The anti-edema effect of therapy with dexamethasone].

We report about two female inpatients aged 58 and 24, suffering from non-purulent meningoencephalitis, in the first case caused by varizella-zoster-virus, in the second case probably due to viral infection. Both patients developed a diffuse brain edema associated with a progressive loss of consciousness. The adjunctive treatment with dexamethasone led to rapid improvement of clinical symptoms. Computed tomography revealed a significant reduction of brain edema. These results of these two cases support the efficacy of corticosteroids as adjunctive treatment of diffuse brain edema caused by non-purulent meningoencephalitis. The pathophysiological mechanisms are discussed.

Adult↗

["Ghost and mimicry-tumor"--primary CNS lymphoma].

In recent years, the frequency of primary cerebral lymphoma (PCNSL) has increased, even among immunocompetent patients. In order to treat the disease optimally, early diagnosis is important. We present three patients with atypical courses of this disease and stress the importance of PCNSL in the differential diagnosis for optimal treatment. In a 75-year-old man, a space-occupying, radiopaque, enhancing CNS lesion disappeared completely after biopsy and short steroid therapy. One year later, the tumor recurred on the other side and again regressed after steroid therapy. The first biopsy showed signs of a papillary tumor, so a choroid plexus papilloma was suspected initially. A 57-year-old woman developed progressive bilateral hearing dysfunction. Lymphocytic pleocytosis led to a primary diagnosis of chronic lymphocytic meningitis. During the further course of disease, the patient developed multiple space-occupying cerebral lesions. Stereotactic biopsy revealed PCNSL. Despite combined chemo- and radiotherapy, a relapse occurred. A 49-year-old woman rapidly developed memory and concentration disturbances. Computed tomography revealed diffuse edema in both hemispheres and MRI detected severe, diffuse, white matter lesions. The CSF revealed lymphocytic pleocytosis including plasma cells. Herpes encephalitis and, after lack of clinical improvement and progression of the MRI changes, acute disseminated encephalomyelitis (ADEM) were suspected. Corticosteroid treatment was initiated. After enormous clinical improvement, a clinical relapse occurred and MRI detected bitemporal and singular space-occupying lesions in the corpus callosum and hypothalamus. Finally, open biopsy showed PCNSL. However, on examination of the treatment history of patient 1, the initial diagnosis must be revised; a PCNSL seems most probable. The phenomenon of tumor remission under steroid administration is rare. In patients 2 and 3, atypical clinical signs and symptoms delayed diagnosis of PCNSL. This tumor can mimic diverse neurological diseases and remit following corticosteroid treatment alone. In unclear cerebral disease, biopsy should be performed early for exact diagnosis and optimal treatment.

Aged↗

[Temporal lobe epilepsy: effect of focus side on the autonomic regulation of heart rate?].

Epileptic activity can modulate reactions of the autonomic nervous system. Although there is some evidence of a differential left/right hemispheric influence on the cardiovascular system, diverse investigations have shown controversial results. In our study, complex partial seizures of patients with temporal lobe epilepsy were recorded using subdural electrodes, thus providing reliable information on the focus side. We analyzed the preictal and ictal heart rates of 27 patients, 16 revealing right and 11 revealing left temporal foci. During the seizures, both groups showed a significant increase in heart rate. Preictal tachycardia was only significant in the right focus group, whereas no significant change in heart rates could be detected in the left focus group. Our results confirm a right hemispheric lateralization of sympathetic cardiac control.

Adult↗

[Outcome quality of treatment for chronic low back pain under primary care conditions].

BACKGROUND: Little is known about the outcome quality of treatment for chronic low back pain under primary care conditions in Germany. METHODS: All physicians (2100) of middle Franconia, a region of Bavaria with 1.6 million inhabitants, involved in outpatient management were asked to include consecutively patients who suffered from low back pain of at least 4 weeks duration without decreasing intensity. Before and after a 6-month interval patients documented the following outcome data in a questionnaire: pain intensity during the last 24 hours (numerical rating scale), pain-dependent disability (Brief Pain Inventory, German version), health-related quality of life (SF-36, German version), depression (Allgemeine Depressionsskala), pain chronification state (Mainz Pain Staging System) and the days of inability to work within 3 months before start and end of the interval. Treatment of patients was not standardized and included the natural spectrum of non-surgical therapies for low back pain except multimodal pain therapy programs. RESULTS: Thirty-five physicians participated in the study. "Before and after" data of 157 patients (43+/-12 years) could be analysed. Initially 20% were classified in pain chronification state I, 57% in state II and 23% in state III. The pain intensity, pain-dependent disability, depression and quality of life improved significantly but mean differences and effect sizes were small (p<0.41). Less than one third of patients improved by 30% or more from baseline or by one step in the chronification state of pain. Days off work did not change significantly. Predictors for positive therapy response could not be identified. CONCLUSIONS: Monodisciplinary treatment procedures are not sufficient to ameliorate problems of patients in advanced chronification states of back pain.

English Abstract↗

[Outcome-quality of treatment for headache on primary care conditions].

BACKGROUND: Little is known about the outcome-quality of treatment for headache on primary care conditions in Germany. METHODS: All physicians (2100) of middle franconia, a bavarian greater district with 1,6 Mio. inhabitants, involved in outpatient management were asked to include consecutively patients in the study which suffer from migraine (at least 2 attacks/month) and/or tension type headache (at least 8 days/month) of at least 4 weeks duration. Before and after a 6 months interval patients documented the following outcome data in a questionnaire: pain intensity during the last attack (numeric rating scale), pain dependent disability (Brief Pain Inventory, German version), health related quality of life (SF-36, German version) and depressivity (Allgemeine Depressionsskala). The pain chronification state (Mainz Pain Staging System) has been assessed by the physician. Therapy was not standardized and included the natural spectrum of medicamental and non-medicamental therapy of headache. Agreement of therapy with recommendations of the "Arzneimittelkommission der Deutschen Aerzteschaft" has been assessed. RESULTS: 24 physicians participated in the study. Pre-post-data of 80 patients (46+/-14 y) could be analysed. Initially 67% were classified in pain chronification state I, 27% in state II and 6% in state III. Medicamental therapy agreed with recommendations in approximately 50% of patients, non-medicamental therapy has been used rarely. The pain intensity, pain dependent disability, depression and quality of life improved significantly. 45% and 55% of patients improved in at least 2 of 6 outcome-parameters by 30% of baseline value or by half standard deviation of the corresponding pre-post-differences, respectively. The latter outcome-measure reflects a medium effect size. CONCLUSIONS: On primary care conditions about 50% of patients suffering from migraine and/or tension type headache (predominantly low chronification stae) perceive a therapy effect that corresponds to a medium effect size.

English Abstract↗

Experimental tissue acidosis leads to increased pain in complex regional pain syndrome (CRPS).

The aim of this study was to investigate the role of local acidosis in the generation of pain in complex regional pain syndrome (CRPS). We investigated ten patients with CRPS of the upper extremity with a mean duration of the disease of 43 weeks (range 4-280 weeks) and ten control subjects for sensitivity to infusion of fluids with low pH (pH 6.1). Another group of five CRPS patients and three healthy controls was investigated using the same protocol but neutral infusion fluid (pH 7.4). A motorized syringe pump was installed for a constant infusion of synthetic interstitial fluid (SIF, either acidified (pH 6.1) or neutral) into the skin at the back of the hands and, thereafter, into the interosseus I muscle on both sides. A flow rate of 30 ml/h was chosen for intradermal and 7.5 ml/h for intramuscular infusion over a period of 10 min. The magnitude of pain was rated on an electronic visual analogue scale. Patients were requested to give their ratings every 10 s during the whole stimulation period. The ratings were normalized as fractions of individual grand mean values. We found significantly increased pain perception during infusion of acidified SIF on the affected side in CRPS patients. Low pH fluid into the skin was significantly more painful between 4 and 6 min (ipsi 1.27 normalized rating (NR) (0. 19-1.94), contra 0.31 NR (0.03-0.51), P<0.02) and between 8 and 10 min (ipsi 1.38 NR (0.19-1.94), contra 0.08 NR (0-0.27), P<0.03) on the affected side, while analysis over the whole stimulation period just failed to reach statistical significance (ipsi 281 area under the curve (AUC) (187-834), contra 87 AUC (28-293), P=0.059). Low pH infusion into the muscle was significantly more painful on the affected side during the whole infusion time (ipsi 861 AUC (308-1377), contra 190 AUC (96-528), P<0.01). The quality of the deep pain during infusion into the muscle was described by the patients as very similar to the CRPS-related pain. In controls we found no side differences of pain intensity during low pH stimulation. Neutral SIF evoked no pain at all, neither in CRPS patients (ipsi 0 AUC, contra 0 AUC) nor in healthy controls. Our results suggest that hyperalgesia to protons is present in patients with CRPS. Further, we could demonstrate that pain is not only restricted to the skin but is also generated in deep somatic tissue of the affected limb.

Acidosis↗

Density of sympathetic axons in sural nerve biopsies of neuropathy patients is related to painfulness.

In this study, differences of unmyelinated nerve fiber density in sural nerve biopsy material from patients suffering from neuropathies of unknown origin with (n=14) or without pain (n=13) were analyzed. Immunocytochemistry was applied to differentiate afferent sensory and efferent sympathetic nerve fibers. All patients were evaluated for deficits of small fiber function with thermotesting, quantitative sudomotor-axon reflex-testing and testing of painfulness of mechanical stimuli before performing the biopsy. No difference was found between patients with and without pain concerning clinical deficits or results in any of the neurophysiological examinations. There were also no histopathological differences concerning the density of afferent C-fibers. However, absolute and relative density of efferent sympathetic nerve fibers was significantly higher in patients with painful neuropathy (P<0.001), although none of the patients demonstrated clinical sympathetic abnormalities. We conclude that an imbalance between afferent and sympathetic nerve fiber density in the periphery may contribute to neuropathic pain even in those patients without obvious clinical autonomic disturbances.

Adult↗

Neurological findings in complex regional pain syndromes--analysis of 145 cases.

Early diagnosis is a prerequisite for a successful treatment of complex regional pain syndrome (CRPS). In order to describe neurological symptoms which characterize CRPS, we evaluated 145 patients prospectively. Two-thirds of these were women, the mean age at time of investigation was 50.4 years. CRPS followed limb trauma, surgery and nerve lesion. Employing the current IASP criteria 122 patients were classified as CRPS I and 23 as CRPS II. All patients were assessed clinically pain was quantified using the McGill pain questionnaire, skin temperature was measured by an infrared thermometer and a subgroup of 57 patients was retested in order to determine thermal thresholds (QST). Of our patients 42% reported stressful life events in a close relationship to the onset of CRPS and 41% had a history of chronic pain before CRPS. The latter group of patients gave a higher rating of CRPS pain (P<0.05). The major symptoms were pain at rest in 77% and hyperalgesia in 94%. Typical pain was deep in the limb having a tearing character. Patients getting physical therapy had significantly less pain than those without (P<0.04). Autonomic signs were frequent (98%) and often changed with the duration of CRPS. Skin temperature was warmer in acute and colder in chronic stages (P<0.001). Likewise edema had a higher incidence in acute stages (P<0.001). We found no correlation between pain and autonomic dysfunction. Motor dysfunction (present in 97%) included weakness, tremor, exaggerated tendon reflexes, dystonia or myoclonic jerks. QST revealed increased warm perception thresholds (P<0.02) and decreased cold pain thresholds (P<0.03) of the affected limb. The detailed knowledge of clinical features of CRPS could help physicians early to recognize the disease and thus to improve therapy outcome.

Adolescent↗

Progressive muscle pain, weight gain, fatique and unusual body shape change.

Multiple symmetrical lipomatosis (MSL) is a rare syndrome characterized by symmetric unencapsulated lipomas around the axial region and frequently associated with neurological involvement, particularly myopathy and neuropathy (Klopstock et al., 1994). Here we present a typical image of a patient with MSL, explaining this disease for neurologists who might care for these patients in an average day at the neuromuscular consultation unit.

Fatigue↗

[Manifestation of Creutzfeldt-Jakob disease 30 years after corneal transplantation].

BACKGROUND: Creutzfeldt-Jakob disease, currently viewed as one of the prionic diseases, occurs in by far the majority of cases sporadically, sometimes in families, and in rare instances as a transmissible disease with every conceivable interval of latency. HISTORY AND SIGNS: This report of a 45-year-old female concerns a spongiform encephalopathy which appeared almost 30 years after penetrating keratoplasty. The corneal material came from a 63-year-old donor with Creutzfeldt-Jakob disease; the keratoplasty was performed at a time when the transmissibility of certain diseases was still unknown. CONCLUSION: The risk of transmission of the disease is very low but cannot be ruled out.

Creutzfeldt-Jakob Syndrome↗

[Diabetic somatic polyneuropathy. Pathogenesis, clinical manifestations and therapeutic concepts].

Diabetic polyneuropathy is the most frequent neuropathy in western countries. In Germany, there are 3.5 to 4 million diabetic patients. Diagnosis should rule out other polyneuropathies and assess two out of the five diagnostic criteria: neuropathic symptoms, neuropathic deficits, pathological nerve conduction studies, pathological quantitative sensory testing and pathological quantitative autonomic testing. So far, the pathophysiology of diabetic neuropathy remains to be fully understood. Among the various pathophysiological concepts are the Sorbitol-Myo-Inositol hypothesis attributing Myo-Inositol depletion to the accumulation of Sorbitol and Fructose, the concept of deficiency of essential fatty acids with reduced availability of gamma-linolenic-acid and prostanoids, the pseudohypoxia- and hypoxia-hypothesis attributing endothelial and axonal dysfunction and structural lesions to increased oxidative stress and free radical production. Obviously, the hyperglycemia induced generation of advanced glycation end products (AGEs) also contributes to structural dysfunctions and lesions. Elevated levels of circulating immune complexes and activated T-lymphocytes as well the identification of autoantibodies against vagus nerve or sympathetic ganglia support the concept of an immune mediated neuropathy. The reduction of neurotrophic factors such as nerve growth factor, neurotrophin-3 or insulin-like growth factors also seems to further diabetic neuropathy. The symmetrical, distally pronounced and predominantly sensory neuropathy is far more frequent than the symmetrical neuropathy with predominant motor weakness or the asymmetrical neuropathy. The painless neuropathy manifests with impaired light touch sensation, position sense, vibratory perception and diminished or absent ankle deep tendon reflexes. The painful sensory diabetic neuropathy primarily affects small nerve fibers and accounts for decreased temperature perception and paresthesias. The proximal, diabetic amyotrophy evolves subacutely or acutely, induces motor weakness of the proximal thigh and buttock muscles and is painful. Cranial nerve III-neuropathy is also painful and has an acute onset. Truncal radiculopathy follows the distribution of truncal roots and frequently causes intense pain. Autonomic neuropathy occurs with and without somatic neuropathy. The most important therapy is to attempt optimal blood glucose control, to reduce body weight and hyperlipidemia. Symptomatic therapy includes alpha-lipoic acid treatment, as the antioxidant seems to improve neuropathic symptoms. Aldose reductase inhibitors might reduce sorbitol and fructose production and normalize myo-inositol levels. However, there are no aldose reductase inhibitors available in Europe as yet. Evening primrose oil, containing gamma-linolenic acid, might improve nerve conduction velocities, temperature perception, muscle strength, tendon reflexes and sensory function. Substitution of nerve growth factor showed promising results in pilot studies but failed in a large-scale multicenter study. Symptomatic pain treatment can be achieved with tricyclic antidepressants, selective serotonin reuptake inhibitors, anticonvulsants such as carbamazepine, gabapentin or lamotrigine, or anti-arrhythmic drugs such as mexiletine. Topical capsaicin application should reduce neuropathic pain but also induces local discomfort in the beginning of therapy. Vasoactive substances, so far have not proven to be of major benefit in diabetic neuropathy. Physical therapy and thorough footcare are of primary importance and allow prevention of secondary complications such as foot amputations.

Diabetic Neuropathies↗

[Physiology and methods for studying the baroreceptor reflex].

The baroreflex is of major importance for the moment-to-moment maintenance of arterial pressure particularly during orthostatic stress. Blood pressure increase stimulates the receptors e.g. in the carotid sinuses and the aortic arch, and rapidly increases the receptor discharge rate. Blood pressure decrease induces arrest of impulse transmission to the nucleus of the solitary tract. The impulses are modulated by the nucleus ambiguous, the rostral ventrolateral medulla, the dorsal nucleus of the vagus nerve, parabrachial and paraventricular nuclei and other central structures. Blood pressure increase induces an increase of cardiovagal activity resulting in cardiodeceleration and a decrease of sympathetic peripheral vasoconstrictor outflow. The receptor firing rates show adaptation and resetting to longer lasting blood pressure changes, hysteresis, i.e. firing rates that are higher with rapid blood pressure increase than during the return to baseline pressure. The receptors interact with respiration, chemoreceptor stimulation, central stimuli, exercise and sleep, etc. Baroreceptor function and interaction e.g. with chemoreceptors is compromised in diseases such as diabetic autonomic neuropathy. Guillain-Barré syndrome, arterial hypertension, heart failure and probably in most stroke patients. Fatal complications may result from baroreceptor malfunction. Subtle analysis of the baroreflex is therefore crucial for a refined pathophysiological understanding of these diseases. Pharmacological testing and "neck chamber" negative pressure stimulation of the receptors are as useful as the non-invasive computerized analysis of the interaction of spontaneous blood pressure and heart rate fluctuations.

Aorta, Thoracic↗

[30 years multiple system atrophy concept: retrospect and overview of multiple system atrophy].

Multiple system atrophy represents an enigmatic, clinico-pathologically defined neurodegenerative disease. According to findings of the last three decades, the historically derived, previously used terms olivopontocerebellar atrophy, striatonigral degeneration, and Shy-Drager-syndrome should be avoided in clinical use because of both the clinical and morphological overlap between these syndromes. Complex neurodegenerative syndromes other than multiple system atrophy according to recently developed criteria, should rather be referred to as multiple system degenerations.

Adult↗

[Mechanisms of cerebral autoregulation, assessment and interpretation by means of transcranial doppler sonography].

Cerebrovascular autoregulation assures constancy of cerebral perfusion despite blood pressure changes, as long as mean blood pressure remains in a range between 50-170 mmHg. Static and dynamic myogenic mechanisms dampen sudden blood pressure changes. Neurogenic influences of sympathetic, noradrenergic fibers modulate primarily proximal, large diameter segments of cerebral arteries, but also small 15-20 microns diameter vessels. Parasympathetic, vasodilating impulses are of less influence. Monoaminergic brainstem centers such as the dorsal raphe nucleus, locus coeruleus or nucleus reticularis pontis oralis also influence vessel tone. Metabolic, local parenchymal and endothelial substances have major impact on cerebral vessel tone. Particularly important are nitric oxide, calcitonin gene related peptide, substance P, endothelin, potassium channels and autocoids such as histamine, bradykinin, arachidonic acid, prostanoids, leucotrienes, free radicals or serotonin. The clinical examination of autoregulation is mostly based on brief blood pressure changes induced by drugs such as angiotensin, phenylephrine or sodium nitroprusside, or by challenge maneuvers. Frequently, blood pressure is challenged by a tilt-table maneuver, the "leg-cuff"-method according to Aaslid, or a Valsalva maneuver. The analysis of coherence and phase relation between spontaneous or metronomic breathing modulation of blood pressure and brain perfusion also assesses autoregulatory function. Cerebral blood flow is determined by means of transcranial Doppler sonography, mostly of the proximal segment of the mid-cerebral artery. There is some controversy whether a decrease of cerebral blood flow velocity measured at this segment indicates vasodilatation at the insonated segment or reflects blood flow reduction due to decreased perfusion of down-stream vessel segments. Various clinical and animal studies are presented demonstrating diameter constancy of the insonated mid-cerebral artery segment and thus indicating that slowing of mid cerebral artery blood flow velocity as assessed by transcranial Doppler sonography is due to a decrease of down-stream perfusion. Direct, intraoperative measurements of vessel diameter confirm this conclusion.

Brain↗