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Biomedical subjects

M Dütsch

Publications and source records attributed to M Dütsch.

10 recordsLinked to original sources
PubMed2003

Impaired cardiovagal and vasomotor responses to baroreceptor stimulation in type II diabetes mellitus.

BACKGROUND: In diabetic patients, impairment of the cardiovagal limb of the baroreflex has been well established. However, the role of sympathetic mediated baroreflex vasomotor control of the blood vessels is not well defined. We therefore assessed the vasomotor responses to sinusoidal baroreceptor stimulation in diabetic patients. MATERIALS AND METHODS: We studied 14 type II diabetic patients (age; 57 +/- 7 years) and 18 healthy controls (age; 59 +/- 11 years). Oscillatory neck suction was applied at 0.1 Hz to assess the sympathetic modulation of the heart and blood vessels, and at 0.2 Hz to assess the effect of parasympathetic stimulation on the heart. Breathing was paced at 0.25 Hz. Spectral analysis was used to evaluate the oscillatory responses of RR-interval and blood pressure. RESULTS: The diabetic patients showed a significantly lower RR-interval response (P < 0.05) to the 0.1 Hz neck suction (2.52 +/- 0.50-3.62 +/- 0.54 ln ms2) than the controls (4.23 +/- 0.31-6.74 +/- 0.36 ln ms2). The increase in power of 0.1 Hz systolic blood pressure oscillations during 0.1 Hz suction was also significantly smaller (P < 0.05) in the diabetics (1.17 +/- 0.44-1.69 +/- 0.44 mmHg2) than in the controls (1.60 +/- 0.29 mmHg2-5.87 +/- 1.25 mmHg2). The magnitude of the peak of the 0.2 Hz oscillation in the RR-interval in response to 0.2 Hz neck stimulation was significantly greater (P < 0.05) in the controls (3.42 +/- 0.46 ln ms2) than in the diabetics (1.58 +/- 0.44 ln ms2). CONCLUSION: In addition to cardiovagal dysfunction, baroreflex-mediated sympathetic modulation of the blood vessels is impaired in type II diabetic patients.

Aged↗
PubMed2002

Sympathetic and parasympathetic pupillary dysfunction in familial dysautonomia.

Objective assessment of autonomic dysfunction in familial dysautonomia (FD) is largely based on the analysis of cardiovascular responses to challenge maneuvers such as orthostatic stress. Infrared pupillometry (IPM) provides an additional reliable method for cranial autonomic evaluation and has the advantage of requiring minimal cooperation.This study was performed to determine whether IPM contributes to the assessment of autonomic function in FD patients. In 14 FD patients and 14 healthy controls, we studied absolute and relative light reflex amplitude, pupillary constriction velocity (v(constr)), pupillary diameter, early and late pupillary re-dilatation velocity (v(dil 1), v(dil 2)) after dark adaptation. Prior to IPM, all patients had an ophthamological examination to evaluate refraction and corneal integrity. In comparison to controls, patients had a significant reduction of the parameters reflecting parasympathetic pupillary function (absolute light reflex amplitude 1.34 +/- 0.21 vs. l.86 +/- 0.14 mm, relative light reflex amplitude 22.74 +/- 7.11% vs. 30.76 +/- 3.57%, v(constr) 3.75 +/- 1.09 vs. 5.80 +/- 0.59 mm/s) and of the parameters reflecting sympathetic pupillary function (diameter 5.69 +/- 0.66 vs. 6.35 +/- 0.60 mm, v(dil 1) 1.29 +/- 0.23 vs. 1.95 +/- 0.23 mm/s, v(dil 2) 0.64 +/- 0.13 vs. 0.72 +/- 0.l2 mm/s; Mann-Whitney U-test: p<0.05). The non-invasive technique of IPM demonstrates dysfunction not only of the cranial parasympathetic, but also of the cranial sympathetic nervous system and, thus, further characterizes autonomic dysfunction in FD.

Adolescent↗
PubMed2002

Decrease of sympathetic cardiovascular modulation after temporal lobe epilepsy surgery.

In temporal lobe epilepsy (TLE), there is evidence of ictal and interictal autonomic dysregulation, predominantly with sympathetic overactivity. The effects of TLE surgery on autonomic cardiovascular control and on baroreflex sensitivity (BRS) have not been studied. To evaluate such effects, we monitored heart rate (HR), systolic blood pressure (BP(sys)) and respiration in 18 TLE patients 3-4 months before and after TLE surgery. We used Blackman-Tukey spectral analysis to assess sympathetic and parasympathetic modulation as powers of HR and BP(sys) oscillations in the low frequency (LF, 0.04-0.15 Hz) and high frequency (HF, 0.15-0.5 Hz) bands. BRS was determined as the LF transfer function gain between BP and HR. After surgery, HR, BP(sys), respiration and HF powers remained unchanged, while LF powers of HR (1.57 +/- 1.54 bpm(2)) and BP(sys) (2.19 +/- 1.34 mmHg(2)) and BRS (0.68 +/- 0.31 bpm/mmHg) were smaller than pre-surgical LF powers of HR (3.87 +/- 3.26 bpm(2)) and BP(sys) (4.80 +/- 3.84 mmHg(2)) and BRS (1.12 +/- 0.39 bpm/mmHg; P < 0.05). After TLE surgery, there is a reduction of sympathetic cardiovascular modulation and BRS that might result from decreased influences of interictal epileptogenic discharges on brain areas involved in cardiovascular autonomic control. TLE surgery seems to stabilize the cardiovascular control in epilepsy patients by reducing the risk of sympathetically mediated tachyarrhythmias and excessive bradycardiac counter-regulation, both of which might be relevant for the pathophysiology of sudden unexpected death in epilepsy patients (SUDEP). Thus, TLE surgery might contribute to reducing the risk of SUDEP.

Adrenergic Fibers↗
PubMed2002

Small fiber dysfunction predominates in Fabry neuropathy.

Fabry disease is an X-linked recessive disease with a reduction of lysosomal alpha galactosidase A and consecutive storage of glycolipids e.g., in the brain, kidney, skin, and nerve fibers. Cardinal neurologic findings are hypohidrosis, painful episodes, and peripheral neuropathy. So far, the neurophysiological findings regarding the extent of large and small fiber dysfunction are contradictory. This study evaluated large and small nerve fiber function in a homogeneous group of Fabry patients. In 24 of 30 Fabry patients with creatinine below 194.7 mmol/L the authors assessed median, ulnar, and peroneal motor conduction velocity (MCV) and median, ulnar, and sural sensory conduction velocity (SCV) nerve conduction to study the function of thickly myelinated nerve fibers. In addition, the authors studied sympathetic skin responses (SSR) at both hands and feet in 24 patients. To evaluate A beta nerve fiber function, the authors determined vibratory detection thresholds (VDT) at the first toe in 30 patients. Function of A delta and C fibers was assessed by quantitative sensory testing of cold detection threshold (CDT) and heat-pain detection thresholds (HPDT). Nerve conduction studies showed significantly decreased amplitudes of MCVs and SCVs in Fabry patients as compared to controls. However, individual results of MCV and SCV studies were only mildly impaired. SSRs were present in all tested patients but SSR amplitudes were significantly decreased in Fabry patients in comparison to controls. VDT, CDT, and HPDT were significantly elevated in Fabry patients as compared to controls. However, only six patients had pathologic VDT, 19 had increased CDT, and 25 had elevated HPDT at a high level of stimulation. In Fabry patients, small fiber dysfunction is more prominent than large fiber dysfunction, confirming previous findings of sural nerve biopsies. The results suggest a higher vulnerability of small-diameter nerve fibers than of the thickly myelinated fibers.

Adolescent↗
PubMed2001

[Diabetic autonomic neuropathy].

Diabetic autonomic neuropathy is the most frequent autonomic neuropathy in western countries. Diabetic autonomic neuropathy affects almost every organ. Among the most common symptoms are cardiovascular disturbances such as reduced heart rate variability and pathologic orthostatic reaction. The diagnosis of diabetic autonomic neuropathy is mainly based on the analysis of cardiovascular challenge maneuvers. The following article describes epidemiology, clinical findings, diagnosis, pathogenesis, therapeutic options and prognosis in diabetic autonomic neuropathy.

Autonomic Nervous System Diseases↗
PubMed2001

Hemispheric influence on autonomic modulation and baroreflex sensitivity.

Several studies suggest hemispheric lateralization of autonomic cardiovascular control. There is controversy regarding which hemisphere dominates sympathetic or parasympathetic activity. Hemispheric influences on baroreflex sensitivity (BRS) have not yet been evaluated. To determine hemispheric autonomic control in epilepsy patients, we assessed cardiovascular and baroreflex modulation before and during hemispheric inactivation. For 15 patients with drug-refractory epilepsy, we analyzed autonomic heart rate (HR) and blood pressure (BP) modulation and BRS before and during left and right intracarotid amobarbital procedure (IAP). After Blackman-Tukey spectral analysis, we calculated the low-frequency (LF: 0.04-0.15 Hz) and high-frequency (HF: 0.15-0.5 Hz) power of HR and BP as well as BRS as the LF transfer function gain between BP and HR. Right hemispheric inactivation induced a significant decrease of BP and an increase of HF power of HR and BP (p < 0.05). Left inactivation increased HR, BP, and LF power of both signals and decreased BRS by nearly 30% (p < 0.05). The results confirm previous IAP studies showing sympathetic lateralization in the right hemisphere and, moreover, demonstrate parasympathetic predominance and up-regulation of BRS in the left hemisphere. In epilepsy patients, unilateral electrical activity might derange autonomic balance between both hemispheres and contribute to cardiovascular dysregulation and sudden fatalities.

Adult↗
PubMed1999

[Epilepsy and autonomic diseases].

This review article focuses on the functional anatomy of the central autonomic nervous system and the autonomic symptoms and dysfunctions occurring with epileptogenic activity involving areas of the central autonomic nervous system. Clinical experiences have demonstrated a close relation between epileptic and central autonomic activity. Autonomic symptoms are frequent signs of epileptic seizures and may cause dysfunctions in almost every organ system. Cardiorespiratory dysfunction has been described interictually. The increased frequency of sudden unexplained death in epilepsy patients may be related to disturbances in cardiac autonomic control. In contrast, electrical vagal stimulation reduces epileptogenic activity by influencing the central autonomic nervous system.

Animals↗
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

Vagal and spinal afferent innervation of the rat esophagus: a combined retrograde tracing and immunocytochemical study with special emphasis on calcium-binding proteins.

Vagal afferent neurons contain a variety of neurochemical markers and neuroactive substances, most of which are present also in dorsal root ganglion cells. To test for the suitability of the calcium-binding protein calretinin as a specific marker for vagal afferent fibers in the periphery, immunocytochemistry for this protein was combined with retrograde tracing. Nerve fibers in the rat esophagus, as well as vagal and spinal sensory neurons innervating the esophagus, were investigated for co-localization of calretinin with calbindin, calcitonin gene-related peptide, and NADPH diaphorase. The results indicated that calretinin immunocytochemistry demonstrates neuronal structures known as vagal afferent from other studies, in particular intraganglionic laminar endings. A few enteric neurons whose distribution was unrelated to intraganglionic laminar endings also stained for calretinin. Strikingly, calretinin immunoreactivity was absent from spinal afferent neurons innervating the rat esophagus. In intraganglionic laminar endings and nodose ganglion cells calretinin was highly co-localized with calbindin but not with calcitonin gene-related peptide. On the other hand, calbindin was also found in spinal afferents to the esophagus where it was co-localized with calcitonin gene-related peptide. Vagal afferent neurons innervating the esophagus were never positive for NADPH diaphorase. Thus, calretinin appears to be a more specific marker for vagal afferent structures in the esophagus than calbindin, which is expressed by both vagal and spinal sensory neurons. Calretinin immunocytochemistry may be utilized as a valuable tool for investigations of subpopulations of vagal afferents in certain viscera.

Animals↗