1/22. Postural hypotension in idiopathic Parkinson's disease. Etiopathology.Postural changes in blood pressure were recorded in all 391 patients suffering from Parkinson's syndrome over a period of six years. Intraarterial blood pressure studies were carried out in those with significant postural hypotension. Histological examination of the entire central nervous system and the sympathetic ganglia was performed in six patients suffering from idiopathic Parksinson's disease. Five of the six patients had lewy bodies in the sympathetic ganglia. Loss of nerve cells was noted in the sympathetic ganglia in those patients that demonstrated postural hypotension. The severity of the lesions in the ganglia correlated with the severity of postural hypotension in idiopathic Parkinson's disease, One case of shy-drager syndrome was similarly studied to demonstrate the differences in spinal cord and sympathetic ganglia lesions in the two conditions.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
2/22. Autonomic failure and proximal skeletal myopathy in a patient with primary Sjogren syndrome.Autonomic failure and proximal skeletal myopathy are rare features of the Sjogren syndrome (SS). We describe a 51-year-old woman with primary SS who had development of esophageal dysmotility, urinary retention, severe orthostatism, and skeletal myopathy during a 3-month period after the diagnosis of SS. Her symptoms and signs responded well to corticosteroid therapy. Although dysfunction of the peripheral nervous system has a prevalence rate of 20% in patients with SS, most commonly the nerve dysfunction is a sensory deficit, and autonomic neuropathy is less frequent. Autonomic neuropathy due to SS may be underreported. The cause of our patient's myopathy remains undetermined. We speculate that the myopathy was due to either a form of polymyositis or an immune-mediated neuropathy with muscle involvement.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
3/22. Clinico-pathological features of postural hypotension in diabetic autonomic neuropathy.We report the clinico-pathological features and management of a 49-year-old male with a 30-year history of Type 1 diabetes mellitus who had nephropathy (proteinuria 1.81 g/24 h, creatinine 136 micromol/l), proliferative retinopathy and severe somatic and autonomic neuropathy. A sural nerve biopsy demonstrated marked myelinated fibre loss with unmyelinated fibre degeneration and regeneration combined with extensive endoneurial microangiopathy. The management of the patient's blood pressure problems (supine hypertension) and symptomatic postural hypotension is discussed.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
4/22. life-threatening orthostatic hypotension in a case with bulbo-myelo-radiculo-neuropathy.A 59-year-old female developed acute autonomic failure accompanied by life-threatening orthostatic hypotension. Reduced plasma noradrenaline levels and enhanced pressure response to noradrenaline infusion were compatible with a diagnosis of acute pan-dysautonomia. However, nerve conduction tests clearly revealed motor and sensory nerve involvement and abnormal F-responses. A sural nerve biopsy and catecholamine fluorescence study of the rectal mucosa revealed relatively preserved postganglionic unmyelinated nerve fibers. Six weeks later, the patient developed another episode of bulbar palsy and right hemiparesis; the MRI showed lesions in the medulla oblongata and right cervical spinal cord. The prognosis of acute pan-dysautonomia is usually unsatisfactory, but the present patient showed good steroid-responsiveness probably because impaired preganglionic sympathetic myelinated fibers and medulla oblongata recovered quickly.- - - - - - - - - - ranking = 4keywords = nerve (Clic here for more details about this article) |
5/22. Sympathoinhibition and hypotension in carotid sinus hypersensitivity.carotid sinus reflex hypersensitivity is a known cause of syncope in humans. The condition is characterized by cardioinhibition and vasodepression, each to varying degrees. The extent and importance of sympathoinhibition has not been determined in patients with carotid sinus hypersensitivity. This study reports on the extent of sympathoinhibition measured directly directly during carotid massage with and without atrioventricular sequential pacing, in a patient with symptomatic carotid sinus reflex hypersensitivity. Carotid massage elicited asystole, hypotension and complete inhibition of muscle sympathetic nerve activity. Carotid massage during atrioventricular pacing produced similar sympathoinhibition, but with minimal hypotension. Therefore, sympathoinhibition did not contribute importantly to the hypotension during carotid massage in the supine position in this patient. Further investigations are required to elucidate the relation of sympathoinhibition to hypotension in patients with carotid sinus hypersensitivity in the upright position.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
6/22. Chronic hypovolemia associated with accelerated hypertension and orthostatic hypotension in a patient on continuous ambulatory peritoneal dialysis.We report a patient with nondiabetic end-stage renal disease on continuous ambulatory peritoneal dialysis (CAPD) associated with chronic hypovolemia. Despite the administration of nilvadipine, the patient showed accelerated hypertension and concomitantly orthostatic hypotension. plasma renin activity was markedly high, and blockade of angiotensin ii action by captopril or an angiotension II antagonist decreased the supine blood pressure. This indicated that the enhanced activity of the renin-angiotensin system was the principal cause of the supine hypertension. The plasma concentration of norepinephrine was also very high. After correction of hypovolemia by blood transfusion, the enhancement of the renin-angiotensin system and high plasma norepinephrine level were reduced, and symptomatic orthostatic hypotension disappeared. The accelerated hypertension was easily controlled by the administration of low-dose captopril and nilvadipine. These findings suggest that chronic hypovolemia related to the intractable supine hypertension as well as orthostatic hypotension. hypovolemia-induced enhancement of the renin-angiotensin system and sympathetic nerve activity may cause vasoconstrictive hypertension in patients on CAPD.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
7/22. Provoking vasodepressor syncope with head-up tilt-table testing.head-up tilt testing has proven effective in identifying individuals prone to vasodepressor syncope (VDS). VDS refers to the transient loss of consciousness/cerebral anoxia seen with hypotension produced by autonomic imbalance. In this case, the hypotension is the result of parasympathetic domination. Most episodes appear to be triggered by reduced venous return which stimulates the cardiac mechanoreceptors in the inferior-posterior left ventricle. Once activated, these receptors send out afferent signals along the unmyelinated C of the vagus nerve and cause vasodilation. Once venous return is restored, the usual sympathetic compensations (increased heart rate/force of contraction and vasoconstriction) overcome the parasympathetic domination. A tilt-study allows one to passively tilt the patient up to 40-80 degrees and abruptly reduce venous return in a controlled environment. One can then determine which mechanism will dominate--the usual sympathetic vasoconstriction or the parasympathetic reflex (Bezold-Jarisch)--by frequent observations of blood pressure and ECG. bradycardia/ventricular standstill may also occur during parasympathetic domination. Once susceptibility to vasodepressor syncope is identified by a tilt study, medications to expand the blood volume and/or minimize venous pooling are often needed. Other drugs to block the parasympathetic pathway and/or the effects of excessive catecholamine levels may also be ordered. Dual chamber pacing may be required for malignant episodes of bradycardia or ventricular standstill.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
8/22. Idiopathic orthostatic hypotension from failure of noradrenaline release in a patient with vasomotor innervation.A 26 year old man is described with life-long orthostatic hypotension unrelated to autonomic nerve degeneration and apparently due to failure of peripheral noradrenaline realese. Tests of parasympathetic and sympathetic cholinergic nerve function were normal, but sympathetic adrenergic activity was defective. Thus blood pressure regulation was abnoraml. There was no pressor response to tyramine, an indirect sympathomimetic drug, but a marked pressor response to the directly acting sympathomimetic drugs phenylephrine and noradrenaline. On standing there was a progressive fall rather than a rise in circulating noradrenaline concentrations, although adrenaline levels rose normally. The pupils showed diminished responses to ephedrine and cocaine, and a normal response to phenylephrine. fluorescence microscopy of blood bessels showed that they were innervated with adrenergic nerves. His orthostatic hypotenstion responded well to oral phenylephrine (50 mg five times daily) but not to other forms of therapy. It is suggested that this patient's symptoms were due to failure of noradrenaline release even though sympathetic adrenergic nerves were present. We therfore wish to draw attention to a further cause of orthostatic hypotension, failure of peripheral noradrenaline release without autonomic neuropathy.- - - - - - - - - - ranking = 4keywords = nerve (Clic here for more details about this article) |
9/22. Acute autonomic and sensory neuropathy: a case report.A female patient with acute autonomic and sensory neuropathy is described. Urinary disturbance developed rapidly and was followed by orthostatic syncope, absence of lacrimation, salivation and sweating, and sensory impairment. muscle strength had been consistently normal despite diffuse muscular atrophy. Marked decrease in the number of small myelinated and unmyelinated fibres was revealed in biopsied sural nerve. Eighteen months after the onset, her autonomic symptoms have partially improved.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
10/22. Autonomic dysfunction, peripheral neuropathy, and depression.A 15-year-old boy with diarrhea, dizziness, dysesthesias, and depression is described. On admission, his blood pressure was 110/84 reclining but less than 40 systolic while standing. Vibratory sensation and nerve conduction velocities were decreased in his lower extremities. CSF protein concentration was normal but sural nerve biopsy demonstrated generalized demyelination. Extensive toxicologic and metabolic screening proved unremarkable. norepinephrine concentrations in plasma and urine, and CSF concentration of 3-methoxy-4-hydroxy phenylglycol (MHPG) were markedly reduced. The patient demonstrates a combination of autonomic dysfunction, peripheral neuropathy, and affective disorder. This collection of clinical and neurochemical findings represents a previously unreported entity involving a defect of both central and peripheral noradrenergic systems.- - - - - - - - - - ranking = 2keywords = nerve (Clic here for more details about this article) |
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