Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autonomic failure with orthostatic and postprandial hypotension, bowel and bladder disturbances, and sexual dysfunction are frequent, disabling features in patients with the three most prevalent neurodegenerative movement disorders: Parkinson's disease (PD), dementia with Lewy bodies and multiple system atrophy (MSA), and the related neurodegenerative Lewy-body disorder characterized by isolated severe autonomic failure (pure autonomic failure, PAF). All of these disorders have in common the presence of alpha-synuclein in the cytoplasmic precipitates found in neurons in Lewy body disorders or glia in MSA. Autonomic failure with disabling orthostatic hypotension is the clinical hallmark of PAF. It may also be the initial presentation of MSA, making diagnosis difficult. Within a few years, however, MSA patients develop movement disorders, which are differentiated from PD by the paucity of unilateral resting tremor, the lack of response to levodopa, and their rapidly progressive nature, resulting in disability and death in 7 to 8 years. Moderately effective treatment is available for autonomic symptoms, but management of movement disorders remains unsuccessful. Discoveries relevant to physiology and common pathological conditions were initially made in patients with autonomic failure. Meals induce profound hypotension in these patients. Conversely, commonly used nasal decongestants can produce substantial pressor effects. Even 500 mL of water can increase blood pressure by a previously unrecognized sympathetic reflex. Residual sympathetic tone is able to induce sustained supine hypertension in MSA, because it is resolved after ganglionic blockade. These phenomena were not previously recognized because of the buffering capacity of the baroreflex, but were unmasked in autonomic failure patients.
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PMID:Autonomic failure in neurodegenerative disorders. 1508 56

Autonomic dysfunction is common in Lewy body disorders (Parkinson's disease, Dementia with Lewy Bodies, Pure Autonomic Failure, and REM sleep disorder). The loss of post-ganglionic myocardial sympathetic nerve fibers is a prominent feature of autonomic dysfunction in such disorders. (123)I-metaiodobenzylguanidine (MIBG) scintigraphy that visualizes catecholaminergic terminals in vivo is a biomarker used to detect cardiac sympathetic degeneration. Abnormal MIBG uptake has been consistently reported in Lewy body disorders. Some studies agree in the notion that increasing bradykinesia is related with an incremental cardiac sympathetic denervation, whereas tremor is not closely linked to cardiac denervation. "Atypical" parkinsonian syndromes, including Multiple System Atrophy, Progressive Supranuclear Palsy, and others, show modest reductions of cardial MIBG uptake. MIBG scintigraphy is moderately sensitive and specific in differentiating Parkinson's disease from such syndromes. Conversely, its sensitivity and specificity might be better in cognitively impaired patients, helping differential diagnosis between Dementia with Lewy Bodies, and Alzheimer disease. Confounding factors (comorbidities, comedications) should be carefully controlled before analyzing MIBG scintigraphy.
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PMID:123I-metaiodobenzylguanidine scintigraphy in Parkinson's disease and related disorders. 1987 2