Home About us Contact
|
Home About us Contact | ||
|
|
||
Sympathetic Dysfunction (sympathetic + dysfunction)
Selected AbstractsCardiac autonomic dysinnervation and myocardial blood flow in long-term Type 1 diabetic patientsDIABETIC MEDICINE, Issue 5 2003N. Hattori Abstract Aims The aim of the study was to assess scintigraphically the relationship between myocardial blood flow response and sympathetic dysinnervation in long-term Type 1 diabetic patients. Effects of the iron chelator deferoxamine on myocardial blood flow were studied and they were investigated according to the presence of cardiac sympathetic dysfunction. Methods Myocardial blood flow (MBF) was assessed with N-13 ammonia positron emission tomography in 13 long-term Type 1 diabetic patients and 13 control subjects at rest and in response to sympathetic stimulation (cold pressor test (CPT)). In diabetic patients, the study was repeated after preinfusion with deferoxamine. Furthermore, 123I metaiodobenzylguanidine (MIBG) scintigraphy was applied to assess regional cardiac sympathetic dysinnervation (uptake score 1 = normal, homogeneous uptake , 6 = no uptake). Results In diabetic patients, MBF increased in response to CPT from 78 ± 18 ml/100 g/min to 84 ± 26 ml/100 g (8%, P < 0.001). Control subjects demonstrated an increase from 63 ± 17 ml/100 g to 84 ± 26 ml/100 g (33%, P < 0.001), respectively. Resting MBF was higher in diabetic patients than in control subjects (P < 0.001). In diabetic patients, increase in MBF in response to CPT was significant in regions with a MIBG uptake score of , 3. Regions with a MIBG uptake score of > 3 did not exhibit a significant increase in MBF in response to CPT. After administration of deferoxamine, the increase in MBF in response to CPT was 23% and the magnitude of increase was related to the MIBG uptake score (r = 0.40, P < 0.0001). Conclusions Myocardial blood flow response to sympathetic stimulation is significantly impaired in long-term Type 1 diabetes. After preinfusion with deferoxamine the impairment is partially reversed and a relationship between myocardial blood flow and the extent of cardiac sympathetic dysfunction is observed. Diabet. Med. 20, 375,381 (2003) [source] Migraine: A Chronic Sympathetic Nervous System DisorderHEADACHE, Issue 1 2004Stephen J. Peroutka MD Objective.,To determine the degree of diagnostic and clinical similarity between chronic sympathetic nervous system disorders and migraine. Background.,Migraine is an episodic syndrome consisting of a variety of clinical features that result from dysfunction of the sympathetic nervous system. During headache-free periods, migraineurs have a reduction in sympathetic function compared to nonmigraineurs. Sympathetic nervous system dysfunction is also the major feature of rare neurological disorders such as pure autonomic failure and multiple system atrophy. There are no known reports in the medical literature, however, comparing sympathetic nervous system function in individuals with migraine, pure autonomic failure, and multiple system atrophy. Methods.,A detailed review of the literature was performed to compare the results of a wide variety of diagnostic tests and clinical signs that have been described in these 3 heretofore unrelated disorders. Results.,The data indicate that migraine shares significant diagnostic and clinical features with both pure autonomic failure and multiple system atrophy, yet represents a distinct subtype of chronic sympathetic dysfunction. Migraine is most similar to pure autonomic failure in terms of reduced supine plasma norepinephrine levels, peripheral adrenergic receptor supersensitivity, and clinical symptomatology directly related to sympathetic nervous system dysfunction. The peripheral sympathetic nervous system dysfunction is much more severe in pure autonomic failure than in migraine. Migraine differs from both pure autonomic failure and multiple system atrophy in that migraineurs retain the ability, although suboptimal, to increase plasma norepinephrine levels following physiological stressors. Conclusions.,The major finding of the present study is that migraine is a disorder of chronic sympathetic dysfunction, sharing many diagnostic and clinical characteristics with pure autonomic failure and multiple system atrophy. However, the sympathetic nervous system dysfunction in migraine differs from pure autonomic failure and multiple system atrophy in that occurs in an anatomically intact system. It is proposed that the sympathetic dysfunction in migraine relates to an imbalance of sympathetic co-transmitters. Specifically, it is suggested that a migraine attack is characterized by a relative depletion of sympathetic norepinephrine stores in conjunction with an increase in the release of other sympathetic cotransmitters such as dopamine, prostaglandins, adenosine triphosphate, and adenosine. An enhanced understanding of the sympathetic dysfunction in migraine may help to more effectively diagnose, prevent, and/or treat migraine and other types of headache. [source] Cardiac 123I-MIBG scintigraphy in patients with essential tremorMOVEMENT DISORDERS, Issue 8 2006Phil Hyu Lee MD Abstract In some cases, it is difficult to differentiate essential tremor (ET) from Parkinson's disease (PD), especially in the early stages of the disease. We investigated cardiac sympathetic dysfunction using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in 22 patients with ET, in comparison with early PD and tremor-dominant PD (TDPD). The mean ratio of 123I-MIBG uptake in the region of interest in the heart to that in the mediastinum (H/M ratio) was significantly greater in patients with ET (1.99 ± 0.21) than in those with either TDPD (1.28 ± 0.11) or early PD (1.28 ± 0.17; each P < 0.001). The H/M ratio in all patients with ET was greater than two standard deviations above the range of the ratio in the patients with early PD or TDPD. © 2006 Movement Disorder Society [source] Relation between ictal asystole and cardiac sympathetic dysfunction shown by MIBG-SPECTACTA NEUROLOGICA SCANDINAVICA, Issue 2 2009F. Kerling Objective,,, Tachyarrhythmias are common during epileptic seizures while bradyarrhythmias or asystoles are less frequent. Ictal asystole might be related to epilepsy-induced cardiac sympathetic denervation. Methods,,, To evaluate cardiac post-ganglionic denervation in epilepsy patients with ictal asystoles we assessed I123 -meta-iodobenzylguanidine (MIBG) as a marker of post-ganglionic cardiac norepinephrine-uptake, using single photon emission computed tomography (MIBG-SPECT). Results,,, In five of 844 patients with presurgical video-electroencephalography-monitoring, we recorded ictal asystoles during nine of 37 seizures. Asystole patients underwent cardiologic examination (Holter-electrocardiogram, echocardiogram) and cardiac MIBG-SPECT. We compared cardiac MIBG uptake in the asystole patients to the uptake in 18 temporal lobe epilepsy (TLE) patients without bradyarrhythmias and in 14 controls without cardiac or neurological disease. As the cardiological examinations were unremarkable in all subjects, the heart/mediastinum-MIBG-uptake ratios (H/M-ratios) differed significantly between the three groups (P = 0.004). H/M-ratios were lower in asystole TLE patients (mean ± SD: 1.58 ± 0.3) than in patients without asystole (1.81 ± 0.18; P = 0.037) or controls (1.96 ± 0.16). Conclusions,,, Pronounced reduction in cardiac MIBG uptake of asystole patients indicates post-ganglionic cardiac catecholamine disturbance. Impaired sympathetic cardiac innervation limits adjustment and heart rate modulation, and may increase the risk of asystole and ultimately sudden unexpected death in epilepsy (SUDEP). [source] Inspiration-induced vasoconstrictive responses in dominant versus non-dominant handsCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 2 2005Harvey N. Mayrovitz Summary Single rapid and deep inspirations (inspiratory gasps, IG) result in arteriolar vasoconstriction with concomitant transient decreases in skin blood flow that are most prominent in fingers and toes. Vascular responses (inspiratory gasp responses, IGR) are determined as the maximum percentage reduction in blood flow and have been used to assess sympathetic neurovascular function in several conditions. Previous studies have described various features of the response but there has been no reported systematic investigation of the degree of similarity between IGR obtained on dominant and non-dominant hands. This aspect is important in procedures that may use IGR to evaluate suspected unilateral sympathetic dysfunction of a limb-pair or to test the effectiveness of physiological interventions imposed on a single limb of a pair. Thus, the goal of our study was to compare IGR magnitudes that were simultaneously determined in paired-fingers of dominant and non-dominant hands. In 30 healthy seated subjects, skin blood perfusion via laser-Doppler (SBF) was measured on the dorsum of the middle finger of both hands while subjects performed three sequential IG at 3-min intervals. Analysis of variance for repeated measures revealed no significant difference in IGR between dominant (79·3 ± 11·2%) and non-dominant hands (81·9 ± 11·6%, P = 0·965) with an overall IGR of 80·6 ± 11·4%. These results indicate that hand-dominance is not a factor that is likely to significantly effect IGR differentials determined in paired-limbs. [source] | ||||||||||