Evaluation of autonomic dysfunction in patients with hepatic cirrhosis.

Kandasamy, E (2007) Evaluation of autonomic dysfunction in patients with hepatic cirrhosis. Masters thesis, Madras Medical College, Chennai.


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INTRODUCTION : Cirrhosis of the liver leads to a number of complications, some of which may eventually prove fatal. For more than a century, chronic alcoholics have been known to have peripheral neuropathy. It has been observed that alcoholics with liver damage have higher frequency of neuropathy than those without it. There are reports of association of chronic liver disease with autonomic neuropathy However; conflicting reports have also appeared causing much confusion. Patients with cirrhosis and portal hypertension develop hyper dynamic circulation, with increased blood volume and cardiac output, and with a reduced peripheral vascular resistance. This disorder has been related to portal hypertension–induced arterial vasodilatation in the peripheral and splanchnic beds, but other factors may contribute, such as abnormally high levels of circulating vasodilators and false neurotransmitters. Alterations in the autonomic nervous system’s drive to the heart and circulation may also occur in cirrhosis, as suggested by studies based on cardiovascular tests such as cardiovascular responsiveness to postural changes, exercise, and mental stress. These tests, however, have been criticized for being insensitive to early changes in the autonomic function, especially in the sympathetic nervous system. Recent evidence indicates that the spontaneous, small beat-to-beat fluctuations that are usually observed in the continuous recordings of heart rate and arterial pressure reflect the activity of the efferent arc of the autonomic nervous sys tem that is modulating cardiovascular function. In particular, sympathetic and vagal outflows to the heart and circulation generate two main oscillatory rhythms: (1) a short-term rhythm, present in heart period and arterial pressure variabilities and defined as the low-frequency (LF) component, which is considered a marker of the sympathetic activity; and (2) a long-term rhythm, only occurring in heart period variability, related to respiration, and known as the high frequency (HF) component, which is thought to be a marker of the vagal modulation. These oscillatory components of heart rate and arterial pressure signals can be extracted from the variability signals through spectral analysis techniques. BACK GROUND : The enteric nervous system plays an integral role in the regulation of gut mucosal and motor function. It is organized into two major plexuses. The myenteric plexus lies between the external longitudinal and internal circular muscle layers. The submucosal plexus lies between the circular muscle layer and the mucosa.2 Although the enteric nervous system receives input from the central and autonomic nervous systems, it can function independently. Nerves of the myenteric plexus project fibers primarily to the smooth muscle of the gut, with only a few axons extending to the submucosal plexus. Most of the fibers of the submucosal plexus project into the mucosa and the submucosal and myenteric plexuses. AIM OF THE STUDY : The study was conducted with following specific objectives in mind. 1. To investigate autonomic Dysfunctions in patients with cirrhosis of varied etiology (in both alcoholics and non-alcoholics) 2. To analyze characteristics of patients who develop autonomic dysfunction 3. To determine the relationship between severity of liver damage and extent of autonomic function impairment. CONCLUSION : This study shows that autonomic dysfunction is common in patients with cirrhosis and it was comparable frequency both in alcoholics and non-alcoholics. It increases in severity with increase in extent of liver damage, suggesting that liver damage contributes to the neurological dysfunction.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Autonomic Dysfunction ; Patients ; Hepatic Cirrhosis.
Subjects: MEDICAL > Gastroenterology
Depositing User: Kambaraman B
Date Deposited: 13 Jul 2017 04:04
Last Modified: 13 Jul 2017 04:04
URI: http://repository-tnmgrmu.ac.in/id/eprint/1552

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