Autonomic nervous system

The increased basal sympathetic tone may manifest as tachycardia and alteration of bladder function and bowel motility. Episodes of marked sympathetic overactivity occur, with increased vascular resistance, increased central venous pressure, increased cardiac output, hypertension, pallor, cyanosis of the digits, pyrexia, and sweating. These sympathetic crises are thought to be mediated by loss of spinal inhibition of the adrenal glands. Therefore epidural anesthesia may attenuate or eliminate them.

The role of the parasympathetic nervous system in the pathogenesis of tetanus is uncertain. Episodes of bradycardia, loss of peripheral vascular resistance, low central venous pressure, and a profound fall in blood pressure are seen, and are frequently preterminal. Sudden and repeated cardiac arrests occur, particularly in intravenous drug abusers with tetanus. Most authors have attributed these events to total absence of sympathetic tone, since they do not respond to atropine. However, they may be caused by catecholamine-induced myocardial damage or direct damage to the brainstem. Whatever the mechanism, patients afflicted with the autonomic dysfunction of tetanus are at risk of sudden death (Bleckand BiaMQei...19.9.7.).

Tetanospasmin could theoretically spread to higher neurological centers. The possible clinical consequences of this are uncertain. Clinical syndromes

The incubation period (time from injury to onset of symptoms) varies from 2 to 60 days, as does the period of onset (from first symptom to first spasm). Ninety per cent of cases present within 15 days of infection. The incubation period and the period of onset are of prognostic importance, with shorter times signifying more severe disease. Variations in the site of toxin action result in four clinical syndromes ( Oh..aQd Lip.m§.Q...1996).

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Blood Pressure Health

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    Why incresead basal sympathetic tone cause pallor?
    2 years ago

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