The involvement of the sympathetic nervous system in tetanus

Besides the characteristic disturbances of the motor nervous system symptoms indicating an overactivity of the sympathetic nervous system can complicate the course of severe cases of tetanus. These symptoms include fluctuating tachycardia and hypertension, electrocardiographic changes, sweating, constipation with development of paralytic ileus and metabolic disorders. These symptoms are comparable to these developing in patients with phaeochromocytoma. Elevated catecholamine levels in plasma and urine have been found in several patients with tetanus who developed these symptoms. The prolonged over-activity of the sympathetic nervous system is thought to contribute to the still considerably high mortality rate. Myocardial lesions observed at necropsy are comparable to those found in patients dying of phaeochromocytoma. These lesions are suggested to be associated with sudden death from arrhythmias or cardiac failure in patients with tetanus. For the protection of the organism against the overactivity of the sympathetic nervous system a treatment using the combination of beta-adrenergic receptor blocking agents and adrenergic neuron blocking agents has been introduced. A reduction of the mortality rate was achievable by this treatment. Experimental evidence is accumulating that the tetanus toxin affects not only the motor, but also the sympathetic and sensory neurons.