Neuronal pathology in experimental local tetanus. Clinical implications

Tetanus: pathophysiology, management, and prophylaxis

As tetanus has become a rare disease in the developed world, physicians have become less comfortable with its diagnosis and management. The extent of adequate antitetanus immunity in the adult population, especially the elderly, is waning, in great measure because primary care physicians have not made prophylaxis a priority in their routine encounters with patients. Furthermore, as the population of immunocompromised hosts grows, an increasing percentage of our patients may not respond to standard active immunization routines. Unless these trends are reversed, we face a substantial increase in the incidence of this dread disorder. Tetanus is also of interest as a relatively simple model of disordered motor control that can instruct us in the management of the many more common causes of neurogenic muscular rigidity. The toxin produced by Clostridium tetani finds increasing use in laboratories investigating brain function as well. Clinical tetanus is divided into four symptomatic types: generalized tetanus, local tetanus, cephalic tetanus, and neonatal tetanus. This monograph discusses the diagnostic aspects of each type of tetanus, its pathophysiology, diagnosis, differential diagnosis, and treatment. Preventing tetanus should be a high priority for all primary care physicians. Active immunization with tetanus toxoid is remarkably effective and safe. Passive immunization with human tetanus immune globulin is indicated in certain circumstances, which are discussed below.

Outcome and neurological sequelae of patients after tetanus

From 1969-1985, 106 people contracted tetanus in Finland. The outcome of the disease was good in 78 cases (returned to work), poor in 27 (12 died, 5 institutionalized and 10 retired) and unknown in 1. Poor outcome was the result of a disease requiring respirator treatment. Other clinical factors significantly correlated with poor outcome were blood pressure lability, hyperglycemia, hyperthermia, tachycardia and anticoagulation therapy. Forty people who were representative of the whole series with regard to sex, age and severity of disease attended a follow-up study on average 7 years and 4 months later. Forty age- and sex-matched controls had the same examinations, and compared with them, the 40 patients still had significantly more muscle fatigue and cramps, nervousness, decreased mental capacity and difficulties in balance, speech and memory. They also had more clinical findings, such as peripheral paresis, muscular atrophy, decreased or absent tendon reflexes and decreased mental capacity than the controls.

Cephalic tetanus in an immunized patient. Clinical and electromyographic findings

A case of cephalic tetanus that occurred in a fully immunized patient is described. An 18-year-old man presented with bilateral facial spasms, without trismus or more generalized involvement, followed by facial weakness. The difficulties in clinical diagnosis and the contribution of electrophysiological studies to the management of such patients are highlighted. The variable level of protection that is conferred by immunization is discussed.

Intraaxonal and extraaxonal transport of 125I-tetanus toxin in early local tetanus

The distribution of radioactivity in the sciatic nerve, the spinal ganglia, the ventral roots and the spinal cord was studied by means of histoautoradiography after injection of 125I-labelled tetanus toxin into gastrocnemius muscles of cats. In the sciatic nerve the major part of the radioactivity was found in the epineurium, but some axons also contained radioactivity. In the ventral root the radioactivity was strictly confined to a few axons; no radioactivity was found in other parts of the ventral root. In the spinal cord the radioactivity was confined to a few motoneurones where it was found in the soma as well as in the dendrites. Transient cooling of the ventral roots prevented the ascent of radioactivity into the spinal cord. Colchicine and vinblastine, after local application to the sciatic nerve, reduced the amount of radioactivity found in the ventral roots and in the spinal cord. However, the same effect was also obtained but to a lesser degree with lumicolchicine. It is concluded that the intraaxonal compartment is involved in the neural ascent of tetanus toxin into the spinal cord.