414 TETANUS 



a horse. The best method of standardization is that of Roux, who 

 determines the amount of serum necessary to protect a guinea-pig 

 weighing 500 grammes against ten lethal doses of toxin. The result 

 is expressed in terms of the weight of guinea-pig protected against 

 one lethal dose of antitoxin by i c.c. of serum e.g., if ^ c.c. pro- 

 tected a guinea-pig weighing 500 grammes against ten lethal doses, 

 the potency would be 50,000. A potency of 1,000,000 is the least 

 that should be employed. 



The use of tetanus antitoxin in the developed disease is less 

 satisfactory, a fact readily explicable now that the pathology of 

 the disease is more fully understood. In acute tetanus it is 

 practically worthless, though a few cures have been reported. In 

 many cases of chronic tetanus it is without action ; in a few, 

 however, it is decidedly beneficial, each injection greatly alle- 

 viating the patient's suffering. It is always worthy of trial, but 

 it is hardly necessary to say that the non-specific treatment 

 should not be neglected. If the patient has a sufficient degree of 

 immunity to resist the toxin which has already gained access to 

 his nervous system, the antitoxin will be of value in preventing any 

 more from doing so, inasmuch as it will neutralize it as soon as it 

 is formed. 



The doses should be large 20 c.c. or more at first, and 10 c.c. 

 every day, or every alternate day, subsequently. The site of 

 inoculation is of some importance. The injections may be given 

 subcutaneously in a distant region, as in the use of diphtheria 

 antitoxin; but, in view of the fact that it takes an appreciable 

 time for it to be absorbed and time is of the utmost value if the 

 remedy is to be of any use it seems advisable to give the first 

 dose either in the region of the wound or intravenously. 



Various methods have been proposed by which the antitoxin 

 can be brought into closer relation with the nerve elements. 

 The intracerebral injection has most to recommend it on theoretical 

 grounds, and several very decided successes have been recorded 

 in severe cases of the disease. The method is as follows : A 

 small flap of the scalp (with its base downwards) is reflected so 

 as to expose the skull a little to one side of the middle line, and 

 just in front of the fronto- parietal suture. A small trephine hole 

 is made through the skull, and an exploring needle is inserted 

 until the lateral ventricle is reached, and cerebro-spinal fluid 

 escapes through the needle. Ten c.c. or more of the serum are in- 

 jected. This passes down the ventricular system, and bathes the 



