400 THE BIOCHEMISTRY OF B VITAMINS 



that was delivered by a mother with only mild symptoms, however. 30 

 In the Philippines in 1947 about sixty-six per cent of the deaths from 

 beriberi were infants, 18 and it may be that infantile beriberi is commoner 

 in the United States than is generally appreciated. 31, 32 



Thiamine deficiency in the Western world is generally a more subtle 

 affliction, for although outbreaks of beriberi have been known here, it is 

 not common. Generally the result of inadequate thiamine in this case 

 is manifest in one of two ways: by cardiac manifestations 2S or by neuro- 

 logical symptoms. 33-35 The latter type is commonly referred to as nutri- 

 tional polyneuritis, and is a frequent result of chronic alcoholism. Similar 

 to this form, but frequently of less severity, is an almost general incidence 

 of very mild beriberi in the Orient, and below this in severity is the wide- 

 spread existence of so-called "subclinical" thiamine deficiency, 6 which, as 

 medical experience progresses, becomes more and more clearly defined and 

 less and less "sub"-clinical. The epidemic dropsy seen in India and Africa 

 may well be an atypical form of beriberi. 36 Another frequently referred 

 to but relatively rare form of thiamine deficiency is the encephalopathy 

 of Wernicke, or Wernicke's disease. 37 Naturally occurring thiamine 

 deficiency in vertebrates other than man is apparently rare, the "Chastek" 

 paralysis of foxes (p. 292) being perhaps the best known example. In 

 general, the symptoms of thiamine deficiency in most animals follow 

 closely those in human beriberi. 



Beriberi is generally referred to as acute or chronic, and "wet" or "dry," 

 the latter terminology being dependent upon the presence or absence of 

 severe edema. The symptoms of the disease are conveniently considered 

 in three categories: cardiovascular, neurological, and edematous. It 

 appears that palpitation of the heart and dyspnea (difficult or labored 

 breathing) are among the earliest symptoms ; there is hypertrophy of the 

 heart, and its action is increased. Ellis found that in 125 cases of beriberi 

 that came to autopsy the average heart weight was 379 gm as compared 

 with 255 gm for 204 patients dying from other causes. 38 The pulse be- 

 comes rapid (120-130), and subject to change upon the slightest exertion. 

 Diastolic pressure alone is low. Despite these pronounced changes, there 

 is often little change in the electrocardiogram. Nervous symptoms are 

 both motor and sensory but there is seldom any sensory disturbance 

 apparent that is not located peripherally. The sensory symptoms involve 

 hyperaesthesia (increased sensitivity) commencing in the lower extrem- 

 ities and frequently the finger tips, followed by pain and frequently 

 cramps. In severe cases other areas of the body may be involved, but the 

 motor disturbances are generally limited to the lower extremities. 



It is of interest that the sensory disturbances do not reflect the distri- 

 bution of particular nerves, and that both motor and sensory symptoms 



