A FAMILY WITH HEREDITARY 

 (GENOTYPICAL) TREMOR 



BY EMANUEL BERGMAN 



FROM THE MEDICAL DEPARTMENT OK THE UNIVERSITY HOSPITAL OF UPPSALA 

 (ACTING PRINCIPAL PHYSICIAN PROFESSOR G. BERGMARK) 



BY hereditary or genotypical tremor we mean a disease which 

 arises by way of hereditary transmission and of which the only 

 or chief symptom is tremor. This affection is rare, at least it is 

 said to be so in the literature of the subject. But as these cases 

 seldom need a doctor's care or treatment in a hospital, it may be 

 that hereditary tremor is of no such rare occurrence as is generally 

 supposed. In the literature I have found mentioned some fifty 

 instances of families with hereditary tremor. The first cases were 

 made known by Most in 1836, but satisfactory accounts of such 

 cases are not to be found before the eighties of the last century. 

 Little attention has been paid to the question concerning the laws 

 of hereditary transmission of the disease. 



Before proceeding to give an account of the occurrence of the 

 disease in a Swedish family I shall try to give a brief description 

 of the disease itself. 



In addition to heredity certain etiological importance has been 

 claimed for alcohol by some authors. Other investigators point out 

 that not misuse of alcohol has been met with, or at least, that it 

 has not unfavourably influenced the members of the family affected 

 with hereditary tremor. 



Also other chronic intoxications, as those caused by coffee, nico- 

 tine, lead or mercury, seem to be of no importance, nor would it appear 

 as if serious illnesses or psychic and somatic trauma play any parf 

 in the development of the disease. 



In some families with hereditary tremor nervous and mental 

 diseases have been of remarkably frequent occurrence. In most cases, 

 however, there are no marked signs of tlegeneration within the fam- 

 ilies affected. 



The cause of hereditary tremor is unknown. Like other forms of 

 tremor it consists in small, rapid, involuntary and rhythmic contractions 



