CHAPTER LXXXIX 



DISEASES OF THE NERVOUS SYSTEM 



General remarks — Endemic paralytic vertigo — Latah — Banga — Schamanis- 

 mus — Amok — Tropical neurasthenia — Endemic peripheral neuritis — 

 Erythromelalgia tropica — Desert hallucinations — Emotional excitement 

 — Delusions — Auto-suggestion — References. 



GENERAL REMARKS. 



The nerve diseases of the tropics include many general diseases 

 already dealt with— pellagra, leprosy, beri-beri, etc. But 

 apart from these conditions, meningitis, cerehral tumours, cerebral 

 hcBMorrhages , spastic paralysis, alcoholic neuritis, and, more rarely, 

 arsenical neuritis, are all well known. Locomotor ataxia and general 

 paralysis—the so-called parasyphilitic affections — are rare, though 

 syphilis is rampant. The cerebral tumours which we have most 

 commonly met with are endotheliomata and tubercular or syphilitic 

 lesions. Hysteria is common among the better-class natives, 

 especially among the young women educated according to Western 

 ideas. 



As regards insanity, mania and melancholia are the most usual; 

 but dementia, idiocy, and epileptic insanity are not uncommon. 

 According to Spence, the burden of lunacy in Ceylon is light as 

 compared with England, Scotland, or Ireland, and it is possible that 

 this applies not merely to Ceylon, but to other countries. But apart 

 from these diseases, there are some curious nerve or mind affection? 

 which must be considered at greater length. 



Sexual perversions are not uncommonly met with in native races. 



Homicidal tendencies are generally due to alcoholism, or to long 

 brooding over real or fancied injuries. Suicide is not rare, and may 

 be approved by local custom. 



Tropical ' kohler ' has already been mentioned (p. 76), but tropical 

 neurasthenia, endemic vertigo, and other conditions must be briefly 

 touched upon. 



War Zone Neuroses. — The recent war has greatly improved the 

 general knowledge of neurotic conditions. It has been shown that 

 congenital nervous conditions, concussion, chronic alcoholism, and 

 sexual troubles are predisposing causes; while exhaustion due to 

 mental or physical strain, toxaemia, insufficient food, pain, excessive 

 heat, or emotion due to horrors or constant pain, traumatism, particu- 

 larly concussion, are the exciting causes. The neuroses produced 



1981 



