ENTOZOA IN THE NERVOUS' SYSTEM. 197 



associated with the ordinary affections of the brain, 

 ai'e the results of this extensive lesion. The acci- 

 dental complications which supervene after some 

 time, such as sanguineous or serous effusion, soften- 

 ing of the brain, &c., also vary the symptomatic 

 character of the disease. 



Disturbance of the intellect, loss of the mental 

 faculties, and mania or dementia, may mark the 

 presence of hydatids, either from the commencement 

 of the affection, or only towards the period of its 

 termination ; in some cases, however, which have 

 been recorded, the intellect remained perfectly sound. 



The progress of an hydatid tumour, when no new 

 lesion of the brain occurs, is always slow ; and its 

 duration, which cannot be definitely determined, may 

 be for several months, or even for several years. 

 The situation of the tumour must necessarily produce 

 very great differences in the length of time during 

 which the affection lasts, just as it does in the ap- 

 pearance, and in the nature, of the symptoms. 



Generally speaking, the symptoms become gra- 

 dually worse, and the patient dies comatose ; in 

 other cases, cerebral softening, apoplexy, or serous 

 effusion, terminate the malady. Becovery is a rare 

 termination, excepting when an opportunity can be 

 afforded for the removal of the hydatids by tre- 

 phining. 



The invariably small size of the cysticerci, and 

 their frequent multiphcity, produce important diffe- 

 rences in the symptoms to which they give rise, and 

 in the succession and progress of these symptoms, 

 as compared with the corresponding pathological 

 effects which result from the presence of hydatids. 



