DISEASES OF THE BRAIN. 



with greater certainty that the case is not one of cerebral but of me- 

 ningeal haemorrhage. 



Haematoma of the dura mater often runs its course with symptoms 

 from which the disease cannot be certainly diagnosed, and when it 

 occurs in the course of mental affections, as so often happens, we can- 

 not usually make even a probable diagnosis. In other cases, the fol- 

 lowing factors, to which Griesinger has called attention, enable us, 

 with more or less assurance, to make a diagnosis of haematoma of the 

 dura mater ; if circumscribed headaches, gradually increasing to great 

 severity, in the vicinity of the vertex and forehead be the first, and, for 

 a long time, the only trouble of which the patients complain ; and if, 

 between the appearance of these pains and that of other severe brain- 

 symptoms, there be an interval not so short as in acute diseases of 'the 

 brain and its membranes, but shorter than in most chronic diseases of 

 these parts, particularly in the different cerebral tumors, the first sus- 

 picion falls on inflammation of the meninges, particularly of the dura 

 mater, since inflammation of the other membranes has so great a ten- 

 dency to spread, that it is accompanied by diffuse, not by circumscribed, 

 headache. We are the more justified in this, as the form of pachy- 

 meningitis in question occurs just at the point where the patients com- 

 plain of pain. If the patient had been mentally diseased before the 

 commencement of the headache, or given to drinking excessively, or it 

 he had had an injury of the head, particularly of the forehead, some 

 time previously, there is still more reason for supposing the case one of 

 pachymeningitis, as is evident from the etiology. But we also know 

 that this form of meningitis usually leads to a large effusion of blood, 

 encroaching on the cerebral cavity, and that then the effusion is cap- 

 sulated on one or both sides of the sagittal suture. Hence, if the 

 headaches be subsequently accompanied by the signs of compression 

 of the capillaries of the cerebrum, by mental disturbances, loss of mem- 

 ory, diminished power of thought, increased inclination to sleep, which 

 finally increases to coma, a slowly-developing and usually not pure 

 hemiplegia, after excluding various brain-diseases, we must think of 

 haematoma of the dura mater as being in the first rank of those that 

 may possibly be present. Since, in haematoma of the dura mater, there 

 may be reabsorption of the blood and consequent freedom of the brain 

 Irom the pressure on it, a favorable course of the disease and recovery 

 of the patient speak for haematoma in doubtful cases. If the effusion 

 of blood does not take place gradually, as in the course of the disease 

 above described, but occurs suddenly ; if it is large and limited to one 

 side, the symptoms are those of an abundant haemorrhage in one side 

 of the cerebrum. On superficial examination it may appear remarkable 

 that, even in large haematomata of one side, there is occasionally no 



