The Diagnosis of Chronic Subdural HæMatoma of Traumatic Origin.

WITHrI recenIt tillle there has been a considerable increase of the literature on chronic sujbduiral hilematoma. The personal observation of sev.eral cases recently withlin the spaee of a year is evidence of its clinical importance and is perhaps sufficient justification for redrawing attention to this not uncommon condition. Examiniatioii of the literature suggests that certain aspects of the synmptomatology are not receiving the recognition they deserve; the cases helrc recor(led are important in that they illustrate those aspects to which it is desired to draw attention. Failure to bear in mind the possibility of the condition may result not only in valuable time being lost before the correct treatment is instituted, but may prove fatal to the patient. No useful purpose is served by distinguishing between the more acute and the more chronic types of subdural hwmatoma. There is, however, a type of case in which severe and sometimes rapidly fatal symptoms of intracranial heemorrhage develop immediately after trauma. Operation or autopsy show%s that the lesion in some of these cases is an acute subdural h,emorrhage. In the author's opiniioIn such cases should iiot be regarded as examples of chronic subdural hxmatoma. There is sometimes a tendeicv to conlfuse these two states; it is felt that case 6 reported by Kaplan is essentially an example of an acute subdural hoemorrhage. In chronic subdural hwmatoma the latent interval which elapses between the occurrence of trauma and the onset of symptoms varies considerably, and in those cases where symptoms develop immediately after trauma the initial lesion is presumablv a small subdural hemorrhage which passes unrecognized as such and gradually develops into a true hoimatoma; in cases where the latent period is long, it seems probable that the slowly leaking blood collects and does not give rise to symptoms until after a definite hematoma is formed. It is proposed in this paper to give a clinical description of the cases observed anid to linmit subsequent discussion to a conisideration of the occurrence of raised intracranial pressure.