Head injuries, he asserts, have been treated in ‘a much more rational manner’ in the previous 15 years as a result of discoveries and ‘valuable publications’ over that period. He describes the rationale for his treatment and how this changed over time as his knowledge and understanding of the problems progressively increased. He gives ‘a historical view of the gradual progress of the improvements made by others as well as by myself.’
His first patient, a five-year-old boy, sustained a depressed frontal fracture associated with an epidural haematoma (EDH). When the fracture was elevated and the haematoma drained by trepanning the skull, the boy ‘immediately recovered his senses’ but after some days the ‘stupor’ returned, indicating that some matter was lodged under the meninges’. Hill made a cruciate incision in the meninges to drain the haematoma with beneficial effect. Ganz regarded this as the first ever description of a lucid interval associated with a subdural haematoma. This case also demonstrates Hills understanding of the clinical features of cerebral compression: ‘The smallest compression brought on a stupor, a low intermittent pulse, nausea, vomiting and sometimes convulsive twitches.’ From case 3 onwards he avoided dressings which compressed the trepanned area. In case 3 he again relieved the features of cerebral compression by a trepan with drainage of an EDH. In case 5 drainage of a large EDH resulted in restoration of consciousness and resolution of a right sided weakness.
His account of this case also shows that he appreciated the concept that paralysis on one side of the body indicated compression on the opposite side of the brain. This patient, who crucially did not have a fracture, demonstrates Hills appreciation that it was injury to the brain that caused symptoms rather than the fracture itself. Percival Pott (1714–1788) by contrast would only operate if a fracture were present. Hills understanding of concepts of cerebral compression is demonstrated further by his use of the word ‘compression’ and by his recording of cerebral pulsation or tension in all but one of the operations described. Both of his patients who exhibited poor or absent cerebral pulsation had sustained primary cerebral damage and both died. Hill more than any other eighteenth century writer appreciated the importance of cerebral pulsation as an indicator of cerebral health. Further evidence of his understanding of the need to decompress where possible is shown by his use of the technique of relieving pressure by shaving off cerebral hernias caused by raised intracranial pressure, a technique he learned from the writing of Henri Francois Le Dran (1685–1770). Hills outcomes in treating patients with head injury compares favourably with those of his contemporaries with a mortality rate of 25%, much lower than that of le Dran (57%) or Percival Pott (51%). This was the result of Hills appreciation of the concept of cerebral compression and his better understanding of the indication for and location of the trephine.