Neurosurgery: head injury

The Scientific Board of the California Medical Association presents the following inventory of items of progress in neurosurgery. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, research workers, or scholars to stay abreast of these items of progress in neurosurgery that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another.The items of progress listed below were selected by the Advisory Panel to the Section on Neurosurgery of the California Medical Association and the summaries were prepared under its direction.     

Epidemiology of head injury.

To find the incidence of the various types of head injury that occur in the community separate yearly rates (per 10(5) population in Scotland) for deaths, admissions to hospital, and attendance at accident and emergency departments were estimated and compared (when possible) with rates in England and Wales and the United States. Hospital admissions provide the best data for comparing incidences in different geographical areas and rates of attendance at accident and emergency departments the most reliable guide to incidences in the community. Admission rates, however, vary with local facilities and policies, and these also determine the proportion of patients referred to regional neurosurgical units. Such epidemiological data must be sought both for planning health care for head injury and for monitoring the effectiveness of services.     

Serious head injury in sport.

Of 1900 head injuries serious enough to be admitted to the neurosurgical unit in Glasgow over a five year period, 52 (2.7%) were due to "sport." Golf, horse-riding, and Association football were the sports most commonly linked with serious head injury. Golfing injuries were all compound depressed fractures, and all these patients made a good recovery; horse-riding produced more severe injuries, three of the eight patients being left with residual disability. Much attention has been directed to preventing repeated minor head injury in boxing, but this study emphasises the need for preventing both the primary head injury and secondary complications associated with other sports.     

Long-term outcome after severe head injury.

From a consecutive series of 7000 patients with head injuries admitted to the regional accident service, Radcliffe Infirmary, Oxford between 10 and 24 years earlier, every patient was taken who had been amnesic or unconscious for one week or longer. Of these 479 patients, all but ten were traced, and either the cause of death was established or the survivors examined. Ten years after injury 4% were totally disabled, and 14% severely disabled to a degree precluding normal occupational or social life. Of the remainder, 49% had recovered, and the rest were dead. Additionally, a selected series of 64 patients whose unconsciousness had been prolonged for a month or more were studied. Forty of these had survived between three and 25 years after injury and were re-examined. On the basis of age at injury, the worst state of neurological responsiveness, and the duration of posttraumatic amnesia, the outcome of head injury can be predicted reliably in most cases. Patients and relatives need more reassurance and simple psychotherapeutic support, especially in the first few months after injury. Extrapolation from our figures suggests that each year in England and Wales 210 patients survive totally disabled and another 1500 are severely disabled.     

Patients who reattend after head injury: a high risk group.

OBJECTIVE--To assess risk factors for important neurosurgical effects in patients who reattend after head injury. DESIGN--Retrospective study. SUBJECTS--606 patients who reattended a trauma unit after minor head injury. MAIN OUTCOME MEASURES--Intracranial abnormality detected on computed tomography or the need for neurosurgical intervention. RESULTS--Five patients died: two from unrelated causes and three from raised intracranial pressure. On multiple regression analysis the only significant predictor for both abnormality on computed tomography (14.4% of reattenders) and the need for operation (5% of reattenders) was vault fracture seen on the skull radiograph (P < 10(-6)); predictors for abnormal computed tomogram were a Glasgow coma scale score < 15 at either first or second attendance (P < 0.0001) and convulsion at second attendance (P < 0.05); predictive for operation only was penetrating injury of the skull (P < 10(-6)). On contingency table analysis these associations were confirmed. In addition significant associations with both abnormality on computed tomography and operation were focal neurological abnormality, weakness, or speech disturbance. Amnesia or loss of consciousness at the time of initial injury, personality change, and seizures were significantly associated only with abnormality on computed tomography. Headache, dizziness, nausea, and vomiting were common in reattenders but were found to have no independent significance. CONCLUSIONS--All patients who reattend after head injury should undergo computed tomography as at least 14% of scans can be expected to yield positive results. Where this facility is not available patients with predictors for operation should be urgently referred for neurosurgical opinion. Other patients can be readmitted and need referral only if symptoms persist despite symptomatic treatment or there is neurological deterioration while under observation. These patients are a high risk group and should be treated seriously.     

Severe hypotension after first dose of enalapril in heart failure.

The new, long acting converting enzyme inhibitor enalapril was given to 26 patients with moderate to severe heart failure. In 23 cases the mean systolic blood pressure fell from 120 (SD 22) to 108 (25) mm Hg without adverse effects. Profound hypotension with severe bradycardia and sweating, however, occurred in three patients, most pronounced two to four hours after the first dose. The haemodynamic and biochemical changes in these patients were similar to those seen in patients with severe symptomatic hypotension after the first dose of the converting enzyme inhibitor captopril, except that with enalapril the changes occurred later and were longer lasting. Evidence of myocardial damage and reversible renal failure was seen in one patient, and acute reversible deterioration in renal function occurred in one other. In patients with heart failure converting enzyme inhibitors should be administered initially under strict medical supervision with appropriate facilities available for dealing with occasional profound hypotension.     

Synaptic plasticity: rush hour traffic in the AMPA lanes.

Recent experiments indicate that modification of synaptic strength may involve rapid regulation of vesicular traffic on the postsynaptic side of the synapse. The specific vesicular trafficking route taken by postsynaptic receptors appears to depend on the stimulus.