In this address I shall discuss head trauma from an angle which may be unusual for neuroscientists. Our preoccupations are diagnostic challenges and management problems, but that which we experience at the bedside is only a narrow segment of a continuum which started with trauma somewhere in a war, on the road, at home, on the football field, in the boxing ring, and in many other distinct locations. When our role is over, there are only three places where head trauma victims can be found; in cemeteries, where every year, 5,000 new graves are made to accommodate fatal head injuries in Canada; in chronic hospitals, which are already overloaded with victims of various insults to the brain, and, of course, within society, which accepts the fully recovered or tolerates the subtle and not so subtle consequences of so-called ‘minor’ head injuries.

Recombinant DNA techniques have provided the means to generate large numbers of new genetic linkage markers. This technology has been used to identify a DNA marker that coinherits with the Huntington’s Disease (HD) gene in family studies. The HD locus has thereby been mapped to human chromosome 4. The discovery of a genetic marker for the inheritance of HD has implications both for patient care and future research. The same approach holds considerable promise for the investigation of other genetic diseases, including Dystonia Musculorum Deformans.

There are a number of different types of involuntary saccadic eye movements which differ from normal saccades in that they take the fovea away from its target. This article presents a classification and description of these abnormal eye movements and indicates how they may be used to increase the precision of neurologic diagnosis.

Fifty-nine patients were treated in a prospective, randomized comparison of pentobarbital and mannitol for the control of intracranial hypertension resulting from head injury. Patients with elevated intracranial pressure (ICP) after evacuation of intracranial hematomas were randomized to one of two treatment groups; mannitol initially or pentobarbital initially, followed by the second drug as required by further elevation of ICP. Similarly, patients with raised ICP but without hematomas requiring evacuation were randomly assigned to two treatment groups in an identical paradigm.

Those with ICP elevation and no hematoma treated with pentobarbital as initial therapy had a 77% mortality compared to a 41% mortality for those with mannitol as initial treatment. Patients with evacuated hematomas had mortalities of 40% and 43% (no significant difference) for pentobarbital and mannitol respectively. In both no-hematoma and hematoma streams pentobarbital was less effective than mannitol for control of raised ICP.

Multivariate statistical analysis indicates that pentobarbital coma is not better than mannitol for the treatment of intracranial hypertension and may be harmful in no-hematoma patients with intracranial hypertension after head injury.

52 recently abstinent chronic alcoholics were given repeated psychological tests and 20 of these had repeated CT scans. The first scan was done within 5 weeks of the last drink. The degree of measurably reversible cerebral atrophy on CT scan correlated negatively with the interval between the last drink and the first CT scan. Significantly more reversibility of cerebral atrophy was noted in those subjects claiming interscan abstinence. There were positive correlations between functional improvement scores on neurological exam and reversible cerebral atrophy measurements. Significant improvement on psychological test performance was restricted to patients tested initially within 3 weeks of the last drink. Both the CT results and the psychological test results suggest that reversible changes occur soon after the cessation of drinking.

The effect of desipramine, imidazole, thioridazine and trifluoperazine on blood-brain barrier(BBB) permeability after a 24 hour cold lesion was studied in rats. Changes in BBB permeability were determined using a quantitative horseradish peroxidase (HRP) assay. The four drugs tested did not alter the quantity of HRP in the cortex of control animals, or in the contralateral cortex of test animals. However, imidazole, desipramine and trifluoperazine significantly reduced the HRP extravasation in and around the cold lesion. Several mechanisms for this effect are suggested; one possible mechanism common to all these drugs is the reduction of increased vesicular transport in cortical vessels adjacent to the cold lesions.

Thirty-three patients with advanced Parkinson’s disease complicated by end of dose deterioration were treated with bromocriptine. The drug was slowly increased so that by treatment week 24 the mean daily dose of bromocriptine was 22mg and levodopa had been decreased by an average of 15 percent. The majority of improvement in daily fluctuations and Parkinsonian disability score was documented by 8 weeks, at which time the mean daily bromocriptine dose was only 12mg.

End of dose deterioration was reduced in 78 percent of the patients (mean 43% improvement). Total Parkinsonian disability score was decreased by 33 percent. Adverse effects were minimal; the most common was mild transient early treatment nausea which occurred in 15 percent of the patients.

The slow introduction of small doses of bromocriptine, combined with minimal levodopa reduction, can give Parkinsonian patients significant improvement in end of dose deterioration.

Free and total valproic acid (VPA) pharmacokinetic evaluation was carried out at steady state in six young epileptics who were also receiving other anticonvulsants. Subjects received their usual morning dose of VPA after an overnight fast. Blood samples for free and total VPA were taken prior to the dose and frequently thereafter for 12 hours. The calculated pharmacokinetic parameters for total VPA and free VPA were: half-lives of 7.5 ± 1.6 hours and 5.0 ± 1.5 hours, volumes of distribution of 0.189 ± 0.038 l/kg and 1.51 ± 0.98 l/kg, and clearances of 0.30 ± 0.06 and 3.6 ± 2.0 ml/min/kg., respectively. There was a strong correlation between percent free VPA and total VPA (r = 0.81) but marked inter- and intra-subject variations were seen. Studies attempting to correlate VPA levels to clinical response must take such data into account.

Benign and malignant tumors of the choroid plexus in infancy are extremely uncommon. Diagnosis and management of a malignant tumor is described and the literature survey of the problem is presented.

Aneurysmal bone cysts rarely affect the skull. Thirty-six cases including four reported in this paper are reviewed. The condition usually affects children and young adults and progresses rapidly. It may result in raised intracranial or intraorbital pressure. Complete excision of the mass is the treatment of choice, but if not feasible curettage followed by low dose radiotherapy is effective. As the prognosis in this condition is good, prompt diagnosis and early treatment are of utmost importance.

We report a fifty three year old man who presented with progressive visual loss. Investigation disclosed a giant aneurysm with optic nerve compression, which was successfully treated surgically. The patient had typical skin lesions of tuberous sclerosis, but did not suffer from a seizure disorder or mental retardation. In the past he had had an enucleation for glaucoma secondary to a retinal phakoma.

Cerebral aneurysms are discussed in relation to the tuberous sclerosis disease process. After review of the literature, we propose that the aneurysms are secondary to dysplastic change in the vessel walls, this is in keeping with the abnormal tissue proliferations in this disease.

A 24 year old woman with a 15 year history of intractable seizures underwent resection of a small low grade astrocytoma of the right mesial frontal lobe. The tumor arose beneath a benign scalp nevus that had been treated in infancy with radium patches and focal x-irradiation. Neuropathological changes within the tumor were compatible with radiation injury. Meningiomas and sarcomas complicate cranial irradiation but the evidence that gliomas do so is less convincing. Our observations support an association between radiation exposure and the subsequent development of glial tumors.

Measurements of the volume-pressure response (VPR) to determine the relative position of a patient on the graphic volume-pressure curve have been used to derive clinically useful information. One reason that these measurements have not been used more frequently has been the fear of introducing infection into the ventricular system. We have designed an intraventricular catheter that allows repeated VPR measurements and reduces the risk of infection.