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Biomedical subjects

R B Aird

Publications and source records attributed to R B Aird.

At least 19 recordsLinked to original sources
PubMed1988

The importance of seizure-inducing factors in youth.

Of over forty known epileptogenic mechanisms, some eight involve transient conditions, the regulation of which necessarily involves the understanding cooperation of the patient/parents. Tension states, alterations of the wake-sleep cycle, fatigue and sleep deprivation, CNS stimulation by sensory or drug means, and shifts of the water and acid-base balances constitute the bulk of such seizure-inducing factors. The relative lack of CNS homeostatic control, due to immature development of the blood-brain barrier and cerebral maturation, serve to exaggerate these problems in childhood. In a referred group of 150 refractory epileptic children, the seizure-inducing mechanisms were found to be important (50% reduction of seizure incidence) in 20% and to be of "crucial" importance (complete control) in an additional 14%. These results indicate the importance of such mechanisms in selected children with epilepsy, who were only marginally or inadequately controlled by drug therapy. Reviews of the literature have suggested that this more comprehensive approach to the therapeutic management of epilepsy has not been adequately exploited.

Adolescent↗
PubMed1984

A study of intrathecal, cerebrospinal fluid-to-brain exchange.

A cerebrospinal fluid (CSF) to brain exchange has been postulated for lipid-soluble and small molecular substances and has led to nearly 100 attempts per year to produce central effects via intrathecal injections. With few exceptions, however, modern neurological practice has avoided this approach because of its demonstrated ineffectiveness and dangers. The practicability of an intrathecal CSF to brain exchange was tested by cisternal infusions of mock CSF at different infusion pressures that might counteract central nervous system intoxications of systemic origin. Those efforts failed in different test situations with each of three barbiturates. Steady state doses at a selected level of barbiturate anesthesia were the same, whether induced by cisternal infusion or intravenously, and this was true for barbiturates of widely different lipid solubility. The cerebral response to pentylenetetrazol was delayed well beyond its rate of response when introduced intravenously. These results suggested that the bulk clearance rate and venous resorption of CSF were sufficient to prevent significant diffusion of the barbiturate or even mock CSF into the brain following intrathecal injection. Because central effects that follow venous resorption may be confused with direct central effects, many previous clinical reports are questioned. Apparent exceptions to the ineffectiveness of intrathecal therapy, such as spinal anesthesia, were discussed in terms of their special local effects. The relative effectiveness of intrathecal agents should be evaluated by comparing maintenance doses for a given central effect, when produced by both intrathecal and i.v. routes. Previous reports on rates of intrathecal infusion, intracranial pressure relationships, and the relative safety of such infusions were confirmed and extended.

Anesthesia, General↗
PubMed1983

The importance of seizure-inducing factors in the control of refractory forms of epilepsy.

Of over 40 known epileptogenic mechanisms, some 10 vary from hour to hour, depending upon habit factors and the daily activities of the patients. Tension states, alterations of level of consciousness, sleep deprivation, disturbances of water and acid-base balances, sensory and drug stimulation, and drug withdrawal are the principal factors involved. Their importance varies widely in patients, as well as with time. This fact and the concentration of physicians upon drug therapy have served to deemphasize this aspect of antiepileptic therapy. This point was clearly verified by reviews of the literature. In a prospective study of 500 drug-resistant patients, such seizure-inducing mechanisms were studied. Methods of identification, evaluation, and regulation were developed. The results indicate that in selected patients the regulation of such factors may play a significant role in the stabilization and improvement of the underlying epileptic condition. In 17% of a refractory group, such factors were found to be of crucial importance. In spite of intensive efforts with drug therapy over the past 4 decades, the incidence of drug-resistant cases remains high. The more comprehensive approach suggested offers an attractive, partial solution to this difficult problem.

Acid-Base Imbalance↗