Speech-language pathology and dysphagia: A brief historical perspective

In the past decade, speech-language pathologists have taken a leading role in the management of services for patients with oropharyngeal dysphagia. This article presents the historical perspective of this role, the rationale for assuming the responsibility, and suggests directions for continued involvement.     

Magnetic Resonance Imaging of Corticobasal Degeneration

Corticobasal degeneration (CBD) is an adult–onset, progressive parkinsonian syndrome with strikingly asymmetrical features, and signs and symptoms referable to both cerebral cortex and basal ganglia. Although once considered rare, it is now recognized with increasing frequency during life. Eight patients with clinically diagnosed CBD and 8 age– and sex–matched patients with Parkinson's disease underwent high–field–strength magnetic resonance imaging (MRI) of the brain. MRIs were graded by a blinded neuroradiologist using a semiquantitative (0–3) scale. MRI of patients with CBD revealed significantly greater T2–weighted signal hypointensity in the putamena and globi pallidi, and ventricular enlargement. When specifically sought, asymmetrical cortical atrophy was identified in 5 of 8 CBD patients. Increased T2–weighted lenticular signal hypointensity, ventricular enlargement, and asymmetrical cortical atrophy are supportive MRI findings of CBD.     

Synaptic modifications accompanying epileptogenesis in vitro: long-term depression of GABA-mediated inhibition

We used an in vitro model similar to kindling to examine the processes underlying epileptogenesis. A 60 Hz train was applied every 5–10 min to the Schaffer collateral pathways in guinea pig hippocampal slices until epileptiform bursting was elicited in the CA3 region. The resultant alterations in both spontaneous and evoked activities were studied using intracellular recordings from CA3 pyramidal cells. An attempt was made to elucidate the synaptic modifications responsible for the conversion to this state of enhanced excitability. Analyses revealed that the emergence of epileptiform discharge was accompanied by a long-term depression of evoked inhibitory conductances. This tetanus-induced reduction of inhibition involved both the early and late phases of the evoked hyperpolarization, suggesting modification of both the GABA_A and GABA_B receptor-mediated events. Previous studies have suggested that NMDA receptor activation plays an important role in the induction of epileptiform activity in this model. Our data, showing that depression of inhibition can be induced in the presence of CNQX, is consistent with this hypothesis. The parallel development of long-term depression of inhibition and epileptiform bursting following tetanic stimulation suggests that plasticity of the inhibitory transmission process is a potential source of vulnerability contributing to epileptogenesis.     

Physiological Causes of Depression in the Elderly

The author outlines some common physiological causes of depression in the elderly, as well as some of the common manifestations of depressive symptoms seen in individuals within this age group.     

Differential effects of kindling and kindled seizures on place learning in the morris water maze

There is some controversy about the role of long-term potentiation (LTP) in spatial learning. The authors have found that triggering generalized kindled seizures with stimulation of the perforant path disrupts spatial learning in the Morris water maze but that kindling per se does not affect spatial learning. It is suggested that abnormal electrical activity induced by high-frequency stimulation of the perforant path may have been responsible for the disruption of spatial learning previously attributed to LTP saturation.     

Interaction between Marihuana and Ethanol: Effects on Psychomotor Performance

This is a report of the results of a placebo-controlled study in which the effects of the interaction between ethanol and marihuana on drug plasma concentrations, subjective ratings of intoxication, heart rate acceleration, and psychomotor performance were investigated. Six healthy, male, paid volunteers, moderate users of ethanol and marihuana, participated in the study. Ethanol (0.42 g/kg, 0.85 g/kg, or placebo) was administered over a 30-min interval. Fifteen minutes later the subjects smoked, in their customary manner, NIDA cigarettes containing 2.4% or 0.0004% (placebo) delta-9-tetrahydrocannabinol (THC). Each subject was tested in a single-blind, latin-square crossover design with the following six conditions: placebo ethanol/placebo marihuana; low dose ethanol/placebo marihuana; high dose ethanol/placebo marihuana; placebo ethanol/marihuana; low dose ethanol/marihuana; and high dose ethanol/marihuana. The variables measured in the study were: (a) subjective rating of ethanol and/or marihuana intoxication; (b) heart rate; (c) accuracy and latency of response in the Simulator Evaluation of Drug Impairment (SEDI) task; (d) blood ethanol concentration by gas chromatography; and (e) plasma concentration of THC by radioimmunoassay. The results indicate that the decrements due to ethanol in performance of skills necessary to drive an automobile were significantly enhanced by marihuana in an additive and perhaps synergistic manner. The administration of ethanol prior to marihuana smoking did not produce significant effects on the subjective rating of "high," heart rate acceleration, or THC plasma concentration.     

Ethanol-induced Changes in Morphology and Strength of Femurs of Rats

Chronic ingestion of ethanol resulted in ultrastructural and mechanical changes in rat femurs. Scanning electron microscopy of the distal end of the femur revealed that the trabeculae of bones from ethanol-fed rats were thinner, more columnar, and more extensive than those from control rats. Three-point bending tests of the rat femurs showed that the maximum force or so-called "strength" required to break the bone was less in ethanol- than in control-fed animals. A significant inverse correlation was observed between the strength required to break the femur and the dose of ethanol calculated on a body weight basis. For the first time our study presents quantitative proof that a relationship exists between bone strength and the consumption of ethanol in rats. The study revealed that ethanol consumption resulted in a weaker femur compared to controls. We suggest that a common mechanism may be responsible for the decreased bone strength of ethanol-fed rats and the increased incidence of fractures in human alcoholics.     

The role of psychiatry in the public mental health delivery system: An introduction

The papers which follow are revised and expanded versions of presentations made at the Conference on Improving Florida's Services for the Mentally Ill: The Role of Psychiatry, held in Tallahassee, Florida on October 7–8, 1986, and organized by the Florida Mental Health Institute, University of South Florida. The conference was sponsored by the Florida Department of Health and Rehabilitative Services through the Committee on Public Psychiatry. The authors and their organizational affiliations are listed below     

Brief report: Does fenfluramine treatment enhance the cognitive and communicative functioning of autistic children?

This project was supported by two separate research grants from the Trust Fund Board, Washington Association for Retarded Citizens to Richard Neel and Truman E. Coggins. The research was also supported by a training grant to the University of Washington entitled Comprehensive Training in Mental Retardation and Other Handicapping Conditions (MCH-000913, Clifford J. Sells, M.D., Principal investigator); and, a training grant to the University of Arizona entitled Doctoral and Post-Doctoral Leadership Training and Clinical Research, Teaching and Administration: Clinical Language Research Center (G008630088, Linda Swisher, Ph.D., principal investigator). We are indeed grateful to the parents of our five subjects for their patience, understanding, and commitment. Finally, we express our appreciation to Arelene Chaussee for her technical expertise and untiring spirit.