Trends in American Board of Psychiatry and Neurology specialties and neurologic subspecialties.

OBJECTIVE: To review the current status and recent trends in the American Board of Psychiatry and Neurology (ABPN) specialties and neurologic subspecialties and discuss the implications of those trends for subspecialty viability. METHODS: Data on numbers of residency and fellowship programs and graduates and ABPN certification candidates and diplomates were drawn from several sources, including ABPN records, Web sites of the Accreditation Council for Graduate Medical Education and the American Medical Association, and the annual medical education issues of the Journal of the American Medical Association. RESULTS: About four-fifths of neurology graduates pursue fellowship training. While most recent neurology and child neurology graduates attempt to become certified by the ABPN, many clinical neurophysiologists elect not to do so. There appears to have been little interest in establishing fellowships in neurodevelopmental disabilities. The pass rate for fellowship graduates is equivalent to that for the "grandfathers" in clinical neurophysiology. Lower percentages of clinical neurophysiologists than specialists participate in maintenance of certification, and maintenance of certification pass rates are high. CONCLUSION: The initial enthusiastic interest in training and certification in some of the ABPN neurologic subspecialties appears to have slowed, and the long-term viability of those subspecialties will depend upon the answers to a number of complicated social, economic, and political questions in the new health care era.

The neurology clerkship core curriculum.

Neurologic symptoms are common in all practice settings, and neurologic diseases comprise a large and increasing proportion of health care expenditures and global disease burden. Consequently, the training of all physicians should prepare them to recognize patients who may have neurologic disease, and to take the initial steps in evaluating and managing those patients. We present a core curriculum outlining the clinical neurology skills and knowledge necessary to achieve that degree of preparation. The curriculum emphasizes general principles and a systematic approach to patients with neurologic symptoms and signs. The ability to perform and interpret the neurologic examination is fundamental to that approach, so the curriculum delineates the essential components of the examination in three different clinical settings. The focus of the curriculum is on symptom-based rather than disease-based learning. The only specific diseases selected for inclusion are conditions that are common or require urgent management. This curriculum has been approved by the national organization of neurology clerkship directors and endorsed by the major national professional organizations of neurologists. It is intended as a template for planning a neurology clerkship and as a benchmark for evaluating existing clerkships. It should be especially helpful to clerkship directors, neurology chairs, deans of medical education, and members of external accreditation groups.

How much neurology should a medical student learn? a position statement of the AAN Undergraduate Education Subcommittee.

Neurologic disease, already common in the United States, will become even more common in the future. But presently, neurology education at the undergraduate level and in primary care residencies is declining and does not adequately train physicians to manage neurologic illness. The authors maintain that this serious problem can be partially addressed by improving the neurology education of all primary care physicians and by allowing students access to neurology specialists. The education of medical students in the basic and clinical neurosciences must be integrated into a seamless curriculum over the four years of medical education. This education experience must be taught through a team approach and must be led by both a clinician and a basic scientist. All medical students must acquire the knowledge, skills, and attitudes necessary to perform an initial evaluation of the patient with a neurologic complaint. Finally, students must understand the role and recognize the importance of the neurologist and know when consultation is needed. This continuum of neurology education must be financially supported by the institution, and course leaders who show excellence in education must be rewarded with compensation and promotion.

Myofibrillar protein synthesis in young and old men.

We tested the hypothesis that healthy older men (> 60 yr old) have a slower rate of myofibrillar protein synthesis than young men (< 35 yr old). Myofibrillar protein synthesis was determined by the in vivo incorporation of L-[1-13C]leucine into myofibrillar proteins obtained by muscle biopsy. Subjects were eight young (21-31 yr) and eight older (62-81 yr) men, all healthy and moderately active. There was no significant difference in the mean height and weight of the two age groups, but the older group had 12% less lean body mass (determined by 40K counting) and 21% less muscle mass (estimated by urinary creatinine excretion). Upper leg strength was approximately one-third lower in the older subjects according to isokinetic dynamometry. The fractional rate of myofibrillar protein synthesis was 28% slower in the older group (0.039 +/- 0.009 vs. 0.054 +/- 0.010 %/h, mean +/- SD, P < 0.01). Total myofibrillar protein synthesis, estimated as total myofibrillar mass (from creatinine excretion) times the fractional synthesis rate, was 44% slower in the older group (1.4 vs. 2.5 g/h, P < 0.001). Whole body protein synthesis, assessed as the difference between leucine disappearance rate and leucine oxidation, was marginally slower (8%, P = 0.10) in the older group, but not when the data were adjusted for lean body mass. Myofibrillar protein synthesis was a smaller fraction of whole body protein synthesis in the older group (12 vs. 19%). Reduced myofibrillar protein synthesis may be an important mechanism of the muscle atrophy associated with aging.

Effect of testosterone on metabolic rate and body composition in normal men and men with muscular dystrophy.

We have examined the effect of testosterone enanthate injections (3 mg/kg.week, im) on the basal metabolic rate (BMR) estimated by indirect calorimetry and on lean body mass (LBM) estimated by 40K counting in four normal men and nine men with muscular dystrophy. Testosterone treatment increased plasma testosterone levels in all subjects (3-fold mean elevation). BMR increased significantly after 3 months of testosterone treatment (mean, 10%; P less than 0.01; 13% mean increase in the men with muscular dystrophy and 7% mean increase in the normal subjects). BMR remained elevated (mean increase, 9%) after 12 months of testosterone treatment in four men with muscular dystrophy. LBM also was significantly higher after 3 months of treatment (mean, 10%; P less than 0.01) and remained elevated at 12 months. The percent increase in LBM was similar in men with muscular dystrophy (+10%) and normal men (+11%). When BMR was adjusted for the increase in LBM by linear regression, the men with muscular dystrophy had an increase in adjusted BMR after 3 months of testosterone treatment (mean increase, 7%), but not after 12 months. The normal men did not have an increase in adjusted BMR. Testosterone treatment for 12 months slightly reduced body fat, whereas there was an increase in body fat in subjects with muscular dystrophy who were treated with placebo for 12 months. We conclude that there is a significant increase in BMR associated with pharmacological testosterone treatment, which for the most part is explained by the increase in LBM. However, in men with muscular dystrophy, there is a small hypermetabolic effect of testosterone beyond that explained by increased LBM.

Failure of dehydroepiandrosterone to influence energy and protein metabolism in humans.

It was reported recently that 4 weeks of dehydroepiandrosterone (DHEA) treatment [5.55 mmol/day (1600 mg/day), orally] reduced body fat and increased lean body mass in healthy men. The present study was performed to examine whether these effects could be explained by increased energy expenditure and muscle protein synthesis. Eight healthy men were given placebo and DHEA (1600 mg/day) for 4 weeks each in a double blind cross-over study. DHEA treatment caused a 9-fold increase in mean plasma DHEA sulfate concentrations, but had no significant effect on body weight or on two indices of lean body mass (total body water and total body potassium). DHEA had no effect on any of the parameters of energy and protein metabolism, including resting metabolic rate, total energy expenditure (estimated by the 2H2(18)O method during the final 2 weeks of each treatment period), leucine flux (an index of whole body proteolysis), the nonoxidized portion of leucine flux (an index of whole body protein synthesis), and the rate of incorporation of leucine into muscle protein. Circulating levels of cholesterol, T3, and T4 also were unaffected by DHEA. These data suggest that DHEA is not an important regulator of energy or protein metabolism in humans.

Mechanism of muscle wasting in myotonic dystrophy.

Myotonic dystrophy is associated with progressive muscular atrophy. In order to determine the mechanism of muscle wasting in this condition, we measured fractional mixed skeletal muscle protein synthesis in the postabsorptive state in 8 patients with myotonic dystrophy, and compared the results with those of 10 normal subjects. Fractional muscle protein synthesis was determined by measuring the increment of 13C leucine in mixed skeletal muscle protein obtained by needle biopsy from the quadriceps muscle during a primed-continuous infusion of L-(1-13C) leucine. We used plasma 13C alpha-ketoisocaproate (representing intracellular leucine labeling) as the precursor pool for the calculation of fractional muscle protein synthesis and leucine kinetics. Fractional muscle protein synthesis was depressed in the patients with myotonic dystrophy (28% decrease, p less than 0.02). Leucine flux, leucine oxidation, and the nonoxidative portion of leucine flux were not different between the patients with myotonic dystrophy and the normal control subjects. Muscle atrophy in myotonic dystrophy reflects a selective decrease in muscle protein synthesis without any similar decrease in nonmuscle protein synthesis. This decrease may result from an impaired end-organ response to anabolic hormones or substrates.

Neurologic manifestations of pulmonary disease.

Respiratory insufficiency of any cause has significant effects on the nervous system. Headache, mental status changes, papilledema, and numerous motor abnormalities including asterixis are commonly seen. Abnormalities in ventilation and gas exchange result in hypoxia, hypercapnia, and respiratory acidosis, and these, in turn, interfere with cerebral metabolism, increase CBF, and may raise intracranial pressure. Chronic respiratory insufficiency can persist for many months with minimal neurologic symptoms, as numerous compensatory mechanisms, particularly renal, may take effect. Treatment includes restoring adequate ventilation and improving gas exchange and may require tracheal intubation and assisted ventilation. Supplemental oxygen therapy should be carefully monitored, as high rates of flow may suppress the hypoxic drive for respiration and lead to significant carbon dioxide retention. The sleep apnea syndromes are a group of disorders in which abnormal respiratory patterns during sleep result in hypercapnia and hypoxemia. Intermittent obstruction of the upper airway and abnormalities of brainstem respiratory centers cause frequent nocturnal awakenings and apneas in these patients. Treatments vary and include weight loss in obese subjects, respiratory stimulants, tracheostomy, and diaphragmatic pacing. Rapid ascent to high altitudes may result in headache, changes in mental status, papilledema, and other neurologic symptoms in certain individuals: a syndrome known as high-altitude sickness. Hypoxia leading to cerebral edema, nocturnal periodic breathing, and hypobaria produces neurologic symptoms in these individuals. Acetazolamide and dexamethasone may be effective in minimizing symptoms of this disorder. Sustained hyperventilation produces acral and circumoral paresthesias and lightheadedness in anxious individuals and can be maintained by relatively normal ventilatory patterns once established. These symptoms are due to hypophosphatemia and respiratory alkalosis, the latter reducing CBF and causing localized tissue hypoxia. Rebreathing into a paper bag at the first awareness of symptoms is the most effective form of treatment.

Effect of testosterone on muscle mass and muscle protein synthesis.

We have studied the effect of a pharmacological dose of testosterone enanthate (3 mg.kg-1.wk-1 for 12 wk) on muscle mass and total-body potassium and on whole-body and muscle protein synthesis in normal male subjects. Muscle mass estimated by creatinine excretion increased in all nine subjects (20% mean increase, P less than 0.02); total body potassium mass estimated by 40K counting increased in all subjects (12% mean increase, P less than 0.0001). In four subjects, a primed continuous infusion protocol with L-[1-13C]leucine was used to determine whole-body leucine flux and oxidation. Whole-body protein synthesis was estimated from nonoxidative flux. Muscle protein synthesis rate was determined by measuring [13C]leucine incorporation into muscle samples obtained by needle biopsy. Testosterone increased muscle protein synthesis in all subjects (27% mean increase, P less than 0.05). Leucine oxidation decreased slightly (17% mean decrease, P less than 0.01), but whole-body protein synthesis did not change significantly. Muscle morphometry showed no significant increase in muscle fiber diameter. These studies suggest that testosterone increases muscle mass by increasing muscle protein synthesis.

Myotonic dystrophy.

Myotonic dystrophy is an autosomal dominant disorder that results in skeletal muscle weakness and wasting, myotonia, and numerous nonmuscular manifestations including frontal balding, cataracts, gonadal dysfunction, cardiac conduction abnormalities, respiratory insufficiency, and hypersomnolence. Although the gene defect in myotonic dystrophy has been mapped to chromosome 19, the exact metabolic abnormalities responsible for this disorder are unknown. Skeletal muscle has been found to be relatively insulin-resistant in myotonic dystrophy, and a decrease in the anabolic action of insulin on skeletal muscle may be related to muscle wasting in this disorder. Laboratory studies, including electromyography, electrocardiography, and muscle biopsy, are helpful in evaluating patients for this disorder, but the clinical aspects and a careful family history remain the mainstays of diagnosis. A number of management strategies preserve function and prevent complications in myotonic dystrophy.

Levels and causes of stress among residents.

Medical and dental residents at the University of Rochester Medical Center were surveyed to measure stress and its causes. Their stress, as measured by the brief symptom inventory, showed levels slightly above those of an adult comparison group. The average levels of stress decreased with the residents' advancing levels of training. Comparison of the top quartile with the lowest quartile of scores of everyday stress showed significantly elevated stress for rotations in the emergency room, greater frequency of being on call, and lesser amount of sleep. The residents' reports showed that the bleakest three days of residency tended to occur in the first year and during intensive care rotations. Stress during these bleakest times was significantly higher than everyday levels. The residents described the major causes of distress during bleakest times as lack of sleep, inadequate support from senior professionals, large patient load, and competition from peers. "High quality" teaching rounds, a night-float system, and sick leave were felt by the residents to lessen stress. To cope with the stress, the residents reported they talked to others, tried to see humor in the situation, or slept.

Intrathecally administered natural human fibroblast interferon reduces exacerbations of multiple sclerosis. Results of a multicenter, double-blind study.

A randomized, double-blinded, placebo-controlled, two-year multicenter study demonstrated that natural human fibroblast interferon (interferon beta) administered intrathecally (IT) is effective in reducing the exacerbations of exacerbating-remitting multiple sclerosis (MS). The mean reduction in exacerbation rate of 34 patients with MS who received interferon beta administered IT was significantly greater during the study than that of 35 control patients who received placebo. The prestudy exacerbation rates were comparable for both patients who received interferon beta and control patients, but the exacerbation rate of patients receiving interferon beta at the end of the study was significantly lower than that of the control patients. Interferon beta was administered by nine or ten lumbar punctures for the first six months of the study, and observations were continued for two years. In 95% of the recipients, interferon beta therapy was well tolerated, and the side effects experienced were clearly acceptable for the benefits achieved. Low doses of indomethacin dramatically reduced the toxicity of interferon beta therapy and played an important role in successful double blinding. This study confirms a preliminary report on 20 patients that initially suggested that interferon beta administered IT was of benefit in patients with MS. The number of treatments was fewer and the dosage of interferon beta administered was less in the present study than in the preliminary one. It is possible that even fewer treatments with lower doses of interferon beta administered might provide a similar degree of prophylaxis against exacerbations.

Basal metabolic rate in myotonic dystrophy: evidence against hypometabolism.

We studied the basal metabolic rate in 13 males with myotonic dystrophy and 14 normal male subjects. Basal O2 consumption (VO2) and CO2 production (VCO2) were measured by direct gas analysis with a ventilated hood system. Lean body mass was estimated by total body potassium (40K method) and muscle mass by urine creatinine excretion. The basal metabolic rate of patients with myotonic dystrophy was significantly reduced when related to surface area (-9%), but elevated when related to lean body mass (+17%). Previous reports of hypometabolism in myotonic dystrophy did not take into account the amount of muscle wasting in this disorder, and we conclude that in myotonic dystrophy the basal metabolic rate is actually elevated when corrected for lean body mass.