Arthur Dick

Correlation of bruits over the carotid artery with angiographically demonstrated lesions.

THE SEARCH CONTINUES for reliable, nontraumatic methods to diagnose possible stenosis of extracranial vessels and to serve as indicators for angiography. It is now common knowledge that the morbidity and mortality of cerebral angiography demand utilization of all clues that may aid in the selection of patients for this procedure. Over the past several years, attention has been paid to a bruit 0; murmur heard over the neck as a possible indicator of carotid artery stenosis or occlusion, and it has been well established that a stenosed vessel will frequently make known its presence by this sign.182 On the other hand, it has long been known that bruits heard over the neck are not infallible indicators of underlying carotid stenosis, one recent study having shown that a large number of adult patients hospitalized for other than cerebrovascular symptomatology showed such a bruit on examination.2 There have been few studies in which careful correlation has been made of bruits heard over the carotid artery with subsequent angiographic visualization of the arteries in the neck. The amount of reliance that can be placed on the carotid bruit is in direct proportion, of course, to the numbers of false-positive and false-negative findings, and this subject has not been frequently or extensively studied. The present study, carried out in a large group of patients subjected to angiography because of symptoms of cerebrovascular insufficiency, is intended to clarify the reliability of the carotid bruit as a sign of carotid stenosis or occlusion.

Creatine monohydrate in ALS: Effects on strength, fatigue, respiratory status and ALSFRS

Our objective was to determine the effect of creatine monohydrate on disease progression in patients with amyotrophic lateral sclerosis (ALS). One hundred and seven patients with the diagnosis of probable or definite ALS, of less than five years duration from symptom onset, were randomized to either treatment with daily creatine monohydrate (5 g/d) or placebo. In this multicenter, double-blinded study we followed changes in disease progression: using quantitative measures of strength via maximal isometric voluntary contraction, forced vital capacity, ALSFRS, quality of life, fatigue and survival. Patients were followed for nine months. The results showed that creatine monohydrate did not significantly improve motor, respiratory or functional capacity in this patient population. The drug was well tolerated and the study groups well balanced, especially considering the absence of forced vital capacity criteria for entrance into the study. There was a trend toward improved survival in patients taking daily creatine monohydrate and this was identical to the trend seen in another recently published report of creatine in ALS patients 1. In conclusion, creatine monohydrate (5 g/d) did not have an obvious benefit on the multiple markers of disease progression measured over nine months. We measured fatigue during isometric contraction and found no significant improvement despite anecdotal patient reports prior to and during the study. The trend toward improved survival was also found in another recently completed blinded trial using creatine monohydrate. Further investigation on the possible survival benefit of creatine in this patient population is ongoing.

Relative validity of clinical techniques for measuring the body composition of persons with amyotrophic lateral sclerosis

Tracking body composition is necessary to understand how amyotrophic lateral sclerosis (ALS) is affecting a patients morphology and to provide a basis for appropriate nutritional advice throughout disease progression. Dual X-ray absorptiometry (DEXA) has been shown to reliably detect body composition changes in persons with ALS. However, this procedure is expensive and available primarily for research. The purpose of this study was to determine the relative validity of two common clinical techniques, anthropometry and bioelectrical impedance analysis (BIA), for measuring the body composition of persons with ALS. Twenty-three persons with ALS volunteered for the study; seven with primarily bulbar symptoms, five with primarily arm weakness, five with primarily leg weakness, and six with significant weakness in all extremities. On a single day subjects underwent body composition analysis by the three techniques, with DEXA serving as the criterion method. Anthropometry and BIA results were converted to lean and fat mass using eight prediction equations commonly cited in the literature. Anthropometry measures were also converted to estimates of muscle mass using two additional equations. Both BIA and anthropometry tended to overestimate lean mass and underestimate fat mass compared to DEXA. However, the BIA prediction equations had smaller mean differences, larger correlations, and smaller standard errors of estimate than the anthropometry equations. The Lukaski et al. BIA equation (Lukaski, H.C., Bolonchuk, W.W., Hall, C.B., Siders, W.A., 1986. Validation of tetrapolar bioelectrical impedance method to assess human body composition. J. Appl. Physiol. 60, 1327-1332) most closely matched the values derived by DEXA and is probably the best method for measuring the lean and fat mass of persons with ALS, as long as they maintain adequate hydration levels. The Heymsfield et al. equation (Heymsfield, S.B., McManus, C., Smith, J., Stevens, V., Nixon, D.W., 1982. Anthropometric measurement of muscle mass: revised equations for calculating bone-free arm muscle area. Am. J. Clin. Nutr. 36, 680-690) for estimating muscle mass may also be a useful clinical tool for this population. Further longitudinal studies are needed to determine whether the equations that correlated best with DEXA at a single point in time are also sensitive enough to detect changes in body composition over a period of time.

Leg amyotrophic diplegia: Prevalence and pattern of weakness at us neuromuscular centers

Objective: To identify the frequency of leg amyotrophic diplegia (LAD) at a US academic center, describe the pattern of weakness, and provide comparative data from 8 additional major US academic institutions. Background: LAD is a leg onset variant of progressive muscular atrophy (PMA). LAD weakness is confined to the legs for at least 2 years, and there are no upper motor neuron signs. Design/Methods: We present a retrospective chart review of 24 patients with the LAD presentation from the University of Kansas Medical Center ( n = 8 cases) and from 8 US academic institutions (n = 16 cases). Results: Of the 318 subjects identified in the University of Kansas Medical Center Neuromuscular Research Database, 82% (260 subjects) had amyotrophic lateral sclerosis (ALS), 1.9% (6) had familial ALS, 6.6% (21) had primary lateral sclerosis, and 9.2% (29) had lower motor neuron (LMN) disease. Of these 29 cases, 16 had PMA, 5 had brachial amyotrophic diplegia, while 8 had LAD. The mean LAD age of onset was 58 years with a male/female ratio of 3/1. Onset was asymmetric in 7/8. We identified a pelviperoneal pattern of weakness (sparing of knee extension and/or ankle plantar flexion) in 4 cases and distal predominant weakness in 3 cases. All patients had electrodiagnostic findings consistent with motor neuron disease confined to the lower extremities. We present LAD disease duration and survival data from 8 major academic neuromuscular centers. At last follow-up, weakness progressed to involve the arms in 6/24 LAD cases and of these 6 cases, 2 patients died from progression to typical ALS. From onset of symptoms, mean survival in LAD is 87 months, with 92% of cases being alive. Conclusions/Relevance: The natural history of LAD differs from typical forms of ALS and PMA. LAD is a slowly progressive disorder that accounts for a fourth of LMN disease cases. An asymmetric pelviperoneal pattern of weakness should heighten the suspicion for LAD.

Unusual Features of Brain Stem Tumors

Because radiation benefits about 50 percent of patients with brain stem glioma, early diagnosis is important. Diagnosing such lesions is not difficult if multiple cranial nerve palsies and long motor tract and cerebellar signs exist. However, unusual neurologic features, as shown in four cases presented here, may suggest a different cause and thus delay correct diagnosis.

Effect of Age and Depth of Hyperventilation on a Quantitative Electroencephalographic Response

It has long been known that hyperventilation elicits slow wave responses on the electroencephalogram, that these responses are common in the youthful and uncommon in later life and that the amount of slow wave response roughly parallels the levels of hyperventilation. Early studies, however, did not control for levels of hypocapnia 1 and later ones which did have such control contained a relatively small number of subjects. 2 , 3 The norms for the EEG slow wave response to hyperventilation, therefore, remain uncertain, particularly in the older age groups. Delta activity (3 cycles per second) in response to hyperventilation in individuals over the age of 25 is frequently considered an abnormal response. The present study was designed to determine the amount of marked electroencephalographic slowing occurring in a large group of normal individuals of varying ages at known levels of hypocapnia measured in expired air. These normal values will hopefully be of use in subsequent studies of the EEG hyperventilation response in patients with various clinical states.

Independence of glucocorticosteroids and blood-brain barrier amino acid permeability

The effects of abnormal levels of circulating glucocorticosteroids upon the carrier-mediated transport of tyrosine and tryptophan across the blood-brain-carrier of the adult male rat were studied. The uptake of C14 labeled tyrosine or tryptophan was measured relative to that of simultaneously injected 3H2O, a freely diffusible internal standard. Fifteen sec after rapid intracarotid injection the rats were decapitated and brain tissue was homogenized and subjected to liquid scintillation counting. The level of circulating glucocorticosteroids was altered by intraperitoneal injection of cortisol (30 mg/kg) or corticosterone (30 mg/kg) 20 min prior to the amino acid injection. Rats were also injected with cortisol (10 mg/kg) or corticosterone (10 mg/kg) for 14 days. These rats were then injected with cortisol (10 mg/kg) or corticosterone (10 mg.kg) 90 min before the experiment. The amino acid uptake indices were analyzed statistically by the Wilcoxan Rank Sum Test. In no case was the uptake of tyrosine or tryptophan found to differ significantly (p <0·10) between the experimental and control rats. It is concluded that no correlation between levels of circulating adrenal glucocorticosteroids and transport across the blood brain barrier of the amino acid precursors of the putative neurotransmitters, norepinephrine and serotonin, can be demonstrated by this method.