The role of dietary fatty acids in children's behaviour and learning.

A growing awareness and understanding of the profiles of local children in County Durham, UK, experiencing learning and behavioural difficulties throughout the education system, has resulted in a number of school based nutritional intervention studies being undertaken. Evidence suggests that some children and young adults with developmental difficulties have a deficiency of particular omega 3 and omega 6 polyunsaturated fatty acids and supplementation with these nutrients can have an impact on their behaviour, concentration and performance on standardised assessments. The first randomised placebo controlled trial to be carried out on children in Durham with developmental coordination disorder has demonstrated significant effects of fatty acid supplementation on behaviour, reading and spelling performance. We are conducting further scientific studies within Durham and neighbouring Authorities in the North of England to be published at a future time. We have also carried out a number of open label treatment studies within schools to help us understand better the role that nutritional intervention can play across a broader range of age groups and abilities. The results suggest positive outcomes for a substantial proportion of children who are more able to engage with the educational opportunities presented to them. This is an important finding to be shared with educationalists, health professionals and importantly the parents.

Ischemic exercise test: failure to detect partial expression of McArdle's disease.

The forearm ischemic exercise test (FIET) is a very important clinical tool for evaluation of patients suspected to have a metabolic disorder of muscle function. Failure to elevate lactate in blood washed out from ischemically exercised muscles confirms an abnormality of glycolytic metabolism. A normal increase of lactate on FIET is assumed to rule out a disorder of glycolytic metabolism. Two patients with low levels of muscle phosphorylase are presented who produced a normal elevation of lactate on FIET. This suggests that, although the FIET is capable of identifying patients with absence of myophosphorylase, the test cannot identify patients with a partial expression of that disorder. Evaluation of the blood samples for ammonia in addition to lactate can be a significant help in confirming that the exercise performed by the patient was an adequate challenge for the glycolytic pathway. In addition, failure to elevate ammonia on ischemic exercise can identify a relatively new disorder of muscle metabolism.

Functional ability and equipment use among patients with neuromuscular disease.

The relationship between graded functional ability of a neuromuscular disease patient and his routine daily activities remains unknown. Mobility equipment use may provide an indirect measure of routine daily activities. In this study 110 neuromuscular disease patients were evaluated for both functional grade (Brooke upper extremity and Vignos lower extremity scales) and equipment use. Although several of the Vignos and Brooke categories did not describe significant numbers of these patients, the Vignos scale was able to predict whether or not a given patient would use a wheelchair with 94% accuracy, while the Brooke scale was only 85% accurate. It was not possible to predict manual vs electric wheelchair use based on functional rating scores. Patients with proximal weakness, regardless of diagnosis, displayed a similar pattern of functional outcome and equipment use, which was significantly different from the pattern displayed by groups with distal weakness. As expected, as functional ability diminished, wheelchair use increased; however, wheelchair use began at surprisingly high functional levels. Patients generally preferred a combination of manual and electric wheelchair use.

Upper extremity functional rating for patients with Duchenne muscular dystrophy.

The corresponding deterioration of upper extremity strength and functional capability with increasing age and the relationship between average strength and function were evaluated in 28 boys with Duchenne muscular dystrophy (DMD). Manual muscle testing (MMT) was used to evaluate strength and the Brooke upper extremity grading scale to rate upper extremity function. Mean MMT was found to relate to age in logarithmic fastion, ie, a 1% increase in age led to a 0.9% decrease in mean MMT. Functional grade (FG) related to age in a more complex fashion, revealing three groups based on age: under age 10, all in FG 1; between ages 10 and 13, concentration in FG 2 through 4; and over age 13, eight of ten in FG 5. Regression analysis did not contribute further useful information. Finally, mean MMT was found to be highly significantly related to FG. The plot of mean MMT against FG revealed an S-shaped curve, with rapidly rising functional grade once an average upper extremity strength of 4w was reached. The Brooke scale appears to be useful in describing upper extremity function among DMD patients, although it may reflect a three-grade rather than a six-grade discrimination capability. In describing the natural history of DMD, this scale demonstrates a pattern of rapid functional deterioration during the early adolescent years. This functional deterioration apparently takes place when the decline in strength reaches a threshold which cannot be compensated by muscle substitutions. At that time function deteriorates along a relatively rapid but undefined course.

Ultrasound treatment of reflex sympathetic dystrophy.

Three cases of lower extremity reflex sympathetic dystrophy (RSD) responded dramatically to a daily low dose ultrasound (0.5 watts/cm2 X 5 minutes) therapy to the tarsal tunnel and plantar nerve distribution, and the use of a shoe insert. Two of the three cases had been refractory to more standard therapy for RSD, including pharmacologic agents. All three patients preferred a conservative approach to surgical sympathectomy. No complications were observed, and all three cases are now symptom free. Daily ultrasound treatments are time-consuming and costly but are safe and may be useful for patients who refuse surgical sympathectomy. We hypothesize that ultrasound may have affected peripheral sympathetic nerve fibers. However, more indirect effects of ultrasound, such as increased blood flow to the limb, may be part of the action mechanism as well.

Upper vs lower extremity functional loss in neuromuscular disease.

Functional rating scales have been developed for evaluation of upper extremity (UE) and lower extremity (LE) function in Duchenne muscular dystrophy (DMD). The Vignos scale is accepted for LE function and the Brooke scale for UE evaluation. The assumption that UE functional loss parallels LE loss has never been tested. Furthermore, there are no studies examining the relationship between UE/LE strength. This study tests the hypothesis that UE/LE strength and functional losses are parallel in DMD and other neuromuscular disorders. Vignos grades, Brooke grades, and manual muscle test scores were determined for 27 patients with DMD, 10 patients with fascioscapulohumeral muscular dystrophy (FSH), 24 patients with myotonic muscular dystrophy (MMD) and 29 patients with other (Becker's dystrophy and limb-girdle syndrome) proximal myopathies (PM). Spearman correlation coefficients were calculated for UE vs LE functional grade and strength scores and subjected to significance analysis. While all correlations were statistically significantly different from zero (p less than 0.01), all were also significantly different from one (p less than 0.01), none representing perfect equivalence. Coefficients of determination indicated that a maximum of 86% (FSH) of variation in UE rank could be explained purely by observing LE rank. While there is a significant relationship between UE/LE strength and functional grade, these measurements were not found to be entirely equivalent. Therefore, while measures of lower body function or strength might be used as a substitute for UE measurements in drug trials in which global effects are expected, the two measurements are not equivalent when evaluating an individual's clinical status.

Depression in myotonic muscular dystrophy.

Depression was studied in adults with myotonic muscular dystrophy (MMD). The subject groups consisted of 27 MMD patients, an able-bodied control group of 27 adults (CON), a nonprogressively disabled control group of 17 adult paraplegics (SCI), and a progressively disabled neuromuscular disease control group of 11 adults with limb-girdle syndrome (LGS). The study utilized a test battery consisting of the Minnesota Multiphasic Personality Inventory (MMPI), the Institute of Personality and Ability (IPAT) Depression test, the Suicide Probability Scale (SPS), and the California Psychological Inventory (CPI). The MMD group scored significantly higher on the MMPI Depression scale, the IPAT Depression Test, and the SPS Hopelessness subscale, than the CON or SCI groups. Conversely, the MMD group showed lower levels of positive mental health than these two groups on the MMPI Ego Strength and CPI Well-Being scale scores. The MMD group did not differ significantly from the LGS group in any of the five measures. A definite tendency toward depression was evident among MMD patients. A similar tendency was noted in the small LGS group. The progressive and disabling nature of the disease appears to be the major reason for depression in MMD patients. Our data do not support the concept that depression is an intrinsic characteristic of MMD.

Intellectual and cognitive function in adults with myotonic muscular dystrophy.

Intellectual and cognitive function was studied in 43 patients (21 men and 22 women) with myotonic muscular dystrophy (MMD). The inheritance distribution was 18 paternal, 10 maternal, and 15 unknown. All patients received the Wechsler Adult Intelligence Scale-Revised, the Wechsler Memory Scale, the Halstead-Reitan Neuropsychological Test Battery, and the Aphasia Screening Test. Significantly lower scores (p less than 0.05) were found on all intellectual and cognitive impairment tests in both men and women of the maternal inheritance MMD subgroup, compared with the paternal inheritance MMD subgroup and with the normative data. Scores for patients with paternally inherited disease did not differ significantly from normative data for verbal, performance, or full scale intelligence quotients and memory quotients. There were no significant differences in intellectual and cognitive test scores between men and women for the group as a whole, for the maternal inheritance subgroup, or for the paternal inheritance subgroup. It is suggested that inheritance pattern is a necessary variable in studies investigating intellectual and cognitive function in MMD. Although the reason for the association of lower intellectual and cognitive function in MMD of maternal inheritance is not known, the data presented here may be useful for genetic counseling.

Psychometric evaluation in myotonic muscular dystrophy.

Systematic psychometric evaluations were performed in 16 patients with myotonic muscular dystrophy (MMD). All patients received the Wechsler Adult Intelligence Scale-Revised and Wechsler Memory Scale-1. In addition, 13 patients received the Reitan-Halstead Neuropsychological Test Battery (R-H), including the Aphasia Screening Test. Despite the high reported incidence of mental retardation in MMD, none of our pilot population showed mental retardation. However, 5 of the 13 patients showed evidence of possible organic mental dysfunction on the R-H. Problems in previous studies which could explain these discrepancies include the following: (1) small sample size, (2) studies limited to young children, and (3) a complete lack of systematic psychometric data in the previous reports. Systematic cooperative studies are suggested to elucidate the degree and type of cognitive involvement in MMD.

Effect of pentobarbital on contractility of mouse skeletal muscle.

Pentobarbital is a hypnotic drug commonly used as anesthesia for in vivo studies in various animals. A direct effect of pentobarbital on the central nervous system and skeletal neuromuscular junction has been known for at least 30 years. A recent study using single fiber preparations from amphibian muscles indicated a significant acute and direct effect on muscle contractility at drug concentrations within the anesthetic range. The present study using whole muscles from mice demonstrated a similar augmentation of twitch tension and rate of tension development whereas tetanic tension was reduced by this drug at similar concentrations. In addition, most time parameters of contraction were prolonged. It is of interest that the slow (oxidative) muscles were considerably more sensitive to pentobarbital than the fast (primarily anaerobic) muscles. We suggest that pentobarbital should not be used as the anesthetic agent for in vivo studies of other interventions when conclusions are based on changes in muscle contractility.