Failure to confirm a vascular cause of muscular dystrophy.

The vascular hypothesis of the cause of muscular dystrophy suggests that ischemia is responsible for the muscle fiber necrosis. A xenon 133 clearance study of muscle blood flow in Duchenne and other muscular dystrophies showed no obvious difference between the response to exercise and arterial occlusion compared with control subjects. Radioautographic study of distribution of 4-125l-antipyrine in skeletal muscle of mice with muscular dystrophy showed no abnormal areas of ischemia. A statistical examination was also made of the grouping of damaged fibers, one of the observations on which the vascular hypothesis was based. Only 0.9% of fibers undergoing phagocytosis occurred in groups of four or more fibers in greater frequency than would have been expected by chance, and 70% of such fibers were isolated. These studies argue strongly against the vascular hypothesis of the cause of muscular dystrophy.

Dystonia of the legs induced by walking or passive movement of the big toe in a patient with cerebellar ectopia and syringomyelia.

A 45-year-old man with dystonia of the legs was found to have cerebellar ectopia and syringomyelia. Both walking and passive movements of the big toes evoked dystonic postures of the legs. Electrophysiologic studies suggested that the dystonic movements were reflex in origin. We propose that the cervical spinal cord lesion, involving propriospinal pathways, resulted in an abnormal response of spinal interneurons to peripheral stimuli.

The management of dural tear resulting from mid-facial fracture.

This study examines the relative risks and benefits of conservative and surgical management of dural tear secondary to middle third facial fracture and ascertains the type of skull and facial injury most often associated with the development of posttraumatic meningitis. Two projects were undertaken. First, the histories of 247 cases of major middle third facial fracture were reviewed with a recent follow-up of those patients who also sustained a dural tear. Second, 280 cases of bacterial meningitis were reviewed and particular attention was given to cases of posttraumatic meningitis. Of the 247 cases of middle third facial fractures studied, 43% (107/247) had evidence of a dural tear; of this group, 76 patients were managed conservatively and 31 patients were managed surgically. In the former group, there were three instances of recurrent cerebrospinal fluid rhinorrhea (CFR). In the surgically managed group, 77% (24/31) sustained surgical complications including two cases of posttraumatic meningitis and 21 cases of neurological deficit. Of the 280 cases of bacterial meningitis, 48 patients had sustained dural tear following trauma. The prognosis for posttraumatic meningitis is considerably better than for other forms of meningitis. The preceding trauma involved the vault of the skull in 90% (43/48) of cases, and discrete middle third facial fracture in one case (2.1%). Posttraumatic meningitis followed a previous operative repair in 15% (7/48) of the patients. The results of this study indicate that dural tear subsequent to middle third facial fractures is a different proposition than dural tear subsequent to direct skull trauma.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes and the family.

The reaction of the family to the presence of chronic illness depends on the composition of the family, the presence of significant others, the cultural background, the education of family members, the stage of family development, and finally the health-belief model adopted by the family.

Persistent superior oblique paresis as a manifestation of familial periodic cerebellar ataxia.

A brother and sister complained of persistent diplopia due to superior oblique palsies. The cause of their symptoms became apparent when they were diagnosed as having familial periodic cerebellar ataxia (FPCA), a rare autosomal dominant condition. Oral acetazolamide (250 mg twice daily) not only prevented all the periodic symptoms but also relieved their diplopia, which had been present between attacks.

The effect of hypertension on ischemic cerebral edema in spontaneously hypertensive rats.

Cerebral ischemia was produced in spontaneously hypertensive rats (SHR) with a range of blood pressures (BP). Measurements were made at 4 hours of the edema produced (% H2O), the damage to the blood brain barrier (BBB) and, the blood flow (CBF) in both hemispheres and the cerebellum and brain stem. There was a statistically significant correlation between CBF and BP and between CBF and % H2O, but the correlation between BP and % H2O was not significant. The BBB is not open to technecium pertechnetate in this model at this time interval. Systemic hypertension is not a significant factor in the early development of ischemic edema in this model because the blood flow in the ischemic area falls with rising blood pressure, probably due to autoregulation in the collateral circulation.

Hospital reimbursement for pediatric trauma care.

PURPOSE: Despite the proven efficacy of pediatric trauma centers, their continued development is threatened by the perception that their cost exceeds the reimbursement for their services. The authors reviewed actual reimbursement for a group of pediatric trauma patients and compared with that for a group of appendectomy patients chosen to reflect the authors' surgical population at large. METHODS: The records of 209 consecutively treated trauma patients and 37 age-matched appendectomy patients treated in 1992 and 1993 were reviewed. Trauma patients were divided into two groups: moderate injury (ISS < or = 9; n = 134) and serious injury (ISS > or = 10; n = 75). RESULTS: Hospital bills for the appendectomy patients were reimbursed at 72% of charges and 112% of costs. Payment was received at a mean of 36 days (range, 9 to 62 days) after discharge. Reimbursement for moderately injured patients was 104% of charges and 137% of costs and was received at a mean of 81 days (range, 3 to 270 days) after discharge. Six months postdischarge, reimbursement for seriously injured patients was 63% of charges and 86% of costs. Reimbursement was slow for some children who sustained severe injury, but as legal actions brought by patient's families were completed, open accounts were settled, and revenue in both groups totaled 76% of charges and 103% of costs 18 months postdischarge. CONCLUSION: Hospital reimbursement for care at a level I pediatric trauma center exceeds 75% of charges and 100% of costs, no different from the overall rate for the general hospital surgical population. Analysis of reimbursement rates for trauma patients may be time-dependent.

Criteria for diagnosing brain stem death.

KIE: Criteria for diagnosing brain stem death that follow Britain's Department of Health and Social Security recommendations are set out in a form suitable for inclusion in a patient's records.^ieng

Epilepsy and pregnancy.

PIP: According to a London physician, women with epilepsy taking antiepileptic drugs can take combined oral contraceptives (OCs). It is usual to recommend a combined OC preparation containing at least 50 mcg of estrogen (Ovran) from patients taking enzyme-inducing antiepileptic drugs; this can be increased to 60 mcg by taking 2 30 mcg pills, and if necessary to 80 mcg. To ensure that ovulation is inhibited, the blood progesterone concentration can be measured on day 21 of the 1st cycle. The higher doses of estrogen should be accompanied by higher doses of progestogen. The commonest fetal malformations are cleft lip and palate and congenital heart disease, usually septal defects. These abnormalities may be caused by all the major antiepileptic drugs. Phenytoin has been particularly implicated and may cause minor defects in up to 30% of infants and major defects in about 5%. The incidence of cleft palate and heart defects with phenytoin is 1.8% compared with 0.7% in the general population. With sodium valproate, neural tube defects occur in about 1.5% of pregnancies. Present evidence suggests that carbamazepine is the safest drug. Folic acid supplements reduce the risk of neural tube defects in women at risk, therefore women taking antiepileptic drugs who are contemplating pregnancy should be given a small folic acid supplement or a diet rich in folate. To reduce the risk of bleeding in the perinatal period, pregnant women taking enzyme-inducing antiepileptic drugs should be given oral phytomenadione (vitamin K1) 20 mg daily for at least 1 week before delivery. Vitamin K1 should be given to the newborn immediately after delivery. Only phenobarbitone and primidone might be contraindicated for breast feeding. Mothers with uncontrolled major epilepsy should not be left alone with small children. If there is already 1 sibling with epilepsy the risk of inheriting epileptic liability rises to about 10% and if both parent have epilepsy the risk is 15-20%.^ieng

Metabolic adaptations to heat stress in growing cattle.

To differentiate between the effects of heat stress (HS) and decreased dry matter intake (DMI) on physiological and metabolic variables in growing beef cattle, we conducted an experiment in which a thermoneutral (TN) control group (n=6) was pair fed (PF) to match nutrient intake with heat-stressed Holstein bull calves (n=6). Bulls (4 to 5 mo old, 135 kg body weight [BW]) housed in climate-controlled chambers were subjected to 2 experimental periods (P): (1) TN (18 degrees C to 20 degrees C) and ad libitum intake for 9 d, and (2) HS (cyclical daily temperatures ranging from 29.4 degrees C to 40.0 degrees C) and ad libitum intake or PF (in TN conditions) for 9 d. During each period, blood was collected daily and all calves were subjected to an intravenous insulin tolerance test (ITT) on day 7 and a glucose tolerance test (GTT) on day 8. Heat stress reduced (12%) DMI and by design, PF calves had similar nutrient intake reductions. During P1, BW gain was similar between environments and averaged 1.25 kg/d, and both HS and PF reduced (P<0.01) average daily gain (-0.09 kg/d) during P2. Compared to PF, HS decreased (P<0.05) basal circulating glucose concentrations (7%) and tended (P<0.07) to increase (30%) plasma insulin concentrations, but neither HS nor PF altered plasma nonesterified fatty acid concentrations. Although there were no treatment differences in P2, both HS and PF increased (P<0.05) plasma urea nitrogen concentrations (75%) compared with P1. In contrast to P1, both HS and PF had increased (16%) glucose disposal, but compared with PF, HS calves had a greater (67%; P<0.05) insulin response to the GTT. Neither period nor environment acutely affected insulin action, but during P2, calves in both environments tended (P=0.11) to have a blunted overall glucose response to the ITT. Independent of reduced nutrient intake, HS alters post-absorptive carbohydrate (basal and stimulated) metabolism, characterized primarily by increased basal insulin concentrations and insulin response to a GTT. However, HS-induced reduction in feed intake appears to fully explain decreased average daily gain in Holstein bull calves.