Pyriformis syndrome in a 10-year-old boy as a complication of operation with the patient in the sitting position

We present a case of sciatic neuropathy due to the pyriformis syndrome after operation in the sitting position. Neither sciatic nerve injury nor the pyriformis syndrome has been reported after operation in the sitting position, although a low incidence of common peroneal nerve injury has been reported as a complication of operation on patients who are in the sitting position. The clinical findings of sciatic neuropathy, external rotation of the ipsilateral foot in the position of comfort, and a therapeutic response to local anesthetic injection into the pyriformis muscle are diagnostic of the syndrome. Nerve conduction studies should be performed to aid in the differentiation between a common peroneal and sciatic neuropathy. The syndrome may occur because of extreme flexion of the hips and prolonged pressure while in the sitting position, leading to pyriformis muscle trauma, resultant spasm, and sciatic compression. The prognosis is for complete recovery after symptomatic treatment with nonsteroidal antiinflammatory medication and physical therapy.

Exercise-induced muscle damage, repair, and adaptation in old and young subjects

This study examined exercise-induced muscle damage, repair, and adaptation in 10 college age women and 10 women over age 60. On two sessions spaced 7 days apart, subjects performed an eccentric exercise of the forearm flexors consisting of 24 muscle actions at an intensity of 115% of isometric strength. Serum creatine kinase activity, flexed and relaxed elbow joint angles, and muscle pain were assessed prior to and for 5 days after each exercise session. The exercise resulted in similar changes in CK, muscle pain, and inability to fully flex the forearm for old and young subjects. The old group demonstrated greater muscle shortening (a decrease in the relaxed elbow joint angle). The old and young groups adapted to the first exercise such that changes in all criterion measures were reduced following the second exercise. For the physically active subjects in this study, the damage process (with the exception of muscle shortening) takes a similar course for old and young. The repair process is equally as effective in old and young, and older subjects show the same ability to adapt to the damage as young subjects.

Aldosterone-producing adenoma presenting with hypokalemic myopathy. Case report and review

A 9-year-old boy who complained of fatigue, myalgias, and progressive weakness was found to have a markedly elevated serum creatine phosphokinase (CPK). He developed polyuria with polydipsia and was noted to be hypertensive and severely hypokalemic. Treatment with potassium and spironolactone alleviated his signs and symptoms and normalized the blood pressure and CPK. Initial studies revealed low plasma renin activity that did not increase with change from supine to upright position. Plasma aldosterone was consistently elevated in the supine position, decreased with upright posture, and was not suppressed by administration of dexamethasone. Plasma 18-hydroxycorticosterone also was elevated. Enhanced computerized tomography (CT) revealed a mass in the left adrenal that had not been seen on the initial unenhanced scan. Adrenal vein catheterization confirmed elevated plasma aldosterone on that side. Adrenalectomy was performed, and a well-encapsulated adenoma was found at examination of the surgical specimen. Postoperatively, suppression of plasma renin activity continued for many months without signs of aldosterone deficiency.

Postanesthetic hind limb adductor myopathy in five horses

Five horses that underwent prolonged anesthesia (greater than 3 hours) in dorsal recumbency for a surgical procedure were unable to stand after recovery and were euthanatized. A provisional diagnosis of postanesthetic myopathy was confirmed at necropsy in all 5 horses. However, distribution of affected muscles in these horses was atypical, because there was bilateral hind limb adductor muscle involvement.

Creatine kinase and muscle soreness after repeated isometric exercise

This study examined adaptation to isometric exercise with regard to changes in serum creatine kinase (CK) activity and muscle soreness. Forty-five college-age males were placed into six groups, each performing two bouts of strenuous isometric exercise of the knee extensors. In experiment 1 (N = 27), after performing the first bout of exercise, groups A, B, and C performed the second bout 3, 6, and 9 wk later, respectively. In experiment 2 (N = 18), groups D, E, and F performed the second exercise bout 1, 2, and 3 wk after the first bout, respectively. In experiment 3, group D performed two additional exercise bouts; thus, this group performed a total of four bouts spaced 1 wk apart. Muscle soreness and CK were assessed prior to and 6, 18, and 24 (or 42) h following each exercise. In experiment 1, no significant difference in soreness or serum CK was found between bouts 1 and 2. In experiment 2, a significant decrease in the CK and soreness responses was found on bout 2 compared with bout 1 (P less than 0.05). In experiment 3, serum CK and soreness responses were highest following bout 1 while bouts 2, 3, and 4 were not significantly different from one another. Performance of this isometric exercise results in an adaptation that lasts approximately 3 wk, with the greatest adaptation occurring after one bout.

Modification of collagen and noncollagenous proteins in radiation-induced muscular fibrosis

Six months after acute local gamma irradiation of the pig skin and adjacent muscle, the muscular tissue is replaced by a large mutilating and proliferative fibrosis deliminated by a perifibrotic inflammatory zone. The content and biosynthesis of collagen and noncollagenous proteins were studied in both fibrotic and perifibrotic zones after incubation of the biopsies with [14C]proline or [35S]methionine for 24 hr. Cells of perifibrotic and fibrotic regions synthesize about 10 times more proteins than those in the nonirradiated muscle. When compared to normal muscle tissue, our results indicate an important increase in collagen content and biosynthesis in fibrotic tissue. The increase in collagen biosynthesis in the irradiated tissue is more pronounced for type III collagen than for type I collagen. Biosynthesis of type III and type I collagens increases 20- and 10-fold, respectively, compared to the normal muscle. Type I to III collagen ratio in irradiated tissue decreases from 2.3 in normal tissue to 1.1 in fibrotic tissue. Histological examination of the biopsies as well as the protein pattern by polyacrylamide gel electrophoresis show striking differences in the perifibrotic and fibrotic areas as compared to the normal muscular tissue with a progressive disappearance of the myotubes replaced by a dense sclerotic tissue. The results indicate that the perifibrotic inflammatory area is engaged in a remodeling process and that the fibrotic tissue remains active in the neosynthesis of the extracellular matrix macromolecules with a high proportion of type III collagen. This high biosynthetic activity of the irradiated tissue may explain the pseudosarcomatous character of the radiation-induced lesions.

Rate of reperfusion blood flow modulates reperfusion injury in skeletal muscle

The mechanisms of ischemia-reperfusion (I-R) injury in skeletal muscle remain controversial. We investigated the effect of the rate of reperfusion blood flow on I-R injury in an isolated in vivo canine gracilis muscle model in six anesthetized dogs. In all animals, both gracilis muscles were subjected to 6 hr of ischemia followed by 1 hr of reperfusion. During reperfusion, one gracilis artery was partially occluded to limit the rate of reperfusion blood flow to its preischemic rate (limited reperfusion, LR), while the contralateral artery was allowed to perfuse freely at a normal rate (normal reperfusion, NR). Muscle injury was quantified by histochemical staining (triphenyltetrazolium chloride, TTC) with computerized planimetry of the infarct size, and by spectrophotometric determination of technetium-99m pyrophosphate uptake. Endothelial permeability was quantified by measurement of gracilis muscle weight gain and 125I-albumin radioactivity after intravenous injection. Results are presented as the means +/- SEM, and differences are considered to be statistically significant if P less than 0.05 by Student's t test for paired data. LR resulted in significantly less blood flow (9.7 +/- 1.7 cc/min/100 g) when compared to NR (55.7 +/- 11.6 cc/min/100 g). I-R injury was significantly reduced by LR as evidenced by a decrease in TTC infarct size from 41 +/- 7% to 11 +/- 5%, and a decrease in technetium-99m pyrophosphate uptake from 512 +/- 20 to 163 +/- 44 X 10(3) counts/min/g. LR also significantly decreased the postreperfusion edema formation as evidenced by a reduction in the muscle weight gain from 27 +/- 6 to 9 +/- 1 g, and a reduction in the 125I-albumin radioactivity from 45 +/- 14 to 32 +/- 8 counts/min/g. These data suggest that the hyperemic rate of reperfusion blood flow is a significant factor in the pathophysiology of postreperfusion edema and that clinical control of reperfusion injury in skeletal muscle may be achieved by limiting the rate of reperfusion blood flow.

Effects of selenium and vitamin E status on plasma creatine kinase activity in calves

In four experiments, attempts were made to induce nutritional myopathy in calves given a selenium- and vitamin E-deficient diet (less than 0.01 mg Se/kg, less than 2 mg total vitamin E/kg). In housed calves, combined selenium and vitamin E deficiency was insufficient to provoke the large increase in plasma creatine kinase activity typical of muscle damage. Such increases were only obtained when selenium- and vitamin E-deficient calves were turned out from indoor housing in small pens to open pasture. The rises in plasma creatine kinase activity on turnout were prevented when the calves had consumed diets supplemented with 0.1 mg Se/kg (as Na2SeO3). The percentage of the polyunsaturated fatty acid, linolenic acid (18:3 omega 3), in plasma total fatty acids was up to 10-fold higher in calves consuming fresh grass at pasture or indoors than in those housed indoors and fed purified diet. However, in the housed calves there were no rises in plasma creatine kinase activity, whereas large increases occurred in those turned out to pasture. Thus, because increased dietary polyunsaturated fatty acid at turnout is not the sole trigger for the development of myopathy in selenium- and vitamin E-deficient calves, additional unidentified dietary or environmental factors must also be involved.

Myalgia in outpatient surgery: comparison of atracurium and succinylcholine

We studied 60 outpatients randomly divided into two groups. Anesthesia was induced with fentanyl 1.5 micrograms.kg-1 plus thiopentone 5-7 mg.kg-1. Patients in Group I were intubated with the aid of succinylcholine 1.5 mg.kg-1 after pre-treatment with d-tubocurarine 0.05 mg.kg-1. Group II received atracurium 350 micrograms.kg-1 three minutes after a priming dose of 50 micrograms.kg-1. Anesthesia was maintained with isoflurane 1-2 per cent in a mixture of nitrous oxide 60 per cent and oxygen 40 per cent. No supplemental doses of fentanyl or atracurium were given. Intubation conditions were satisfactory for all patients in both groups. There was no significant difference in intubation score between the two groups. The incidence of myalgia was 76 per cent in the succinylcholine group compared to 23 per cent in the atracurium group (p less than 0.005). Fifty per cent of the patients in the succinylcholine group had myalgia necessitating bed rest or analgesics compared to 23 per cent in the atracurium group (p less than 0.05). We conclude that atracurium is a suitable neuromuscular relaxant for outpatient surgery and that myalgia is a major morbidity factor in this population that can be reduced by the use of atracurium instead of succinylcholine.

Muscle fatigue and pain after eccentric contractions at long and short length

1. The effect of muscle length on the development of muscle pain and fatigue has been studied. 2. Eight normal young adults performed maximal eccentric contractions of the elbow flexors. The muscles of one arm were exercised at short length, and the contralateral muscle at long length. Each contraction lasted approximately 1 s, and was repeated once every 10 s for 30 min. 3. Muscle strength and frequency-force characteristics were measured from isometric contractions before, immediately after and at 24 h intervals for the next 4 days. Muscle tenderness was assessed daily. 4. The muscle strength was reduced by approximately 10% by exercise at short length, and by 30% by exercise at long length. 5. The 20:100 ratio (force generated by stimulation at 20 Hz/force generated at 100 Hz) fell by 30% after exercise at short length and had recovered after 24 h. Exercise at long length reduced this ratio by 65% and the muscles had not fully recovered 4 days later. 6. Muscle pain developed after both exercise regimens, but was slightly worse after that at long length. 7. It is concluded that there is a length-dependent component in the development of pain and fatigue after eccentric exercise, which had previously been thought to be caused solely by high force generation.

Polysaccharide storage myopathy

In a woman with a slowly progressive adult onset proximal myopathy, muscle biopsy showed storage of PAS positive material in type 1 fibers. This material consisted of a branched chain polysaccharide associated with a mucoprotein. No abnormality of glycogen-pathway enzymes was detected. This suggested that this polysaccharide accumulation occurred because the polysaccharide was laid down in a non-bioavailable form. The clinical and histochemical features in this patient and in the few similar reported cases indicate that polysaccharide storage myopathy is a distinct entity that is allied to the glycogen storage myopathies.

[Computerized tomography in the evaluation of abdominal involvement in paracoccidioidomycosis]

A tomografia computadorizada foi utilizada para avaliar o comprometimento abdominal em 25 doentes deparacoccidioidomicose. Existiam lesões intra-abdominais em, respectivamente, 75%e23% dos doentes com asformas aguda ("juvenil") e crônica ( do adulto '). A alteração mais freqüente foi o aumento dos gânglios linfáticos abdominais (12/25 casos); outras lesões foram: calcificação de gânglios linfáticos em 4 casos; obstrução das vias biliares em 5 doentes ictéricos; abscessos ou calcificação esplénica em 3 casos; 2 doentes mostraram lesões incomuns: aumento e irrgularidade do pâncreas em um e múltiplos abscessos nos músculos psoas em outro. Conclui-se que a tomografia computadorizada é procedimento útil na avaliação da disseminação da paracoccidioidomicose ao abdome e no diagnóstico de suas complicações abdominais.

Spontaneous bilateral quadriceps tendon rupture in a patient on hemodialysis

Since the initiation of maintenance dialysis and renal transplantation, the course of patients with chronic renal disease has been altered. One of the frequent complications found in such patients is the development of secondary hyperparathyroidism, which is commonly associated with metastatic calcification and a variety of bone lesions collectively referred to as renal osteodystrophy. Bilateral rupture of the quadriceps tendon is a rare complication and previous reports have prescribed surgical correction of the ruptured tendon. The present case is that of a patient on chronic hemodialysis with secondary hyperparathyroidism and bilateral spontaneous rupture of the quadriceps tendon who was treated successfully without surgery.

Musculoskeletal manifestations of systemic lupus erythematosus

The musculoskeletal system is involved in nearly all patients with SLE. Transient arthralgias or arthritis are common and, in some patients, there is a progression to rheumatoid-like nonerosive hand deformities (Jaccoud's syndrome). The major disabling type of joint disease in lupus is articular osteonecrosis, often induced by high-dose corticosteroids. Rare forms of musculoskeletal manifestations of lupus include spontaneous tendon rupture, crystalline arthropathies, subcutaneous calcifications, and inflammatory myopathy.

Evaluation and treatment of AIDS-associated illnesses: an approach for the primary physician

The acquired immunodeficiency syndrome (AIDS) has become a problem of enormous clinical importance in the United States. This article describes the major clinical syndromes in adults with AIDS and offers approaches to their evaluation and treatment.

Clinical Spectrum of Mucolipidosis Type IV

To the Editor.—

We read with interest the presentation by Amir et al1 concerning the clinical spectrum and natural history of mucolipidosis type IV. Based on their experience with 20 patients, they try to provide guidelines for the clinical diagnosis of this lysosomal storage disease. It appears that severe visual impairment (due mainly to corneal opacities, myopia, and retinal degeneration) and psychomotor retardation are the cardinal features of this entity.

However, corneal clouding and mild motor delay in their early stages may frequently be missed by even experienced pediatricians and we recently examined a 15-month-old boy who was referred to us for evaluation of a possible congenital myopathy.