121/150. A Japanese boy with myalgia and cramps has a novel in-frame deletion of the dystrophin gene. We report a Japanese Becker muscular dystrophy (BMD) patient with occasional myalgia and cramps during normal activity that developed at the age of 28 months. His family history was negative for neuromuscular diseases. Muscle biopsy analyses, including dystrophin immunostaining, disclosed no clinically relevant findings. The diagnosis of BMD was initially made at the age of 10 years, when indications of persistent high serum levels of CK prompted us to screen deletions in the dystrophin gene by amplification of 19 deletion-prone exons from the genomic dna by the polymerase chain reaction (PCR). Among the exons examined, exons 13 and 17 were deleted. To clarify the size of the deletion, the dystrophin transcript was analyzed by reverse transcription PCR. The determined nucleotide sequence of the amplified product encompassing exons 10 to 20 disclosed that the entire segment corresponding to exons 13 to 18 (810 bp) was absent, a deletion that would be expected to cause the production of a dystrophin protein lacking 270 amino acids from the rod domain. This result indicates that occasional myalgia and cramps could be early clinical manifestations of mild BMD, especially in patients who have a deletion in the rod domain, and that deletion screening of the dystrophin gene might be the only reliable method to diagnose such cases. ( info) |
122/150. Generator sites for spontaneous activity in neuromyotonia. An EMG study. A 16-year-old female patient with symptoms and signs compatible with neuromyotonia was studied with various neurophysiological tests and with muscle biopsy. Nerve conduction studies revealed signs of axonal motor neuropathy. EMG showed denervation in distal muscles, and moderate neurogenic changes in other muscles. Abundant spontaneous motor unit activity was recorded in all muscles. This activity did not disappear upon proximal nerve blockade with local anaesthetics. Based on the shape of spontaneous discharges and their behaviour on nerve stimulation and during voluntary effort, the site of generation was suggested. This varied for different discharges, from proximally in the nerve, to various sites along the intramuscular nerve tree. In some axons there were signs of conduction block proximal to the generation site for the spontaneous discharges. Different axons showed various degrees of abnormality; local hyperexcitability triggering new impulses only after the passage of a preceding impulse, increased hyperexcitability generating spontaneous activity, total impulse blocking, and finally axonal degeneration. Treatment with dihydantoin reduced the spontaneous activity with concomitant clinical improvement. ( info) |
123/150. Heat cramps during tennis: a case report. A 17-year-old, nationally ranked, male tennis player (AH) had been experiencing heat cramps during tennis match play. His medical history and previous physical exams were unremarkable, and his in-office blood chemistry profiles were normal. On-court evaluation and an analysis of a 3-day dietary record revealed that AH's sweat rate was extensive (2.5 L.hr-1) and that his potential daily on-court sweat sodium losses (89.8 mmol.hr of play-1) could readily exceed his average daily intake of sodium (87.0-174.0 mmol.day-1). The combined effects of excessive and repeated fluid and sodium losses likely predisposed AH to heat cramps during play. AH was ultimately able to eliminate heat cramps during competition and training by increasing his daily dietary intake of sodium. ( info) |
| magnesium deficiency is more common than is believed. This article discusses florid magnesium deficiency in two patients and the results of treatment. While neither case was difficult to diagnose, the severity of symptoms was unusual. magnesium deficiency should always be included in the differential diagnosis of patients who present with persistent or severe muscle pain. ( info) |
| An 8-year-old boy who was bitten by a black widow spider was seen in the emergency department twice, as well as by his private family physician, within a 24-hour period of time before being admitted to the hospital. This patient should have been observed for a longer period of time in the emergency department or admitted to the hospital on the day of presentation for observation with conservative management. The current literature is reviewed with special emphasis on the pediatric patient, and management guidelines are recommended. ( info) |
126/150. McArdle's disease with non-insulin-dependent diabetes mellitus: the beneficial effects of hyperglycemia and hyperinsulinemia for exercise intolerance. A 64-year-old female with McArdle's disease and non-insulin-dependent diabetes mellitus (NIDDM) is reported. She had none of the characteristic symptoms of McArdle's disease such as muscle cramps but her serum creatine kinase level was elevated. Muscle biopsy with negative muscle phosphorylase staining showed McArdle's disease. Modified forearm ischemic exercise test was done at two conditions; fasting and two hours after a meal. When fasting, the level of lactic acid did not elevate after exercise. After a meal, however, the serum lactic acid level rose with the elevation of plasma glucose and IRI. Thus, we suggested that high plasma glucose and insulin due to NIDDM may induce blood-borne glucose uptake with exercise. ( info) |
127/150. myotonia congenita with painful muscle cramps. A sporadic Japanese case of myotonia congenita with painful muscle cramps is reported. Electromyographic examinations disclosed myotonic discharge with dive bomber sounds at insertion, and high-amplitude, high-frequency motor unit potentials during the muscle cramps. Biopsied muscle specimens and EMG findings showed non-specific mild myopathic changes. There was no abnormal expansion of CTG repeat within the myotonic dystrophy gene. This patient's disorder closely resembles Becker's myotonia congenita Type II though the family history of was non contributory. ( info) |
128/150. Partial deficiency of phosphoglycerate mutase with diabetic polyneuropathy: the first Japanese patient. We report here findings in a 51-year-old Japanese man with non-insulin-dependent diabetes mellitus who complained of exercise-induced cramps. Muscle biopsy showed scattered regenerating fibers, small angular fibers and increased PAS positive particles. Electron microscopic examination revealed an abnormal accumulation of glycogen particles in subsarcolenmmal areas and between myofibrils while chemical studies showed an increased glycogen concentration and decreased phosphoglycerate mutase (PGAM), 46.9% of the normal mean value. Thus, partial PGAM deficiency, insulin resistance and mild diabetic sensory-motor polyneuropathy can induce severe cramps. ( info) |
129/150. Colonic motility in proctalgia fugax. Intraluminal pressure recordings were obtained from the rectum and sigmoid colon in two patients experiencing attacks of proctalgia fugax. In each patient the pain appeared to result from contractions of the sigmoid colon, and not from spasm of the levator ani, rectal wall muscle, or anal sphincters, all of which have previously been suggested as the source of such pain. Proctalgia fugax therefore appears, at least in some patients, to be an unusual variant of the irritable bowel syndrome, in which pain is referred from the sigmoid colon to the rectum. ( info) |
130/150. Cramps and minimal EMG abnormalities as preclinical manifestations of spinal muscular atrophy patients with homozygous deletions of the SMN gene. The characterization of deletions in the SMN gene provides a helpful tool to confirm the diagnosis of spinal muscular atrophy (SMA). However, there may be homozygous deletions of the SMN gene in some unaffected siblings of SMA type II and III patients. We present two SMA families with affected siblings demonstrating a homozygous deletion of the SMN gene with extremely different phenotypes. We propose a preclinical category of an SMA patient with homozygous deletion of the SMN gene: those with minimal expression of the disease including cramps and EMG abnormalities that may develop the complete SMA phenotype in the future. ( info) |