Biomedical subjects

R Barohn

Publications and source records attributed to R Barohn.

9 recordsLinked to original sources

PubMed2003

Practice parameter: immunotherapy for Guillain-Barré syndrome: report of the Quality Standards Subcommittee of the American Academy of Neurology.

OBJECTIVE: To provide an evidence-based statement to guide physicians in the management of Guillain-Barré syndrome (GBS). METHODS: Literature search and derivation of evidence-based statements concerning the use of immunotherapy were performed. RESULTS: Treatment with plasma exchange (PE) or IV immunoglobulin (IVIg) hastens recovery from GBS. Combining the two treatments is not beneficial. Steroid treatment given alone is not beneficial. RECOMMENDATIONS: 1) PE is recommended for nonambulant adult patients with GBS who seek treatment within 4 weeks of the onset of neuropathic symptoms. PE should also be considered for ambulant patients examined within 2 weeks of the onset of neuropathic symptoms; 2) IVIg is recommended for nonambulant adult patients with GBS within 2 or possibly 4 weeks of the onset of neuropathic symptoms. The effects of PE and IVIg are equivalent; 3) Corticosteroids are not recommended for the management of GBS; 4) Sequential treatment with PE followed by IVIg, or immunoabsorption followed by IVIg is not recommended for patients with GBS; and 5) PE and IVIg are treatment options for children with severe GBS.

Adrenal Cortex Hormones↗

PubMed2001

A placebo-controlled trial of gabapentin in spinal muscular atrophy.

OBJECTIVE: To evaluate the efficacy of gabapentin in increasing muscle strength of patients with spinal muscular atrophy (SMA). BACKGROUND: Preclinical data in experimental models of motor neuron disease suggest a neuroprotective effect of gabapentin. METHODS: Gabapentin (1200 mg), or placebo, was administered three times daily in a randomized, double-blind trial for 12 months. The primary outcome measure was the average percent change from baseline, based on the measurement of strength in four muscles (elbow flexion and hand grip bilaterally) for each patient. Drug efficacy was examined by comparing the percent change in strength for patients on drug vs. placebo. Secondary efficacy variables included: forced vital capacity (FVC), SMA functional rating scale (SMAFRS), and mini-Sickness Impact Profile (SIP). RESULTS: Eighty-four patients, with type II or III SMA, were enrolled at eight sites across the United States. There were no differences in baseline features. There was no difference between the placebo and drug groups in any outcome measure. CONCLUSIONS: This study demonstrates the feasibility of this trial design and provides data for the design of future clinical trials in SMA.

Acetates↗

PubMed2001

Mutations in Kir2.1 cause the developmental and episodic electrical phenotypes of Andersen's syndrome.

Andersen's syndrome is characterized by periodic paralysis, cardiac arrhythmias, and dysmorphic features. We have mapped an Andersen's locus to chromosome 17q23 near the inward rectifying potassium channel gene KCNJ2. A missense mutation in KCNJ2 (encoding D71V) was identified in the linked family. Eight additional mutations were identified in unrelated patients. Expression of two of these mutations in Xenopus oocytes revealed loss of function and a dominant negative effect in Kir2.1 current as assayed by voltage-clamp. We conclude that mutations in Kir2.1 cause Andersen's syndrome. These findings suggest that Kir2.1 plays an important role in developmental signaling in addition to its previously recognized function in controlling cell excitability in skeletal muscle and heart.

Alleles↗

PubMed1997

Andersen's syndrome: a distinct periodic paralysis.

A previous study of 4 patients defined Andersen's syndrome (AS) as a triad of potassium-sensitive periodic paralysis, ventricular dysrhythmias, and dysmorphic features. AS appears to be distinct in terms of its genetic defect from the alpha-subunit of skeletal muscle sodium channel and the cardiac potassium channel responsible for most long QT syndromes (LQT1). We studied 11 additional patients with AS from 5 kindreds. Spontaneous attacks of paralysis were associated with hypokalemia, normokalemia, or hyperkalemia. All 11 patients had similar dysmorphic features. The QT interval was prolonged in all patients although only 4 were symptomatic. Genetic linkage studies excluded linkage to the alpha-subunit of the skeletal muscle sodium channel and to four distinct LQT loci. In addition, none of the common dihydropyridine receptor mutations responsible for hypokalemic periodic paralysis were present. We conclude that (1) AS is a genetically unique channelopathy affecting both cardiac and skeletal membrane excitability, (2) attacks of paralysis may be either hypokalemic or hyperkalemic, (3) a prolonged QT interval is an integral feature of this syndrome, and (4) a prolonged QT interval may be the only sign in an individual from an otherwise typical AS kindred. This may be confused with more common, potentially lethal LQT syndromes.

Adolescent↗

PubMed1996

Relationship of the Tufts Quantitative Neuromuscular Exam (TQNE) and the Sickness Impact Profile (SIP) in measuring progression of ALS. SSNJV/CNTF ALS Study Group.

The Tufts Quantitative Neuromuscular Exam (TQNE) is a standardized tool for measuring muscle strength and pulmonary function in patients with amyotrophic lateral sclerosis (ALS). We describe the relationship of TQNE scores to functional disability and health-related quality of life as measured by the Sickness Impact Profile (SIP) in 524 ALS patients. There was a significant relationship (p < 0.0001) between TQNE and SIP scores, both in cross section and over time. TQNE scores strongly relate to ALS patients' quality of life and ability to perform activities of daily living.

Activities of Daily Living↗

PubMed1995

Model for the neuromuscular complications of systemic lupus erythematosus.

The purpose of this study is to evaluate nerve and muscle physiology and histopathology in a murine lupus model. Muscle strength, compound muscle action potentials (distal latency and amplitude), proximal limb muscle, sciatic nerve and joint specimens were studied in MRL/lpr (lupus model) and MRL/++ (control) mice. MRL/lpr mice showed decreased muscle strength (P < 10(-6, Wilcoxon rank sum), lower compound muscle action potential mean amplitude and prolonged distal latency (P = 0.005 and 0.042. Mann-Whitney U-test), and muscle and nerve inflammation (P = 0.002 and P = 0.037, Fisher's exact test) compared with MRL/++ mice. The MRL/lpr strain evaluated in this study demonstrated muscle weakness, abnormal motor nerve conduction studies and inflammation of both muscle and nerve. These features make it an excellent model for studying the neuromuscular complications of lupus.

Action Potentials↗

PubMed1994

Taxol neuropathy. Electrodiagnostic and sural nerve biopsy findings.

Taxol has recently been approved for the treatment of ovarian cancer that has failed to respond to other chemotherapeutic agents. A predominantly sensory neuropathy has been reported in patients receiving taxol, but corresponding nerve changes have not been described. The patient described herein received taxol at a dose of 275 mg/m2 every 21 days. The sural nerve biopsy performed after 17 courses of taxol (cumulative dose, 6603 mg) showed severe nerve fiber loss, axonal atrophy, and secondary demyelination. Axonal regeneration was absent. The findings are compatible with a cell body disease or a length-dependent, distal neuropathy with failure of axonal regeneration. The findings observed in taxol-induced neuropathy are important to document for comparison with other neoplastic and paraneoplastic neuropathies affecting patients with cancer.

Electrodiagnosis↗

PubMed1994

Metabolic myopathies.

Metabolic myopathies are disorders of muscle energy production that result in skeletal muscle dysfunction. Cardiac and systemic metabolic dysfunction may coexist. Symptoms are often intermittent and provoked by exercise or changes in supply of lipid and carbohydrate fuels. Specific disorders of lipid and carbohydrate metabolism in muscle are reviewed. Evaluation often requires provocative exercise testing. These tests may include ischemic forearm exercise, aerobic cycle exercise, and 31P magnetic resonance spectroscopy with exercise.

Carnitine↗

PubMed1993

Effect of sympathetic block demonstrated by triple-phase bone scan.

The triple-phase bone scan is frequently used in the diagnosis of reflex sympathetic dystrophy although the etiology of the abnormal findings is not well established. This study evaluated the effect of increased blood flow secondary to sympathetic block on the triple-phase bone scan. In 15 reflex sympathetic dystrophy patients, all of whom had significant relief with sympathetic block, baseline and postsympathetic block bone scans were analyzed. There was a significant linear relationship between change in counts from baseline to postsympathetic block on the blood pool image and bone uptake image. As the blood pool and bone uptake counts increased, the likelihood of typical reflex sympathetic dystrophy findings on visual inspection also increased. These results strongly support the concept of increased vascular flow as the cause of increased periarticular uptake.

Autonomic Nerve Block↗