Search PubMed⌕ Search

Biomedical subjects

R J Barohn

Publications and source records attributed to R J Barohn.

At least 73 records · Page 4Linked to original sources
PubMed1996

Isolated vitamin E deficiency.

A 22-year-old man presented with progressive gait instability, tremor, and dysarthria since childhood. Electrophysiologic studies revealed a sensorimotor polyneuropathy. Laboratory studies documented vitamin E deficiency; however, no gastrointestinal, hepatic, or lipoprotein disorder could be identified. Vitamin E therapy normalized the serum level, but there was no neurologic improvement. Isolated vitamin E deficiency, in the absence of lipid malabsorption, should be considered in the evaluation of children and adults with ataxia and peripheral neuropathy.

Adult↗
PubMed1996

A placebo-controlled trial of recombinant human ciliary neurotrophic (rhCNTF) factor in amyotrophic lateral sclerosis. rhCNTF ALS Study Group.

Preclinical investigations indicated that recombinant human ciliary neurotrophic factor (rhCNTF) may have potential as therapy for amyotrophic lateral sclerosis (ALS). We evaluated the safety and efficacy of rhCNTF in a prospective, double-blind, placebo-controlled trial in 570 patients with ALS. Patients were randomized to receive 0.5, 2, or 5 micrograms/kg/day rhCNTF, or placebo, for 6 months. The primary efficacy end point was the change from baseline to the last on-treatment value of a combination megascore for limb strength (maximum voluntary isometric contraction) and pulmonary function. Secondary end points included individual arm and leg megascores, pulmonary function tests, an activities-of-daily-living outcome measure, and survival. The four treatment groups were similar at baseline with respect to age, sex, disease duration, and muscle strength values. At all doses tested, rhCNTF had no beneficial effect on the primary or secondary end points. Certain adverse events, as follows, appeared to be dose related: injection site reactions, cough, asthenia, nausea, anorexia, weight loss, and increased salivation. There was an increased number of deaths at the highest dose level. rhCNTF had no beneficial effect on any measure of ALS progression. There were increased adverse events in the 5 micrograms/kg group and increased deaths.

Adult↗
PubMed1996

Inclusion body myositis: clinical and pathological boundaries.

Inclusion body myositis, polymyositis, and dermatomyositis are three distinct categories of inflammatory myopathy. Some authorities commented on the selective early weakness of the volar forearm muscles, quadriceps, and ankle dorsiflexors in inclusion body myositis. The most important feature distinguishing inclusion body myositis from the other two inflammatory myopathies is the lack of responsiveness to immunosuppressive treatment. Although most patients with inclusion body myositis have characteristic muscle biopsy findings, some cannot be distinguished histologically early from polymyositis. Predicting responsiveness to immunosuppressive medications, independent of muscle histology, would be valuable to clinicians. We retrospectively reviewed the pattern of weakness and other clinical features of 46 patients newly diagnosed with either inclusion body myositis, polymyositis, or dermatomyositis. Asymmetrical muscle weakness with prominent wrist flexor, finger flexor, and knee extensor involvement was specific for inclusion body myositis and unresponsive polymyositis. Male sex, lower creatine kinase levels, slower rate of progression, and peripheral neuropathy were also more common in inclusion body myositis and unresponsive polymyositis than in responsive polymyositis and dermatomyositis patients. Repeat muscle biopsy in 2 patients in the unresponsive polymyositis group demonstrated histological features of inclusion body myositis. We suspect that patients with clinical features of inclusion body myositis but lacking histological confirmation may nonetheless have inclusion body myositis. Our study supports the recently proposed criteria for definite and possible inclusion body myositis.

Aged↗
PubMed1996

Cerebrospinal fluid and nerve conduction abnormalities in HIV positive individuals.

We studied whether there was an association between nerve conduction studies (NCS), CSF, and CD4-T lymphocyte parameters in a large cohort of HIV positive individuals. Two hundred and twenty-eight HIV positive individuals underwent motor and sensory nerve conduction studies, CSF evaluation, peripheral CD4-T lymphocyte count, and neurologic evaluation to determine the presence or absence of peripheral neuropathy. We compared NCS of HIV positive subjects with and without abnormal CSF parameters in the entire cohort. We also compared CSF parameters in a subset of CD4-matched patients with and without neuropathy. CSF abnormalities (in excess of laboratory norms) occurred frequently in the entire study group. There was no statistically significant relationship between NCS and CSF parameters. In addition, there was no significant difference in the CSF findings in the group of patients with clinical neuropathy compared to the group without neuropathy. However, there was an association (p < 0.05) between lower CD4 counts and NCS parameters. In general, abnormal CSF findings are not associated with deteriorating peripheral nerve function in HIV infected patients and are just as likely to be found in an HIV positive patient whether or not a peripheral neuropathy is present.

Adult↗
PubMed1996

Peripheral neuropathy secondary to docetaxel (Taxotere)

Docetaxel (Taxotere), a semisynthetic analogue of the antitumor agent paclitaxel, inhibits tubulin depolymerization. Paclitaxel produces a peripheral neuropathy. This study delineates clinically and electrophysiologically the characteristics of a peripheral neuropathy due to docetaxel. In 186 patients receiving docetaxel in phase I and phase II protocols, we performed serial neurologic exams. As patients became symptomatic, quantitative sensory testing and nerve conduction studies were done. Twenty-one patients developed mild to moderate sensory neuropathy on taxotere at a wide range of cumulative doses (50 to 750 mg/m2) and dose levels (10 to 115 mg/m2). Ten of these patients also developed weakness of varying degree in proximal and distal extremities. Nine of the 21 patients had received neurotoxic chemotherapy before; 16 were treated with docetaxel at a dose level of 100 to 115 mg/m2. In summary, docetaxel produced a sensorimotor peripheral neuropathy in 11% of our patient population.

Antineoplastic Agents, Phytogenic↗
PubMed1996

Isolated neck extensor myopathy: a common cause of dropped head syndrome.

We report four patients with "dropped head syndrome," a recently described nonprogressive myopathy characterized by severe neck extensor weakness. This relatively benign condition may be confused with more ominous neuromuscular disorders that also present with prominent neck weakness. We compared clinical and laboratory data from the patients with dropped head syndrome with findings from patients with head drop caused by other neuromuscular conditions. Patients with "isolated neck extensor myopathy," a term we prefer to "dropped head syndrome," could be readily identified with electrophysiologic, radiographic, and histologic studies.

Aged↗
PubMed1996

Placebo-controlled trial of gabapentin in patients with amyotrophic lateral sclerosis. WALS Study Group. Western Amyotrophic Lateral Sclerosis Study Group.

We designed a phase II trial to evaluate the efficacy of gabapentin in slowing the rate of decline in muscle strength of patients with amyotrophic lateral sclerosis (ALS) and to assess safety and tolerability. Gabapentin (800 mg) or placebo was administered t.i.d. in a randomized, double-blinded, placebo-controlled, trial for 6 months. We enrolled 152 patients at eight sites in the United States. The primary outcome measure was the slope of the arm megascore, the average maximum voluntary isometric strength from eight arm muscles standardized against a reference ALS population. A secondary outcome measure was forced vital capacity. Slopes of arm megascores for patients on gabapentin were compared with slopes of those taking placebo using a two-way ANOVA. We observed a nonstatistically significant trend (p = 0.057-0.08) toward slower decline of arm strength in patients taking gabapentin compared with those taking placebo (mean difference 24%, median 37%). We observed no treatment effect on forced vital capacity. Gabapentin was well tolerated by patients with ALS. These results suggest that further studies of gabapentin in ALS are warranted.

Acetates↗
PubMed1995

Childhood-onset oculopharyngodistal myopathy with chronic intestinal pseudo-obstruction.

Oculopharyngodistal myopathy is characterized by the adult onset of ptosis, external ophthalmoplegia, dysphagia, and distal weakness. Although dysphagia is common, other gastrointestinal involvement has not been described. We report a case with childhood onset who developed chronic intestinal pseudo-obstruction. Other myopathies associated with ophthalmoplegia and intestinal pseudo-obstruction such as mitochondrial cytopathies were excluded. Whether oculopharyngodistal myopathy is a variant of oculopharyngeal muscular dystrophy or a distinct neuromuscular disorder is unknown and requires further study.

Adult↗
PubMed1995

The myotubular myopathies: differential diagnosis of the X linked recessive, autosomal dominant, and autosomal recessive forms and present state of DNA studies.

Clinical differences exist between the three forms of myotubular myopathy. They differ regarding age at onset, severity of the disease, and prognosis, and also regarding some of the clinical characteristics. The autosomal dominant form mostly has a later onset and milder course than the X linked form, and the autosomal recessive form is intermediate in both respects. These differences are, however, quantitative rather than qualitative. Muscle biopsy studies of family members are useful in some cases, and immunohistochemical staining of desmin and vimentin may help distinguish between the X linked and autosomal forms. Determining the mode of inheritance and prognosis in individual families, especially those with a single male patient, still poses a problem. Current molecular genetic results indicate that the gene for the X linked form is located in the proximal Xq28 region. Further molecular genetic studies are needed to examine the existence of genetic heterogeneity in myotubular myopathy and to facilitate diagnosis.

DNA↗
PubMed1995

Inclusion body myositis: explanation for poor response to immunosuppressive therapy.

We treated eight patients who had inclusion body myositis (IBM) with oral prednisone therapy, and we performed muscle biopsies before and after treatment. We documented the patients' clinical response to therapy and changes in serum CK. Although the serum CK level fell, muscle strength worsened after prednisone treatment. In addition, while inflammation decreased in the muscle biopsy specimens, the number of vacuolated and amyloid-positive fibers increased after oral prednisone therapy. These observations indicate that the inflammatory response in IBM may play a secondary role in the pathogenesis of IBM. The unique findings of intracellular amyloid deposits and rimmed vacuoles distinguishing IBM from other inflammatory myopathies, and recognition that suppression of inflammation has no effect on the clinical course, suggest that IBM may represent a degenerative muscle disorder.

Aged↗
PubMed1994

Immunosuppressive treatment of motor neuron syndromes. Attempts to distinguish a treatable disorder.

OBJECTIVE: To determine if response to immunosuppressive treatment in motor neuron syndromes could be predicted on the basis of clinical features, anti-GM1 antibodies, or conduction block. DESIGN: Prospective, uncontrolled, treatment trial using prednisone for 4 months followed by intravenous cyclophosphamide (3 g/m2) continued orally for 6 months. SETTING: All patients were referred to university hospital medical centers. PATIENTS: Sixty-five patients with motor neuron syndromes were treated with prednisone; 11 patients had elevated GM1 antibody titers, and 11 patients had conduction block. Forty-five patients received cyclophosphamide, eight of whom had elevated GM1 antibodies and 10 had conduction block. RESULTS: One patient responded to prednisone, and five patients responded to cyclophosphamide treatment. Only patients with a lower motor neuron syndrome and conduction block improved with either treatment. Response to treatment did not correlate with GM1 antibodies. CONCLUSIONS: GM1 antibodies did not serve as a marker for improvement in patients with motor neuron syndrome treated with immunosuppressive drugs. Patients with amyotrophic lateral sclerosis failed to improve irrespective of laboratory findings.

Adult↗
PubMed1994

Prolonged paralysis due to nondepolarizing neuromuscular blocking agents and corticosteroids.

The long-term use of nondepolarizing neuromuscular blocking agents (ND-NMBA) has recently been implicated as a cause of prolonged muscle weakness, although the site of the lesion and the predisposing factors have been unclear. We report 3 patients (age 37-52 years) with acute respiratory insufficiency who developed prolonged weakness following the discontinuation of ND-NMBAs. Two patients also received intravenous corticosteroids. Renal function was normal but hepatic function was impaired in all patients, and all had acidosis. Electrophysiologic studies revealed low amplitude compound motor action potentials, normal sensory studies, and fibrillations. Repetitive stimulation at 2 Hz showed a decremental response in 2 patients. The serum vecuronium level measured in 1 patient 14 days after the drug had been discontinued was 172 ng/mL. A muscle biopsy in this patient showed loss of thick, myosin filaments. The weakness in these patients is due to pathology at both the neuromuscular junction (most likely due to ND-NMBA) and muscle (most likely due to corticosteroids). Hepatic dysfunction and acidosis are contributing risk factors.

Adrenal Cortex Hormones↗
PubMed1994

Paramyotonia congenita: abnormal short exercise test, and improvement after mexiletine therapy.

The diagnosis of paramyotonia congenita (PC) can be aided by demonstrating a decrease in compound motor action potential amplitude after exercise and a decrement on repetitive stimulation, following cold exposure. We report a patient with PC who presented with complaints of cold-induced hand and jaw stiffening, in the absence of any episodes of weakness. Treatment with mexiletine led to resolution of the abnormalities exhibited during a short exercise test and repetitive stimulation following ice bath immersion. Molecular genetic analysis revealed a missense mutation (cytosine to thymidine) on chromosome 17 in the alpha-subunit of the skeletal muscle sodium channel gene that results in the replacement of threonine with methionine. This case demonstrates that, despite the absence of weakness, the short exercise test following cold exposure can be used to confirm the diagnosis of PC in patients without episodic weakness. Furthermore, improvement of the electrophysiologic abnormalities with mexiletine was documented, corresponding with clinical improvement.

Cold Temperature↗
PubMed1994

Acute peripheral neuropathy due to hereditary coproporphyria.

A 23-year-old man with epilepsy and a past history of abdominal pain and ileus, developed hypertension and arm and bulbar weakness when valproic acid and carbamazepine were reinitiated. Electrophysiologic studies demonstrated a peripheral neuropathy with features of axonal degeneration and demyelination. Axonal degeneration was documented by sural nerve biopsy. Markedly elevated urinary delta-aminolevulinic acid and porphobilinogen indicated a diagnosis of acute porphyria. Other laboratory studies were most consistent with hereditary coproporphyria. Motor function improved considerably but incompletely over 1 year. An acute, primarily motor neuropathy can occur in several forms of porphyria, including acute intermittent porphyria, variegate porphyria, and hereditary coproporphyria, sometimes even in the absence of concomitant gastrointestinal symptoms.

Acute Disease↗
PubMed1994

Evaluation of myosin-reactive antibodies from a panel of myasthenia gravis patients.

In the study described below, 97 myasthenia gravis (MG) patients have been evaluated for antibody reactivity against muscle myosin. With few exceptions, we could clearly observe a positive correlation between the presence of circulating serum anti-myosin antibodies and disease severity. Unlike some studies of anti-striational antibodies in MG patients, no association with thymoma was apparent. Moreover, no relationships were revealed between the severity of disease symptoms demonstrated and absolute anti-myosin antibody titers or prominent IgG subclasses. Therefore, we suggest that expression of myosin reactivity may be one useful parameter for predicting disease severity in those patients, but it is not prerequisite for induction of MG.

Antibodies↗