Biomedical subjects

W W Bryan

Publications and source records attributed to W W Bryan.

29 records · Page 2Linked to original sources

PubMed1997

Electrophysiologic findings in multifocal motor neuropathy.

We performed detailed electrophysiologic studies on 16 patients with clinically defined multifocal motor neuropathy and found a wide spectrum of demyelinating features. Only five patients (31%) had conduction block in one or more nerves. However, in 15 patients (94%) at least one nerve showed other features of demyelination. We also noted a significant degree of superimposed axonal degeneration in 15 patients. Eight patients (50%) had individual nerves with pure axonal injury, despite the presence of demyelinating features in other nerves. Antiganglioside antibodies were elevated in four of five patients with conduction block and five of 11 patients without conduction block. We conclude that multifocal motor neuropathy is characterized electrophysiologically by a wide spectrum of axonal and demyelinating features. Diagnostic criteria requiring conduction block may lead to underdiagnosis of this potentially treatable neuropathy.

Adult↗

PubMed1996

Tomaculous neuropathy: a clinical and electrophysiological study in patients with and without 1.5-Mb deletions in chromosome 17p11.2.

Tomaculous neuropathy is the descriptive term for the "sausagelike" swellings of myelin characteristic of hereditary neuropathy with liability to pressure palsies (HNPP). A 1.5-Mb deletion in chromosome 17p11.2 is present in the majority but not all cases of HNPP. We reviewed the clinical and electrophysiological features of 18 patients with tomaculous neuropathy and compared these features between patients with and without the typical large deletion. Patients presented with a variety of pressure-induced nerve palsies and brachial plexopathies. Two patients presented with generalized symmetric sensorimotor polyneuropathies. Four patients were older than their respective probands but were as yet asymptomatic. Nerve conduction studies demonstrated prolonged distal latencies out of proportion to slowing of conduction velocities, suggesting a distally accentuated myelinopathy. DNA analysis revealed the 1.5-Mb deletion in all the familial cases and in 3 of the sporadic patients. The clinical and electrophysiological features were similar between patients with and without the 1.5-Mb deletion in chromosome 17p11.2.

Adolescent↗

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

The effect of a muscle wrap on nerve healing in a rat model.

Sixty Sprague-Dawley rats were studied to determine if peripheral nerve healing could be enhanced by translocation of an injured segment of sciatic nerve from an interfascial to an intramuscular environment. Group 1 (n = 12) were unoperated controls; Group 2 (n = 12) were sham-operated; Group 3 (n = 12) sustained an acute, double-crush injury to the sciatic nerve; and Group 4 (n = 12) sustained the same acute, double-crush injury as in Group 3, but the injured segment of nerve was transposed intramuscularly. All animals had sciatic function indices (SFI) computed at weekly intervals. At 2 weeks, Group 4 appeared to have improved gait function (SFI), compared to Group 3 (-39.7 vs. -56.4, p < 0.08). The experiment was repeated for Groups 3 and 4 using two groups of six additional rats each. The data were collected three times for each rat in the second experiment. No statistically significant differences in return of gait function or in nerve conduction evaluation could be demonstrated between the two study groups. From the results of this study, it appears that an intramuscular location does not enhance nerve recovery, compared to an interfascial location.

Animals↗

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

Toxicity and tolerability of recombinant human ciliary neurotrophic factor in patients with amyotrophic lateral sclerosis.

We examined the toxicity of both single and multiple subcutaneous injections of recombinant human ciliary neurotrophic factor (rhCNTF) in 72 patients with ALS, in doses ranging from 2 to 100 micrograms/kg. Adverse events were generally dose related and ranged from mild to severe. The tolerability of daily subcutaneous rhCNTF was equivalent to placebo at doses < or = 5 micrograms/kg/day. At higher doses, anorexia, weight loss, reactivation of herpes simplex virus (HSV1) labialis/stomatitis, cough, and increased oral secretions occurred.

Adult↗

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↗

PubMed1993

MRI-guided biopsy in inflammatory myopathy: initial results.

The purpose of this report is to describe our initial experience with techniques employing magnetic resonance imaging (MRI) to guide the choice of muscle to be biopsied in patients suspected of having inflammatory myopathy. Five patients with a clinical diagnosis of inflammatory myopathy (IM) were studied. Four were imaged prior to biopsy. Four had repeated examinations, either immediately following biopsy or to evaluate disease progression. Use of MRI to localize muscle lesions was associated with abnormal pathologic findings in all cases, including histopathologic demonstration of lymphocyte infiltration in three cases of idiopathic polymyositis; nonspecific myopathic changes were seen in one patient with probable dermatomyositis and in one patient with chronic inflammatory polyneuropathy and high serum creatine kinase levels (> 45,000 IU/ml). The precise location of the area sampled by biopsy was visible in only one of four postbiopsy images. MRI shows promise in identifying pathologic muscle in patients suspected of having one of the inflammatory myopathies; however, further refinement of localization techniques may be needed to optimize histopathologic diagnoses.

Acquired Immunodeficiency Syndrome↗

PubMed1993

Denervated human skeletal muscle: MR imaging evaluation.

Because determination of neurologic integrity after severe limb trauma is crucial in patient care, the authors assessed magnetic resonance (MR) imaging as a tool to map denervated motor units of skeletal muscle in patients with traumatic peripheral neuropathy. Denervation was confirmed in 22 patients with use of electromyography, surgery, or both. MR imaging was performed with moderately T1- and T2-weighted spin-echo and short-tau inversion-recovery (STIR) sequences. MR imaging was unreliable in depicting acute denervation. Muscles of patients with subacute denervation had prolonged T1 and T2, which contributed to conspicuous hyperintensity on STIR images. Chronically denervated muscles showed marked atrophy, variable changes on STIR images, and conspicuous fatty infiltration on T1-weighted images. Normal variants in motor unit anatomy were seen in denervated muscle volumes outside the expected distribution of the injured nerve. MR imaging is promising for the noninvasive mapping and monitoring of denervated muscle in subacute and chronic phases of peripheral neuropathy.

Extremities↗

PubMed1991

Locomotor system assessment by muscle magnetic resonance imaging.

Clinical evaluation of the locomotor system has long been hampered by difficulty in assessing the morphologic and functional integrity of skeletal muscles. Diagnostic imaging represents a major advance in the diagnosis and management of patients with locomotor dysfunction through the possibility of probing beyond overlying soft tissues to identify muscle lesions, determine their extent, characterize their composition, direct invasive procedures, and monitor therapies. Magnetic resonance imaging (MRI) appears to be the most promising of available imaging methods, because of its great sensitivity to changes in muscle water distribution and fat content. Also, it can distinguish between individual deep and superficial muscles. Serial evaluations of many muscles are practical because of the safety of MRI. While the cost effectiveness in the workup of locomotor dysfunction remains to be determined, the scientific and practical clinical information now available merits further investigation by clinicians and radiologists alike. The purpose of this review is to describe the potential role of skeletal muscle MRI in evaluating the locomotor system.

Humans↗