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Biomedical subjects

D R Cornblath

Publications and source records attributed to D R Cornblath.

At least 127 records · Page 7Linked to original sources
PubMed1988

Cerebrospinal fluid abnormalities in homosexual men with and without neuropsychiatric findings.

We have studied cerebrospinal fluid obtained from 38 homosexual or bisexual men participating in a prospective study of the neuropsychological disorders associated with human immunodeficiency virus (HIV) infection. Twenty-two subjects had neuropsychiatric findings and seropositivity, 11 asymptomatic subjects had seroconverted within 6 to 24 months, and 5 subjects were seronegative controls. Only 1 had acquired immunodeficiency syndrome-related complex, and none had the acquired immunodeficiency syndrome when initially studied. There was a high rate of cerebrospinal fluid abnormalities in men with neuropsychiatric findings, including pleocytosis (41%), elevated IgG and IgG index (47%), and oligoclonal bands (18%). Even in the absence of neuropsychiatric findings, the asymptomatic HIV-seropositive subjects frequently had spinal fluid abnormalities. Of those with neuropsychiatric findings, HIV p24 antigen was detectable in cerebrospinal fluid in only 1 individual, yet HIV was isolated in 11 of 16 (69%) compared to 2 of 7 (29%) of those without neuropsychiatric findings. The identification of cerebrospinal fluid abnormalities in individuals known to have become infected within 6 to 24 months supports the hypothesis that the nervous system is an early target for HIV.

Adolescent↗
PubMed1988

Treatment of the neuromuscular complications of human immunodeficiency virus infection.

Neuromuscular disorders are increasingly being reported in individuals with human immunodeficiency virus (HIV) infection. The majority of these disorders resemble diseases occurring in HIV-seronegative patients and include inflammatory demyelinating polyneuropathies, multiple mononeuropathies, and polymyositis. In HIV-seronegative patients, these diseases are believed to be immune system-mediated. It is likely that similar pathogenic mechanisms are present in HIV-seropositive patients and reflect an altered immune system caused by viral infection and the loss of CD4 cells. Therapy is similar in both seropositive and seronegative patients with inflammatory demyelinating polyneuropathies, but plasmapheresis is preferred in seropositive patients as it is less likely than corticosteroids to induce further immunosuppression. Distal sensory neuropathy is characteristic in patients infected with HIV, especially those with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex, and may be a consequence of HIV infection. Therefore, antiviral agents may have a therapeutic role for this disorder.

Acquired Immunodeficiency Syndrome↗
PubMed1988

A treatable multifocal motor neuropathy with antibodies to GM1 ganglioside.

We report 2 patients with a treatable, immune-mediated motor polyneuropathy associated with antibodies to defined neural antigens. In these patients asymmetrical weakness developed in one arm and progressed over 2 to 3 years to involve the other arm, legs, and trunk. Both patients were initially diagnosed as having lower motor neuron forms of amyotrophic lateral sclerosis. However, repeated electrophysiological testing eventually showed multifocal conduction blocks in motor but not sensory fibers compatible with patchy selective demyelination. Serum testing by thin-layer chromatography and enzyme-linked immunosorbent assay revealed that both patients had high titers of antibody directed against GM1 and other gangliosides. Initial therapeutic trials of prednisone (100 mg daily for 4 to 6 months) and plasmapheresis were unsuccessful. Treatment with cyclophosphamide, however, was followed by marked improvement in strength in both patients.

Adult↗
PubMed1988

Assessment of thoracic paraspinal muscles in the diagnosis of ALS.

The distribution of muscle involvement, assessed clinically and electromyographically, was analyzed prospectively in 55 consecutive amyotrophic lateral sclerosis (ALS) patients and in 54 patients with other predominantly motor syndromes, some of whom were referred with suspected ALS. In ALS patients, distal limb muscles and thoracic paraspinal muscles were affected most frequently, more so than proximal limb and cranial muscles. The incidence of bulbar symptoms in ALS was greater in women than in men. These patterns suggest selective vulnerability of specific neuronal populations. The vulnerability of truncal muscles, illustrated by thoracic paraspinal wasting or head and shoulder drooping, was a helpful differential sign in diagnosing ALS. Thoracic paraspinal electromyography was especially valuable in distinguishing ALS from other disorders, such as combined cervical and lumbar spondylotic amyotrophy or polymyositis, which may masquerade as ALS. The finding of denervation atrophy on biopsy of thoracic paraspinal muscles was diagnostic in difficult cases. Because the thoracic paraspinal muscles are frequently affected in ALS and spared in spondylotic amyotrophy, their assessment provides a practical strategy in differentiating ALS from other motor syndromes.

Aged↗
PubMed1988

Influence of malnutrition on developing rat peripheral nerves.

Animals with experimentally induced neuropathies frequently fail to gain weight normally and appear poorly nourished. To determine whether or not malnutrition alone contributes to peripheral nerve dysfunction in these disorders, we subjected healthy 40-day-old rats to three grades of food restriction. After 4 weeks, food-restricted rats weighed 203 +/- 5 (mean +/- SE), 152 +/- 12, and 97 +/- 5 g, respectively, whereas control rats having free access to food weighed 379 +/- 22 g. Posterior tibial nerves of food-deprived rats had smaller endoneurial areas, fewer large-diameter fibers, and shorter internodes than did the nerves of control animals. However, the number of fibers was similar to controls, and there was no evidence of active degeneration or demyelination. Motor and mixed nerve conduction velocities along the same nerves increased with age and did not differ among control and malnourished groups. In growing rats, food deprivation sufficient to impair somatic growth interferes with the maturation of large-caliber myelinated fibers, but does not effect standard electrophysiologic measurements of nerve function.

Action Potentials↗
PubMed1988

Role of therapeutic plasmapheresis in the acute Guillain-Barré syndrome.

Plasmapheresis modifies the course of the acute Guillain-Barré syndrome (GBS) in terms of time-related parameters such as time on a respirator or time to achieve a specific area of improvement at specific times after onset of the illness such as at 1 month and at 6 months. Certain factors are associated with poorer outcomes in acute GBS. These include amplitude of compound muscle axon potentials on stimulating distally, time of onset of disease of 7 days or less, need for ventilatory support, and older age. Plasmapheresis, the only variable that the physician can influence, has a beneficial effect over and above all these factors.

Acute Disease↗
PubMed1988

Gracile tract degeneration in patients with sensory neuropathy and AIDS.

At autopsy, four homosexual men with acquired immunodeficiency syndrome (AIDS) were found to have selective degeneration of the gracile tract, a finding previously unreported in AIDS. Clinically, these patients had progressive lower extremity paresthesias and dysesthesias with reduced or absent ankle jerks, and eventually they developed dementia. Postmortem examination of spinal cords showed a striking loss of both axons and myelin sheaths confined to the fasciculus gracilis, with the most severe involvement in upper thoracic or cervical segments. Lumbar dorsal columns showed only a mild fiber loss, and no fiber loss was observed in lumbar dorsal roots. Lumbar dorsal root ganglia were available from one patient and showed a mild sensory ganglionitis. In all cases examined, microglial nodules were present in the brain. In 23 other individuals with AIDS who had autopsies consecutively with these four subjects, none had sensory neuropathy and the gracile tracts were normal. The combination of distal sensory neuropathy and gracile tract degeneration suggests a "dying-back" process of dorsal root ganglia neurons.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Predominantly sensory neuropathy in patients with AIDS and AIDS-related complex.

The most common type of peripheral neuropathy associated with human immunodeficiency virus (HIV) infection, predominantly sensory neuropathy, affects 10-30% of patients with acquired immunodeficiency syndrome (AIDS). From 40 individuals with peripheral neuropathy and HIV infection, we have identified 26 patients with this syndrome. All had constitutional symptoms when neuropathic symptoms developed; 20 had AIDS and six had AIDS-related complex. The most common complaint was pain on the soles. Paresthesias were frequent and usually involved the entire foot. Signs of peripheral neuropathy were present in all; the most frequent finding was absent or reduced ankle reflexes. Electrophysiologic studies revealed abnormal sensory and motor conduction, studies suggesting a dying-back axonopathy. Over time, the neuropathy progressed in all except one patient with ARC, who had spontaneous subjective improvement. Tricyclic antidepressants provided partial symptomatic relief. In three patients, the neuropathy did not change during azidothymidine treatment. Predominantly sensory neuropathy in HIV infection appears to be a distal axonal degeneration primarily involving sensory neurons. The mechanism is unknown, but the neuropathy is associated with the late manifestations of HIV infection.

AIDS-Related Complex↗
PubMed1987

Inflammatory demyelinating peripheral neuropathies associated with human T-cell lymphotropic virus type III infection.

Nine patients with inflammatory demyelinating polyneuropathies (IDP) were found to have human T-cell lymphotropic virus type III (HTLV-III) infection. The 8 men, 6 of whom were homosexual, and 1 woman, a former intravenous drug user, presented with progressive weakness. Two had lymphadenopathy but all were otherwise asymptomatic. Six had chronic IDP and 3 had Guillain-Barré syndrome. In addition to an elevated cerebrospinal fluid (CSF) protein level (mean, 193 mg/dl), most patients had cerebrospinal fluid pleocytosis (mean, 23 cells/mm3), a distinctive feature. All had reduced T4:T8 T-cell ratios. Results of nerve conduction studies were characteristic of demyelination. Nerve biopsies revealed intense inflammatory cell infiltrates and macrophage-mediated demyelination. The patients recovered either spontaneously or following treatment with corticosteroids or plasmapheresis. During a mean interval of 20 months after presentation, only 1 patient had developed acquired immune deficiency syndrome. Patients with HTLV-III infection have disordered immune function, and the mechanism of the development of the IDP is likely to be immunopathogenic. As a result of our experience, we suggest that all patients with IDP be tested for evidence of HTLV-III infection. We also found, although in uncontrolled trials, that treatment with either prednisone or plasmapheresis was followed by clinical improvement; since plasmapheresis is not likely to further depress cell-mediated immunity, we suggest that it be the initial therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Immunoreactive myelin basic protein in cerebrospinal fluid of patients with peripheral neuropathies.

The presence of myelin basic protein (MBP)-like material in cerebrospinal fluid (CSF) usually reflects breakdown of central nervous system myelin. Immunoreactive MBP levels were measured in 70 CSF specimens from 66 patients with a variety of peripheral neuropathies. Immunoreactive MBP was present in CSF in 70% (16 of 23) of patients with biopsy-proved chronic demyelinating polyneuropathies, whereas in neuropathies producing primarily axonal damage it was present in only 22% (5 of 23). In Guillain-Barré syndrome, 45% (9 of 20) of patients had immunoreactive MBP in the CSF. We conclude that MBP-like material is present in the CSF of most patients with longstanding demyelinating polyradiculoneuropathies and probably reflects detection of peripheral nervous system P1 protein.

Demyelinating Diseases↗
PubMed1986

Disorders of neuromuscular transmission in infants and children.

Disorders of neuromuscular transmission in infants and children can be divided into two groups. The first group includes conditions similar to those seen in adults: autoimmune myasthenia gravis, Lambert-Eaton myasthenic syndrome, and botulism. The second includes several disorders that are unique to this age group, such as the congenital myasthenias and infantile botulism. This review discusses the diseases of neuromuscular transmission found in the pediatric population, with emphasis on electrodiagnosis. The distinctive clinical and electrophysiologic features allow the clinician to identify these illnesses correctly, so that appropriate treatment can be instituted or further specialized investigation can be undertaken.

Autoimmune Diseases↗
PubMed1986

Monitoring azathioprine therapy in myasthenia gravis.

Azathioprine (AZA) is used increasingly in the treatment of selected patients with myasthenia gravis (MG). The "usual" dose is 2 to 3 mg/kg/d, but guidelines do not exist to determine a specific dose for an individual patient. We reviewed our previously reported MG patients to determine what laboratory studies correlated with therapeutic efficacy. Among the studies examined, red cell mean corpuscular volume (RBC MCV) was the most useful: in 10 patients who responded to AZA, MCV increased by 15 +/- 2 fl (mean +/- SD), while in 6 nonresponders, MCV increased by only 4.5 +/- 6 fl (p less than or equal to 0.01). RBC MCV may be helpful in monitoring AZA therapy in patients with MG.

Azathioprine↗
PubMed1985

Transient conduction block following acute peripheral nerve ischemia.

We studied the effects of transient focal ischemia on the electrophysiologic function of rat sciatic nerves. Focal and generalized impairment of impulse conduction, measured by falling evoked muscle and nerve compound action potential amplitudes, occurred within 10 minutes of femoral artery occlusion. Conduction failure reached a nadir at 45-60 minutes and then improved to normal within 24 hours. Fastest motor and mixed nerve conduction velocities were reduced less than 15% of baseline values during the period of acute conduction block. There were no detectable morphological abnormalities at the site of conduction failure. Transient ischemia produces reversible conduction block without evident structural changes. The fall in amplitude without significant conduction slowing implies that slower conducting myelinated fibers are relatively more sensitive to the effect of acute ischemia.

Animals↗
PubMed1984

Azathioprine in the treatment of myasthenia gravis.

Twenty-four patients with myasthenia gravis were treated with azathioprine. Eighteen of the patients tolerated the drug. Six discontinued azathioprine therapy because of toxicity. Of the 18 patients, 15 (83%) improved while receiving azathioprine; in 8 (44%) improvement was felt to result solely from azathioprine. Initial response was seen after 4 to 10 months of treatment, with a mean of 6.4 months. Patients continued to improve for up to 24 months, with the mean time of peak improvement being 14 months. Relapse occurred within one year in all 6 patients in whom azathioprine administration was discontinued. Azathioprine is a reasonable alternative to corticosteroids in selected myasthenic patients requiring immunosuppression.

Adult↗
PubMed1984

Chronic demyelinating polyneuropathy in systemic lupus erythematosus.

Mononeuritis multiplex and acute demyelinating polyneuropathy (Guillain-Barré syndrome) are well known in systemic lupus erythematosus (SLE). Chronic acquired demyelinating polyneuropathy has been reported rarely in SLE. Two young women had monophasic progressive weakness, areflexia, elevated CSF protein, and slow nerve conduction velocities as the first manifestation of SLE. Sural nerve biopsy in one patient revealed mild loss of myelinated fibers and an increased number of thinly myelinated fibers. Steroid therapy led to improvement in both patients. These patients demonstrate that chronic demyelinating polyneuropathy can be an unusual presentation of SLE, even preceding characteristic systemic disease by months.

Adult↗
PubMed1982

Neurophysiological and neuropsychological function in mercury-exposed dentists.

In a study of the relation between cumulative exposure to mercury and chronic health impairment 298 dentists had their mercury levels measured by an X-ray fluorescence technique. Electrodiagnostic and neuropsychological findings in the dentists with more than 20 micrograms/g tissue mercury levels were compared with those of a control group consisting of dentists with no detectable mercury levels. 30% of the 23 high mercury dentists had polyneuropathies. No polyneuropathies were detected in the control group. The high mercury group had mild visuographic dysfunction; they also had more symptom-distress than did the control group. These findings suggest that the use of mercury as a restorative material is a health risk for dentists.

Adult↗
PubMed1980

Creutzfeldt-Jakob disease in a 20-year-old woman.

A 20-year-old woman developed ataxia, extrapyramidal movements, myoclonus, and progressive dementia. Brain biopsy disclosed status spongiosus, diagnostic of Creutzfeldt-Jakob disease; this is the youngest spontaneous case ever reported. Creutzfeldt-Jakob disease can occur in young adulthood.

Adult↗