Biomedical subjects
D A Chad
Publications and source records attributed to D A Chad.
Motor neuron disease and paraproteinemia.
We studied two patients with motor neuron disease and paraproteinemia. One had amyotrophic lateral sclerosis (ALS) and IgG lambda monoclonal gammopathy. The second had slowly progressive muscular atrophy and an IgM kappa paraprotein, followed by a biclonal gammopathy when an IgA kappa paraprotein appeared. Treatment with immunosuppressive agents and plasmapheresis lowered the serum concentration of the paraproteins. The ALS syndrome progressed despite therapy. The other patient improved, was stable for several years, but then deteriorated despite continued therapy.
Sciatica: an early manifestation of thoracic vertebral osteochondroma.
We describe a 36-year-old woman with a thoracic vertebral osteochondroma who presented with radicular leg pain. This benign tumor is uncommon in the vertebral column, and radicular pain is an unusual manifestation of a thoracic spinal lesion. Myelography and computed tomography aided in diagnosis; surgical resection resulted in an excellent clinical response.
Neuropathy associated with cryoglobulinemia.
A patient with severe subacute sensory ataxia was found to have an IgM (kappa) cryoglobulin. Clinical, electrophysiologic, and sural nerve biopsy studies indicated that axonal degeneration and segmental demyelination both played a role in the pathogenesis of this neuropathy. Corticosteroid therapy was associated with notable clinical improvement and a 50% decrease in cryoglobulin concentration.
Motor fibers in the sural nerve.
In an ischemia-induced model of an acute motor neuron disorder, there is anterior horn cell damage with Wallerian degeneration in ventral roots; dorsal root ganglia and dorsal roots are unaffected. In a mixed nerve there is axonal degeneration reflecting loss of motor fibers. The sural nerve is normal showing that it does not contain motor fibers. This observation is relevant to the neuropathology of motor neuron disease where axonal degeneration found in the sural nerve suggests involvement of sensory fibers.
Perineuritis and ulcerative colitis.
We describe the association of chronic polyneuropathy with ulcerative colitis. Electrophysiologic studies disclosed a severe neuropathy with both axonal and demyelinating features. The CSF protein content was 875 mg/dl. Sural nerve biopsy revealed perineuritis. Peripheral neuropathy with perineuritis may be an immunologically mediated extraintestinal manifestation of ulcerative colitis.
Slow resolution of multifocal weakness and fasciculation: a reversible motor neuron syndrome.
A 25-year-old man with multifocal weakness and fasciculation was thought to have motor neuron disease. Signs progressed for 1 year, plateaued, and 3 years later resolved almost completely. There was no evidence of paraproteinemia, lymphoproliferative disorder, or vasculitis, and myelography was normal. Electrodiagnostic study disclosed multifocal, acute and chronic denervation that evolved into a picture consistent with residuals of old multifocal radiculopathy without active denervation. Prolongation of F response, absence of H-reflex, and conduction block in a proximal nerve segment suggested multifocal demyelination. A proximal motor neuropathy, perhaps demyelinating, may cause some of the benign motor neuron syndromes that simulate motor neuron disease.