Search PubMed⌕ Search

Biomedical subjects

S J Bird

Publications and source records attributed to S J Bird.

At least 37 records · Page 2Linked to original sources
PubMed1998

Iatrogenic superior gluteal mononeuropathy.

Injuries to the superior gluteal nerve (SGN) have been reported as a result of trauma, pyriformis muscle entrapment, injections, and lumbar lordosis and inadequate back stabilization. We report 3 patients who developed isolated SGN injuries, 1 after a partial nephrectomy and 2 following revision of a total hip arthroplasty. SGN should be suspected in anyone developing an abnormal gait after hip or pelvic surgery or after prolonged lateral decubitus positioning.

Adult↗
PubMed1997

Direct muscle stimulation in acute quadriplegic myopathy.

We have previously found that muscle is electrically inexcitable in severe acute quadriplegic myopathy (AQM). In contrast, muscle retains normal electrical excitability in peripheral neuropathy. To study the relationship between muscle electrical excitability and all types of flaccid weakness occurring in the intensive care unit, we identified 14 critically ill, weak patients and measured the amplitude of compound muscle action potentials (CMAPs) obtained with direct muscle stimulation (dmCMAP) and with nerve stimulation (neCMAP). In 11 of 14 patients dmCMAP amplitudes were reduced and the ratio of the neCMAP amplitude to the dmCMAP amplitude (nerve/muscle ratio) was indicative of loss of muscle electrical excitability. In 2 other patients, the nerve/muscle ratio indicated neuropathy. Direct muscle stimulation may allow differentiation of AQM from neuropathy even in comatose or encephalopathic critically ill patients. AQM may be more common than has previously been appreciated.

Action Potentials↗
PubMed1997

Autosomal dominant transmission of Dejerine-Sottas disease (HMSN III).

Hereditary motor-sensory neuropathy type III (HMSN III) (Dejerine-Sottas disease) is a severe demyelinating neuropathy that is traditionally considered autosomal recessive. We report a father and daughter diagnosed with HMSN III by clinical, electrophysiologic, and pathologic criteria, thus showing that it may be transmitted in an autosomal dominant fashion in selected families.

Adolescent↗
PubMed1996

Muscle is electrically inexcitable in acute quadriplegic myopathy.

We directly stimulated muscle in three patients with acute quadriplegic myopathy to determine whether paralyzed muscle in this syndrome is electrically excitable. Two of the patients had been treated with neuromuscular blocking agents and corticosteroids, and one patient had been treated with corticosteroids alone. We found that paralyzed muscle is electrically inexcitable in affected patients. Muscle regained electrical excitability over weeks to months. The recovery of muscle excitability paralleled the clinical recovery of patients, suggesting that paralysis in this syndrome is secondary to electrical inexcitability of muscle membrane.

Acute Disease↗
PubMed1996

Chronic inflammatory demyelinating polyneuropathy associated with malignant melanoma.

We report three patients who developed chronic inflammatory demyelinating polyneuropathy (CIDP) in association with malignant melanoma. In two cases, melanoma was discovered during the initial evaluation for neuropathy. Two patients also had vitiligo, an antibody-mediated disorder that may complicate melanoma. Melanoma cells and Schwann cells are both of neuroectodermal cell origin, with shared surface antigens. Shared immunoreactivity may account for the association between melanoma and CIDP, as with vitiligo.

Adult↗
PubMed1995

Mechanism of lysosome rupture by dipeptides.

Low concentrations of some neutral dipeptides, such as L-Ala-L-Ala, rapidly disrupt rat liver lysosomes. The phenomenon has been attributed to an osmotic imbalance generated by the production of amino acids in the lysosome by lysosomal dipeptidase activity. This hypothesis is challenged by testing several pairs of dipeptides available in both D- and L-forms and a range of dipeptides whose susceptibility to lysosomal dipeptidase activity is known. A good correlation was found between the lytic ability of dipeptides and their capacity to cross the lysosome membrane and be hydrolysed by lysosomal dipeptidase. The osmotic-imbalance hypothesis is critically evaluated in the light of the results and of recent information concerning the carrier-mediated transport of amino acids and dipeptides across the lysosome membrane. It is concluded that intralysosomal generation of amino acids remains the most plausible explanation of the lytic activity of dipeptides, and that the dipeptide porter(s) in the lysosome membrane must have higher Km than the amino acid porters.

Animals↗
PubMed1995

Site of autonomic dysfunction in a patient with Ross' syndrome and postganglionic Horner's syndrome.

Ross' syndrome is a rare peripheral nervous system disorder defined by Adie's tonic pupil, hyporeflexia, and segmental anhidrosis. Injury to postganglionic cholinergic fibers is believed to account for the tonic pupil and sweating disturbance. We report a 47-year-old man found to have Ross' syndrome in combination with a complete postganglionic Horner's syndrome. Pharmacologic and sudomotor tests in this unique patient provide further evidence that Ross' syndrome results from injury to sympathetic and parasympathetic ganglion cells or to their postganglionic projections.

Heart Rate↗
PubMed1994

Prolonged muscle weakness after neuromuscular blockade in the intensive care unit.

As noted, quadriparesis with reduced reflexes and difficulty with ventilator weaning may be seen as a result of a number of neuromuscular disorders. The clinical approach relies on exclusion of a central cause first, followed by careful examination of peripheral nerve and muscle function. Persistent neuromuscular blockade should be excluded initially because it is a readily reversible condition. Use of a train of four stimulation with a peripheral twitch monitor can quickly establish integrity of conduction across the neuromuscular junction. If necessary, further electrophysiologic studies allow differentiation among the relevant diagnostic possibilities. CIP is characterized by nerve conduction and EMG findings consistent with axonal degeneration of sensory and motor fibers. GBS is distinguished by evidence of demyelination on nerve conduction studies, in addition to elevated spinal fluid protein. Persistent neuromuscular blockade is identified by a decremental response on repetitive stimulation studies of neuromuscular transmission. The acute myopathy following neuromuscular blockage does not involve sensory responses. Needle EMG examination reflects a myopathic pattern, rather than a neurogenic one as seen in CIP or GBS. In myopathic patients who are unable to move their limbs at all (precluding a full EMG examination), a muscle biopsy identifies muscle as the site of involvement.

Adult↗
PubMed1992

Spontaneous remission of a third-nerve palsy in meningeal lymphoma.

We report on a patient with spontaneous remission of a third-nerve palsy who was subsequently found to have meningeal lymphoma. Initial magnetic resonance images (MRI) showed bilateral enhancement of the third nerves. Follow-up MRI 7 months later, without treatment, showed complete resolution. One year after initial presentation, the patient developed multiple lumbosacral radiculopathies and examination of a nerve root biopsy specimen disclosed a B-cell lymphoma. Serial cerebrospinal fluid analyses over the previous year showed occasional atypical cells, later found to resemble closely the biopsy cell type. We conclude that meningeal lymphoma may have a protracted course, with spontaneous remission of both clinical and neuroimaging findings.

Aged↗