Biomedical subjects

S Allpress

Publications and source records attributed to S Allpress.

7 recordsLinked to original sources

PubMed1991

Sensory nerve pathology in amyotrophic lateral sclerosis.

A detailed morphometric study was performed on sural nerve biopsies to determine the consistency of sensory nerve pathology in amyotrophic lateral sclerosis (ALS) and to seek a correlation between the severity of peripheral nerve pathology and disease duration. Nerve biopsies from patients with ALS consistently showed evidence of early axonal atrophy, increased remyelination and a shift in the diameter distributions curve towards smaller fiber diameters. Importantly, the severity of sensory nerve pathology in ALS patients correlated with disease duration. The peripheral nerve sodium pump concentration of patients was not reduced. It is concluded that an ingravescent dorsal root ganglion neuronopathy is seen in the incipient stages of ALS, preferentially affecting the largest neurons and resulting in turn in progressive axonal atrophy, secondary demyelination-remyelination and finally in nerve fiber degeneration. Etiologically, a parallel involvement of motor and sensory neurons suggests a more widespread metabolic disturbance in ALS than simply "sick" motor neurons.

Adult↗

PubMed1988

Peripheral neuropathy in elderly CBA mice.

A late-onset peripheral neuropathy in a mouse with a wider progressive neurological disorder is morphologically characterized for comparison with late life human neuropathies. Preliminary studies indicate the presence of a proximal, predominantly motor, axonopathy in the mouse model.

Age Factors↗

PubMed1984

Peripheral nerve morphometry in stroke patients.

Sural nerve biopsy specimens from affected and non-affected limbs of stroke patients were examined morphometrically. Two principle abnormalities of peripheral nerve were found in hemiparetic and hemiplegic limbs. First, the frequency of abnormal teased nerve fibers was significantly increased with abnormal internodes frequently "clustered" and showing a 50% or more reduction in myelin thickness. Second, the mean diameter of myelinated nerve fibers was reduced. These results suggest a primary atrophy of peripheral nerve fibers in the affected limbs of stroke patients with secondary demyelination. Possible aetiological factors include disuse, transynaptic degeneration, ischemia, pressure effect, and decreased axoplasmic flow. It would seem that the structural integrity of peripheral nerve is frequently compromised following a cerebral lesion.

Adult↗

PubMed1983

Peripheral neuropathy in Tangier disease.

Peripheral nerve morphometry was assessed in four patients with Tangier disease. Three patients with a relapsing and remitting multiple mononeuropathy had prominent peripheral nerve demyelination and remyelination with affected internodes clustered along particular nerve fibres. Putative lipid vacuoles were almost exclusively confined in this multifocal neuropathy syndrome to Remak cells. By contrast a fourth patient with a slowly progressive syringomyelia-like neuropathy had advanced peripheral nerve degeneration and a more global distribution of lipid vacuoles within peripheral nerve. A review of Tangier disease in the literature indicated the possibility of additional peripheral nerve syndromes. The clinical heterogeneity raises the possibility of different metabolic errors in Tangier disease or a common metabolic error subject to genetic influences. The results of this study indicate that normal serum cholesterol levels do not exclude a diagnosis of Tangier disease. It is therefore advisable to determine both high density lipoproteins and serum cholesterol levels in patients with undiagnosed multifocal neuropathy or syringomyelia-like syndromes.

Adult↗

PubMed1981

Experimental cold injury to peripheral nerve.

Focal non-freezing injury to rat sciatic nerve resulted in nerve conduction block and cessation of axoplasmic transport. Rats showed early functional recovery but subsequently developed a slowly progressive sciatic nerve paralysis. Horseradish peroxidase studies revealed prominent nerve oedema with early enhanced pinocytosis and later, passive leakage through damaged endoneurial capillaries. Detailed microscopy indicated a striking selective vulnerability to cold based on nerve fibre diameter. Unmyelinated fibres were spared while large myelinated nerve fibres showed severe axonal degeneration. Paranodal and segmental demyelination were infrequent findings and may have resulted from early axonal swelling. Possible pathogenic mechanisms to explain the degeneration of myelinated fibres in hypothermic injury are discussed. It is concluded that the gradient of clinical severity seen in limb hypothermic injuries has a pathological correlate in peripheral nerve.

Animals↗

PubMed1980

Clinical and morphological features of gold neuropathy.

Three cases of gold-related neuropathy are reported. Clinical features include an acute, symmetrically progressive polyneuropathy, focal or generalized myokymia and a tendency for initial neurological deterioration followed by improvement, after cessation of chrysotherapy. The degree of clinical recovery related to maximal disability. Morphological findings on sural nerve biopsies revealed both axonal degeneration and segmental remyelination. Similar peripheral nerve histology was seen in a parallel animal study in which the severity of the neuropathy was dose-related.

Adult↗

PubMed1977

Peripheral nerve abnormality in multiple sclerosis.

Biopsy specimens of sural nerve from 10 patients with multiple sclerosis (MS), of whom only 1 was severely disabled, were assessed by morphometric techniques and compared to nerves from age-matched controls. The frequency of abnormal teased fibers was increased in MS nerve, with many internodes showing at least a 50% reduction in myelin thickness. Myelinated nerve fiber densities were not significantly different in MS and control nerves. Regression analysis of axonal area on number of myelin lamellae indicated a generalized reduction of myelin lamellae in this disorder. It is suggested that peripheral myelin may be involved in multiple sclerosis.

Axons↗