PubMed Health⌕ Search

Biomedical subjects

A E Harding

Publications and source records attributed to A E Harding.

At least 217 records · Page 12Linked to original sources
PubMed1987

Serum vitamin E concentrations are normal in Friedreich's ataxia.

Serum vitamin E concentrations and vitamin E:cholesterol ratios in 31 patients with Friedreich's ataxia were not significantly different from values obtained from either disabled or ambulant control subjects. Although the clinical features of Friedreich's ataxia are similar to those associated with severe vitamin E deficiency, there are subtle but important clinical and neurophysiological differences between the two disorders.

Adolescent↗
PubMed1987

Adult onset supranuclear ophthalmoplegia, cerebellar ataxia, and neurogenic proximal muscle weakness in a brother and sister: another hexosaminidase A deficiency syndrome.

An Ashkenazi Jewish brother and sister developed progressive ataxia and proximal neurogenic muscle weakness, associated with supranuclear ophthalmoplegia, in the fourth decade of life. Hexosaminidase A activity, assayed using both synthetic and natural substrates, was severely reduced in the patients' plasma, leukocytes, and skin fibroblasts. Enzyme activity in their parents was in a similar range to that seen in heterozygotes for Tay-Sachs disease. The increasing evidence for marked clinical and molecular heterogeneity in the GM2 gangliosidoses warrants their consideration in the diagnosis of multisystem degenerative neurological disorders, even if onset of symptoms is in adult life.

Age Factors↗
PubMed1987

Vitamin E and the nervous system.

There is increasing evidence that vitamin E is essential for normal neurological function. In abetalipoproteinemia, which is the most severe deficiency state known in man, development of the associated spinocerebellar syndrome can be prevented by early vitamin E therapy. A neurological disorder similar to that seen in abetalipoproteinemia, comprising progressive ataxia, hyporeflexia, and proprioceptive loss, has been described in children and adults with chronic fat malabsorption and vitamin E deficiency. The neuropathological changes in such patients resemble those seen in vitamin E-deficient monkeys. Recent reports suggest that spinocerebellar degeneration may be caused by a selective defect of vitamin E absorption without other evidence of gastrointestinal disease.

Animals↗
PubMed1986

The clinical features of mitochondrial myopathy.

The clinical features of 66 patients with histologically defined mitochondrial myopathy are described. The age of onset of symptoms ranged from birth to 68 years, but was before 20 years in 61%. Nineteen patients had similarly affected relatives. Three groups of cases could be identified clinically: a combination of progressive external ophthalmoplegia and weakness of the limbs induced or increased by exertion (55%); such limb weakness alone (18%); and those with clinical features, such as ataxia, dementia, deafness, involuntary movements and seizures, predominantly or exclusively arising from the CNS (27%). There was considerable overlap between these groups, and pigmentary retinopathy, present in 36% of patients, occurred in all three. At a mean disease duration of twenty years, 9 patients (all from Group 3) were severely disabled but 42 were still able to work. In vitro studies of mitochondrial metabolism, performed in 33 cases, most commonly showed deficiencies of the mitochondrial respiratory chain localized to complex I (18 patients) or complex III (9). No typical clinical picture emerged for any of the identifiable biochemical defects.

Adolescent↗
PubMed1986

Peripheral neuropathy associated with the sicca syndrome.

Three patients with the sicca syndrome and chronic sensory neuropathy are described; in two of them neuropathy was the presenting feature of the disease. The sicca syndrome can give rise to a characteristic neurological syndrome comprising areflexia and asymmetrical sensory loss, particularly of proprioception, in the limbs. This is often associated with tonic pupils and trigeminal anaesthesia.

Aged↗
PubMed1985

The retinal manifestations of mitochondrial myopathy. A study of 22 cases.

In a series of 61 patients with the morphologic and histochemical features of mitochondrial myopathy, 22 (36%) had pigmentary retinopathy. Three patterns of retinopathy were identified. Eighteen patients had a "salt and pepper" type of retinal appearance, which was usually associated with good visual function. Two had many features of retinitis pigmentosa, and two others showed generalized loss, or atrophy, of the retinal pigment epithelium and choriocapillaris. These last four patients had markedly reduced visual acuities, with optic atrophy and attenuated retinal vessels. Electroretinography and electro-oculography were performed in 11 patients. Both rod and cone mediated electroretinographic functions were subnormal in eight patients, while only cone mediated functions were depressed in the remaining three. The electro-oculographic changes were variable.

Adolescent↗
PubMed1985

Encephalomyeloneuropathy in the absence of a detectable neoplasm. Clinical and postmortem findings in three cases.

The clinical and postmortem findings in three cases of encephalomyeloneuropathy are reported. Two patients presented with subacute sensory neuropathy and one with amnesia and confusion. In none of these cases was a tumour detected clinically or at autopsy. Neuropathological examination showed inflammatory lesions in the brain, spinal cord and posterior root ganglia indistinguishable from encephalomyeloneuropathy occurring as a remote effect of carcinoma.

Aged↗
PubMed1985

A study of the relationship between neurological function and serum vitamin E concentrations in patients with cystic fibrosis.

A patient with cystic fibrosis and undetectable serum vitamin E concentrations is described who developed a progressive spinocerebellar syndrome and pigmentary retinopathy with abnormal somatosensory and visual evoked potentials (SSEPs and VEPs). In order to assess the relationship between neurological function and serum vitamin E concentrations in cystic fibrosis, 29 unselected patients who had no neurological symptoms were examined neurologically. Ten were randomly selected for neurophysiological assessment by recording SSEPs and VEPs. Electroretinograms (ERGs) were also performed in five cases. The findings were correlated with serum vitamin E concentrations which were unknown to the neurological investigators prior to completion of the study. Only one patient had definite reflex and sensory abnormalities, and the remaining 28 were clinically normal. The ERG was abnormal in two cases, one of whom had abnormal VEPs. SSEPs were normal in all 10 cases. Twenty six patients had serum vitamin E concentrations below the normal range. In two of the three patients who had definite neurological or electrophysiological abnormalities serum vitamin E concentrations were below the median value for the whole group.

Adult↗
PubMed1985

A study of the effects of isaxonine on vincristine-induced peripheral neuropathy in man and regeneration following peripheral nerve crush in the rat.

Administration of isaxonine (6 mg/kg powdered diet) had no effect on regeneration following sciatic nerve crush in the rat. In 10 patients undergoing treatment with vincristine (1.4 mg/m2 twice monthly) development of peripheral neuropathy was quantitated by neurological symptoms, signs and electrophysiological tests. Five also received isaxonine (1.5 g daily). All patients developed evidence of neuropathy, but in none was it severe. The three lowest disability scores were obtained in isaxonine treated patients, but the highest score was also in an isaxonine treated patient. The equivocal findings in this small study could not be amplified because the drug was withdrawn from clinical use on account of its hepatotoxicity.

Animals↗
PubMed1984

Demyelination following diphtheria toxin in the presence of axonal atrophy.

In 23 guinea-pigs a constricting ligature was placed on the tibial nerve in the thigh on one side, in order to produce axonal atrophy in the distal part of the nerve. Either before or after ligature, 10 of the guinea-pigs received subcutaneous diphtheria toxin into the abdominal wall, in a dose insufficient to cause generalised paralysis or reduced motor conduction velocity (MCV). In 7 of the 10 animals, MCV distal to the ligature fell below the range seen after ligature alone. In animals which had received toxin histological studies revealed paranodal and segmental demyelination in the distal tibial nerve, which was more extensive on the side of the ligature than in the opposite leg. Occasional paranodal but no segmental demyelination was seen distal to ligature alone. These results indicate that a small dose of systemic diphtheria toxin is more likely to produce peripheral nerve demyelination if an axonal abnormality is also present.

Action Potentials↗
PubMed1984

Autosomal dominant late onset cerebellar ataxia with myoclonus, peripheral neuropathy and sensorineural deafness: a clinicopathological report.

Three members of a family were affected by an autosomal dominant disorder comprising cerebellar ataxia, sensorineural deafness, myoclonus, and peripheral neuropathy. This is the second kindred with this syndrome reported to date. Necropsy of the proband showed loss of cells in the dentate nuclei, a reduced amount of cerebellar white matter, and pallor of the gracile tracts in the spinal cord.

Adult↗
PubMed1984

Peroneal muscular atrophy with pyramidal features.

Twenty-five cases of peroneal muscular atrophy with pyramidal features from 15 families are described. This disorder has been referred to as hereditary motor and sensory neuropathy (HMSN) type V by Dyck. Onset was usually in the first two decades of life with difficulty in walking. The clinical syndrome superficially resembled that of HMSN types I and II with distal wasting and weakness involving the legs more than the arms. The tendon reflexes in the upper limbs and at the knee tended to be normal or increased but the ankle jerks were often absent. The plantar responses were extensor in 22 patients, absent in two and flexor in one. Increased tone and weakness in the proximal lower limb muscles were found in about 30% of cases. Mean motor nerve conduction velocity was lower than in normal controls and sensory nerve action potentials were reduced in amplitude or absent in two thirds of the patients studied. Inheritance was autosomal dominant in the majority of families. The disorder was slowly progressive but did not lead to severe disability.

Adolescent↗
PubMed1984

Autosomal recessive late onset multisystem disorder with cerebellar cortical atrophy at necropsy: report of a family.

A sister and brother developed a progressive syndrome comprising bulbar palsy, supranuclear ophthalmoplegia, facial impassivity, and cerebellar ataxia together with a mixed pyramidal and extrapyramidal deficit in the limbs, in the fourth decade of life. Their parents were unaffected and inheritance was probably autosomal recessive. The female patient, who presented initially with bulbar and extrapyramidal dysfunction, was found to have cerebellar cortical atrophy at necropsy. The basal ganglia and brainstem were normal.

Adult↗