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Biomedical subjects

D Malapert

Publications and source records attributed to D Malapert.

At least 19 recordsLinked to original sources
PubMed2001

[Toe phasic posture reflex: description and distribution among patients with neurological disease and in the general population].

A clinical sign is described consisting of a brief extension of the toes after upward tapping of the plantar surface of their terminal phalanges. Electrological data support the hypothesis of a long loop reflex, which we call the "toe phasic posture reflex" (TPPR). In a preliminary study, this sign was observed in patients with central nervous system disease, especially in subcortical brain disorders regardless of etiology. In Parkinson's disease, it was seen mostly in severe and postural forms. Among 237 healthy subjects, it was observed in none of those under 70 years old (n=116), and in 10p. cent of those over 69 years and doing no sport (n=132), but in none of those doing regularly gymnastics or swimming (n=29). TPPR could thus be a sign of motor and especially postural aging.

Adult↗
PubMed1999

Idiopathic spinal cord herniation: value of MR phase-contrast imaging.

We report two patients with an idiopathic transdural spinal cord herniation at the thoracic level. Phase-contrast MR imaging was helpful in showing an absence of CSF flow ventral to the herniated cord and a normal CSF flow pattern dorsal to the cord, which excluded a compressive posterior arachnoid cyst.

Aged↗
PubMed1998

Dominant T-cell clones of unknown significance in patients with idiopathic sensory neuropathies.

OBJECTIVE: To determine whether idiopathic sensory neuropathies could be associated with circulating dominant T-cell clones, a T-cell equivalent to monoclonal gammopathy of unknown significance. BACKGROUND: A number of predominantly sensory neuropathies remain of unknown etiology. Circulating dominant T-cell clones may be observed in the elderly, in autoimmune disorders, and in chronic viral infections. METHODS: Twenty patients with chronic sensory or predominantly sensory neuropathies considered idiopathic after intensive investigation were evaluated for the presence of dominant T-cell clones in blood using PCR amplification of the variable region of the T-cell receptor gamma-chain gene. They were classified as chronic idiopathic axonal polyneuropathy (CIAP) or sensory neuronopathy, i.e., chronic idiopathic ataxic neuropathy (CIAN), according to clinical and electrophysiologic criteria. RESULTS: Occurrence of clonal expansions of T cells was strikingly high in patients with idiopathic sensory neuropathies (16/20, 80%), with a similar proportion in CIAP (12/15, 80%) and CIAN (4/5, 80%), as compared with elderly normal controls (2/10, 20%), elderly controls with degenerative neurologic diseases (2/10, 20%), and elderly patients with idiopathic chronic inflammatory demyelinating polyneuropathy (2/10, 20%) (all p < 0.005). CONCLUSION: Both CIAN and CIAP are associated with dominant T-cell clones of unknown significance that cannot simply be attributed to the age of patients. Relevance of T-cell clones to the pathogenesis of idiopathic sensory neuropathies remains to be determined.

Adult↗
PubMed1996

Overproduction of proinflammatory cytokines imbalanced by their antagonists in POEMS syndrome.

The polyneuropathy, organomegaly, endocrinopathy, M protein, skin changes (POEMS) syndrome is a rare multisystem disorder of obscure pathogenesis associated with osteosclerotic myeloma. Circulating levels of proinflammatory cytokines (tumor necrosis factor-alpha (TNF-alpha) interleukin-1 beta [IL-1 beta], IL-2, IL-6, and interferon-gamma [IFN-gamma]), anti-inflammatory cytokines (transforming growth factor beta 1 [TGF beta 1], IL-4, IL-10, and IL-13), the cytokine carrier protein alpha 2 macroglobulin, IL-1 receptor antagonist (IL-1ra), soluble TNF receptors (sTNFr) p55 and p75, and soluble IL-6 receptor (sIL-6r) were determined in 15 patients with POEMS syndrome and 15 with multiple myeloma. Patients with POEMS syndrome had higher serum levels of IL-1 beta, TNF-alpha, and IL-6 and lower serum levels of TGF beta 1 than did patients with multiple myeloma. Serum levels of IL-2, IL-4, IL-10, IL-13, IFN-gamma, alpha 2 macroglobulin, and sIL-6r were similar in both groups. IL-1ra and sTNFrs were increased in POEMS syndrome, but out of proportion to the increase of IL-1 beta and TNF-alpha. Serial evaluations in 1 patient showed that proinflammatory cytokine serum levels paralleled disease activity assessed by platelet count and neurologic involvement. Our results suggest that the manifestations of POEMS syndrome might be regarded as the result of a marked activation of the proinflammatory cytokine network (IL-1 beta, IL-6, and TNF-alpha) associated with a weak or even decreased (TGF beta 1) antagonistic reaction insufficient to counteract the noxious effects of cytokines.

Adult↗
PubMed1994

Elevated levels of interleukin-1 beta (IL-1 beta) and IL-6 in serum and increased production of IL-1 beta mRNA in lymph nodes of patients with polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome.

To evaluate a possible implication of cytokines in the pathogenesis of polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome, we studied five consecutive patients with this condition, of which four had sclerotic bone lesions and four had multicentric Castleman's disease. Interleukin-1 beta (IL-1 beta) and IL-6 serum levels were determined in these patients (13 serum samples) and in patients with multiple myeloma (5) and Waldenström's macroglobulinemia (5). In situ hybridization of the relevant mRNAs was performed on lymph node specimens of two patients with POEMS syndrome who had Castleman's disease. Elevated serum levels of IL-1 beta (13/13 samples), and IL-6 (7/13 samples) were found in patients with POEMS syndrome. In the other patients, serum IL-1 beta was undetectable or slightly increased and IL-6 was elevated in a single patient with Waldenström's macroglobulinemia. Abundant IL-1 beta mRNA-producing cells were present in interfollicular spaces in the two tested patients, while IL-6 mRNA-producing cells were rare. We conclude that IL-1 beta and IL-6 serum levels may be chronically elevated in patients with POEMS syndrome, and that lymph node may be one site of IL-1 beta overproduction. These results are in keeping with the hypothesis that cytokines mediate systemic manifestations of POEMS syndrome.

Adult↗
PubMed1994

Early weight loss and high serum tumor necrosis factor-alpha levels in polyneuropathy, organomegaly, endocrinopathy, M protein, skin changes syndrome.

We studied tumor necrosis factor-alpha (TNF-alpha) levels in serial serum samples from 3 consecutive patients who had a complete form of POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, skin changes) syndrome and early weight loss. Serum TNF-alpha levels were compared with those of 10 patients with multiple myeloma (5) or Waldenström's macroglobulinemia (5). Elevated serum levels of TNF-alpha were found in the patients with POEMS syndrome (two- to eightfold increase in 10 of 11 samples) and not in those with other malignant plasma cell dyscrasias. These results are in keeping with the hypothesis of a role for nonimmunoglobulinic mediators in the pathogenesis of the POEMS syndrome, and are consistent with previous reports of TNF-alpha overproduction in inflammatory demyelinating neuropathies and cachectic states.

Adult↗
PubMed1994

Rest tremor and extrapyramidal symptoms after midbrain haemorrhage: clinical and 18F-dopa PET evaluation.

A 25 year old man had an acute subarachnoid haemorrhage due to the rupture of a right peduncular subthalamic arteriovenous malformation. Seven months later he developed a left rest tremor associated with mild bilateral extrapyramidal symptoms and responsive to levodopa treatment. Surface EMG recording showed synchronous activity of agonist and antagonist muscles in the left limbs. A PET 18F-dopa study showed a large decrease of the Ki value in the right striatum. One year after the stroke a persistent postural component developed in the tremor.

Adult↗
PubMed1993

Late-onset familial amyloid polyneuropathy with the TTR Met 30 mutation in France.

Four unrelated French cases of familial amyloid polyneuropathy are reported. Clinical onset ranged from the sixth to the ninth decade. Sensory signs were predominant initially in the lower limbs; motor changes, and in one case autonomic involvement, appeared later. Amyloid disease was clinically limited to the peripheral nervous system. In two cases, there was no evidence of familial disease. DNA analysis was performed in these four patients and in two children of Patient 1. Restriction analysis of amplification products of exon 2 of the transthyretin gene was positive for the valine 30 to methionine mutation. These four unrelated patients live in different areas of France. Further studies are needed to determine whether these mutations have a common origin and whether they are related to the Portuguese mutation.

Aged↗
PubMed1990

Organic arsenic-induced Guillain-Barré-like syndrome due to melarsoprol: a clinical, electrophysiological, and pathological study.

A young woman suffering from sleeping sickness was treated with melarsoprol. Thirty-eight days after the first administration of this organo-arsenic compound, myalgias, distal paresthesias and rapidly progressive weakness developed in all four limbs. Electrophysiological studies were misleading for Guillain-Barré syndrome. Neuropathological data included massive distal wallerian degeneration in peripheral nerves and abnormalities in dorsal ganglia and spinal cord where vacuolation of anterior horn cells and axonal neurofilamentous masses were observed. Very high concentrations of arsenic were found in the spinal cord, contrasting with undetectable levels in peripheral nerves. Our findings are consistent with an arsenic neuronopathy manifested by initial proximal demyelination and delayed distal axonal damage. Renal and hepatic dysfunctions, which were implicated in the toxic arsenic accumulation, should be systematically detected before administration of melarsoprol. The diagnosis of Guillain-Barré syndrome must be considered with caution in patients treated with this compound.

Adult↗
PubMed1990

Giant gangliocytic paraganglioma of the filum terminale. Case report.

The clinical and pathological features of a giant cauda equina paraganglioma arising from the intradural filum terminale is described. Scattered mature large neurons characterized the tumor as a gangliocytic paraganglioma. Histologically, these neoplasms have considerable similarity with ependymoma and the diagnosis can be easily missed unless special techniques are employed.

Adult↗
PubMed1990

Somatosensory evoked potentials from median nerve; normative data.

The somatosensory evoked potentials from median nerve were studied in a group of 127 normal adults aged from 19 to 79. The latencies of elbow, Erb's, cervical N11 and N13 as well as cortical N20 and P25 potentials were analyzed as a function of height and age. Two central conduction times, N20-N11 and N20-N13, were equally studied. The corresponding regression formulae were calculated and can be used to predict normative values of these parameters over a wide range of height and age. Standard error estimates are given for all parameters.

Adult↗
PubMed1989

[Painful legs and moving toes. Neuropathy caused by cytarabine].

A new case of painful legs and moving toes syndrome is reported in a patient with a neuropathy due to high-doses of cytosine arabinoside (Ara C). A few cases of this complication have been reported. The neuropathy was sensory, axonal, and incompletely regressive. Carbamazepine had a dramatic effect on pain and involuntary movements.

Adolescent↗