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Biomedical subjects

S Attarian

Publications and source records attributed to S Attarian.

27 records · Page 2Linked to original sources
PubMed2001

Terminal latency index and modified F ratio in distinction of chronic demyelinating neuropathies.

OBJECTIVE: To evaluate indexes calculated from standard electrophysiological data in differentiating chronic demyelinating polyneuropathy (CDP). METHODS: Nerve conduction study of upper limbs was investigated in 19 chronic inflammatory demyelinating polyneuropathy (CIDP) patients, 25 anti-myelin-associated glycoprotein/sulfated glucuronyl paragloboside antibodies (MAG/SGPG) CDP patients, 13 Charcot-Marie-Tooth disease type 1A (CMT1A) patients and 22 controls. Terminal latency index (TLI) was used to compare the wrist-to-thenar muscle segment with the elbow-to-wrist conduction velocity. Modified F ratio (MFR) was used to compare the spinal cord-to-elbow segment latency with that of the wrist-to-thenar muscle segment. RESULTS: Compared with controls, TLI was decreased in 21 anti-MAG/SGPG CDP patients while MFR was either decreased or was normal. In 16 CIDP patients, MFR was increased while TLI was either normal or increased. In CMT1A both TLI and MFR were in normal ranges. The sensitivity of MFR as a supportive finding in CIDP was found to be 84% and its specificity 89%. The sensitivity of TLI as a mean of diagnosis of anti-MAG/SGPG CDP was found to be 93% and its specificity 90%. CONCLUSIONS: The results of TLI and MFR facilitates distinction between different types of CDP. In CIDP, MFR was significantly higher and TLI showed no change; in the anti-MAG/SGPG CDP, TLI and MFR were significantly lower; in CMT1A, TLI and MFR showed no change in comparison with the controls.

Adult↗
PubMed2001

[Proximal myotonial myopathy (PROMM): clinical and histology study].

We report 13 French patients with proximal myotonic myopathy. PROMM is a recently delineated multisystem disorder with dystrophic myopathy, myotonia and cataracts. This syndrome is genetically distinct from myotonic dystrophy (DM) by the absence of abnormal CTG repeat expansion. The geographical origin varies but 4 families originated from Poland. Of late onset, muscle weakness is diffuse and predominantly affected proximal and axial muscles. Facial involvement and myotonia were moderate or absent, but in all cases myotonic discharges were detected on EMG. 6 patients suffered from myalgia. Cataracts occurred in 11 patients, mainly indistinguishable from those in DM. Cardiac arrythmia occurred in 7 patients. Muscle biopsy revealed rare structural changes of the muscle fibers and selective type I atrophy, common in DM, could not be found on morphometric analysis. PROMM has a distinct clinical spectrum from DM which includes a predominantly proximal muscle weakness, with troubling pain, a more favourable prognosis and a different histopathological pattern.

Adult↗
PubMed2000

Transcranial magnetic stimulation (TMS): compared sensitivity of different motor response parameters in ALS.

Owing to the low sensitivity of clinical signs in assessing upper motor neuron (UMN) involvement in ALS, there is a need for investigative tools capable of detecting abnormal function of the pyramidal tract. Transcranial magnetic stimulation (TMS) may contribute to the diagnosis by reflecting a UMN dysfunction that is not clinically detectable. Several parameters for the motor responses to TMS can be evaluated with different levels of significance in healthy subjects compared with ALS patients. The central motor conduction time, however, is not sensitive in detecting subclinical UMN defects in individual ALS patients. The amplitude of the motor evoked potential (MEP), expressed as the percentage of the maximum wave, also has a low sensitivity. In some cases, the corticomotor threshold is decreased early in the disease course as a result of corticomotor neuron hyperexcitability induced by glutamate. Later, the threshold increases, indicating a loss of UMN. In our experience, a decreased silent period duration appears to be the most sensitive parameter when using motor TMS in ALS. TMS is also a sensitive technique for investigating the corticobulbar tract, which is difficult to study by other methods. TMS is a widely available, painless and safe technique with a good sensitivity that can visualize both corticospinal and corticobulbar tract abnormalities. The sensitivity can be improved further by taking into account the several MEP parameters, including latency and cortical silent period decreased duration.

Amyotrophic Lateral Sclerosis↗
PubMed2000

[Lower motor neuron disease and signs of dysimmunity].

Twenty-two patients (12 men, 10 women, age range 16 to 60) affected with an adult-onset, sporadic, lower motor neuron disease were studied. Motor weakness was associated with a severe muscular atrophy but never in a peripheral nerve distribution. Weakness predominated in the proximal parts of the limbs in 3 cases, in distal parts in 10 cases involving predominantly the upper limbs in 10. It was diffuse in all four limbs in six cases and was monomelic in the last 2 two others. Reflexes were generally lost in weak muscles. Electrodiagnostic findings consisted of pure motor axonal features, subtle sensory involvement was present in 3 cases with an IgM monoclonal gammopathy, in only one case the neurological syndrome was associated with a lymphoproliferative disorder despite complete investigations. All patients had dysimmune biological features (MGUS or anti-GM1 antibodies). We studied SMN gene in 12 patients and found no deletion. 16 patients were treated with IVIg and five improved but in 2 cases the improvement was transcient and lasted less than six months. Intravenous cyclophosphamide (1g/m(2) repeated monthly during 6 to 9 months) was used in six patients and three improved. Among these three patients two received also plasma exchanges on two days before the infusion. In all three patients, muscle weakness gradually deteriorated in the months following the end of the treatment. Nor the weakness pattern nor the type of biological marker was predictive of a good response to treatment. Lower motor neuron diseases appear to be much less sensitive to treatment than multifocal motor neuropathy with conduction block. However, treatment with IVIg or cyclophosphamide must be considered in the most severe forms or in case of a young onset.

Adolescent↗
PubMed1999

[Epilepsy in an adult with chromosome 22q11 micro-deletion].

Chromosome 22q11 deletion is a frequent genetic anomaly, recently discovered, responsible for DiGeorge syndrome and velo-cardio-facial syndrome. The spectrum of clinical features is large: dysmorphic syndrome, mental delay, conotroncal cardiopathy; neurologic manifestations are not rare. Case report is a 28 year old man who presented a symptomatic epilepsy caused by stroke, associated with conotroncal cardiopathy, mental delay, hypocalcemia and facial dysmorphy. A cytogenetic study confirmed the chromosome 22q11 deletion.

Adult↗
PubMed1997

Microinfusion of the metabotropic glutamate receptor agonist 1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid into the nucleus accumbens induces dopamine-dependent locomotor activation in the rat.

Although the striatum has one of the highest densities of metabotropic glutamate receptor (mGluR) binding sites in the brain, little is known about their physiological role. In this study we characterized the contribution of mGluRs located in the ventral part of the striatum (the nucleus accumbens) to the control of extrapyramidal motor function. Activation of mGluRs by local infusion of the selective agonist 1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD; 25, 50 and 100 nmol/0.5 microl) into the nucleus accumbens induced a dose-dependent increase in locomotor activity in rats. Intra-accumbens infusion of a selective antagonist of mGluRs, alpha-methyl-4-carboxyphenylglycine (MCPG) did not modify spontaneous locomotion but decreased the locomotor response to 1S,3R-ACPD. This effect appeared to be mediated by dopamine, since blockade of dopamine receptors with haloperidol (0.05 and 0.1 mg/kg i.p.) dose-dependently reduced 1S,3R-ACPD-induced locomotor activation. Furthermore, D-amphetamine (0.5 mg/kg, i.p.) combined with intra-accumbens infusion of 1S,3R-ACPD (100 nmol) potentiated the locomotor hyperactivity response to a higher level than that seen with a single treatment with either drug. In contrast, D-amphetamine-induced hypermotility was abolished by infusion of MCPG (100 nmol) into the nucleus accumbens. These results demonstrate that glutamate may control extrapyramidal motor function through metabotropic receptors. Furthermore, activation of metabotropic glutamate receptors appears to act in synergy with the dopamine system at the level of the nucleus accumbens to produce a motor stimulant response.

Analysis of Variance↗
PubMed1997

[Guillain-Barré syndrome of axonal type, Campylobacter jejuni infection and anti-ganglioside GM1 antibodies].

Infection by Campylobacter jejuni (C. jejuni) has been reported in 17 to 55 p. 100 of the GBS. The "axonal" GBS has been recently attributed to such an association. It is characterized by rapid progression to severe widespread paralysis, respiratory failure, poor and delayed recovery. The acute "axonal" form of Guillain-Barré syndrome has been and remains a matter of controversy. A typical case of GBS with serological evidence of recent C. jejuni infection and increased antibodies to GM1 is reported. An immune mechanism remains most likely. Recent studies have suggested the hypothesis of "shared epitope" between C. jejuni and peripheral nervous system cell (Gal beta 1-3 N Acetylgalactosamine epitope). Such a cross-reactivity could provoke a severe form of GBS with a poor recovery in some predisposed hosts (antiganglioside antibodies, HLA "immunogenic" groups such as B8, B35 or DR3).

Antibodies↗
PubMed1995

[A case of transient amnesia caused by cerebral thrombophlebitis: contribution of neuroimaging to physiopathogenesis of transient amnesia].

We report a case of transient global amnesia (TGA), in a right-handed woman, which was due to a cerebral venous thrombosis. In our knowledge it is the first case reported. MRI and SPECT revealed the existence of a dysfunction in the right internal temporal region. Such a localization leads us to discuss the specialisation of each hippocampus.

Amnesia, Retrograde↗