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Biomedical subjects

C Meyrignac

Publications and source records attributed to C Meyrignac.

At least 19 recordsLinked to original sources

[Type II split cord malformation of late clinical onset].

A 68-year-old patient suffered for 8 years from radicular S1 pain on the left side, which was aggravated by walking. After an increased effort, he experienced a violent dorsal pain and sensitive troubles in the left T1 and T2 territories. Low back pain and painful paresthesiae of right leg came on next. Physical examination revealed proprioceptive symptoms on the left, a left pyramidal syndrome and a sacral pilonidal sinus. MRI showed on level of L2 vertebra, a spinal cord duplication in a unique dural tube, corresponding to diplomyelia or split cord malformation (SCM) type II. The patient had low conus medullaris anchored on L3-L4 level. A syringomyelia surmounted this medullar dysraphia. Split cord malformations, SCM type I (diplomyelia) or SCM type II (diastematomyelia), are usually revealed in infancy or early childhood. They are very rarely discovered late in the life. With progress in noninvasive spinal cord imaging, such diagnoses will undoubtedly be made more often in adults.

Age of Onset↗

[Left unilateral melokinetic apraxia and left dynamic apraxia following partial callosal infarction].

A 69 year-old right-handed man suffered from an infarct in the left anterior cerebral territory's artery, involving the anterior and middle parts of the corpus callosum, and the cingulum. He had a right crural hemiparesis with a grasp reflex of the right hand, and ipsilaterally a melokinetic and a dynamic apraxia. Agility of the left fingers was lost: fast and nimble movements of theses fingers, and repetitive gestures of the left hand were defective. Execution of motor sequences with the left hand was disrupted by a lack of litheness in gesture series. By analogy with unilateral left ideomotor apraxia, we suggest melokinetic and dynamic apraxia could be symptomatic of an interhemispheric disconnection. Premotor cortex could have a dominance for both digital movements and programmation of gestual sequences. As a general rule, the left cortex could be preferentially activated by the nature of some tasks, particularly the execution of complex gestual series, which implie an internal speech. In theses conditions, an interhemispheric disconnection could lead some difficulties to make theses gestures with the left hand.

Aged↗

[Sarcoid optic neuropathy].

Sarcoidosis is a multisystem granulomatous disease mostly involving the chest. Sarcoid optic neuropathy is an uncommon but serious manifestation that requires long-term corticosteroid treatment. We report here the case of a 50-year-old black patient complaining of a recent blurred vision on his left eye. The ophthalmologic examination was normal. Goldmann visual field and visual evoked potentials confirmed the diagnosis of retrobulbar optic neuropathy. Sarcoidosis was presumed on a chest radiography and computed tomography and confirmed with a transbronchial biopsy. Symptoms disappeared with intravenous bolus of corticosteroids. Three months later, without treatment, a right inferior eyelid tumor was observed. Magnetic resonance imaging (RMI) showed two orbital masses and multiple meningeal lesions enhancing with contrast suggesting neurosarcoidosis which decreased with a long-term high-dose corticosteroid therapy (1 mg/kg/d). Optic neuropathy is a rare manifestation of neurosarcoidosis, mostly accompanied by optic-disc involvement with papillary lesions. Chest roentgenogram and computed tomography give a presumption of sarcoidosis. But biopsy is mandatory to confirm the diagnosis demonstrating the histologic lesion of a non caseating granulomatous. Corticosteroid therapy is dramatically efficient but sometimes several months treatment is required.

Black People↗

Hepatitis C associated with Guillain-Barré syndrome.

Hepatitis C is frequently associated with immune-mediated diseases, such as cryoglobulinemia. Guillain-Barré syndrome is an acute demyelinating neuropathy of probable immune pathogenesis. We describe two patients with Guillain-Barré syndrome, and associated chronic hepatitis C, the second one previously treated with interferon. The link between both conditions may be hepatitis C being the trigger of this immune polyneuropathy. Guillain-Barré syndrome should be added to the list of conditions associated with hepatitis C.

Adolescent↗

Diphtheritic neuropathy.

A 29-year-old Haitian man had a sore throat with a marked tonsillar exudate followed by the onset of increasingly blurred vision with swallowing difficulties and, then, a diffuse acute demyelinating neuropathy. Cerebrospinal fluid showed moderate pleiocytosis and elevated protein content. Serological testing for diphtheria, but not for tetanus and poliomyelitis, was markedly positive. Other tests including HIV1 and 2, HTLV1 and Lyme disease were negative. Diphtheritic neuropathy should be considered in the differential diagnosis of Guillain-Barré syndrome in nonvaccinated patients.

Adult↗

Selective deficit of visual size perception: two cases of hemimicropsia.

Hemimicropsia is a rare disorder of visual perception characterized by an apparent reduction of the size of objects when presented in one hemifield. We report two cases of hemimicropsia resulting from focal brain lesions. The first patient was an art teacher and could accurately depict his abnormal visual perception. He subsequently died and his brain was examined post mortem. In the second patient, micropsia was assessed by a quantified size comparison task. The size of a given object is normally perceived as constant across any spatial position. Hemimicropsia may thus be considered a limited violation of the size constancy principle. Behavioural and anatomical data are discussed in relation to the neural basis of visual object perception in humans.

Autopsy↗

Muscle mitochondrial DNA in encephalomyopathy and ragged red fibres: a Southern blot analysis and literature review.

Various mitochondrial DNA abnormalities have been described in patients with encephalomyopathies. We performed Southern blot analysis of skeletal muscle mitochondrial DNA in nine adult patients with clinical features and ragged red fibres suggesting mitochondrial dysfunction. Two patients with encephalomyopathy and two with the MERRF syndrome (myoclonus epilepsy with ragged red fibres) had the normal PvuII restriction pattern of muscle mitochondrial DNA. In contrast, mitochondrial DNA deletion was observed in two of six patients with ophthalmoplegia. One suffered from typical Kearns-Sayre syndrome and the other from isolated external ophthalmoplegia. None of these patients had affected relatives. The detection of mitochondrial DNA deletion in external ophthalmoplegia and their site and size support previously reported data.

Blotting, Southern↗

Focal myelin thickenings in a peripheral neuropathy associated with IgM monoclonal gammopathy.

Nerve biopsy in peripheral neuropathies associated with an IgM monoclonal gammopathy may occasionally display focal myelin thickenings. In a patient with such an IgM neuropathy, in whom an anti-myelin-associated glycoprotein (MAG) antibody activity was present in the serum, single-fiber preparations revealed 34% of internodes bearing myelin swellings. The morphometric, morphological and ultrastructural findings were reminiscent but not identical to those of the hereditary tomaculous neuropathy with liability to pressure palsies. Atypical features for tomacula included lack of spiralization of the redundant loops of myelin around the axons and their predominant external situation with regard to the myelin sheath. The frequent colocalization of myelin thickenings and the widening of myelin lamellae typical of IgM neuropathies, are highly suggestive of some pathogenetic link between the two abnormalities. The redundant loops of myelin in IgM neuropathies possibly result from a defect in the axon-myelin adhesion secondary to the binding of IgM on an epitope of MAG directly involved in cell-cell adhesion.

Aged↗

[Papilledema caused by minocycline: apropos of a case].

Benign intracranial hypertension with papilloedema developed in a 18-year-old woman following Minocycline administration. Tetracycline therapy was prescribed for acne vulgaris. One month after the beginning of the treatment, she presented with headache, nausea and vomiting; there were no visual symptoms. Visual acuity and visual field were normal, fundus examination showed bilateral papilloedema. After Minocycline was discontinued and steroid therapy was administrated, symptoms rapidly resolved and papilloedema disappeared. Minocycline is known to penetrate into the central nervous system more effectively and to have a greater lipoid solubility than the other antibiotics of the same group. However the pathogenesis of benign intracranial hypertension after Minocycline therapy remains unknown.

Acne Vulgaris↗

[Writer's cramp and left frontal meningioma].

A 55 year-old, right-handed, man developed a progressive writer's cramp spreading to a right hemidystonia. He had a left paramedian frontal meningioma. The association of an hemidystonia with contralateral lesions in the basal ganglia has been often reported. Its occurrence with a frontal lesion appear to be much less frequent. This association suggests a possible disorder of frontostriatal connections.

Dystonia↗