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Biomedical subjects

F Viader

Publications and source records attributed to F Viader.

At least 19 recordsLinked to original sources
PubMed1992

Right motor neglect associated with dynamic aphasia, loss of drive and amnesia: case report and cerebral blood flow study.

A 30-year-old right-handed man had right motor neglect, amnesia, aphasia and loss of drive following bilateral thalamic and subthalamic infarctions. Serial resting cerebral blood flow (CBF) measurements with either Xenon 133 inhalation or positron emission tomography at 1, 8 and 10 months post-onset showed a widespread and long-lasting low CBF in the cortex. An additional CBF measurement, during motor tasks, showed a marked interhemispheric asymmetry in the pattern of activation: whereas left hand movement resulted in a CBF increase in contralateral superior rolandic and prerolandic areas, no significant regional CBF changes were seen during right hand movement, despite recovery from motor neglect. This loss of CBF increase in cortical motor and premotor areas during voluntary movement of the previously neglected side points to a disruption of cortico-subcortical pathways subserving motor activation. The pathophysiology of aphasia, loss of drive and amnesia as well as their relationships to motor neglect, may also be discussed on the basis of thalamo-cortical disconnections.

Adult↗
PubMed1992

[Familial parkinsonian syndrome with athymhormia and hypoventilation].

Five cases of parkinsonism with athymhormia observed in a single family are reported. Death caused by central respiratory disorders occurred after 6 to 8 years of progressive course. In 2 cases with autopsy, there was a severe neuronal loss predominant in the substantia nigra. Other brain stem nuclei (locus coeruleus, dorsal motor nucleus of the vagus nerve, nucleus of the tractus solitarius) were involved, as well as the striatum, pallidum and frontal cortex. No Lewy body was seen. In the surviving patient, positron emission tomography demonstrated, 4 years after the onset, a bilateral frontal hypometabolism. This disease is a rare variety of familial parkinsonism of dominant inheritance, already reported in 2 Canadian families by Perry et al. (1975) and Purdy et al. (1978) and in a family of West Virginia by Roy et al. (1988). The respiratory disorders can be explained by the involvement of the dorsal medullary nuclei. The peculiar neuropsychological disorder and motor slowing are best accounted for by the functional impairment of both motor and limbic striato-pallido-thalamo-frontal loops.

Cerebral Cortex↗
PubMed1992

[Diffuse cerebral gliomatosis. An anatomoclinical case].

A 52-year old man had a generalized seizure followed by progressive memory disturbances, affective changes, right hemiplegia and aphasia. He died 4 years later after a period of coma. Neuropathological findings included slight cortical atrophy, pallor of the centrum ovale, and infiltration of the cortex and subcortical white matter by neoplastic glial cells, with neither major neuronal loss nor spongiosis. Microglial rod cells were observed. The gliomatosis extended within the thalamus and subthalamic area on both sides, whereas the brain stem was much less involved. The spinal cord and peripheral nerves were not examined. Abnormal glial cells were stained by the glial fibrillary acid protein, which confirms the astrocytic differentiation of the tumoral cells.

Brain↗
PubMed1991

[Aphasic disorders of written language].

After a short overview of classical neuropsychological knowledge about the disorders of written language, the authors review the data of cognitive psychology in this field. They first consider the general principles of cognitive analysis and then describe the specific syndromes of phonological and lexical routes impairment both in reading and writing. The possible correlations between these syndromes and other higher brain function impairments or anatomical localization are briefly considered. Finally an analysis of the impairments to peripheral writing processes, i.e. graphemic buffer and allographic conversion system syndromes, is given. In conclusion the contribution of cognitive psychology to daily neuropsychological practice is discussed.

Aphasia↗
PubMed1991

[Accidental poisoning with podophyllin: a case with study of peripheral nerve].

A 53 year-old veterinary surgeon accidentally ingested 0.8 g of podophyllin. Twelve hours later, he was deeply comatose, with clinical and EMG signs of extensive axonal sensorimotor and autonomic peripheral neuropathy. In addition, transient bone marrow and hepatic toxicity occurred. The coma lasted 2 weeks. Systemic and neurological disturbances started to improve at 3 months post-onset, but the patient died four months later from gastro-intestinal bleeding. Sural nerve biopsy showed loss of myelinated fibers and signs of axonal degeneration with type E teased fibers. The cytoplasm of Schwann and endothelial cells was vacuolated and swelled. Diffuse interstitial aedema was noted. Podophyllin acts as a spindle poison, binds microtubular proteins and inhibits axoplasmic flow.

Accidents↗
PubMed1991

[Isolated exertion headache and Chiari's malformation].

A 47 year-old woman had been suffering from exertional headache for 2 1/2 years. Neurological examination was normal. X-rays of the skull and cranio-cervical junction and CT were normal. MRI sagittal sections disclosed a Chiari type I malformation. The headache disappeared after occipital craniectomy and atlas laminectomy.

Arnold-Chiari Malformation↗
PubMed1990

Identification and discrimination disorders in auditory perception: a report on two cases.

Auditory perception was investigated in two brain-damaged subjects. The first patient had a left temporoparietal ischaemic lesion. He presented a right-ear extinction in dichotic tasks, as well as difficulties in understanding and repeating verbal material and impaired identification of melodies. All discrimination tests were well performed. The second patient had a right capsulolenticular and frontal ischaemic lesion. He presented a left ear dichotic extinction and severe difficulties in discrimination of environmental sounds and melodies but no major difficulty in naming and identification. From these results, it is hypothesized that identification and discrimination involve distinct mechanisms within the processing of auditory stimuli, and that they may be selectively disrupted in brain-damaged subjects.

Adult↗
PubMed1989

Regional cerebral blood flow during comprehension and speech (in cerebrally healthy subjects).

Regional cerebral blood flow (rCBF) was measured by the xenon-133 inhalation method in 10 cerebrally healthy subjects at rest and during linguistic activation tests. These consisted of a comprehension test (binaural listening to a narrative text) and a speech test (making sentences from a list of words presented orally at 30-s intervals). The comprehension task induced a moderate increase in the mean right CBF and in both inferior parietal areas, whereas the speech test resulted in a diffuse increase in the mean CBF of both hemispheres, predominating regionally in both inferior parietal, left operculary, and right upper motor and premotor areas. It is proposed that the activation pattern induced by linguistic stimulation depends on not only specific factors, such as syntactic and semantic aspects of language, but also the contents of the material proposed and the attention required by the test situation.

Adult↗
PubMed1989

Auditory agnosia with relative sparing of speech perception.

We report a case of auditory agnosia in which the initial clinical picture began with generalized auditory agnosia for verbal and non verbal sounds, but rapidly changed to a selective auditory agnosia confined to the perception of non verbal sounds. CT scanning and MRI did not demonstrate cortical or subcortical damage, except for bilateral ventricular enlargement. The patient was submitted to audiological investigations including physical and psychoacoustic studies. Deficits were revealed during the decay and loudness discrimination test, but no temporal auditory acuity deficit was observed. The results of these studies are discussed in relation to the clinical picture. Also the dissociation between verbal perception and non verbal perception is discussed.

Adult↗
PubMed1989

Infarct of the anterior limb of the right internal capsule causing left motor neglect: case report and cerebral blood flow study.

A sixty-nine year old hypertensive man had left motor neglect following an infarct of the anterior limb of the right internal capsule. He also had left auditory extinction on verbal dichotic listening and a sligh constructional apraxia. Regional cerebral blood flow (CBF) was measured at rest with Xenon 133 inhalation and was found to be slightly decreased in a diffuse fashion. Motor activation of the right hand resulted in an increase of CBF in the contralateral superior rolandic area, whereas no such increase was found during motor activation of the left hand. This lack of cortical CBF increase on contralateral motor activation is interpreted as a consequence of the failure of some corticosubcortical connexions involved in motor arousal. The specifically dynamic appearance of regional CBF abnormalities, i.e. during selective activation as opposed to rest measurements, is consistent with the functional character of neglect.

Aged↗
PubMed1989

[Familial myopathy with "cytoplasmic body" (or "spheroid") type inclusions, disclosed by respiratory insufficiency].

Three patients, 72, 45 and 18 years old belonging to 3 successive generations presented with respiratory insufficiency. The clinical onset was at about 40 years of age in the two older patients and at 18 years in the youngest one. Serum enzymes of muscle origin were within normal range as well as leucocyte maltase activity. The muscle biopsy in all three patients showed numerous cytoplasmic (spheroid) bodies within type I muscle fibers. Familial cytoplasmic body myopathy with familial incidence has rarely been reported and still more rarely has been revealed by respiratory insufficiency in adult life.

Adolescent↗
PubMed1989

[Neurologic forms of Lyme disease. 12 cases].

Twelve cases of Lyme's disease with neurological complications are reported. Seven patients had meningoradiculitis of the Garin-Bujadoux-Bannwarth type, with facial palsy in 2 cases. In 1 case the radiculitis involved only the cauda equina. Two more patients had meningomyelitis. Of the remaining 3, 1 had subacute inflammatory polyneuritis with albumino-cytologic dissociation, 1 had probable dorsal epiduritis, and the last one developed parkinsonism and communicating hydrocephalus after an otherwise classical meningoradiculitis. Three patients recalled a tick bite but only one a cutaneous eruption. No arthritis or cardiac involvement were observed. In 2 cases the CSF contained pseudo-neoplastic cells. Severe pain was a prominent feature in most cases. Pain consistently and rapidly improved on high-dose intravenous penicillin, while other signs or symptoms (e.g. paresthesias or fatigue) often lasted several months. Parkinsonism and hydrocephalus were not influenced by penicillin, and both required specific therapy. Isolated neurological (both central and peripheral) involvement is not unusual in Lyme's disease and may give rise to a wide range of signs and symptoms. This diagnosis is to be considered even when other features of Borrelia burgdorferi infection are lacking.

Adult↗
PubMed1989

[Chronic spinal amyotrophy involving the upper limbs in young adults (O'Sullivan and McLeod syndrome). MRI study of the cervical spinal cord].

In 5 cases of sporadic spinal muscular atrophy in young adults the muscular atrophy was localized in the hands and forearms. Age at onset ranged from 7 to 20 years. The duration of the disease was less than 5 years in 3 patients and more than 15 years in 2. Electromyography showed neurogenic anomalies in all wasted muscles, denervation potentials being also present in the proximal muscles of the upper limbs and distal muscles of the lower limbs in 2 patients. Motor nerve conduction velocity and sensory nerve action potentials were normal. Advantages of a topographic classification of the distal form of chronic spinal muscular atrophy are discussed. Spinal cord MRI was performed in 4 patients with a 0.5 Tesla superconducting magnet using surface coils, using a T1-weighted spin-echo technique (ET 26 ms; RT 500 ms) and a T2-weighted spin-echo technique (ET 90, 180 ms; 2,000 ms). With the T1 technique, axial MRI sections 7 to 9 mm thick of spinal cord showed a normal image between C1 and C4, and a flattened image between C5 and T1. This was considered as a possible spinal cord segmental atrophy.

Adolescent↗