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Biomedical subjects

G Besson

Publications and source records attributed to G Besson.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Vascular accidents of the brain stem].

Cerebrovascular accidents (CVA's) of the brain stem have the same causes and physiopathological mechanisms as CVA's of the hemispheres, but they are ten times less frequent. They correspond to ischaemic or haemorrhagic lesions in the territories of the vertebral arteries and the basilar artery, including their collateral, circumferential and perforating branches. Clinically, CVA's of the brain stem are characterized by the association of unilateral motor and/or somatosensory symptoms on the side opposite the lesion, and by involvement of the ipsilateral cranial nerves, which helps in evaluating the level of the CVA. Motor or somatosensory symptoms may be bilateral or on alternate sides. The complexity of these CVA's reflects the rich anatomical organization of the brain stem. Their severity in case of extensive lesions is due to the fact that they affect structures that are vital to consciousness and cardiorespiratory regulation. Patients with CVA's of the brain stem must be hospitalized in neurology departments.

Brain Stem↗
PubMed1990

Effects of passive tactile and auditory stimuli on left visual neglect.

Patients with left-sided visual neglect fail to copy the left part of drawings or the drawings on the left side of a sheet of paper. Our aim was to study the variations in copying drawings induced by passive stimulation in patients with left-sided visual neglect. No stimulation at all, tactile unilateral and bilateral, binaural auditory verbal, and nonverbal stimuli were randomly applied to 14 patients with right-hemisphere strokes. Only nonverbal stimuli decreased the neglect. As nonverbal stimuli mainly activate the right hemisphere, the decrease in neglect suggests right-hemispheric hypoactivity at rest in these patients. The absence of modification of neglect during verbal stimulation suggests a bilateral hemispheric activation and the persistence of interhemispheric imbalance. Our results showed that auditory pathways take part in the network involved with neglect. Passive nonverbal auditory stimuli may be of interest in the rehabilitation of patients with left visual neglect.

Acoustic Stimulation↗
PubMed1990

Prospective study of lacunar infarction using magnetic resonance imaging.

Using computed tomography and magnetic resonance imaging, we prospectively studied 100 patients hospitalized with a lacunar infarct. Our aim was to evaluate the capabilities of magnetic resonance imaging in the detection and delineation of lacunes in a project of clinicotopographic correlations. Seventy-nine patients had a classic lacunar syndrome; 35 had pure motor stroke, 26 had ataxic hemiparesis, seven had sensorimotor stroke, and 11 had pure sensory stroke. A miscellaneous group of 21 patients had less typical lacunar syndromes, primarily with brainstem signs and symptoms. Among a total of 153 lacunes, magnetic resonance imaging detected at least one lacune appropriate to the symptoms in 89 patients. In 16 patients at least two lesions correlated with the clinical features, and precise clinicotopographic correlations were possible in 68 patients. Magnetic resonance imaging was more effective when it was performed a few days after the stroke. Lesions causing different types of lacunar syndromes had significantly different volumes, suggesting that the size of the lesion may influence clinical features. Magnetic resonance imaging may be the imaging technique of choice in the study of lacunar syndromes.

Aged↗
PubMed1990

Hemiplegia in posterior cerebral artery occlusion.

We report 4 patients with hemiplegia due to a posterior cerebral artery occlusion. Associated clinical signs were aphasia, alexia or a neglect syndrome, hemianopia, and hemisensory loss. Hemiplegia was due to infarction in the lateral midbrain. The level of the occlusion in the posterior cerebral artery may be located distal to the junction with the posterior communicating artery.

Aged↗
PubMed1989

Pure sensory stroke due to a pontine lacune.

A 53-year-old hypertensive man presented with the sudden onset of an isolated lemniscal sensory syndrome of the entire left side of his body. Magnetic resonance images showed a small lacune in the right paramedian pons corresponding to the location of the medial lemniscus.

Cerebral Infarction↗
PubMed1988

[Treatment of vasospasm in aneurysmal meningeal hemorrhage using intravenous nimodipine. Multicenter cooperative study].

We present a multicentric randomized double-blind study of the curative effect of intravenous Nimodipine on the post hemorrhagic vasospasm after aneurysmal rupture. On 122 validated cases out of 188 analyzed patients, the study demonstrates a significative effect on the mortality and severe morbidity related to vasospasm: the reduction of the risk is appreciated to 72%. The major effect is obtained on the mortality risk. A selective effect can be demonstrate on the isolated vasospasm.

Double-Blind Method↗
PubMed1988

[Magnetic resonance imaging in horizontal oculomotor paralysis caused by infarction].

Four patients with focal brainstem ischemic strokes and various types of horizontal oculomotor disturbances have been studied clinically and radiologically. One had a six nerve palsy, one a unilateral internuclear ophthalmoplegia, one a Fisher's one-and-a-half syndrome, and one a paramedian pontine reticular formation syndrome with a sixth nerve palsy. In all patients a C.T. Scan and a Magnetic Resonance Imaging (MRI) were obtained. The MRI study was performed on a CGR Magniscan 5000 with a superconducting magnet of 0.5 Tesla. In all patients a hypersignal in T2 weighted images was shown and corresponded to the brainstem infarct. MRI allowed accurate delineation of the lesion and clinico-radiologic correlations in three patients. But the low specificity of MRI does not permit to distinguish edema from necrosis, gliosis or demyelination in a region with a pathological MRI signal. In one patient this low specificity and perhaps partial volume effects decreased the accuracy of the clinico-topographic correlation.

Abducens Nerve↗
PubMed1988

[Magnetic resonance imaging and laterobulbar infarction].

Six patients with a clinical diagnosis of lateral medullary infarction have been studied by CT scan and Magnetic Resonance Imaging (MRI). The MRI study was performed on a CGR Magniscan 5000 with a superconducting magnet of 5 Tesla. In all patients T2 weighted images (TR = 2000, TE 60, 120) in joined section of 9 or 6 mm thickness were obtained in the axial plane. Three patients were also studied in T1 weighted sequences (TR = 500, TE = 28). A lateral medullary infarct was shown in 5 patients. MRI findings were consistent with a hemorrhagic infarct in one case. Occlusion of a vertebral artery was suggested in 2 cases and was confirmed by angiography. In 3 cases, an associated ipsilateral cerebellar infarct was demonstrated. The CT scan had only shown bleeding in the medulla oblongata in the hemorrhagic infarction case, and a cerebellar infarction in another case. Some clinical manifestations are discussed with regard to the results of MRI. MRI appears as the best current method to improve clinico-topographic correlations in medullary infarcts.

Aged↗
PubMed1987

[Syringomyelia and scoliosis in children and adolescents. Apropos of 14 cases].

The authors report their experience of 14 cases of scoliosis in children or young adults in association with syringomyelia. The neurological lesion was discovered at a variable time during the development of the scoliosis which may appear to be idiopathic for several years. There were 11 cases of syringomyelia or hydromyelia and three intramedullary tumours with cyst formation. The neurological lesion must be treated first and sufficiently early to avoid the development of muscle weakness and scoliosis. The scoliosis can be treated by normal without risk of additional complications.

Adolescent↗
PubMed1986

[Lateralized periodic activity and cerebral infarct].

A series of EEG recordings shows the evolution of a periodic activity (PA) in a 57-year-old man with acute cerebral infarction. The complexes ranged from 100 to 150 microV, the duration was 750 msec; the periodic occurrence repeated itself every 2 sec. PA is obliterated during the onset of electroclinical seizures. The CT scan shows temporal brain infarction.

Brain↗
PubMed1984

[Pituitary adenoma secreting somatotropic hormone. Gigantism and peripheral neuropathy. A case].

Gigantism, an extremely rare condition, develops before puberty or in subjects in whom puberty is not yet completed. Hypersecretion of somatotropic hormone results in a tremendous surge in growth (our patient was 2.36 m tall). Among other clinical symptoms disabling peripheral neuropathy predominates and changes in nerve conduction velocity are not merely due to the increase in height. The increase in growth hormone concentrations combined with hypogonadotrophic hypogonadism with normal prolactinaemia is associated with peculiar cutaneous symptoms and with low levels of sex hormone-binding protein.

Adenoma↗
PubMed1984

[Intramandibular segment of Meckel's cartilage in the rabbit embryo. Its cytological expression and osteogenetic fate].

Meckel's cartilage undergoes typical endochondral ossification within a model of the mandible, the ossification of which is then intramembranous. The concurrent development of two different osteogenetic processes in the 28 day-old rabbit embryo results in the formation of a single bony framework. These observations are based upon the assumption that Meckel's cartilage is not merely a supportive, primitive shaft without a definite ontogenetic future role, but rather an active participant in mandibular osteogenesis.

Animals↗
PubMed1983

[VIP removes the inhibition of prolactin secretion induced by dopamine in patients with prolactinoma].

PRL responsitivity after Vaso-active intestinal Peptide (VIP) infusion was studied during a Dopamine (DA) infusion, in normal women and women with a prolactinoma. VIP alone (6.2 micrograms/min., 12 min.) increases PRL in normal females, but does not remove DA-induced PRL-decrease (1 microgram X kg X X min.-1). It has no effect in women with prolactinoma. In these women, PRL increases when VIP is administered at the 200th minute of DA infusion (1 microgram X kg/min.). A PRL release by VIP in women with a prolactinoma, could imply the restitution of a DA inhibitory control. The same dose of VIP does not modify PRL, when administered during a 4 microgram X kg/min. infusion of DA, in women with a prolactinoma.

Dopamine↗
PubMed1983

[Kinetics of prolactinemia after withdrawal of dopamine perfusion and during the administration of domperidone. Normal and hyperprolactinemic subjects (prolactinomas and suprahypophyseal lesions)].

Fifteen normal menstruating women in the early follicular phase of their menstrual cycle, fifteen patients with prolactin secreting adenomas, two patients with a suprahypophysial lesion and an hyperprolactinemia, underwent a dopamine infusion (4 micrograms/kg/mn for four hours and an orally administration of domperidone (40 mg). Prolactin rebound after the arrest of dopamine infusion and during domperidone are + 400% and + 2,300% in normal subjects. These same studies are followed by similar and reduced prolactin response in suprahypophyseal lesion and prolactinomas. Such results suggest an abnormality of central dopaminergic control and/or a primary abnormality of lactotropes in prolactinomas. In two prolactinomas the normalization of both prolactin level and prolactin responses during the same tests is in favor of a primary abnormality of adenomatous lactotrope. These data justify neuro-surgical adenomectomy.

Adenoma↗
PubMed1982

[Prognostic value of the trigemino-facial reflex in severe post-traumatic comas].

The blink reflex (BR) study has been carried out on 40 severe head injury cases (average age 24.3 years). The recording was conducted several times between the 2nd and the 12th day and was repeated during the first month and beyond in prolonged comas. 23 patients did not respond even to high intensity stimuli. 17 patients displayed delayed and low amplitude latency responses: one of the components, early R1 or late R2 could be missing. The existence of a detectable focalized hemispheric lesion had no effect on the disappearance of the delayed lateral response. No BR was observed in mesencephalic, protubering comas and in 4 cases of subcortical and diencephalic comas. BR was observed in subcortical or diencephalic comas and in 5 cases of mesencephalic comas. The evolution of patients who did not display any electrical response during the first recording was unfavourable in 15 cases. Among the 5/8 remaining comatose cases, the BR was missing on the 2nd day and back on the 7th day. Among the 17 patients who displayed BR their evolution proved to be very favourable or favourable in 13 cases. In all the patients who survived beyond a month the response latencies proved normal, yet their amplitude was considerably lowered. The lack of BR is temporary but it is an element of unfavourable prognosis if it persists beyond a span of 8 days.

Adolescent↗
PubMed1982

Spontaneous spinal epidural hematoma in a 22-month-old girl.

The authors report the case of a 22-month-old girl who developed cervical pain, neck stiffness, and quadriparesis over 12 days. An epidural hematoma was removed, with complete recovery after 6 months. There was no history of trauma. A search of the literature revealed eight previous cases of spontaneous spinal epidural hematomas in children under the age of 10 years.

Female↗