Search PubMed⌕ Search

Biomedical subjects

G Farnarier

Publications and source records attributed to G Farnarier.

At least 19 recordsLinked to original sources
PubMed1992

[Evoked potentials in HIV infection].

The study of the literature data on the multimodal evoked potentials in HIV infected patients shows many abnormalities as well in asymptomatic subjects without AIDS as in AIDS subjects with or without neurological signs. Visual evoked potentials (VEPs) reveal prolonged P100 wave latency in 22% of HIV asymptomatic subjects and in 26% of HIV symptomatic subjects; brainstem auditory evoked potentials (BAEPs) reveal an increase of the interpeak latency I-V in 16% of asymptomatic subjects and in 32% of symptomatic subjects; somatosensory evoked potentials (SEPs) by median nerve stimulation reveal prolonged central conduction time in 6% of asymptomatic subjects and in 11% of symptomatic subjects; somatosensory evoked potentials (SEPs) by tibial nerve stimulation reveal prolonged central conduction time in 4% of asymptomatic subjects and in 45% of symptomatic subjects; motor evoked potentials (MEPs) by magnetic stimulation reveal prolonged central motor conduction time in 46% of asymptomatic subjects.

Adult↗
PubMed1992

Sleep electroencephalogram at the early stage of Creutzfeldt-Jakob disease.

We describe sleep EEG studies in three patients at the early stage of Creutzfeldt-Jakob disease. Little work has been devoted to the study of the sleep EEG in the course of the CJ disease: disorganized sleep architecture was noted, associated with a decrease in stage 4 and an almost complete disappearance of the REM stage. Our patients were considered to have normal stage 2; yet spindles and K complexes were rare at this stage. No evolution towards stage 4 was noted. The percentage of rapid eye movement sleep was significantly low in two cases and normal in one case. Sleep disturbances in the other dementing disorders are reported.

Aged↗
PubMed1991

Different susceptibilities of the geniculate and extrageniculate visual pathways to human Creutzfeldt-Jakob disease (a combined neurophysiological-neuropathological study).

Flash evoked visual potentials (FEPs) of 7 patients with advanced Creutzfeldt-Jakob disease (CJD) were compared with those recorded in 7 patients with senile dementia of the Alzheimer type (SDAT), in 13 age- and sex-matched healthy volunteers and in 7 neuropsychiatrically normal subjects whose occipital evoked responses were increased in amplitude (amplitude controls). Post-mortem examination was performed in 4 of 7 CJD patients in order to map pathological changes along the visual pathways, including the retino-geniculo-striate and extrageniculate pathways. Normal FEPs were typified by 2 constant early components (P1 and N2) followed by several (3 or more) late components that were characterized by marked interindividual variability. Amplitude controls had enlarged (from 14 to 44.8 microV, mean 25.7) P1 component. Both SDAT and CJD patients had normal early FEP waves (P1 and N2) and important alterations of the late FEP components. Moreover, a late positive component was responsible for abnormally enlarged FEPs (52.6 and 58.2 microV) in 2 CJD patients. Finally, electroretinograms, recorded in 1 CJD patient, were normal. These findings suggested relative functional integrity of the retino-geniculo-striate pathway associated with important dysfunction of the cortical visual processing in both SDAT and CJD patients. Pathological studies disclosed preservation of optic nerves, chiasmas, lateral geniculate nuclei and Gennari's strip of the striate cortex but associated with important spongiform change, neuronal loss and gliosis in the superior colliculi (layer II), pulvinar, extrastriate cortex and layers II-III, V and VI of the striate cortex. We conclude that different visual pathways have different susceptibilities to CJD: important functional and anatomical alterations of the intracortical and extrageniculate pathways contrast with relative preservation of the retino-geniculo-striate pathway.

Adult↗
PubMed1991

Sensory evoked potentials in herpes simplex encephalitis.

Flash visual potentials (FEPs), somatosensory evoked potentials (SEPs) and auditory brainstem responses (ABR) were recorded in a 66-year-old patient presenting with clinical, EEG and CT brain scan features of herpes simplex encephalitis (HSE). At the time of evoked potential study (10 days after onset of the disease) the patient was treated with iv barbiturate on controlled respiration (lidocaine and phenytoin were not utilized); core temperature was 37 degrees C and pupils were dilated and nonreactive. Cortical FEPs were not recognizable on 02 lead, whereas they were clearly evident on 01 with normal latency of early N1, P1, N2 waves and delayed P2 component. SEPs showed normal peripheral and central conduction times, but N20 peak was bilaterally absent with unrecognizable (on P3) or delayed (on P4) N33 wave. No ABR (including wave I) were found on stimulation of the right ear, whereas delayed wave V with prolonged interpeak I-V latency was found on stimulation of the left ear. In conclusion, changes in sensory evoked potentials in HSE seem to be caused either by necrotic-hemorrhagic damage (with the disappearance of some cortical responses), by coma (with alterations in middle-latency cortical responses) and by increased intracranial pressure (with subsequent ABR abnormalities).

Aged↗
PubMed1990

Multimodal evoked potentials in HIV infected patients.

We studied 126 HIV seropositive patients (106 men, 20 women; mean age: 32 years): 45 had neurological signs, 81 had none. Multimodal evoked potential (MEP) assessment included: visual EPs by flash and reversal checkerboard; brain-stem auditory EPs; somatosensory EPs by stimulation of the median nerve. Evaluation also included: electroencephalography, electromyography with measurement of conduction velocities, neuroimaging (CT scan and MRI). We found abnormal MEPs for all modalities. The prevalence of abnormal results was high in neurologically symptomatic patients; in non-neurological subjects, the changes were more dramatic as HIV infection progressed. Whatever the stage of the disease, the modalities were equally affected. MEPs were abnormal in 54.7% of patients: in 41.8% of those without neurological signs vs. 85.7% of those with these signs. Comparison of MEPs and other electrophysiological procedures and neuroimaging techniques showed the high sensitivity of MEPs at all stages of the disease. EMG was sensitive and complementary to MEPs. EEG and neuroimaging showed abnormalities principally at the neurological symptomatic stage. Our results agree with those found in the literature. Abnormal MEPs may: (1) indicate latent neurological involvement of the visual, auditory and somatosensory pathways, (2) help diagnose an encephalitis suspected on neuropsychological, non-quantifiable testing.

Adolescent↗
PubMed1990

Sensory evoked potentials in Creutzfeldt-Jakob disease.

Eight patients presenting with intermediate or terminal evolution of Creutzfeldt-Jakob disease (CJD) were investigated by means of evoked potentials. Fifteen age-matched healthy subjects served as controls. The 8 patients had well-recognizable but simplified flash evoked potentials (FEPs) consisting of P1 and N2 waves followed by a single late positive (P2) deflection. Enlarged FEPs were found in 2 of the 8 patients. The somatosensory central conduction time was normal in 3 of 5 patients, and it resulted in upper normal limits or was moderately slowed in 2 patients. No enlarged somatosensory scalp potentials were recorded. Cortical somatosensory responses were characterized by an unrecognizable (4 patients) or delayed (2 patients) N33 wave. Brainstem auditory evoked responses, recorded in 6 patients, were normal. In CJD very important functional impairment of the sensory cortical areas is associated with absent or mild dysfunction of the subcortical sensory pathways.

Acoustic Stimulation↗
PubMed1990

Brainstem auditory evoked potentials in alternating hemiplegia: ictal vs interictal assessment in one case.

The authors report a case of alternating hemiplegia (AH) in a 3yr 6m old boy who had presented, from the age of 4 months on, episodes of alternating hemi- or quadriplegia. Brainstem auditory evoked potentials were recorded both in the interictal state and, for the first time, during an attack. There was no significant difference between the two states. These findings suggest that a massive involvement of the posterior vascular territory is not likely to be associated with attacks in AH.

Brain Stem↗
PubMed1990

[Multimodal evoked potentials in human immunodeficiency virus infection].

We have studied 95 HIV seropositive patients (77 males and 18 females; mean age: 31 years): 67 had no neurological symptoms or signs, 28 had various neurological symptoms and signs. This study included a full multimodal evoked potentials (MEP) assessment: visual evoked potentials by flash and reversal checkerboard; brainstem auditory evoked potentials; somatosensory evoked potentials obtained by stimulation of the median nerve. Patient evaluation further included: electroencephalography, electromyography with measurement of conduction velocities and neuroimaging (brain CT scan and/or MRI). We found abnormal MEP for all modalities. The prevalence of abnormal results was high in neurological symptomatic patients; in non neurological ones, the changes tended to be more frequent with the progression of the HIV infection. Whatever the stage of the disease, the various modes were equally affected. MEP were abnormal in 54.7 p. 100 of the cases: in 41.8 p. 100 (28/67) of patient without neurological signs (in 4/12 of fully asymptomatic subjects, 11/34 ARC patients and 13/21 AIDS patients) vs 85.7 p. 100 of neurological symptomatic patients. In neurological asymptomatic patients, a similar proportion of abnormal MEP was found in asymptomatic and ARC patients, while the evolution into AIDS was associated with a higher prevalence of abnormal MEP. In the latter group, MEP changes were nearly as frequent as in neurological symptomatic patients. Comparison between MEP and other electrophysiological procedures (EEG, EMG) and with neuroimaging techniques (CT Scan, MRI) showed the high sensitivity of the MEP technique at all stages of the disease. EMG was a sensitive method and complementary to MEP. The EEG and neuroimaging techniques showed abnormalities principally at the neurological symptomatic stage. Previous studies could not be properly compared.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Multimodal evoked potentials in partial epilepsy in children].

A multimodal evoked potential study was realised in three groups of children or adolescents 5 to 15 years old. The first group included 25 normal non-epileptic subjects; the second group was composed of 27 subjects with partial idiopathic epilepsy (PIE) (benign childhood epilepsy with centro-temporal spike; childhood epilepsy with occipital paroxysms); the third group was formed of 20 subjects with partial symptomatic epilepsy (PSE) without patent anatomical lesion or with anatomical lesion. Recording for each subject included: flash visual evoked potentials, pattern visual evoked potentials, brainstem auditory evoked potentials and somatosensory evoked potentials. Each curve obtained was studied for the response morphology, the measure of the different wave latencies, the inter-peak latencies (conduction time) and the amplitudes. A statistical treatment of the data was performed to evaluate the significance of variation of the different parameter values obtained for the various groups. Among the significantly modified parameters, we found: an increase of the amplitudes in the PIE and a decrease in the PSE, specially when an anatomical lesion exists; an asymmetrical amplitude of the somatosensory responses in the PIE with centro-temporal spike; an increase of the central somatosensory conduction time in the PSE with anatomical lesion.

Adolescent↗
PubMed1987

Subacute spongiform encephalopathy with periodic paroxysmal activities: clinical evolution and serial EEG findings in 20 cases.

Evolution of both clinical and EEG abnormalities was analyzed in 20 (16 pathologically confirmed) patients suffering from subacute spongiform encephalopathy with periodic paroxysmal activities (PPA) on the EEG. Illness duration was less than 4 and greater than 17 months in 65% and 10% of cases, respectively. All data but EEG were utilized to assess 3 conventional clinical stages in 20 patients. The early clinical stage was characterized by gradual presentation of gait disturbances, mental deterioration, sensory or autonomic disorders. In contrast with other reports, no PPA were observed in 10 EEG recordings from 7 patients examined at the early clinical stage. Both clinical and EEG findings were not in contrast with a hypothetic subcortical onset of disease. Similar to recent data in the literature, early PPA appeared within 12 weeks of disease evolution in 88% of patients who underwent EEG recordings in the first 3 months of disease. Nonetheless, these early PPA always occurred at an intermediary stage, when our patients showed a marked worsening of the clinical picture. Focal, segmental and/or generalized myoclonic jerks were observed in 15%, 53% and 100% of cases at prodromal, intermediary and terminal stages respectively. Different kinds of PPA were observed: bi-tri-phasic periodic complexes (PC), periodic complexes with multiphasic configuration (PPC) and periodic polyspiking discharges (PPD). Abnormal "pacing" of PC by slowly repeated flashes was found in 4 patients presenting visual hallucinations or cortical blindness. Burst-suppression activity was frequently found at the terminal stage in decorticate patients.

Aged↗
PubMed1985

[Somatosensory evoked potentials and action myoclonus].

The authors studied the somatosensory evoked potentials (SEPs) in 16 cases of myoclonic encephalopathies: 8 cases of dyssynergia cerebellaris myoclonica (DCM); 2 cases of dyssynergia cerebellaris progressiva (DCP); 2 cases of Lafora's disease; 1 case of ceroid lipofuscinosis; 3 unclassifiable myoclonic syndromes. The mean age of the patients was 18 years and the mean duration of pre-study evolution was 10 years. All the patients had been treated by anticonvulsant drugs (phenobarbital, valproic acid, benzodiazepines). The amplitude of the complex P1N2 at the level of the contralateral parietal cortex, with stimulation of the median nerve at the wrist, was found to be enlarged in only 6 cases and giant responses (over 40 microV) were obtained in 2 cases. Only half of the patients with DCM presented a high amplitude response. There was no correlation either with clinical parameters (and in particular, certain patients with marked action myoclonic jerks have a normal SEP), or with the EEG data: on the contrary, the amplitude variations of the SEPs are most often similar to variations of the visual evoked potentials.

Adolescent↗
PubMed1985

Brainstem auditory evoked responses in Lafora disease.

Brainstem auditory-evoked responses (BAERs) have been studied in five patients suffering from Lafora-type of progressive myoclonus epilepsy proven by skin biopsy and in ten healthy volunteers. At the time of examination the patients were not taking benzodiazepines and showed myoclonic jerks. In all patients the central conduction time (interpeak latencies I-V, I-III, III-V) and the amplitude (amplitude ratio I/V) of BAERs were within the +/- 2 S.D. limits of the normal values. Since Lafora disease is a neuropathologically prevalent grey-matter illness (typical inclusion bodies are stored intraneuronally) these data indicate that diseases primarily affecting the brainstem grey-matter are usually associated with normal BAERs.

Adolescent↗
PubMed1984

[Absence status with unilateral EEG predominance (apropos of a personal case report)].

The authors describe a 33-year-old woman who, from the age of 15 years, presented many generalized epileptic seizures per year starting with right-sided adversion or gyration, several times per month long absences and occasional absence status lasting up to 3 days. In this patient, the hyperpnoea provoked a clinically typical absence status with 3 c/sec rhythmic continuous spike-and-wave discharges which were more evident on the left frontal regions of the scalp. This electro-clinical picture is compared to similar cases described in the literature and its nosological specificity is discussed.

Adult↗
PubMed1984

Electroencephalographic and anatomo-clinical evidences of posterior cerebral damage in hypertensive encephalopathy.

The authors describe two patients suffering from hypertensive encephalopathy associated with epileptic seizures and anatomo-clinical evidences of posterior cerebral damage. The concordant electroencephalographic features with clinical signs and anatomic lesions of these two patients are discussed, in order to make some considerations about the role played by the blood-brain-barrier damage on the physiopathology of the hypertensive encephalopathy.

Adult↗
PubMed1983

[Vomiting: symptom of an epileptic seizure].

The authors present 3 cases of ictal vomiting with 2 seizures recorded on the EEG. The critical vomiting is always sudden, projectile, and lasts a short period. The interictal and ictal EEG recording showed a focus or a seizure involving the frontal temporal regions. The seizures were kept under control by a therapy with carbamazepine. Vomiting can be a particular semiological aspect of a possible seizure as are other vegetative features. The authors stress this critical aspect on one hand differentiating it from non-epileptic ictal phenomena (in particular children's cyclic vomiting), on the other hand from post-ictal vegetative phenomena of a major or partial seizure.

Adult↗
PubMed1983

[Prolonged confused seizure state of frontal origin in an aged patient].

The authors discuss the case of a man who, at the age of 63, presented episodes of prolonged confusional state de novo. The EEG recordings showed the existence of an electrical status with widespread spikes and polyspike-and-waves of the "absence status." Further recordings showed a focal onset of one of the episodes of prolonged confusional state. The electric and clinical characteristics of this observation indicate that a frontal localisation with secondary generalization of the discharge is probable. This electro-clinical picture is compared to other literature on the subject and its nosological specificity is discussed.

Cognition Disorders↗
PubMed1982

[Sodium cromoglycate eyewash in allergic conjunctivitis. Multicentric controlled double-blind study. Review of the literature].

A randomized double-blind trial was conducted in 143 out-patients with allergic conjunctivitis (281 eyes). Active sodium cromoglycate collyre was compared with placebo in parallel groups over a four-week period. Highly significant advantage for active drug was demonstrated for subjective and objective symptoms as well as for overall assessment by patients and physicians. Results were compared with international data concerning this well-known anti-allergic compound.

Adult↗