Axonal neuropathy and late detection of Refsum's disease.
Explore the source record for details and available documents.
Axons↗
Biomedical subjects
F Tabaraud
Publications and source records attributed to F Tabaraud.
Modulation of tau neuronal expression induced by NMDA, non-NMDA and metabotropic glutamate receptor agonists.
We have analysed changes in tau protein immunoreactivity in rat embryonic neurons degenerating in response to treatment with N-methyl-D-aspartate (NMDA), non-NMDA and metabotropic agonists. Glutamate agonists were applied in Mg(++)-free and glycine-supplemented medium 8 days after initial plating. Cell viability was assessed by fluorescein diacetate staining and neuronal survival was evaluated by cell counting. Immunocytochemical and confocal laser microscopic studies used a tau2 monoclonal antibody. Acute and chronic NMDA treatment induced a concentration-dependent increase in intraneuronal tau immunoreactivity. Increased tau immunolabelling during chronic NMDA toxicity was dramatically attenuated by tetrodotoxin and also by 6-cyano-7-nitroquinoxaline-2,3-dione. Non-NMDA and metabotropic receptor agonist treatment produced a weaker augmentation in tau2 immunoreactivity. These findings suggest that, in this model, glutamate-receptor and sodium-channel coactivation are together needed to produce changes in tau immunoreactivity.
Analysis of Variance↗
Non-Hodgkin malignant lymphomas and peripheral neuropathies--13 cases.
Non-Hodgkin's malignant lymphomas (NHML) are malignant lymphoid proliferations which may be of B or T cell type. Thirteen observations of an association between peripheral neuropathy and B type NHML are reported. None of the cases had evidence of meningeal propagation or neurotoxicity from chemotherapy. The NHML were classified according to the Working Formulation and Kiel classifications. The various mechanisms of peripheral neuropathy in these cases were split into four broad groups. Group I consisted of four cases in which the peripheral nerve lesions were directly linked to a propagation of malignant cells into the peripheral nervous system; this was revealed by autopsy and/or nerve biopsy. Malignant B cell proliferation was demonstrated in three out of four of these cases by immunolabelling of the infiltrates. Group II included three patients whose serum contained a monoclonal immunoglobulin (IgM) with antimyelin activity, and two who had pathological IgM deposits in endoneurial connective tissue. Group III comprised two cases. The immune dysfunction of the NHML was responsible for a Guillain-Barré syndrome in one, and for a chronic inflammatory demyelinating polyneuropathy in the other. Group IV included two patients in whom the mechanism of the peripheral neuropathy, although almost certainly directly related to the NHML, could not be determined beyond doubt. The peripheral neuropathy might have been a result of a paraneoplasic process or, possibly, an undetected lymphomatous invasion of nervous tissue. All these cases of clinically diverse peripheral neuropathy, which either occurred before the discovery of the haemopathy or arose as complications of it, are discussed along with similar observations reported in the literature. Immunolabelling of lymphomatous proliferations and nerves is now of considerable value for classifying and indicating the exact aetiology of the peripheral neuropathy. It can also detect pathogenic consequences of any associated monoclonal dysglobulinemia. In any event, a direct link between the peripheral neuropathy and NHML represents an indication for intensification of specific chemotherapy, which in some of our patients led to significant regression of the peripheral neuropathy. Nonetheless, in some cases, the link between peripheral neuropathy and NHML could not be established with certainty. Long-term follow-up is essential in such cases. The present results show the importance of a case by case study of patients with NHML and peripheral neuropathy.
Aged↗
[Early diagnosis of Guillain-Barré syndrome by electric stimulations of the nerve roots].
Ulnar nerve electrical stimulations from motor roots to wrist were used in the early Guillain-Barré syndrome (GBS), to improve the electrophysiological diagnosis yield. 22 patients with a GBS were investigated with this technique between 3 to 17 days after the onset. Conventional electrophysiological examination was sufficient to diagnose an Acute Inflammatory Demyelinating Polyneuropathy in 12 cases. In 10 other patients, standard examination remained negative or not conclusive, and vertebral electrical stimulations were decisive for the diagnosis, showing conduction bloks. This method could be routinely performed for an early diagnosis, in association with conventional motor conduction measurements. This study confirms the possibility of a pure proximal demyelinating impairment of the peripheral nervous system in the early GBS.
Adolescent↗
Widenings of the myelin lamellae in a typical Guillain-Barré syndrome.
The so-called "widening of the myelin lamellae" are thought to be specific ultrastructural features of peripheral nerve myelin in patients with peripheral neuropathy associated with a monoclonal dysglobulinemia of IgM type and antiglycolipid activity. We report here a case of Guillain-Barré syndrome with no evidence of serum monoclonal dysglobulinemia, presenting the typical widenings of the myelin lamellae in small-diameter myelinated fibers from a sural nerve biopsy. In view of the positive reaction with anti-C3d complement on direct immunofluorescence, an immunological mechanism may be involved in the widenings of the myelin lamellae.
Axons↗
[The distribution of sleep and wakefulness in human African trypanosomiasis].
Last century, patients with human African trypanosomiasis were described as sleepy by day and restless by night, and physicians referred to this condition as sleeping sickness. Such a description could have evoked a disturbance of circadian rhythms. However, it is only in 1989 that the first 24-hour recording was performed by our team in Niamey (Niger) in a patient with sleeping sickness. The patient was a Niger-born farm worker who had contracted the disease near Gagnoa (Côte d'Ivoire). Polysomnographic recordings (electroencephalogram, EEG, electrooculogram, electromyogram, electrocardiogram, buccal and nasal airflow, and chest respiratory movements) showed a disappearance of the circadian distribution of sleep and wakefulness, which tended to occur evenly throughout day and night, with a sleep-wake alternation of approximately 80 minutes. Two investigations were conducted thereafter. The first one was done at Daloa (Côte d'Ivoire) in 8 patients who were recorded during two 24-hour periods, with and without hourly blood samples; the second at Brazzaville (Congo) in 10 patients recorded for 24 hours before and after treatment with melarsoprol. All patients were at the stage of early meningoencephalitis. At Daloa, polysomnographic recordings were taken on two 8-channel EEG machines (Alvar Minihuit, and T3-ECEM), as well as on a portable Oxford Medilog 9000 system from the same electrodes. Sleep and wake structure was altered in the most severely sick patient, the EEG trace being loaded with slow waves. Stages 1 and 2, and stages 3 and 4 could not be distinguished from one another. In the other patients, all sleep stages were easily scored. No difference was seen between recordings, regarding blood collection.(ABSTRACT TRUNCATED AT 250 WORDS)
Circadian Rhythm↗
[Myogenous or muscular syndrome. Diagnostic orientation].
Explore the source record for details and available documents.
Adult↗
[Effects of isoflurane and halothane on motor evoked potentials in the rabbit].
The effects of isoflurane or halothane on motor evoked potentials (MEPs) were assessed and compared in the rabbit, in order to contribute to devise a rigorous human anaesthetic protocol to be used for monitoring of MEPs in corrective spinal surgery. Ten black adult New Zealand rabbits were anaesthetised twice at a month interval, once with isoflurane and once with halothane. Once a control cortical stimulation had been carried out after the animal had breathed pure oxygen for three minutes, the following concentrations of anaesthetic agent were given for 3 min each: respectively 0.3 vol %, 0.5 vol % and 1 vol % of isoflurane, and 0.5 vol % and 1 vol % of halothane. Cortical stimulation was carried out every minute. The signs of anaesthesia (diameter decrease of the pupil, eye covered by the nictating membrane), muscle relaxation (ears drop) and breathing rate were recorded. MEPs were recorded 1, 2, 3 and 5 minutes after the end of anaesthesia. Isoflurane had a stronger effect on MEPs than halothane. The effect was more pronounced on amplitude than on latency. MEPs remained present whatever the concentration of halothane. In 70% of cases, MEPs, discontinued with isoflurane, more rapidly, more deeply, and for a longer time. Mean latency was more constantly increased in the isoflurane than in the halothane group. The effect of volatile halogenated anaesthetics on mean latency of MEPs seemed to be more delayed than that on amplitude. One should also take into account an individual sensitivity, it is concluded that the interpretation of MEPs during anaesthesia with volatile halogenated agents should be carried out with caution.
Anesthesia, Inhalation↗
Sleep-wake cycle in human African trypanosomiasis.
Sleeping sickness patients are classically described as sleepy by day and restless by night. Prior to this study, we had objectively confirmed this description by recording 24-h sleep patterns in a patient with human African trypanosomiasis. We report 24-h polysomnographic recordings (EEG, electrooculogram, electromyogram, electrocardiogram, and nasal, buccal, and thoracic respiratory traces) performed on two eight-channel electroencephalographs in eight patients with untreated sleeping sickness at an early stage of meningoencephalitis. As in our previously reported patient, there was no hypersomnia. The patients presented mainly a disorganization of the circadian alternation of sleeping and waking, with no or little alteration in the states of vigilance at this early stage of the disease. The disorganization was proportional to the degree of severity of the clinical symptoms. It may be due to an alteration in biological clock mechanisms.
Adolescent↗
Monitoring of the motor pathway during spinal surgery.
Paraplegia caused by irreversible lesions of the spinal cord is one of the major possible complications after scoliosis surgery. Several monitoring methods have been proposed but none are completely satisfactory. Since 1986 the authors assessed motor pathways during scoliosis surgery, using electrical stimulation of the motor cortex and lower limb muscle recordings (tibialis anterior muscle). Twenty-seven patients were included in this study: 25 with idiopathic scoliosis and 2 with dorsal kyphosis. Recordings in anesthetized patients with hypothermia were performed before and after spinal derotation during the surgical procedure. Magnetic cortical stimulation was carried out in ten awake patients before and after surgery. Reproducible responses were obtained in 22 patients under anesthesia. In eight patients no difference of the latency of the muscle response was detected before and after the correction of the spinal angulation. In 14 patients the increase of latency ranged from 0.4 ms to 5.2 ms. No correlation was found between the slowing of motor conduction and the magnitude of spine correction. No central neurologic complications were seen after surgery. The authors concluded that their study demonstrated that motor pathway assessment in anesthetized patients can be performed at different times during the surgical procedure. This technique should help in the future monitoring spinal function during scoliosis surgery.
Adolescent↗
[Polyneuropathies and monoclonal gammopathies, so-called benign].
As all other monoclonal dysglobulinaemias, the allegedly benign monoclonal dysglobulinaemia (also called of undetermined nature) can be responsible for peripheral neuropathy. It must be noted that electrophoresis and immuno-electrophoresis may be insufficient to demonstrate its presence and that this can be done with specific immunological techniques, such as ELISA or immunoblot). Once the monoclonal gammopathy has been recognized, its relation to the peripheral nerve lesion is not always easy to prove. Antibody activity against certain constituents of the nerve can sometimes be evidenced, notably for IgM. It is interesting to point out that almost all IgM-related neuropathies have highly characteristic clinical, histological and immunological features. Various other mechanisms, often still unknown, are most probably involved.
Adult↗
Improvement in motor evoked potentials and clinical course post-steroid therapy in multiple sclerosis.
Motor evoked potentials (MEP) were recorded in 23 patients with definite relapsing multiple sclerosis before and after treatment with a short course of high dose of methylprednisolone. MEP were performed together with clinical examination just before treatment, and 6 and 60 days later. The following results were observed: (1) a statistically significant relationship between the corticospinal deficit and the alteration in MEP, (2) a significant improvement in latency of MEP by day 6, (3) a significant correlation between the change in the Kurtzke disability scale rating and the improvement in MEP. The results provide further evidence for the possible effectiveness of short courses of high dose corticosteroids in the treatment of relapses of multiple sclerosis and the usefulness of MEP in its assessment.
Adult↗
Study of evoked potentials in human African trypanosomiasis.
Human African trypanosomiasis or sleeping sickness has a stage of neurological involvement characterized by the onset of diffuse meningoencephalitis with sleep disturbances and decreased wakefulness. The pathogenesis of this disease is not well understood. We studied auditory, visual, sensory, and motor evoked potentials in 16 patients with trypanosomiasis in the early stage of meningoencephalitis. In all patients, the brain-stem auditory evoked response (BAER) and the pattern-reversal visual evoked response (PVER) were normal. On the other hand, abnormalities of the somatosensory evoked response (SSER) or the motor evoked response (MER) were found in only five cases; however, their relationship to the illness could not be definitely confirmed. The study results indicate that the evaluated pathways were essentially intact, in particular at the level of the brain-stem in the early stage of the disease. Sleep disturbances and decreased wakefulness noted at this stage were thus linked more closely to functional involvement at the level of the sleep centres than to any detectable specific anatomic lesion.
Adolescent↗
Acute or subacute alcoholic neuropathy mimicking Guillain-Barré syndrome.
Over the last 10 years we have encountered 8 patients with chronic alcoholism who presented with severe symmetrical polyneuropathy, primarily proximal in 6, which evolved over a period of 24 h to 3 weeks. In 3 cases, artificial ventilation was required. Sensory symptoms were in all instances intense, and tendon reflexes absent. CSF protein levels were normal. The course was one of gradual improvement, often incomplete with residual motor and distal sensory deficits. Three patients died within 2 months to 2 years with multiple and severe pathologies attributable to chronic alcoholism. There was no evidence for disorders other than the alcoholism and malnutrition. Electrophysiological findings were consistent with predominantly axonal lesions and nerve biopsy specimens confirmed acute and severe axonal lesions. Several of these patients had been referred to us with a possible diagnosis of Guillain-Barré syndrome due to the severity of the neuropathy and the rapidity of its onset (Landry syndrome). Acute alcoholic neuropathy is distinguishable, however, on clinical, electrophysiological and morphological grounds.
Acute Disease↗
[Circadian analysis of sleep, rectal temperature and immunological and endocrinological variables in sleeping sickness: preliminary study].
A multidisciplinary study was conducted in 8 patients with neurological Human African Trypanosomiasis. The sleep-wake cycle followed an ultradian pattern which was more pronounced in patients with more severe symptoms. The EEG trace was consistently interrupted by numerous cyclic activation patterns with K complexes, rapid low amplitude elements and slow high voltage elements. Circadian rhythmicity was also disturbed in other physiological (rectal temperature), immunological (interleukins) or hormonal (cortisol, prolactin) variables, the disturbance being greater in severely hit patients.
Adolescent↗
[4 cases of Guillain-Barré syndrome with axonal lesions].
We report the neurological features observed in 4 patients who developed a clinically typical Guillain-Barré syndrome. Electrophysiological and histological data displayed an unusual number of axonal lesions, although these were always associated with demyelination. These cases must be distinguished from the rare cases of Guillain-Barré syndrome with pure axonal lesions. Three patients had a poor functional recovery. This confirms the more severe prognosis of Guillain-Barré syndrome with major axonal degenerative changes.
Adult↗
Motor evoked responses after lumbar spinal stimulation in patients with L5 or S1 radicular involvement.
Motor evoked responses were recorded bilaterally in the tibialis anterior and soleus muscles after lumbar spinal stimulation in 45 patients suffering from L5 or S1 radiculopathies due to disc protrusion, and in 25 healthy controls. A significant prolongation (P less than 0.01) of motor evoked response latency was observed in 72% of the patients with L5 radiculopathy and in 66% of the patients with S1 radiculopathy. These anomalies were observed in patients with objective neurological signs as well as in patients free of objective signs. These findings indicate that subclinical compressive radiculopathy can be detected by this method which represents a useful adjunct in the assessment of radicular pain of discopathic origin.
Adolescent↗
Central motor conduction and glutamate deshydrogenase: activity in olivo-ponto-cerebellar atrophy.
Central motor conduction was investigated by way of magneto-electric cortico-spinal stimulation in 6 patients with sporadic olivo-ponto-cerebellar atrophy. Two patients were found to have reduced leucocyte GDH activity. Only the 3 patients with corticospinal deficits displayed increased central conduction rates, which were predominant in the lower limbs. The duration of the disease is statistically longer in patients with corticospinal deficit compared to patients with no corticospinal deficit. In OPCA, evoked motor potentials are useful in assessing the corticospinal deficit which does not appear to be linked to reduced leucocyte GDH activity.
Adult↗