Epilepsy surgery: A therapeutic patient education program

Before the creation of a therapeutic patient education (TPE) program for epilepsy surgery, a needs analysis was conducted with 29 people, including patients (n=13), family members (n=9) and healthcare providers (n=7). Most of them highlighted the psychological difficulties of the surgical process, and the need for considerably more precise information concerning the immediate postoperative period. In addition, several patients and/or family members requested meeting with a patient who had undergone the surgery. The majority of subjects were interested in epilepsy-surgery TPE. These data were important in the creation of our TPE program and, more generally, for the management of these patients.

Continuous EEG monitoring in adults in the intensive care unit (ICU)

Continuous EEG monitoring in the ICU is different from planned EEG due to the rather urgent nature of the indications, explaining the fact that recording is started in certain cases by the clinical team in charge of the patient's care. Close collaboration between neurophysiology teams and intensive care teams is essential. Continuous EEG monitoring can be facilitated by quantified analysis systems. This kind of analysis is based on certain signal characteristics, such as amplitude or frequency content, but raw EEG data should always be interpreted if possible, since artefacts can sometimes impair quantified EEG analysis. It is preferable to work within a tele-EEG network, so that the neurophysiologist has the possibility to give an interpretation on call. Continuous EEG monitoring is thus useful in the diagnosis of non-convulsive epileptic seizures or purely electrical discharges and in the monitoring of status epilepticus when consciousness disorders persist after initial treatment. A number of other indications are currently under evaluation.

Intraoperative neurophysiologic monitoring in spine surgery. Developments and state of the art in France in 2011

Intraoperative spinal cord monitoring consists in a subcontinuous evaluation of spinal cord sensory-motor functions and allows the reduction the incidence of neurological complications resulting from spinal surgery. A combination of techniques is used: somatosensory evoked potentials (SSEP), motor evoked potentials (MEP), neurogenic motor evoked potentials (NMEP), D waves, and pedicular screw testing. In absence of intraoperative neurophysiological testing, the intraoperative wake-up test is a true form of monitoring even if its latency long and its precision variable. A 2011 survey of 117 French spinal surgeons showed that only 36% had neurophysiological monitoring available (public healthcare facilities, 42%; private facilities, 27%). Monitoring can be performed by a neurophysiologist in the operating room, remotely using a network, or directly by the surgeon. Intraoperative alerts allow real-time diagnosis of impending neurological injury. Use of spinal electrodes, moved along the medullary canal, can determine the lesion level (NMEP, D waves). The response to a monitoring alert should take into account the phase of the surgical intervention and does not systematically lead to interruption of the intervention. Multimodal intraoperative monitoring, in presence of a neurophysiologist, in collaboration with the anesthesiologist, is the most reliable technique available. However, no monitoring technique can predict a delayed-onset paraplegia that appears after the end of surgery. In cases of preexisting neurological deficit, monitoring contributes little. Monitoring of the L1-L4 spinal roots also shows low reliability. Therefore, monitoring has no indication in discal and degenerative surgery of the spinal surgery. However, testing pedicular screws can be useful. All in all, thoracic and thoracolumbar vertebral deviations, with normal preoperative neurological examination are currently the essential indication for spinal cord monitoring. Its absence in this indication is a lost opportunity for the patient. If neurophysiological means are not available, intraoperative wake-up test is a minimal obligation.

[French guidelines on the use of repetitive transcranial magnetic stimulation (rTMS): safety and therapeutic indications]

During the past decade, a large amount of work on transcranial magnetic stimulation (TMS) has been performed, including the development of new paradigms of stimulation, the integration of imaging data, and the coupling of TMS techniques with electroencephalography or neuroimaging. These accumulating data being difficult to synthesize, several French scientific societies commissioned a group of experts to conduct a comprehensive review of the literature on TMS. This text contains all the consensual findings of the expert group on the mechanisms of action, safety rules and indications of TMS, including repetitive TMS (rTMS). TMS sessions have been conducted in thousands of healthy subjects or patients with various neurological or psychiatric diseases, allowing a better assessment of risks associated with this technique. The number of reported side effects is extremely low, the most serious complication being the occurrence of seizures. In most reported seizures, the stimulation parameters did not follow the previously published recommendations (Wassermann, 1998) [430] and rTMS was associated to medication that could lower the seizure threshold. Recommendations on the safe use of TMS / rTMS were recently updated (Rossi et al., 2009) [348], establishing new limits for stimulation parameters and fixing the contraindications. The recommendations we propose regarding safety are largely based on this previous report with some modifications. By contrast, the issue of therapeutic indications of rTMS has never been addressed before, the present work being the first attempt of a synthesis and expert consensus on this topic. The use of TMS/rTMS is discussed in the context of chronic pain, movement disorders, stroke, epilepsy, tinnitus and psychiatric disorders. There is already a sufficient level of evidence of published data to retain a therapeutic indication of rTMS in clinical practice (grade A) in chronic neuropathic pain, major depressive episodes, and auditory hallucinations. The number of therapeutic indications of rTMS is expected to increase in coming years, in parallel with the optimisation of stimulation parameters.

[Autoimmune autonomic ganglionopathy: a case series of six patients and literature review]

PURPOSE

Auto-immune autonomic ganglionopathy is a recently described clinical entity within the spectrum of autonomic neuropathies. Patients with auto-immune autonomic ganglionopathy typically present with rapid onset of severe autonomic failure. Acetylcholine receptor ganglionic antibodies, directed against ganglionic synapsis, disrupt synaptic transmission in autonomic ganglia and lead to autonomic failure. These antibodies are specific for auto-immune autonomic ganglionopathy and are present in 50% of patients.

METHODS

Descriptive retrospective study. We report six French patients who presented with auto-immune autonomic ganglionopathy diagnosed between 1996 and 2002.

RESULTS

Four patients were men and the median age at diagnosis was 45 years. All patients presented with a subacute autonomic failure with constant severe orthostatic hypotension. Serological testing of acetylcholine receptor ganglionic antibodies was performed in four out of the six patients and was found positive in three. All the patients received intravenous immunoglobulin and a clinical improvement was observed in four of them.

CONCLUSION

Auto-immune autonomic ganglionopathy is an unusual and overlooked disorder. However, this autonomic neuropathy deserves to be better known as most of the patients respond to immunomodulatory therapy.

Pain relief by rTMS: differential effect of current flow but no specific action on pain subtypes

OBJECTIVES

To assess, against placebo, the pain-relieving effects of high-rate repetitive transcranial magnetic stimulation (rTMS) on neuropathic pain.

METHODS

Double-blind, randomized, cross-over study of high-rate rTMS against placebo in 28 patients. The effect of a change in coil orientation (posteroanterior vs lateromedial) on different subtypes of neuropathic pain was further tested in a subset of 16 patients. Pain relief was evaluated daily during 1 week.

RESULTS

High-frequency, posteroanterior rTMS decreased pain scores significantly more than placebo. Posteroanterior rTMS also outmatched placebo in a score combining subjective (pain relief, quality of life) and objective (rescue drug intake) criteria of treatment benefit. Changing the orientation of the coil from posteroanterior to lateromedial did not yield any significant pain relief. The analgesic effects of posteroanterior rTMS lasted for approximately 1 week. The pain-relieving effects were observed exclusively on global scores reflecting the most distressing type of pain in each patient. Conversely, rTMS did not modify specifically any of the pain subscores that were separately tested (ongoing, paroxysmal, stimulus-evoked, or disesthesic pain).

CONCLUSIONS

Posteroanterior repetitive transcranial magnetic stimulation (rTMS) was more effective than both placebo and lateromedial rTMS. When obtained, pain relief was not specific of any particular submodality, but rather reduced the global pain sensation whatever its type. This is in accord with recent models of motor cortex neurostimulation, postulating that its analgesic effects may derive in part from modulation of the affective appraisal of pain, rather than a decrease of its sensory components.

Myoclonus-dystonia: clinical and electrophysiologic pattern related to SGCE mutations

OBJECTIVE

To clarify the clinical and neurophysiologic spectrum of myoclonus-dystonia patients with mutations of the SGCE gene.

METHODS

We prospectively studied 41 consecutive patients from 22 families with documented mutations of the SGCE gene. The patients had a standardized interview, neurologic examination, and detailed neurophysiologic examination, including surface polymyography, long-loop C-reflex studies, and EEG jerk-locked back averaging.

RESULTS

We noted a homogeneous electrophysiologic pattern of myoclonus of subcortical origin with short jerks (mean 95 msec, range 25 to 256 msec) at rest, during action, and during posture; there were no features of cortical hyperexcitability (specifically no abnormal C-reflex response and no short-latency premyoclonic potential on back-averaging studies). Myoclonus was either isolated or associated with mild to moderate dystonia, and predominated in the neck/trunk or proximal upper limbs in most cases. We found that 22% of the patients had a spontaneous improvement in their dystonia before reaching adulthood and that hypotonia can occasionally be a presenting symptom of the disorder.

CONCLUSION

We describe the myoclonus in patients with mutations in the SGCE gene and characterize the electrophysiologic pattern of this myoclonus. This pattern may help to improve the sensitivity of molecular tests and to define homogeneous populations suitable for inclusion in therapeutic trials.

[Cervical spondylotic myelopathy: motor and somatosensory evoked potentials, clinical and radiological correlation]

Somatosensory and motor evoked potentials (EPs) have been recorded in 38 patients with cervical spondylosis, documented by MRI. All were symptomatic, 23 presented with myelopathy. Somatosensory evoked potentials were abnormal in 66p.cent as well as motor evoked potentials. The N13 potential, generated by the posterior dorsal horn of the cervical spinal cord, was abnormal in 63p.cent of patients and was the only disorder detected in 12p.cent. Together, somatosensory and motor evoked potentials were abnormal in 82p.cent of patients. There was no correlation between EPs findings and radiological data. Similary, MRI and clinical data were agreeing in only 50p.cent of patients. When a spondylotic myelopathy is suspected, SEPs proved more sensitive to detect somatosensory dysfunctionning than clinical testing and radiological data were discordant with clinical status in 50p.cent of cases. In order to obtain a high sensitivity, both somatosensory and motor evoked potentials should be recorded on all limbs with a special attention to segmental cervical and cervico-medullary responses. EPs data help to identify patients with cervical cord dysfunction and thus contribute to the therapeutic decision for surgery.

[Diagnostic criteria of multiple sclerosis: electrophysiological criteria]

We have made a review on the use of evoked potentials in multiple sclerosis (MS) for the past 30 years, in the diagnosis of MS, to disclose subclinical lesions or to assess atypical symptoms. Yet the role of evoked potentials in evaluation of multiple sclerosis has been changed since MRI is now widely and easily used for the diagnosis of MS. Evoked potentials are useful when symptoms are atypical without any objective impairment and when symptoms have already recovered at the time of clinical examination. Visual evoked potentials and somatosensory evoked potentials are widely used thanks to their diagnostic value and their ability to disclose spatial dissemination of multiple sclerosis. Evoked potentials have to be recorded in validated technical conditions such as to ensure reliability of data and have to be interpreted in reference to a population of healthy people recorded in the same conditions and in the same age range as MS patients.

Special types of periodic lateralized epileptiform discharges associated with confusional state in cerebral circulation insufficiency

A peculiar type of periodic lateralized epileptiform discharges (PLEDs) was recorded on 22 EEGs performed in 11 patients. They were characterized by bursts of sinusoid activity around 7-9 Hz, usually followed by a slow wave, lasting less than 500 ms, with a period less than 2 s, and these sequences could be continuous over several days. We propose to name this pattern 'periodic sinusoid paroxysmal activity' (PSPA). PSPA was recorded mainly over both parieto-temporo-occipital regions, although asymetrically. Sensory stimulations and anticonvulsants had no effect on PSPA. In three cases, mobilization of the head blocked PSPA. The spontaneous disappearance of PSPA was sometimes followed by classical PLEDs. PSPA was always associated with a confusional state and behavioural disturbances, and erratic distal clonic movements were seen in 6 cases. These symptoms disappeared as soon as PSPA ceased. Patients had either vascular risk factors or a previous cerebrovascular insult. The confusional state was associated with either lowered carotidian bloodflow or probable global cerebral hypoperfusion due to a systemic pathology. A vascular origin of PSPA is likely, due to the presence of vascular risk factors, to the morphology of PSPA and to the provoking and inhibiting factors.

[Exploration of intraspinal tumors using evoked motor potentials (EMP): correlations with data of evoked somatosensory potentials]

MEPs to transcutaneous magnetic stimulation have been recorded in 43 patients with an intraspinal tumor documented by MRI. The tumor was extramedullary in 18 patients and intramedullary In 25. MEPs were abnormal in 62.8% of patients. There were no significant differences in the rate of MEP abnormalities according to the lesion site or the histological findings, except for meningiomas which showed abnormal MEPs in all eight patients included in this series. The percentage of patients with abnormal MEPs was 9.3% despite the absence of any clinical symptom of central motor pathway dysfunction. Infraclinical MEPs abnormalities were observed in 24% of explored limbs. Median and tibial nerves somatosensory evoked potentials (SEPs) were recorded in 41 patients and showed abnormalities of central conduction or of segmental spinal responses in 65.9% of the cases. When combining data from MEP and SEPs, abnormalities were observed in 70.7% of patients (29/41). Five patients (12.2%) had abnormal MEPs, but normal SEPs, and four other patients (9.8%) had abnormal SEPs, but normal MEPs. This finding suggests that both MEPs and SEPs should be recorded for presurgical evaluation of-intraspinal tumor.