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Marc Sindou

Publications and source records attributed to Marc Sindou.

17 recordsLinked to original sources
PubMed2006

Differential brain opioid receptor availability in central and peripheral neuropathic pain.

This study used positron emission tomography (PET) and [11C]diprenorphine to compare the in vivo distribution abnormalities of brain opioid receptors (OR) in patients with peripheral (n=7) and central post-stroke pain (CPSP, n=8), matched for intensity and duration. Compared with age- and sex-matched controls, peripheral neuropathic pain (NP) patients showed bilateral and symmetrical OR binding decrease, while in CPSP binding decrease predominated in the hemisphere contralateral to pain. In CPSP patients, interhemispheric comparison demonstrated a significant decrease in opioid binding in posterior midbrain, medial thalamus and the insular, temporal and prefrontal cortices contralateral to the painful side. Peripheral NP patients did not show any lateralised decrease in opioid binding. Direct comparison between the central and peripheral groups confirmed a significant OR decrease in CPSP, contralateral to pain. While bilateral binding decrease in both NP groups may reflect endogenous opioid release secondary to chronic pain, the more important and lateralised decrease specific to CPSP suggests opioid receptor loss or inactivation in receptor-bearing neurons. Opioid binding decrease was much more extensive than brain anatomical lesions, and was not co-localised with them; metabolic depression (diaschisis) and/or degeneration of OR neurons-bearing secondary to central lesions appears therefore as a likely mechanism. Central and peripheral forms of NP may differ in distribution of brain opioid system changes and this in turn might underlie their different sensitivity to opiates.

Adult↗
PubMed2006

Very late frontal relapse of medulloblastoma mimicking a meningioma in an adult: usefulness of 1H magnetic resonance spectroscopy and diffusion-perfusion magnetic resonance imaging for preoperative diagnosis: case report.

OBJECTIVE AND IMPORTANCE: We present a rare case of very long-term medulloblastoma relapse in an adult patient and discuss the pattern of recurrence and metabolic imaging of the tumor. CLINICAL PRESENTATION: A 45-year-old man was referred for evaluation of a frontobasal midline tumor 21 years after treatment of a cerebellar medulloblastoma by surgery followed by chemotherapy and craniospinal radiotherapy. Magnetic resonance images were suggestive of a meningioma. Several hypotheses were discussed, such as other radio-induced tumors, sarcomas, high-grade gliomas, or lymphomas (previous chemotherapy) and even recurrence of medulloblastoma. Preoperative exploration included H magnetic resonance single-voxel spectroscopy (35 and 135 ms echo time), diffusion imaging, and perfusion magnetic resonance imaging. INTERVENTION: On magnetic resonance spectroscopy, N-acetyl-aspartate and an elevated choline/creatine ratio were retrieved, with a huge unidentified peak at 1.27 parts per million (ppm). Myoinositol signal was present at both echo times. On diffusion imaging, the tumor appeared hyperintense, with a low apparent diffusion coefficient value of 0.689. In the perfusion study, the maximal relative cerebral blood volume was 2. Metabolic imaging favored the diagnosis of medulloblastoma over the initially suspected diagnosis of meningioma. The patient underwent complete removal of the tumor that was confirmed to be a metastasis of his primary medulloblastoma. The postoperative course was uneventful, and complementary courses of radiotherapy and chemotherapy were planned. CONCLUSION: Late relapse should be considered, even after several decades, on occurrence of a second intracranial tumor in this context. Our observation validates the clinical interest of preoperative metabolic imaging for brain tumors with distinctive pattern.

Cerebellar Neoplasms↗
PubMed2006

Long-term functional results of selective peripheral neurotomy for the treatment of spastic upper limb: prospective study in 31 patients.

OBJECT: To manage refractory upper-limb spasticity, selective peripheral neurotomy (SPN) is proposed when the spastic muscles to be treated are under the control of a single or a few peripheral nerves. The aim of this study was to assess prospectively the long-term effects of SPN. METHODS: Thirty-one patients with disabling upper-limb spasticity were selected by a multidisciplinary team using clinical, analytical, and functional scales as well as nerve block tests for assessment. Sixty-four SPNs were performed at the level of the musculocutaneous (15 SPNs), the median (25 SPNs), and the ulnar (24 SPNs) nerves. Results of a long-term follow up (mean 4.5 years) showed statistically significant improvement on 1) analytical assessment (p < 0.01): resting position, active amplitude, and motor strength; 2) Ashworth Scale scoring (p < 0.01); 3) hand function assessment (p < 0.01); and 4) rating of daily activities. Four patients with severe painful spasticity experienced complete pain relief after surgery. On the basis of a Visual Analog Scale ranging from 0 to 100, the mean degree of patient satisfaction was 61.5. Complications occurred in five patients (15%): two postoperative hematomas, one (temporary) hypesthesia, and one transient paresia of the wrist and finger flexors. CONCLUSIONS: Selective peripheral neurotomy leads to long-term satisfactory improvement in function and/or comfort with a low morbidity rate in appropriately selected patients suffering from severe harmful spasticity of the upper limb that has been refractory to conservative therapy. Patients must be selected after complete assessment by a multidisciplinary team.

Adolescent↗
PubMed2005

Motor cortex stimulation for refractory neuropathic pain: four year outcome and predictors of efficacy.

Thirty-one patients with medically refractory neuropathic pain were included in a prospective evaluation of motor cortex stimulation. The long-term outcome was evaluated using five variables: (a) rate (percentage) of pain relief, (b) pain scores as assessed on VAS, (c) postoperative decrease in VAS scores, (d) reduction in analgesic drug intake, (e) a dichotomic (yes/no) response to the question whether the patient would accept, under similar circumstances, to be operated on again. Pain relief was rated as excellent (>70 % pain relief) in 10 % of cases, good (40-69 %) in 42 %, poor (10-39 %) in 35 % and negligible (0-9 %) in 13 %. Intake of analgesic drugs was decreased in 52 % of patients and unchanged in 45 % (unavailable data in 3 %), with complete withdrawal of analgesic drugs in 36 % of patients. Twenty-one patients (70 %) declared themselves favourable to re-intervention if the same beneficial outcome could be guaranteed. Neither preoperative motor status, pain characteristics, type or localisation of lesions, quantitative sensory testing, Somatosensory Evoked Potentials, nor the interval between pain and surgery were found to predict the efficacy of MCS. The level of pain relief, as evaluated in the first month following implantation was a strong predictor of long-term relief (regression analysis, R=0.744; p<0.0001). These results confirm that MCS can be a satisfactory and durable alternative to medical treatments in patients with refractory pain, and suggest that the efficacy of MCS may be predicted in the first month of therapy.

Adult↗
PubMed2005

Auditory and electrophysiological patterns of a unilateral lesion of the lateral lemniscus.

Auditory disorders resulting from focal brainstem lesions are rarely symptomatic. Isolated lesions of the inferior colliculus have previously been reported, whereas no detailed description of a localized involvement of the lateral lemniscus is yet available. We report a unilateral lesion of the lateral lemniscus by a bleeding in a cavernoma. Symptoms included strictly contralateral tinnitus and auditory impairment, with normal pure-tone and speech audiometry. Conversely, the dichotic listening test revealed an extinction of contralateral ear input. The brainstem auditory evoked potentials disclosed a reduced and delayed wave V only after contralateral ear stimulation, while the middle latency evoked potentials were normal. This observation shows that a unilateral lesion of the lateral lemniscus can produce auditory symptoms. The dysfunction of auditory pathways is associated with specific electrophysiological abnormalities that can be assessed by evoked potential recording.

Adult↗
PubMed2005

Ipsilateral head deviation in frontal lobe seizures.

PURPOSE: The lateralizing value of ictal head deviation (HD) in frontal lobe epilepsy (FLE) is a matter of debate. Although FLE is typically associated with tonic or clonic HD contralateral to seizure onset, ipsilateral HD has been noted in numerous reports. Whether both types of HD can be distinguished according to their clinical patterns has not yet been specifically investigated. METHODS: We studied the clinical pattern and time of occurrence of HD of 129 seizures in 13 consecutive patients, who underwent successful surgery for FLE, including 12 investigated with an intracerebral stereotactic EEG procedure. RESULTS: Ictal HD was ipsilateral to the epileptogenic zone (EZ) in four (30%) patients and 27 (20.9%) seizures and contralateral in five (38%) patients and 15 (11.6%) seizures. Ipsilateral HD was rarely tonic and never associated with clonic manifestation. Contralateral HD was always tonic, unnatural, and associated with hemifacial clonic movements in 86% of seizures. Ipsilateral HD occurred earlier than contralateral HD (p < 0.03), with a mean delay of 1 +/- 2 s after the first detectable ictal sign, as compared with a delay of 17 +/- 11 s for contralateral HD. Moreover, ipsilateral HD always occurred before contralateral HD when both signs coexisted in the same seizure. Our patients with ipsilateral HD demonstrated either an anterior or dorsolateral frontal EZ. CONCLUSIONS: Ipsilateral HD is a common ictal sign during FLE and can be distinguished from contralateral HD by its time of occurrence at or immediately after seizure onset and its lacking association with clonic movements.

Adolescent↗
PubMed2005

Ipsilateral head deviation related to orbito-frontal and fronto-polar seizures.

The localizing and lateralizing values of eye and head ictal deviations during frontal lobe seizures are still matters of debate. In particular, no specific data regarding the origin of ipsilateral head turning in frontal lobe seizures are available. We report a patient with frontal lobe seizures associated with reproducible, early, ipsilateral head deviation, where imaging and video-stereo-electroencephalography data, as well as surgical outcome, demonstrated the fronto-polar and orbito-frontal origin of the epileptic discharge. We conclude that early ipsilateral head deviation, in the context of frontal lobe epilepsy, raises the possibility of fronto-polar or orbito-frontal seizure onset.[Published with video sequences].

Adult↗
PubMed2004

Tectal plate cavernoma-a special entity of brainstem cavernomas: case report.

BACKGROUND: Brainstem cavernous malformations (BCM) have a high incidence of bleeding and rebleeding and carry a high rate of neurologic morbility. Locations in the tectal plate that represent a small percentage of BCMs have rarely been reported in the literature. The authors present a case of a patient with such localization who was successfully operated. CASE DESCRIPTION: A 24-year-old male known for having a tectal plate cavernoma with obstructive hydrocephalus, previously treated by shunting in another hospital, was admitted in our institute because of increasing headaches, gradual drowsiness, and the inability to stand up. Investigations revealed a compressive cavernoma lateralized on the left side of the tectal plate and a residual hydrocephalus in spite of the previous shunting. A new shunting procedure did not improve clinical conditions. Thus, an aggressive surgical resection was decided upon and was performed through an occipital-transtentorial approach with the aid of intraoperative brainstem and middle latency auditory evoked potentials (BAEPs/MLAEPs) monitoring. Total resection was achieved without significant deterioration except a hypovoltage of wave V after stimulation of the right ear, demonstrating a left collicular dysfunction. The patient was discharged on the 36th day after surgery. Seven months later, audiometry was normal, in spite of the persistence of the hypovoltage of the V wave after stimulation of the right ear, and functional status appraised using the Karnofsky score was at 100%. Professional activity could be resumed. CONCLUSION: Tectal plate cavernomas (TPC) represent a special entity of BCM. They are surgically accessible lesions on the dorsal aspect of the brainstem. Our preferred approach is the occipital-transtentorial approach. The use of intraoperative auditory evoked potentials monitoring make the surgical resection safer.

Adult↗
PubMed2004

SEEG-guided RF thermocoagulation of epileptic foci: feasibility, safety, and preliminary results.

PURPOSE: Depth electrodes recordings may be required in some cases of epilepsy surgery to delineate the best region for cortical resection. We usually implant depth electrodes according to Talairach's stereoelectroencephalography (SEEG) method. By using these permanently implanted depth electrodes, we are able to perform radiofrequency (RF)-thermolesions of the epileptic foci. We report the technical data required to perform such multiple cortical thermolesions, as well as preliminary results in terms of seizure outcome in a group of 20 patients. METHODS: Lesions were performed by using 100- to 110-mA bipolar current (50 V), applied for 10 to 50 s. Each thermocoagulation produced a 5- to 7-mm diameter cortical lesion. In total, two to 16 lesions were performed in each of the 20 patients. Lesions were placed without anesthesia. No general or neurologic complication occurred during the procedures. Two transient postprocedure side effects, consisting of paresthetic sensations in the mouth and mild apraxia of the hand, were observed. RESULTS: At a follow-up time of 8 to 31 months (mean, 19 months), 15% of the patients became seizure free, 40% experienced a > or =80% reduction of their seizure frequency, and 45% were not significantly improved. CONCLUSIONS: SEEG-guided RF thermolesions is a safe technique. Our preliminary results indicate that such lesions can lead to a significant reduction of seizure frequency and could be proposed as a palliative procedure if no resective surgery is possible. A randomized controlled trial is needed to determine which patients are likely to respond to SEEG-guided RF thermolesions.

Adult↗
PubMed2004

Clinical manifestations of insular lobe seizures: a stereo-electroencephalographic study.

PURPOSE: In this study, we report the clinical features of insular lobe seizures based on data from video and stereo-electroencephalographic (SEEG) ictal recordings and direct electric insular stimulation of the insular cortex performed in patients referred for presurgical evaluation of temporal lobe epilepsy (TLE). METHODS: Since our first recordings of insular seizures, the insular cortex has been included as one of the targets of stereo-electroencephalographic (SEEG) electrode implantation in 50 consecutive patients with TLE whose seizures were suspected to originate from, or rapidly to propagate to, the perisylvian cortex. In six, a stereotyped sequence of ictal symptoms associated with intrainsular discharges could be identified. RESULTS: This ictal sequence occurred in full consciousness, beginning with a sensation of laryngeal constriction and paresthesiae, often unpleasant, affecting large cutaneous territories, most often at the onset of a complex partial seizure (five of the six patients). It was eventually followed by dysarthric speech and focal motor convulsive symptoms. The insular origin of these symptoms was supported by the data from functional cortical mapping of the insula by using direct cortical stimulations. CONCLUSIONS: This sequence of ictal symptoms looks reliable enough to characterize insular lobe epileptic seizures (ILESs). Observation of this clinical sequence at the onset of seizures on video-EEG recordings in TLE patients strongly suggests that the seizure-onset zone is located not in the temporal but in the insular lobe; recording directly from the insular cortex should occur before making any decision regarding epilepsy surgery.

Adult↗
PubMed2003

Single-unit analysis of the spinal dorsal horn in patients with neuropathic pain.

Despite the key role played by the dorsal horn of the spinal cord in pain modulation, single-unit recordings have only been performed very rarely in this structure in humans. The authors report the results of a statistical analysis of 64 unit recordings from the human dorsal horn. The recordings were done in three groups of patients: patients with deafferentation pain resulting from brachial plexus avulsion, patients with neuropathic pain resulting from peripheral nerve injury, and patients with pain resulting from disabling spasticity. The patterns of neuronal activities were compared among these three groups. Nineteen neurons were recorded in the dorsal horns of five patients undergoing DREZotomy for a persistent pain syndrome resulting from peripheral nerve injury (i.e., nondeafferented dorsal horns), 31 dorsal horn neurons were recorded in nine patients undergoing DREZotomy for a persistent pain syndrome resulting from brachial plexus avulsion (i.e., deafferented dorsal horns), and 14 neurons were recorded in eight patients undergoing DREZotomy for disabling spasticity. These groups were compared in terms of mean frequency, coefficient of variation of the discharge, other properties of the neuronal discharge studied by the nonparametric test of Wald-Wolfowitz, and the possible presence of bursts. The coefficient of variation tended to be higher in the deafferented dorsal horn group than in the other two groups. Two neurons displaying burst activity could be recorded, both of which belonged to the deafferented dorsal horn group. A significant difference was found in term of neuronal behavior between the peripheral nerve trauma group and the other groups: The brachial plexus avulsion and disabling spasticity groups were very similar, including various types of neuronal behavior, whereas the peripheral nerve lesion group included mostly neurons with "nonrandom" patterns of discharge (i.e., with serial dependency of interspike intervals).

Action Potentials↗
PubMed2002

Chordoid glioma of the third ventricle: a report of two new cases, with further evidence supporting an ependymal differentiation, and review of the literature.

The term chordoid glioma of the third ventricle was first used to describe a rare and slowly growing neoplasm of uncertain histogenesis, with chordoid appearance, occurring preferentially in middle-aged women. Herein we report two additional examples of this novel entity together with a literature review based on the 25 cases previously published. Our review fully confirms the strikingly stereotyped clinical, neuroradiologic, and pathologic features of this unique tumor. The female/male ratio was 1.7:1, and the age range was 24-70 years (mean 44.9 years). In all 27 cases imaging findings were similar showing a well-defined mass (mean 2.8 cm in largest dimension), ovoid in shape, hyperdense on CT scans, with uniform and intense contrast enhancement, arising in the hypothalamic/suprasellar/third ventricular region. Histologically, the main consistent characteristics were cords and clusters of epithelioid cells within an abundant mucinous and often vacuolated background. Mitoses were sparse or absent and anaplastic features, endothelial proliferation, and necrosis were not identified. Lymphoplasmacytic infiltrates with Russell bodies were frequent throughout the tumor and its interface with adjacent brain parenchyma. Most of the tumor cells revealed a strong and diffuse expression of vimentin and glial fibrillary acidic protein. Additionally, the vast majority of tumors showed focal coexpression of cytokeratins, CD34, S-100 protein, and epithelial membrane antigen; the MIB-1 labeling indices were uniformly low. Surprisingly for a glioma assigned WHO grade II, the 19 patients with an available but short follow-up (mean 22.5 months; range 6-68 months) experienced a rather poor outcome (three recurrences and seven deaths), probably reflecting the anatomic site of the neoplasm that precludes a complete surgical excision rather than its histologic composition. Ultrastructural examination of 10 cases demonstrated findings in line with a glial derivation and a putative ependymal origin such as cytoplasmic intermediate filaments, microvilli, intermediate junctions or desmosomes, and focal basal lamina formation. In our case no. 1, and for the first time in this tumor, we observed sparse and abnormal cilia in an aberrant juxtanuclear location, a further argument for considering chordoid glioma as a subtype of ependymoma. However, a better understanding of the biologic behavior and histogenesis of this distinctive clinicopathologic entity needs to be investigated with a larger series. Nevertheless, taking into account its strikingly consistent anatomic localization, its unique histopathologic and immunohistochemical profile, in conjunction with the most recent and convincing ultrastructural arguments, we suggest that chordoid glioma of the third ventricle could be better classified as chordoid ependymoma of the lamina terminalis area.

Adult↗
PubMed2002

Clinical and electrophysiological expression of deafferentation pain alleviated by dorsal root entry zone lesions in rats.

OBJECT: The aims of this study were to construct an animal model of deafferentation of the spinal cord by brachial plexus avulsion and to analyze the effects of subsequent dorsal root entry zone (DREZ) lesions in this model. To this end, the authors measured the clinical and electrophysiological effects of total deafferentation of the cervical dorsal horn in rats and evaluated the clinical efficacy of cervical DREZ lesioning. METHODS: Forty-three Sprague-Dawley rats were subjected to total deafferentation of the right cervical dorsal horn by performing a posterior rhizotomy from C-5 to T-1. The clinical effects of this deafferentation, namely self-directed mutilations consisting of scraping and/or ulceration of the forelimb skin or even autotomy of some forelimb digits, were then evaluated. As soon as some of these clinical signs of pain appeared, the authors performed a microsurgical DREZ rhizotomy ([MDR], microincision along the deafferented DREZ and dorsal horn). Before and after MDR, single-unit recordings were obtained in the deafferented dorsal horn and in the contralateral (healthy) side. The mean frequency of spontaneous discharge from the deafferented dorsal horn neurons was significantly higher than that from the healthy side (36.4 Hz compared with 17.9 Hz, p = 0.03). After deafferentation, 81.4% of the rats developed clinical signs corresponding to pain following posterior rhizotomy. Among these animals, scraping was observed in 85.7% of cases, ulceration (associated with edema) in 37.1%, and autotomy in 8.5%. These signs appeared a mean 5.7 weeks (range 1-12 weeks) after deafferentation. Thirteen rats benefited from an MDR; nine (69%) experienced a complete cure, that is, a total resolution of scraping or ulceration (a mean 4.6 weeks after MDR). In contrast, only one of 11 sham-operated animals showed signs of spontaneous recovery (p = 0.01). CONCLUSIONS: These results emphasize the role of the spinal dorsal horn in the genesis of deafferentation pain and suggest that dorsal horn deafferentation by cervical posterior rhizotomy in the rat provides a reliable model of chronic pain due to brachial plexus avulsion and its suppression by MDR.

Animals↗
PubMed1993

Flexion reflexes following anterolateral cordotomy in man: dissociation between pain sensation and nociceptive reflex RIII.

Nociceptive flexion reflexes (RIII response) of the lower limbs were recorded after unilateral cervico-thoracic anterolateral cordotomy (ALC) in 7 patients. Pre-operative recordings were also obtained in 1 patient and follow-up observations in 3 patients. Flexion reflexes ipsilateral to cordotomy remained normal after surgery. Conversely, responses contralateral to the cordotomy exhibited two consistent postoperative changes: first, the RIII reflex was always dissociated from subjective pain, i.e., it appeared in the absence of any pain sensation, and, second, the RIII was depressed in the limb contralateral to ALC in 5 of 7 patients. RIII attenuation ranged from slight reduction to total abolition, and proved to be reversible in 2 of 3 patients tested during the follow-up. The reappearance of withdrawal reflexes was never accompanied by a recovery of pain sensation in the stimulated limb. We conclude that the dissociation between flexion reflexes and pain sensation, which was evidenced even in case of depressed RIII responses, should be attributable to the surgical lesion of spinothalamic fibers. Dissociation between RIII and subjective pain is a landmark indicating a lesion of the spinothalamic fibers, and may be used for the clinical assessment of spinothalamic dysfunction. Conversely, RIII depression after ALC does not depend upon the surgical lesion to the spinothalamic axons, but may be secondary to interruption of ascending spinoreticular fibers in the anterolateral quadrant, and/or of descending excitatory axons in the ventral cord.

Adult↗
PubMed1989

Nociceptive flexion reflexes during analgesic neurostimulation in man.

Nociceptive flexion reflexes of the lower limbs (RIII responses) have been studied in 21 patients undergoing either epidural (DCS, n = 16) or transcutaneous (TENS, n = 5) analgesic neurostimulation (AN) for chronic intractable pain. Flexion reflex RIII was depressed or suppressed by AN in 11 patients (52.4%), while no modification was observed in 9 cases and a paradoxical increase during AN was evidenced in 1 case. In all but 2 patients, RIII changes were rapidly reversible after AN interruption. RIII depression was significantly associated with subjective pain relief, as assessed by conventional self-rating; moreover, in 2 patients it was possible to ameliorate the pain-suppressing effects of AN by selecting those stimulation parameters (intensity and frequency) that maximally depressed nociceptive reflex RIII. We recorded 2 cases of RIII attenuation after contralateral neurostimulation. AN appeared to affect nociceptive reflexes rather selectively, with no or very little effect on other cutaneous, non-nociceptive responses. Recording of RIII reflexes is relatively simple to implement as a routine paraclinical procedure. It facilitates the objective assessment of AN efficacy and may help to choose the most appropriate parameters of neurostimulation. In addition, RIII behavior in patients could be relevant to the understanding of some of the mechanisms involved in AN-induced pain relief.

Adult↗