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Biomedical subjects

M Sindou

Publications and source records attributed to M Sindou.

At least 91 records · Page 5Linked to original sources
PubMed1995

Microsurgical DREZotomy (MDT) for pain, spasticity, and hyperactive bladder: a 20-year experience.

Since 1972, micro-DREZ-tomy has been performed in 367 patients: with cancer pain in 81, neurogenic pain in 139, hyperspasticity in 135, and hyperactive neurogenic bladder in 12. MDT consists of an incision and bipolar coagulations performed ventro-laterally in the Dorsal Root Entry Zone (DREZ) at the entrance of the rootlets into the dorso-lateral sulcus. The lesion is directed at 45 degrees ventro-medially, and 2-3 mm deep according to the pre-operative neurological status and the desired effects. MDT 1 degree interrupts the small (nociceptive) fibres regrouped laterally and the large (myotatic) afferents which runs centrally, whilst sparing part of the large medial (lemniscal) fibres. 2 degrees destroys the (excitatory) medial part of the Lissauer's tract, 3 degrees and the cells of the dorsalmost layers of the dorsal horn, which can be the site of hyperactivity, as we were able to record in patients with deafferentation pain. Best indications are: 1) well localized cancer pain, such as Pan-coast syndrome; 2) neuropathic pain due to: brachial plexus injuries, cauda equina and/or spinal cord lesions especially for pain corresponding to segmental lesions, peripheral nerve injuries-amputation-herpes zoster-(especially when the predominant component of pain is of the paroxysmal type and/or corresponds to provoked hyperalgesia/allodynia); 3) excess of spasticity and 4) neurogenic hyperactive bladder.

Afferent Pathways↗
PubMed1995

Electrical stimulation of precentral cortical area in the treatment of central pain: electrophysiological and PET study.

The clinical, electrophysiological and haemodynamic effects of precentral gyrus stimulation (PGS) as a treatment of refractory post-stroke pain were studied in 2 patients. The first patient had a right hemibody pain secondary to a left parietal infarct sparing the thalamus, while the second patient had left lower limb pain developed after a right mesencephalic infarct. In both cases, spontaneous pain was associated with hyperpathia, allodynia and hypoaesthesia in the painful territory involving both lemniscal and extra-lemniscal sensory modalities in patient 1, extra-lemniscal sensory modality only in patient 2. Both patients were treated with electrical PGS by means of a 4-pole electrode, the central sulcus being per-operatively located using the phase-reversal of the N20 wave of somatosensory evoked potentials. No sensory side effect, abnormal movement or epileptic seizure were observed during PGS. The analgesic effects were somatotopically distributed according to the localization of electrode on motor cortex. A satisfactory long-lasting pain control (60-70% on visual analog scale) as well as attenuation of nociceptive reflexes were obtained during PGS in the first patient. Pain relief was less marked and only transient (2 months) in patient 2, in spite of a similar operative procedure. In this patient, in whom PGS eventually evoked painful dysethesiae, no attenuation of nociceptive RIII reflex could be evidenced during PGS. Cerebral blood flow (CBF) was studied using emission tomography (PET) with O-labeled water. The sites of CBF increase during PGS were the same in both patients, namely the thalamus ipsilateral to PGS, cingulate gyrus, orbito-frontal cortex and brainstem. CBF increase in brainstem structures was greater and lasted longer in patient 1 while patient 2 showed a greater CBF increase in orbito-frontal and cingular regions. Our results suggest that PGS-induced analgesia is somatotopically mediated and does not require the integrity of somatosensory cortex and lemniscal system. PGS analgesic efficacy may be mainly related to increased synaptic activity in the thalamus and brainstem while changes in cingulate gyrus and orbito-frontal cortex may be rather related to attentional and/or emotional processes. The inhibitory control on pain would involve thalamic and/or brainstem relays on descending pathways down to the spinal cord segments, leading to a depression of nociceptive reflexes. Painful dysesthesiae during stimulation have to be distinguished from other innocuous sensory side effects, since they may compromise PGS efficacy.

Aged↗
PubMed1995

Interictal cerebral metabolism and epilepsy in cavernous angiomas.

We studied glucose metabolism in brain tissue surrounding cavernous angioma in 22 patients, using PET, and evaluated its relation to the size, site and epileptogenic nature of the vascular malformation, as well as to the post-surgical seizure outcome. Preoperatively, 18 patients suffered recurrent seizures, the origin of which could be clearly related to the vascular malformation in 14. Brain metabolism surrounding cavernous angiomas was normal in 18 patients (82%), and significantly decreased in four (18%). In these four patients, but in none of the 18 other cases, the vascular malformation disrupted connections between paralimbic areas and the adjacent temporal neocortex where hypometabolism was most pronounced. The latter did not correlate with the size nor with the epileptogenic nature of the cavernomas. Sixteen epileptic patients underwent surgical removal of their cavernoma, without resection of the surrounding cortex. At 1-year postoperatively, seizures have relapsed in seven patients (44%), including those four whose epilepsy could not be clearly related to the vascular malformation. Conversely, the four patients with perilesional hypometabolism on preoperative PET were seizure free postoperatively. Hypometabolism in brain tissue surrounding cavernomas is a rare finding which seems more likely to reflect deafferentation than the epileptogenic process itself.

Adolescent↗
PubMed1995

[Levels of C-reactive protein and complement 4 fraction in hyperthermia secondary to microsurgical vascular decompression for trigeminal neuralgia].

Serial tests for serum C-reactive protein (CRP) and C4 levels were carried out on 20 patients undergoing microvascular decompression (MVD) for trigeminal neuralgia with interposition of synthetic material (Teflon +/- Dacron). These proteins represent important elements of host defense mechanisms against invading pathogens and their serum levels might be of value in distinguishing bacterial meningitis from tissue reaction to synthetic material. According to post-operative pyrexia, patients were classified into three groups: gr 1 (n = 4): apyrexia, gr 2 (n = 11): pyrexia from 38 degrees C to 39 degrees C, gr 3 (n = 5): pyrexia upper 39 degrees C. Such frequent hyperpyrexia provides a clinical dilemma about meningitis. In 2 patients high CRP levels, 4 days after surgery, indicated the presence of meningitis. In all other patients, CRP levels were decreasing rapidly and normal levels were reached by day 8. All C4 levels were normal values. Measurements of CRP contributed to diagnose common meningitis reactions. These reactions seemed more frequent with Dacron and Teflon than with Teflon alone. Though non significative this difference deserves confirmation by fuller investigations.

Adult↗
PubMed1994

[Neurosurgical treatments of chronic pain].

During these last years the methods and the indications of analgesic neurosurgery have respectively changed toward greater multiplicity and more selectivity. The conservative methods of neurostimulation have acquired a prominent place in some types of pain from neuropathic origin. Their aim is to reinforce inhibitory fibre function. Whatever the technique used, stimulation of peripheral nerves, of posterior funiculi of the spinal cord, of the thalamus or the cerebral cortex, it will be effective only if the target structures are not totally, anatomically and functionally, destroyed. Intrathecal morphine administration, has been shown to be useful to control some cancer-induced pain. Lastly, the techniques of interrupting the pathways of pain, achieving greater selectivity in their effects, remain the preferred treatment for some types of localised pain having precise mechanisms.

Chronic Disease↗
PubMed1994

Facial motor responses evoked by direct electrical stimulation of the trigeminal root. Localizing value for radiofrequency thermorhizotomy.

In Sweet's description of RF-thermocoagulation for trigeminal neuralgia, the trigeminal nerve was stimulated at 50 c/s to evoke paraesthesias, in order to check the electrode location before the thermolesion is made. In 1979, we changed the frequency to 5 c/s, so as to produce in addition twitches in the masticatory muscles (in stead of the less detectable tetanization produced by 50 c/s stimulation). Since then, we started to observe, also, twitches in the muscles innervated by the facial nerve. These twitches were not always in the Orbicularis oculi (which corresponds to the classical blink reflex), but also in the lower facial muscles. Such clinically observable evoked motor responses (EMR)-which had not been reported before--were noticed in 44% of the 459 procedures performed from 1979 to 1988. When EMR were present, the threshold to evoke paraesthesias before thermolesion, and the duration of the thermolesion for obtaining a marked hypoaesthesia covering the entire painful territory, were significantly lower, respectively p < 0.01 and p < 0.001, than when EMR were absent. This indicates that the electrode was closer to the nerve when EMR were present. As a probable consequence, recurrence of pain was significantly lower in the EMR (+) group: 1.4%, than in the EMR (-) group: 5.8% (p < 0.05). The twitches corresponded to the territory of the evoked paraesthesias in 95%, and to the hypoaesthetic area created by the thermolesion in 96%. So, getting EMR in the territory of the pain can be a helpful indicator for an accurate location of the electrode in the trigeminal root, according to its somatotopic organization. These EMR are hypothesized to be due to a trigemino-facial reflex. A preliminary intra-operative EMG study clearly shows that for EMR in the upper part of the face we are dealing with blink-like reflexes, whilst for EMR in the lower face, mechanisms still remain unclear and need further study to be understood.

Adult↗
PubMed1994

Role of pia mater vascularization of the tumour in the surgical outcome of intracranial meningiomas.

The authors reviewed a personal series of 150 consecutive cases of intracranial meningiomas operated on between 1974 and 1988 with the aim of finding out the main prognostic factors determining surgical outcome. Severity of pre-operative clinical status and size of the tumour were found to be significant adverse factors, p < 0.001 and p < 0.01, respectively. In this article the authors stress on the role played in prognosis by pia mater vascularization of the tumour. When the tumour vascular supply predominated from pial-cortical arteries, in most cases cleavage could not be found in the arachnoid plane, but only in the subpial plane (because of incorporation of pia mater into the tumour "capsule"). Clinical consequences were that in the most eloquent areas (for example in the central region) a bad outcome--with transient or permanent deficit--frequently occurred when cleaving could not be performed in the arachnoid plane (p < 0.001). The neurological disorders were due to cortical and underlying sub-cortical ischaemia and haemorrhagic infarction. Participation of the pia mater in the tumour vascular supply can be predicted pre-operatively, directly on selective internal/external carotid angiograms, indirectly by the presence of an important peritumoural hypodensity on CT scan (which--according to our findings--is an indication of predominant pial-cortical vascular supply to the tumour). The positive correlation between cortical-pial supply (and its consequences) and tumour size (p < 0.001), pleads for surgery of meningioma at the earliest possible stage provided there are no contra-indications.

Adolescent↗
PubMed1994

Favourable influence of opening the lamina terminalis and Lilliequist's membrane on the outcome of ruptured intracranial aneurysms. A study of 197 consecutive cases.

Opening of the lamina terminalis and Lilliequist's membrane--by facilitating CSF circulation in the basal cisterns--favourably influences the outcome in patients with ruptured intracranial aneurysms. This has been demonstrated by the analysis of a series of 197 consecutive cases of ruptured intracranial aneurysms.

Aneurysm, Ruptured↗
PubMed1994

Intraoperative monitoring of spinal cord SEPs during microsurgical DREZotomy (MDT) for pain, spasticity and hyperactive bladder.

Since 1972, MDT has been performed in 234 patients with chronic pain, 140 with hyperspasticity and 12 with hyperactive neurogenic bladder. In the last 64 patients, the evoked electrospinogram has been recorded intraoperatively from the surface of the spinal cord, to monitor the electrophysiological effects produced by the surgical lesioning, not only on the conduction of lemniscal fibers when entering the dorsal column, but also on the postsynaptic responses of the dorsal horn cells. The decrease in amplitude of the latter responses (N13 or N22) was well correlated with (1) the depth and the width of the DREZ lesion, and (2) the number of spinal segments operated on. In most cases, amplitude was reduced in the order of 2/3, which was considered the best value.

Adolescent↗
PubMed1994

[Respective indications of orbital and/or zygomatic arch removal combined with fronto-pteriono-temporal approaches. 58 cases].

Orbito- and or zygomatic arch removal associated to fronto-pteriono-temporal craniotomy can be useful to minimize brain retraction and achieve optimal exposure with the shortest possible distance and the most adequate view angle, in the approa-ch of difficult lesions located in the vicinity of the skull base via a supratentorial route. Fifty-eight patients admitted for such difficult lesions were operated on by the authors between 1988 and 1993 using orbital and/or zygomatic removal. Mortality rate was 1,7%. Complications due to orbital and/or zygomatic removal amounted at 15%, but were mostly transient. Sequels owned to excessive brain retraction were less than 10%. No bony cosmetic sequel was observed. From this experience, the authors suggest the respective indications orbit-zygomatic: removal for access to the cavernous sinus, supra-sellar region, tentorial notch, inter-peduncular cistern; simple orbital arch removal for access to complex aneurysms of the anterior circulation, to mesio-temporal lesions; simple zygoma arch removal for approaching infra-temporal lesions, the Meckel's cave, the circumpeduncular cistern and aneurysms of the P2 portion of the posterior cerebral artery.

Adult↗
PubMed1993

Microsurgical vascular decompression (MVD) in trigeminal and glosso-vago-pharyngeal neuralgias. A twenty year experience.

Report of the results of treatment in 1380 cases with trigeminal neuralgia and 14 cases with glosso-vago-pharyngeal neuralgia. Trigeminal neuralgia was treated by percutaneous thermorhizotomy in 960 cases and by open micro-approach to the cerebellopontine angle in 420 cases. In cases treated by microsurgical vascular decompression, cure rate was 91%, partial relief 5%, failure 4%. Recurrence occurred in 6%. Glossopharyngial neuralgia was treated by percutaneous thermocoagulation of the Andersch ganglion in 3 cases and by a direct approach to the jugular foramen in 11 cases, in 9 of them with micro-vascular decompression. With microsurgical vascular decompression, all cases had total pain relief without recurrence.

Female↗
PubMed1993

Transcutaneous pressure adjustable valve for the treatment of hydrocephalus and arachnoid cysts in adults. Experiences with 75 cases.

The authors report a series of 75 adults treated over the last four years for hydrocephalus (69 cases) or arachnoid cysts (6 cases) by using a transcutaneous pressure adjustable valve (Sophy SU 8), the mechanism of which is recalled. The shunt was ventriculo-atrial 46 times, ventriculo-peritoneal 23 times and cysto-peritoneal 6 times. The opening pressure of the valve was initially adjusted 56 times to the medium, 9 times to the high, and 10 times to the low position, according to each particular patient's needs. Following the evolution of the neurological status and/or the CT findings, the opening pressure was secondarily modified in 27 patients (i.e., in 36%), and in some of them several times. It was raised 16 times: 10 times because of subdural hygroma(s) (complicated by a subdural haematoma which required surgical removal, in one case), and 6 times because of clinical symptoms of intracranial hypotension associated with hyperdrainage signs on CT. It was diminished 20 times because of the absence of clinical improvement and persistence of dilated ventricles on CT. In these 27 patients the Sophy SU 8 valve allowed modification of its opening pressure according to the clinical and CT evolution, without need for re-operation. It is concluded that the patients who can benefit most from this valve system are patients with normal pressure hydrocephalus or with arachnoid cysts.

Adolescent↗
PubMed1993

Treatment of experimental carotid aneurysms by endoprosthesis implantation: preliminary report.

Four experimental aneurysms were treated by implantation of an endoprosthetic stent. The aneurysms were surgically created by grafting a venous pouch on the carotid artery of mongrel dogs. Aneurysm patency was assessed angiographically. Under systemic heparinization and via a transfemoral approach, the stent measuring 20 mm in length and 5 mm in diameter, was implanted in the lumen of the parent artery at the level of the aneurysmal neck. Good angiographic results were obtained immediately following implantation, showing exclusion of the aneurysm from the circulation. Patency of the parent vessel was preserved in all the experimental aneurysms treated. In one case an angiogram performed 30 days later showed the same findings with excellent tolerance of the device. The technique of endovascular treatment of experimental aneurysms by stent implantation appears feasible and safe in vivo. Further investigations are still necessary before clinical applications.

Aneurysm↗
PubMed1993

[Prognostic factors in the surgery for intracranial meningioma. Role of the tumoral size and arterial vascularization originating from the pia mater. Study of 150 cases].

The authors report a series of 150 consecutive patients operated on for an intracranial meningioma over a period of 14 years (1974-1988). The patients were aged from 15 to 85 years (mean: 58 y; 49 were over 60 y) and severely disabled preoperatively in 42 cases (Karnofsky score 10 to 60). Tumors were located in the convexity in 22% the parasagittal region and falx in 24%, the skull base in 14% and the posterior fossa in 13%. In 21 cases the diameter of the tumor was less than 3 cm, in 86 it ranged from 3 to 6 cm, and in 43 cases it was more than 6 cm (29%). Tumor was hypervascularized in 51% of cases. Peritumoral edema was present in 73 of the 106 patients studied (69%). The tumor was removed completely (grade I and II of Simpson classification) in 136 cases (91%). Post-operative mortality was 10%. 88.5% of the surviving patients had a normal life with a score of 80 to 100 according to Karnofsky scale. Recurrence rate amounted at 3.3%. Mortality and severe morbidity (poor outcome) were assessed and correlated with sex, age, tumor, size, location, vascularization, peritumoral edema and histology. From this retrospective study the only predictives of a poor outcome, statistically significant, were: severe preoperative neurological conditions (p < 0.001) and tumor size (p < 0.01). There was no statistically significant correlation with the other parameters. Cortical arteries participation to tumor vascularization, in a equal part of more than the dural arteries, led to subpial dissection for achieving complete tumor removal. This was a source of hemorrhagic infarction through ischemia, with patent neurological deficits for rolandic meningiomas (p = 0.001). The importance of pial supply of the tumor was correlated with its size (p < 0.001). Pial supply of the tumour and consequently subpial dissection were foreseeable in the preoperative study: on selective angiography (p < 0.001) and the presence of peritumoral edema on CT scan (p < 0.001). The authors conclude that besides the "classic" pronostic factors (preoperative neurological conditions, tumor size), the mode of vascularization of the tumor (pial supply) plays an important role in the possibility or not to find an extra pial plan of dissection from the adjacent parenchyma, and consequently in the neurological outcome of the patients.

Adolescent↗
PubMed1993

[Functional neurosurgery of chronic pain: nociceptive tracts ablation at the level of the peripheral nervous system and spinal cord].

This article is devoted to ablative neurosurgical procedures used for the treatment of chronic pain. The procedures are classified as those directed to the cranial nerves, the peripheral nerves, the spinal roots, the dorsal root entry zone and the ascending spino-reticulo-thalamic pathways. The rational and neurophysiological effects of these operations are stressed. The actual indications for each procedure are specified.

Chronic Disease↗