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Biomedical subjects

M Sindou

Publications and source records attributed to M Sindou.

At least 127 records · Page 7Linked to original sources
PubMed1989

Clinical use of nociceptive flexion reflex recording in the evaluation of functional neurosurgical procedures.

Nociceptive flexion reflexes (RIII) obtained by stimulation of sural nerve were studied in patients with intractable chronic pain before and after functional neurosurgery, either dorsal column stimulation (DCS, n = 15) or posterior selective rhizotomy in the dorsal root entry zone (DREZ, n = 5). Dynamic study of RIII at supraliminal levels provided direct, quantitative and replicable evidence of the inhibition of nociceptive spinal reflexes by DSC. The effects of DSC on the RIII were highly correlated with subjective pain relief. In non-collaborative patients it was still possible to select the best DCS parameters (frequency, intensity) as those providing maximal RIII depression. After posterior selective rhizotomy in the DREZ involving S1-S2 root levels postoperative evidence of selective extralemniscal lesioning could be assessed by the abolition or strong attenuation of nociceptive RIII, whereas preservation of the lemniscal pathways was evidenced by somatosensory evoked potentials. Routine recording of nociceptive reflexes in man proved to be a useful tool for the objective evaluation of anatomo-physiological effects of functional neurosurgical procedures.

Electric Stimulation↗
PubMed1989

Intra-operative spinal cord evoked potentials during cervical and lumbo-sacral microsurgical DREZ-tomy (MDT) for chronic pain and spasticity (preliminary data).

We have undertaken the intra-operative study of spinal cord surface evoked potentials in patients operated upon for pain and/or spasticity using the microsurgical DREZ-tomy (MDT) procedure. The goals of this work were 1) to collect data on spinal cord evoked potential components and 2) to analyze the effects of MDT on spinal cord physiology. The MDT consists of a therapeutic lesion in the ventro-lateral aspect of the dorsal root entry zone, directed to the activatory circuitry, and aiming at returning the dorsal horn physiology towards inhibition. Averaged evoked potentials to peripheral nerve electrical stimulations were obtained from various loci on the surface of the dorsal columns of the cervical and lumbo-sacral spinal cord in 19 patients, using a small uninsulated silver ball electrode. An initial far-field positivity was found, corresponding to a compound action potential in the proximal part of the brachial (or lumbo-sacral) plexus. Pre-synaptic compound action potentials were identified, most often composed of multiple successive sharp peaks. A post-synaptic field potential generated in the dorsal horn was recognized. The MDT caused an immediate and irreversible decrease of amplitude down to a disappearance of the dorsal horn potential. This decrement was proportional to the amount of operated cord segments. In contrast, there has been a relative post-MDT sparing of the pre-synaptic action potentials originating from the operated cord segments, and the scalp contralateral parietal N 20 has been only reversibly affected by the therapeutic lesion. We thus argue for a specific involvement of dorsal horn physiology by the MDT, with a relative sparing of the dorsal column system.

Electric Stimulation↗
PubMed1989

Intra-operative unit recordings in the human dorsal horn with a simplified floating microelectrode.

The authors report on the development, for studies in man, of a tungsten, glass-coated, light and simple microelectrode, that is implanted by hand in open operative conditions under the microscope and floats freely with the moving target tissue. This technique has provided limited but nevertheless satisfactory unit activity isolations. Intra-operative unit recordings were obtained from the dorsal horns of 2 spastic and 2 neurogenic pain patients. In the latter, dorsal horn deafferentation hyperactivities after a peripheral and a centro-peripheral lesion were recorded, characterized by a continuous, spontaneous and unalterable high frequency hyperactivity.

Electrodes, Implanted↗
PubMed1989

Microsurgical DREZ-otomy for the treatment of spasticity and pain in the lower limbs.

The authors report on a series of 53 bedridden patients suffering from harmful spasticity in one (6) or both (47) lower limbs, who were treated with microsurgical DREZ-otomy. Surgery was performed to treat fixed abnormal postures in flexion in 49 patients and hyperextension in 3, and, additionally, to treat pain in 37 patients. Microsurgical DREZ-otomy was introduced in 1972, on the basis of anatomical studies of the human dorsal root entry zone (DREZ) showing a topographical segregation of the afferent fibers according to their size and functional destinations. It consists of a 2 mm deep microsurgical lesion directed at a 45 degrees angle in the posterolateral sulcus and penetrating the dorsal root entry zone in its ventrolateral aspect, at the level of all the rootlets considered involved in spasticity (and pain). It destroys mainly the lateral (nociceptive) and central (myotatic) afferent fibers as well as the facilitatory medial part of the Lissauer tract, while sparing most of the medial (lemniscal) fibers, the suppressor lateral part of the Lissauer tract, and more or less of the dorsal horn (DH). The postoperative results were evaluated after a mean follow-up period of 3 years and 4 months. Both spasticity and spasms were significantly decreased or suppressed in 75% and 88.2% of the patients, respectively. When present, pain was relieved without abolition of sensation in 91.6%. These benefits--combined with complementary orthopedic surgery in 23 patients--resulted in either disappearance or marked reduction of the abnormal postures in 85.3% of the patients and of articular limitations in 96.8%. Mild-to-severe complications occurred in 25 patients and precipitated or were responsible for death in 5. This is explained by the fact that the general and neurological conditions of most of the patients--especially those affected by multiple sclerosis--were precarious. MDT has, however, enabled a majority of these severely disabled patients to sit and lie comfortably, and has allowed them to reach a significantly improved quality of life.

Adolescent↗
PubMed1989

[Amyloid pseudotumor of the sciatic nerve].

A 60 year-old man complained of numbness and pain in the right lower limb, suggesting lesions of the fifth lumbar and first sacral roots. Sixteen months later, CT showed a tumor of 3.5 cm at the emergence of the first right sacral root. Microscopic examination disclosed an infiltration of the fibers of the nerve by numerous masses of hyaline eosinophilic material which stained with Congo red and produced green birefringence under polarized light. The persistence of congophilic properties of the amyloid deposits after permanganate pretreatment suggested an immunoglobulin origin (AL). A research of amyloid deposit in others viscera: heart, kidneys, digestive tract, was negative. We believe that this is the first reported case of amyloid pseudo-tumor involving a peripheral nerve.

Amyloidosis↗
PubMed1989

[Parasellar chondrosarcoma: report of a case operated on through a pteriono-temporal approach and review of the literature].

Cartilaginous tumours represent 0.16% of all intracranial tumours; among them 14% are chondrosarcomas (Ch-S). A majority (56%) arise from the skull base, especially from the spheno-occipital and spheno-temporal synchondroses. The others develop at the level of the dura mater convexity, falx and choroid plexuses, probably from ectopic cartilages or mesenchymatous cells with multiple potentialities. Parasellar Ch-S originate from the spheno-temporal synchondrosis and expand inside the cavernous region. With 21 published cases, they represent 51.2% of the 41 skull base Ch-S and 28.7% of the whole 73 intracranial primary Ch-S. The authors report a recent case of such a parasellar Ch-S, revealed by a left progressive, and finally total, ophthalmoplegia. The responsible mass, which eroded the lateral part of the sella turcica, was shown partially calcified and not enhanced by contrast medium at CT-scan, and was avascular on angiogram. The tumour, which was identified as a low grade myxoid Ch-S, could be entirely removed through an intradural pteriono-temporal approach. After a two-year follow-up, the clinical status was unchanged (total ophthalmoplegia) and the CT-scan did not show any sign of recurrence. The 21 cases of parasellar Ch-S published in the literature are reviewed.

Adult↗
PubMed1988

Pericallosal aneurysms.

The authors report a series of 19 patients with one (17 cases) or two (2 cases) pericallosal aneurysms referred during the past 10 years. Of the 19 patients, 18 had a ruptured pericallosal aneurysm and one was asymptomatic. On admission two were graded I, four graded II, six graded III, and six graded IV. Of the latter group two patients died from rebleeding, and the asymptomatic patient would not undergo surgery. The 16 operated patients underwent surgery after a delay ranging from 6 to 90 days after hemorrhage (25 days on average). The delayed surgery allowed the patients to be operated on in better neurological status: seven were graded I or Ia, six graded II, three graded III, and none graded IV. The results were excellent (with resumption of their previous activity) in 11 cases (69%), good (autonomous but with a slight deficit) in 4 cases (25%), and bad in 1 case (6%). There was no operative mortality or morbidity.

Adult↗
PubMed1988

Selective neurotomy of the tibial nerve for treatment of the spastic foot.

One of the most frequent neurological sequelae seen by the specialist in rehabilitation is the spastic foot. Spasticity in the foot may be responsible for abnormal posture and painful or trophic disturbances impairing standing and walking. This disability can be corrected by a simple neurosurgical procedure, the selective tibial neurotomy. In this procedure, one sections the tibial nerve branches to the muscles sustaining spasticity, i.e., the soleus and/or the gastrocnemius nerves for equinus and ankle clonus or the posterior tibialis branch for varus and the flexor fascicles for tonic flexion of the toes. After microsurgical dissection of each tibial nerve branch at the lower part of the popliteal region and their identification with bipolar electrostimulation, the selected branches are partially sectioned under the operating microscope. The present series consists of 62 operations performed in 53 patients, 9 bilaterally and 44 unilaterally. Operation obtained complete suppression of the disabling spasticity that had been present for 2 to 17 years (4 on average), total pain relief, and consequently improvement of the residual voluntary movements (by achieving a better balance between agonist and antagonist muscles) in 51 of the 62 spastic feet (i.e., 82% of the cases). For all of these patients, the beneficial effects were long-lasting over the 1- to 10-year follow-up (3 years on average). Selective neurotomy of the tibial nerve should be considered only after failure of intensive prolonged kinestherapy and of all available medical treatment. It must take place, however, before the onset of irreversible articular disturbances and musculotendinous retractions, which require complementary orthopedic corrections.

Adolescent↗
PubMed1988

[Intramedullary mature teratoma associated with an attached cord and an intradural lipoma. Apropos of a surgically treated case. Review of the literature].

The authors report the case of a 33 year-old male with urinary disturbances referred for removal of a spinal intradural mass associated with a L4 spina bifida occulta. At operation three types of lesions were present: a tethered cord, an intradural lipoma of the cauda equina and conus medullaris and an intramedullary mature teratoma. A total removal of teratoma and lipoma and a section of the filum terminale achieved a normalization of urological function. Such mature teratoma that consists of all three germ layers only represent 2% of all intramedullary tumors. Pathogenesis is dysembryoplastic but still remains unclear: germinal cells might have been displaced into the dorsal midline during their normal migration from yolk sac to gonadal ridges. Their association with other dysgenetic lesions such as lipoma or spina bifida is not rare but the links between these different pathologies remain unknown.

Adult↗
PubMed1988

Microsurgical procedures in the peripheral nerves and the dorsal root entry zone for the treatment of spasticity.

When spasticity becomes severe and harmful, in spite of physical and medical therapy, neurosurgery can give functional improvement. This paper deals with the long term results of Selective Peripheral Neurotomies of the Tibial Nerve and Selective Posterior Rhizotomies in the Dorsal Root Entry Zone, in 123 patients with spastic disorders localized to the limbs. The micro-techniques and intra-operative electro-stimulation for identification of the nervous structures responsible for the spastic components, can give a substantial reduction of the harmful spasticity, without suppressing the useful muscle tone and impairing the residual motor and sensory functions. The results were effective, with a 1 to 13 year follow-up (5 on average), in 89% of 47 Selective Peripheral Neurotomies of the tibial nerve for spastic foot, in 92% of 53 Selective Posterior Rhizotomies for paraplegia and in 87% of 23 Selective Posterior Rhizotomies for hemiplegia. In the most severe situations ("comfort" indications), correction of the abnormal postures and relief of pain facilitated nursing and physiotherapy. Sometimes there was reappearance of some useful voluntary movements. In the less affected patients ("functional" indications), the suppression of the harmful spastic components made the persistant capacities more effective.

Adolescent↗
PubMed1988

[Neurinoma of the trigeminal nerve. Excision by combined suboccipital and pteriono-temporal approach].

The authors report a recent personal case of trigeminal neurinoma with a topographical extension both in the cerebello pontine angle and the middle cerebral fossa. This 33 year-old female suffered from progressive sensory disturbances of her right hemiface associated with a right fifth nerve motor deficit, a right VI nerve palsy and a tinnitus. CT scan and angiogram were evocative of a right hourglass trigeminal neurinoma. Two successive operative stage through suboccipital route and a pteriono-temporal extra and intradural approach allowed a complete removal of the tumour. A post-operative rhinorrhea dried up with 10 days. The patient complained with a right hemiface anesthesia and a palsy of the masseter muscles; the VI nerve palsy recovered within 3 months. From the review of the literature (118 cases) the authors summarize the anatomical, clinical and radiological features of these tumours and point out. The difficulty of their surgical removal that was only complete in half of cases. The high frequency of hourglass neurinomas explains that a single suboccipital or subtemporal approach--even with opening of the tentorium--only allowed 23 complete removal among the 58 published or quoted interventions. This justifies that in a majority of cases a combined approach must be preferred, using successively a suboccipital and an intradural subtemporal route, the latted giving access to the cavernous sinus in case of its invasion.

Adult↗
PubMed1988

[Extra-intracranial shunts by venous grafts interposed on the carotid system].

Patients with occlusive arterial diseases, tumors invading the vascular structures of the skull base or giant aneurysms may benefit from an EICB. Most of the time this can be achieved using a scalp artery. But in cases of a thrombotic ECA, excessively short or thin scalp branches or destruction of those by prior cranial surgery, an interposed venous graft is needed. In the author's series, which consists of 16 patients, the bypass was performed for ICA occlusive diseases in 5, before complete removal of cavernous sinus tumours in 4 and prior to cervical internal carotid ligation for giant aneurysms in 7. The grafts were always harvested from the internal saphenous vein. The proximal site of implantation was CCA (2 cases), ECA (6 cases), ICA (1 case), superior thyroid A (2 cases)--i.e. 11 long grafts--and the trunk of the occipital A--i.e. short grafts in 5 cases. In this series, there was no mortality and no morbidity related to revascularization. The early patency rate, checked with arteriography, was 62.5% (10 cases) and the late one 56.2% (9 cases). Causes of failure, partially related to technical difficulties in 2 cases, were almost always due to an insufficient extra-intracranial pressure gradient (4 cases). Excepted in one case, there was no correlation between patency and the use or not of anti-aggregant and/or heparin. Literature data are summarized and discussed. They all confirm the importance--besides the absence of technical errors--of a sufficient extra-intracranial gradient for obtaining a good patency rate.

Arterial Occlusive Diseases↗
PubMed1987

Microsurgical selective posterior rhizotomy in the dorsal root entry zone for treatment of limb spasticity.

SPR in the DREZ, which was introduced in 1972 by the senior author on the bases of anatomical studies in humans, selectively interrupts the (lateral) nociceptive and the (central) myotatic fibers, while sparing the (medial) lemniscal fibers. In addition it enhances the inhibitory mechanisms of the Lissauer's tract and dorsal horn. The procedure was effective--with a follow-up ranging from 1 to 14 years--in 93% of the paraplegic patients with flexion-adduction postures (50 cases) or severe hyperextension (3 cases) and in 89% of the hemiplegic patients with irreducible flexion of the upper extremity (23 cases) or lower limb (5 cases).

Extremities↗
PubMed1987

[Neurosurgical treatment of trigeminal neuralgia. Direct approach of percutaneous method?].

During the fifteen past years, the treatment of trigeminal neuralgia resistant to medical therapy has benefited from several neurosurgical techniques, either with percutaneous methods (RF-thermorhizotomy, cisternal injection of glycerol, balloon compression of the gasserian ganglion) or direct approach (microsurgical selective section of pars major, microvascular decompression). The respective advantages and disadvantages of these techniques are presented, both from the authors' experience (609 thermocoagulations, 150 direct approaches in the cerebello-pontine angle) and a review of some important series of the literature.

Cerebellopontine Angle↗
PubMed1987

["De novo" aneurysms. Apropos of a surgically treated case].

The authors report the case of a 26 years old woman who developed four "new" T aneurysms, ten years after the successful clipping of a vertebro-basilar system aneurysm. This observation is discussed in relation to the literature; current views supporting that aneurysms may result from a combination of inherent and acquired tissue weakness associated with hemodynamic effects are cited. Another twelve cases of "de novo" aneurysms developed in patients without previously carotid ligation and reported in the literature are reviewed. Their characteristics in relation to their localisation and their interval time discovery are discussed. The advisibility of repeated angiograms in some patients with aneurysm is discussed as these patients are at an increased risk of hemorrhage from another "new" aneurysm.

Adolescent↗
PubMed1987

[Selective posterior rhizotomy at the posterior radiculomedullary junction in the treatment of hyperspasticity and pain in the lower limbs].

The authors report a series of 53 bedridden patients having harmful spasticity in one (6) or both (47) lower limb(s) and treated with selective posterior rhizotomy (SPR) in the dorsal root entry zone (DREZ). This severe spasticity was associated with irreducible flexion contracture in 49 cases and hyperextension in 3 others. 37 of these patients also had painful manifestations. The method was introduced in 1972 on the basis of anatomical studies of the DREZ in humans which showed a topographical segregation of the afferent roots according to their anatomico-functional destinations. The technique consists of a 2 mm deep DREZ microsurgical cut directed at a 45 degree angle into the posterior lateral sulcus just ventral to DREZ and Lissauer's tract of the spinal cord. The procedure was carried out at each sensory rootlet considered to be responsible for the harmful spasticity and pain. SPR interrupts selectively the lateral nociceptive and central myotactic afferent fibers curving toward Lissauer's tract and the anterior spinal cord, while sparing most of the medial lemniscal fibers curving toward the dorsal columns, as well as the fibers of the inhibitory circuitry of Lissauer's tract and dorsal horn. The results were evaluated after a 1 to 14 year follow-up. Mild to severe complications occurred in 25 patients (47.1%) and were responsible for death in 5 (9.4%). Both spasticity and spasm were significantly decreased or completely eliminated in 75% and 88.2% respectively; when present, pain was relieved without a total suppression of sensation in 91.6%. These benefits-combined with complementary orthopedic surgery in 23 patients--resulted in either a complete resolution or marked reduction of the abnormal postures and articular limitations (85.2% complete and 96.75 marked reduction). Because of the extreme severity of the pre-operative neurological deficits in almost all the patients in this series, surgery improved voluntary movements with a significant functional benefit in only 5 cases and vesico-sphincter function in none. Thanks to its valuable effects on hyperspasticity and pain, SPR in the DREZ made it possible for these very disable patients to be more comfortable in bed and wheel-chair and it allowed effective nursing and kinesitherapy to be resumed.

Adult↗