[Symptomatic aneurysms of the postero-inferior cerebellar artery. A multicenter retrospective study of 29 cases]. / Anévrysmes symptomatiques de l'artère cérébelleuse postéro-inférieure. Etude rétrospective multicentrique de 29 cas.

A multicenter retrospective study of 29 cases of posterior inferior cerebellar artery is reported. Over a period of 21 years, the frequency of posterior inferior cerebellar artery aneurysm among all intracranial aneurysm was estimated to 1.38 p. 100 of cases of aneurysms followed by 3 University Hospitals. Frequency of rupture appeared to be very high (93 p. 100) in this series probably because of the type of selection. Average grade of presentation according to Hunt and Hess classification being < III in 3 fourth of the cases. Neither clinical presentation nor suspicious etiological factors were specific of this localization. Only two cases were of pseudotumoral appearance. Positive diagnosis of subarachnoid hemorrhage was made by CT scan. Angiograms gave diagnosis of localization of the malformation and its type. Intraventricular hemorrhage was found in 62 p. 100 of our cases: all had hemorrhage of the fourth ventricle. Hydrocephaly was more frequent as compared to supratentorial localizations, Vasospasm was less frequent as in supratentorial localizations. Nimodipin seems to be efficient. Therapeutic possibilities are primary dominated by surgery with good results when it is possible. Endovascular treatment is under evaluation.

[Neurosurgical treatment of complications of intra-disk injections of triamcinolone hexacetonide. Value of a radio-clinical classification]. / Traitement neurochirurgical des complications des nucléorthèses à l'hexacétonide de triamcinolone. Intérêt d'une classification radio-clinique.

Epidural granulomas following intra-discal injection of triamcinolone hexacetonide are a well-known complication of this procedure, which is still encountered, even if its utilization was discontinued several years ago. According to the results of their experience, the authors propose a new radio-clinical grading system: grade I: disc calcification with aspect of "sub-ligamentar hernia" on CT scan; grade II: ascendant or descendant retrosomatic migration of distal content; grade III: pseudotumoral epidural infiltrate producing progressive narrowing of the spinal canal with neurological disturbance. Surgical indications in these cases can be drawn from their evolution: posterior approach can be used, with or without laminectomy, for excision as complete as possible of the involved disc (grades I and II); anterior approach should be preferred in cases of multiples recurrences after medical treatment and failure of classical posterior approach, or in case of necrotico-inflammatory proliferation with narrowing of the spinal canal (grade III).

[Proximal aneurysms of the postero-inferior cerebellar artery. Therapeutic consideration upon a multicenter retrospective study of 24 cases]. / Anévrismes proximaux de l'artère cérébelleuse postéro-inférieure (PICA). Considération thérapeutique au vu d'une série rétrospective multi-centrique de 24 cas.

Aneurysms of the postero inferior cerebellar artery (PICA) are relatively rare as it accounts for only 0.5% to 3% of all intracranial aneurysms, even though this localization is in second place for frequency in the posterior fossa, after aneurysms of the basilar artery. Among them, origin from the anterior or latero-medullary segment of PICA would account for 80% of cases. In this retrospective multicenter study, we report 24 cases of PICA aneurysms with their clinical and anatomic features as well as either their surgical or endovascular treatment. We also carried out an exhaustive review of the literature in order to propose the typical clinical features of this type of lesion. Of particular significance: a predominance of female patients of approximately 50 years of age ; posterior direction; constancy of hemorrhage in the fourth ventricle in case of ventricular involvement of subarachnoid hemorrhage. The various therapeutic possibilities are discussed and their results are analyzed. The prognosis for PICA aneurysms would seem to be favorable, depending, of course, on initial clinical grade.

[Use of a transcutaneous neuro-stimulator as peroperative stimulator in neurosurgical treatment of spasticity and traumatic lesions of the peripheral nerves and brachial plexus]. / Utilisation d'un neuro-stimulateur transcutané comme stimulateur per-opératoire dans le traitement neurochirurgical de la spasticité et des lésions traumatiques des nerfs périphériques et du plexus brachial.

We have had the opportunity to use a standard percutaneous stimulator as an intraoperative stimulator, with the use of sterile leads, in order to palliate the sudden failure of our usual surgical stimulator. The simplicity and the possibility of modulation of the device, brought us to use it several times in different purposes of surgical work for spasticity, neurotization of the brachial plexus and treatment of fresh wounds of the nerves. Important features of this new way of using this device are simplicity of programation (width and frequency rates), good stability of chosen parameters, low diffusion allowing selective stimulation, and above all low cost versus standard devices used for this purpose.

[Surgery of the foot in equinus deformity in hemiplegic adults]. / La chirurgie du pied équin chez l'adulte hémiplégique.

The authors report the results of surgical treatment of the equinus deformity of the foot in adult hemiplegia performed on 23 patients with a long term follow-up for 20 of them. Surgical treatment required two phases. Firstly, a spasticity correction by scopiform neurotomy of the posterior tibial nerve: this operation had to be done 14 times because of the importance of the spasticity. Secondly, a phase of truly orthopaedic surgery which involved successively, a treatment of the equinus deformity by lengthening of the Achilles tendon, a restoration of the dorsal flexion by anterior muscle transfer and some complementary operations on the forefoot. An astragalo-scaphoid arthrodesis was associated in the 13 most recent cases. Results were subjectively judged very good or good for 17 patients. Objectively, walking appliances have been reduced, gait was more secure and a greater autonomy has been reached. However, the goals of this surgery are limited as it has no incidence on central interferent lesions and neuropsychological troubles resulting from brain damage. The quality of the result is, in other respects, conditional upon the gait pattern of the whole limb, particularly upon the importance of the flexion of the knee during the step cycle.

[Percutaneous nucleotomy-diskectomy techniques. Automated and manual techniques. Indications and results]. / Les techniques de nucléotomie-discectomie percutanée. Technique automatisée et technique manuelle. Indications et résultats.

The authors review the percutaneous techniques: automated (Nucleotome) manual, with and without motorization ("shavers") with and without discoscopy. These techniques are indicated in less than 15% of cases of disc herniations; but, if the proper indications are respected, a rate of success between 75 and 85% can be expected. The guidelines of the indications are the following: contained disc herniation (longitudinal ligament not ruptured), subacute clinical course, no lateral spinal stenosis, age under 45.... Although the percutaneous techniques are simple and safe, they must be always preceded by a medical treatment during at least 6 weeks. The pre-operative imaging is of paramount value to assess the wholeness of posterior longitudinal ligament: computerized discography (C.T.-scan+discography), M.R.I., disco-manometry.... The authors advocate for percutaneous discectomy versus chemonucleolysis, but surgical approach by micro-technique remains indicated in most cases of lumbar herniated discs, especially in cases of ruptured discs (extruded or uncontained herniations), acute clinical course, spinal canal stenosis, age more than 45, or particular anatomical situations (such as deep-seated lumbosacral space or post-operative fibrosis).

[Normal pressure hydrocephalus and lumbar neurinoma]. / Hydrocéphalie à pression normale et neurinome lombaire.

A 76-year-old man presented with gait disturbances, mental deterioration and urinary incontinence. CT and MRI suggested a normal pressure hydrocephalus. Because of a raised protein content of CSF, a spinal MRI was performed and revealed a lumbar neurinoma. The patient improved after removal of the neurinoma and ventricular derivation.

[Posterior spinal cord neurostimulation in lumbar radiculitis pain. Apropos of 14 cases]. / Neurostimulation cordonale postérieure dans les lombo-radiculalgies. A propos de 14 cas.

In 14 patients, spinal cord stimulation in lumbar radiculopathy follow multiple exploration or iterative surgery. For 10 out of this 14 patients treatment was successful; pain relief lasted a mean time of 12.7 months in 9 out of them.

[Extradural arachnoid cyst of the dorsal region with relapsing and recurrent development]. / Kyste arachnoïdien extradural de la région dorsale d'évolution régressive et à rechute.

An extradural arachnoid cyst of the thoracic spine was diagnosed and operated in a 39 year-old woman with a history of two regressive attacks of spastic paraplegia during a 19 year-period. The diagnosis was established by magnetic resonance imaging and myeloscan, which demonstrated the cyst and its consequences on the spinal cord and the spine. Theories of etiology and development of extradural arachnoid spinal cysts are reviewed.

[Sciatica. Neurofibrosarcoma of the thigh]. / Sciatique tronculaire. Neurofibrosarcome de la cuisse.

A 61-year-old patient had complained of sciatica in the left lower limb for three years. The pain was located in the posterior area of the thigh and leg and radiated to the first toe. Examination showed a tumor of the middle part of the thigh. A sciatic nerve tumor was confirmed at operation. Pathological examination revealed a neurofibrosarcoma. The patient died from pulmonary metastasis 17 months later.

[Neurinoma of the vagus nerve, contralateral peripheral facial paralysis]. / Neurinome du nerf pneumogastrique, paralysie faciale périphérique contralatérale.

A right facial paralysis led to the discovery of a tumor on the left side of the medulla oblongata. A neurinoma was suspected on MRI and confirmed by surgery and pathological examination. Ultrasonic aspiration was on interest in this case. The mechanism of the facial paralysis is uncertain: ischemia, compression and pure coincidence may be considered.

[Pain following traumatic lesions of the brachial plexus (radicular avulsions and truncular lesions)]. / Les douleurs après lésions traumatiques du plexus brachial (avulsions radiculaires et lésions tronculaires).

Pain in avulsions lesions of the brachial plexus is related with deafferentation; experimental studies demonstrate that spontaneous discharges can be recorded with micro electrodes in the dorsal horn, after division of the dorsal roots. These discharges ("firing") are related with the loss of control of the inhibitory effects of the large caliber sensory fibers. This pathophysiological concept drawn from the Melzack and Wall's theory (gate control) allows a good meaning of the paradoxical results observed after neurotization (via accessory or intercostal nerves), namely immediate relief of pain, observed in several cases after surgery. This theory helps to explain the efficiency of the neurostimulation techniques (by inhibition of the "firing") and of the technique of "dorsal root entry zone coagulation" in the avulsed area, on the spinal cord, by direct destruction of the hyperactive cells in the posterior horn. These technical advances and early return to work and to community offer the best prospect of relief of pain. Incidence of intractable pain problem is less than 10% after 10 years.

[Biomechanical bases of dorsal and lumbar spinal osteosynthesis]. / Bases biomécaniques des ostéosynthèses rachidiennes dorsales et lombaires.

The authors report the results of their biomechanical experimental study on the fixation of various lesions of the spine, using Roy Camille metal plates, and the results of Fischer -- Gonon (using Harrington rods) and Kempf -- Jaeger (using Kempf rods). They conclude to: the efficiency of the posterior techniques of fixation, the necessity, in the thoraco-lumbar and lumbar segments to associate an anterior graft (fibula), in order to reinforce the late stability, the best functional results achieved by a "short" fixation in association with an anterior graft (double approach technique). According to their experience, the authors advocate for the use of Roy Camille metal plates screwed in the pedicles, the Harrington or Kempf rods helping in the per operative course to gain further reduction, namely in cases of disymetrical displacements.

[Microsurgery of common discal sciatica. Technics and results]. / Microchirurgie de la sciatique discale commune. Technique et résultat.

The authors report their own experience of microsurgery for surgical treatment of lumbar disc herniation. Series include 30 cases with a one year of mean follow up. Comparative studies are discussed according to others microsurgical series already published. Good care of peridural fat and gently retraction of the root seem to be main factors for good functional result.

[Traumatic elongation-traction lesions of the roots of the sciatic nerve, secondary to fractures of the pelvis]. / Lésions d'élongation-traction traumatique des racines du nerf sciatique, secondaires aux fractures de la ceinture pelvienne.

Three cases of complex pelvic fractures associated with lumbo sacral roots lesions are reported. The authors stress this possible association should be suspected through clinical and conventional radiological findings. The contrast sacco-radiculography brings up confirmation. However the so called pseudo-meningocele is by far of less topographical value than the same myelographic findings at cervical level (for brachial plexus avulsion injuries). Direct and concise evaluation is performed by surgical approach of roots during a homolateral hemi-laminectomy. This procedure allows to appreciate the anatomical lesions and to clarify the anatomo-radiological discrepancies. Moreover endodural closure and reduction of volume of meningoceles and removal of arachnoidal adhesions is to pain relief value and may prevent delayed complications of neighboring roots compression related to increase in volume of meningocele. According to the literature and our findings, in future, the aim should be microsurgical repair of such roots lesions as they ar not avulsed from the conus but merely more distally ruptured on the cauda equina. We could not so far achieve this procedure, because of difficulties to identify the distal part of root, often retracted far away from its spinae foramen.

[Conservative lumbar laminectomies. Technic and results]. / Laminectomies conservatrices lombaires. Technique et résultats.

The patient is lying on his left side. Paravertebral muscles of the right side are separated from the spinous processes and from the right laminae. Spinous processes are then cut at their base, and hold with a strong retractor Laminectomies are then feasible, as wide as necessary. Reconstruction is particularly strong. Our 3 years experiences of 200 cases, with clinical and radiologically very good late results, is underlined.