Motor and sensitive axonal regrowth after multiple intercosto-lumbar neurotizations in a sheep model.

STUDY DESIGN: Experimental animal study. OBJECTIVE: To evaluate motor and sensitive axonal regrowth after multiple intercosto-lumbar neurotizations in a sheep model. SETTING: France. METHODS: Fifteen sheep were separated into three groups. Five sheep had multiple intercosto-lumbar neurotizations and a spinal cord lesion, five sheep were neurotized without any spinal cord lesion and five sheep had a spinal cord lesion without any neurotizations. Six months after the initial surgery, histological study of the neurotized roots was performed. RESULTS: The length of the three rerouted intercostal nerves was sufficient in the 10 sheep to perform an intercosto-lumbar neurotization in good conditions. Eight sheep out of the 15 had postoperative complications responsible for the animal's death in five cases. Histological cross-sections of all the neurotized L2, L3 and L4 roots showed numerous myelinated regenerated axons. Dorsal root ganglions of neurotized roots showed both large and small neurons with normal nucleus and cytoplasm. The fluorescent retrograde labeling of 18 roots revealed labeled motor neurons in five cases. CONCLUSIONS: This study demonstrates the technical feasibility of intercosto-lumbar neurotizations in a big mammalian model. Intercostal nerve harvesting and rerouting was successfully performed in all the cases. Our histological results proved, in all the animals studied, the ability of motor and sensitive neurons to regenerate through the neurotization area. In the context of the future clinical application of strategies aimed at promoting axonal regeneration after severe spinal cord injury, the present data suggest that multiple intercosto-lumbar neurotization could be helpful to promote lower limb muscular strength recovery after spinal cord injuries.

[Craniocerebral gunshot wounds: a study of outcome predictors]. / Les plaies crâniocérébrales d'origine balistique: recherche d'arguments pronostiques.

BACKGROUND AND PURPOSE: A retrospective study about craniocerebral gunshot wounds was done to better identify outcome predictors. METHODS: We reported and analyzed the clinical and radiological data of 18 patients admitted to Le Kremlin-Bicêtre institute for a craniocerebral gunshot wound between January 2000 and December 2005. The Glasgow Outcome Scale (GOS) was used to analyze patient outcome. RESULTS: There were 17 men and one woman, mean age 43 years (range 17-84). Fifteen patients died, two had a GOS equal to 2 and one GOS equal to 3. There were 16 suicides and two murders. All patients with areactive bilateral mydriasis and all patients with Glasgow Coma Scale (GCS) less than seven died except one. The 10 patients with intraventricular hemorrhage died. The bullet crossed the midline for 13 patients and all of them died. None of the patients underwent emergency surgery for the treatment of craniocerebral gunshot wounds because of low Glasgow Coma Scale. CONCLUSIONS: This study shows some interesting prognosis patterns: bilateral areactive mydriasis, GCS less or equal to 7 and bullet trajectory (if crossing the midline) are the most important factors predicting a fatal outcome.

[Endoscope-assisted biopsy for the diagnosis of neurosarcoidosis]. / Biopsie endoscopique diagnostique d'un cas de neurosarcoïdose.

A 56-year-old woman was followed in the neurological department for febrile mental confusion. The diagnosis of sarcoidosis was suggested on the ground of associated abdominal lymphadenopathy, elevated serum angiotensin-converting enzyme level, aseptic meningitis and intracranial hypothalamic lesion. Nevertheless, radiological, biological and histological analyses could not assert the diagnosis of systemic sarcoidosis. Six months later, cerebral MRI showed a recent enhanced nodule, located near the right choroid plexus, inducing a dilatation of the right temporal ventricular horn. A surgical endoscope-assisted biopsy of that lesion was decided. The endoscope was introduced in the right trapped temporal ventricle. The limits between normal and pathological tissues were clearly identified. The biopsy was thus accurately performed. Histological analysis definitely confirmed the diagnosis of neurosarcoidosis. No postoperative complication was noted. We report a case of neurosarcoidosis which was diagnosed by ventricular endoscope-assisted biopsy. The discussion stresses the potential advantages of endoscopy for the diagnosis of small periventricular lesions when ventricular dilatation is associated.

Multimodal cerebral monitoring and decompressive surgery for the treatment of severe bacterial meningitis with increased intracranial pressure.

Bacterial meningitis is still associated with a high mortality, mainly because of cerebral herniation as a result of increased intracranial pressure. Published data stress the necessity of an early diagnosis and immediate start of antibiotic therapy. Nevertheless, there are only few reports in which therapeutic strategy was based on the monitoring and the reduction of intracranial pressure (ICP). We report one case of bacterial meningitis caused by Neisseria meningitidis with an initial ICP value of 60 mmHg, which was treated by large hemicraniectomy and ventriculostomy, leading to a favorable neurological long-term result. The surgical decision was accelerated by an accurate ICP evaluation based on cerebral monitoring [transcranial Doppler ultrasonography (TCD) and intracranial ICP-device]. In selected patients with bacterial meningitis and clinical and radiological evidence of elevated ICP, cerebral monitoring and aggressive reduction of ICP may be crucial to improve survival and neurological outcome. When maximal medical ICP treatment fails to reduce severe intracranial hypertension, decompressive craniectomy should be rapidly proposed.

MR diffusion tensor imaging and fiber tracking in 5 spinal cord astrocytomas.

Spinal cord astrocytomas are rare neoplasms that can result in alteration of the spinal cord structural integrity, which can be assessed by using diffusion tensor imaging methods. Our objective was to visualize the deformation of the posterior spinal cord lemniscal and corticospinal tracts in 5 patients with low-grade astrocytomas compared with 10 healthy volunteers by using 3D fiber-tracking reconstructions.

[Endoscope-assisted microsurgery for invasive endo- and suprasellar pituitary macroadenomas: a consecutive retrospective study with 13 patients]. / Endoscopie et traitement chirurgical des macroadénomes hypophysaires endo- et suprasellaires invasifs. Une série consécutive rétrospective de 13 patients.

BACKGROUND AND PURPOSE: Surgery of invasive endo- and suprasellar pituitary macroadenomas remains difficult. The records of 13 consecutive patients who underwent transsphenoidal surgery were analyzed in order to evaluate advantages and limitations of endoscopy for surgery of invasive pituitary macroadenomas. METHODS: A transseptal transsphenoidal intersepto-columellar approach was performed with a nasal 0-degree endoscope. Removal of the macroadenoma was performed under the control of a microscope. When the tumor seemed to be completely removed with microscope, a rigid 30-degree endoscope was inserted in the intrasellar and suprasellar regions in order to detect residual adenoma tissue. These residues were removed when technically possible. RESULTS: No rhinologic complication was noted. In 7 patients, the intra- and suprasellar endoscopic view detected a tumor residue which could be removed in each case. Two cases of cerebrospinal fluid leakage occurred during the complementary tumor resection. Two cases of diabetes insipidus and two of rhinorrhea were reported postoperatively. The analysis of the postoperative MRIs showed a complete removal in 23% of the patients (3/13), 75 to 100% removal in 54% of the patients (7/13), 50 to 75% removal in 8% of the patients (1/13) and 50% removal in 15% of the patients (2/13). More than 75% removal was thus achieved in 77% of the patients (10/13). The mean follow-up was 27.2 months. CONCLUSIONS: Rhinologic morbidity was reduced with the endoscopic endonasal approach. Endoscopy complemented with a microscope offered an optimal view of the intra- and suprasellar regions. Endoscopy also improved tumor resection of the invasive endo- and suprasellar pituitary macroadenomas by visualizing hidden suprasellar tumor residues. However, endoscopy was associated with a higher rate of postoperative rhinorrhea.

Cross-neurotization of the caudal brachial plexus with the contralateral C-8 ventral nerve branch in the cat. Potential surgical applications, effects of graft collection on the healthy donor limb and results.

Contralateral transfer of the right, eighth ventral nerve branch (C8) (C8 cross-transfer - C8CT) was performed in 6 adult cats, in which the caudal part of the left brachial plexus (C8 and T1) had been severed, in order to mimic nerve root avulsion. Clinical and electrophysiological parameters, muscle contraction force measurements and histology were used to evaluate the effects of the surgery in a 14- to 36-month follow-up. The right forelimb (donor side) was clinically normal (no lameness) in all the cats at the end of the study. Electromyography performed 14 days after surgery revealed denervation fibrillation potentials in both forelimbs. Fibrillation potentials disappeared in all the cats at the end of the study. Direct stimulation of the right C8 ventral branch induced motor and sensory evoked potentials in the left limb muscles in all the cats. The left to right contraction ratio of the extensor carpi radialis muscle was approximately 1. This experimental study demonstrates that C8CT enables re-innervation of the contralateral brachial plexus and allows the establishment of new functional neuromuscular units. This can in turn enable the restoration of function, and could potentially lead to partial recovery after caudal brachial plexus avulsion in the cat.

[Temporary vessel occlusion]. / Clampage vasculaire temporaire.

UNLABELLED: In many situations, temporary artery occlusion is an integral component of aneurysm surgery. The use of temporary clip may allow safer and easier aneurysmal dissection and clipping. Several points, concerning the duration and overall risks of temporary occlusion and the method of choice for cerebral function monitoring have to be discussed. MATERIAL AND METHODS: Non exhaustive review of neurosurgical literature. DISCUSSION: Temporary clip application decreases the risk of intraoperative aneurysmal rupture. The analysis of data published in the literature showed that several questions remain open concerning the optimal method of neuroprotection and cerebral function monitoring, as well as the limit of occlusion duration. Other clinical trials are needed to assess the efficacy and safety of this technique.

Effects of surgery on the sensory deficits of syringomyelia and predictors of outcome: a long term prospective study.

OBJECTIVE: To quantify the effects of surgery on the thermal deficits of syringomyelia and assess the predictors for such effects. METHODS: The subjects were 16 consecutive patients (12 men, 4 women; mean (SD) duration of sensory symptoms, 5.1 (4.5) years) presenting with the typical symptoms of syringomyelia related to Chiari I malformation or trauma, and requiring surgical treatment. They were evaluated before surgery, then at six months and two years. Sensory evaluation included determination of the extent of thermal deficits and quantitative assessment of thermal, mechanical, vibration detection, and pain thresholds. Neuropathic pain intensity was evaluated on visual analogue scales. Magnetic resonance imaging was done before and after surgery to measure syrinx dimensions. RESULTS: The magnitude and extent of thermal deficits improved in a subgroup of patients and this was best predicted by the duration of sensory symptoms: patients operated on less than two years after the onset of their symptoms tended to improve, while those operated on later were stabilised or deteriorated slightly. The effect of surgery on thermal deficits was correlated with the duration of sensory symptoms. Surgery also affected vibration deficits in patients with the Chiari malformation, neuropathic pain on effort, and syrinx dimensions. CONCLUSIONS: The duration of sensory deficits is the best predictive factor of the efficacy of surgery for the thermal symptoms of syringomyelia. Early surgery is required if these deficits are to be minimised.

Experimental bypass surgery between the spinal cord and caudal nerve roots for spinal cord injuries.

Spinal cord injuries often cause permanent neurological deficits and are still considered as inaccessible to efficient therapy. Injured spinal cord axons are unable to spontaneously regenerate in adult mammalians. Re-establishing functional activity especially in the lower limbs by reinnervating the caudal infra-lesional territories could represent an attractive therapeutic strategy. For several years, we have studied and developed surgical bypasses using peripheral nerve grafts bridging the supra-lesional rostral spinal cord to the caudal infra-lesional lumbar roots. Main objectives were: 1- to overcome the spinal cord lesion and the consecutive glial barrier blocking the axonal regeneration; 2- to find and bring an alternative source of regenerating axons; 3- to guide those axons toward precisely definite targets (for example, lower limb muscles). We report here the results of our experimental research, which led us from animal experimental models (rodents, primates) to the first human experimentation. Limitations of the method (especially technical pitfalls) are numerous. However, we have obtained encouraging results in our attempts to "repair" the motor pathway. Functional recovery with strong evidence of centrifugal axonal regeneration from the spinal cord to the periphery has been observed. Regarding the sensory pathway, we have found evidence of centripetal axonal regeneration from the periphery toward the spinal cord. Further studies are obviously advocated, but our experimental model of spinal cord - nerve roots bypasses may be integrated in future "repair" strategies of both motor and sensory pathways following spinal cord injury.

Partial return of motor function in paralyzed legs after surgical bypass of the lesion site by nerve autografts three years after spinal cord injury.

Spinal cord injuries often result in irreversible loss of motor and somatosensory functions below the lesion level. Treatment is limited to physiotherapy aimed at compensating disability. We previously showed that re-establishment of tissue continuity can be achieved in animal models through nerve autografts implanted between the rostral spinal ventral horn and the caudal ventral roots. Rostral motor neuron axons could thus reach peripheral targets, leading to some return of motor function. We used a similar approach in a paraplegic patient with stabilized clinical states three years after spinal cord traumatic damage at the T9 level. Three segments from autologous sural nerves were implanted into the right and left antero-lateral quadrant of the cord at T7-8 levels, then connected to homolateral L2-4 lumbar ventral roots, respectively. Eight months after surgery, voluntary contractions of bilateral adductors and of the left quadriceps were observed. Muscular activity was confirmed by motor unit potentials in response to attempted muscle contraction. Motor-evoked potentials from these muscles were recorded by transcranial magnetic stimulation. These data support the hypothesis that muscles have been re-connected to supra-spinal centers through motor neurons located in the rostral stump of the damaged cord. They suggest that delayed surgical reconstruction of motor pathways may contribute to partial functional recovery.

[Nocardia farcinica brain abscess: clinical and specific radiological findings and management. Report of two cases in immunononcompromised patients]. / Abcès cérébraux à nocardia farcinica: spécificités cliniques, radiologiques et thérapeutiques. A propos de deux cas chez des patients immunocompétents.

Nocardia spp. cerebral abscesses are rare and usually occur in immunocompromised patients. We report two recent cases of cerebral abscesses due to Nocardia farcinica in immunocompetent patients and review the literature about diagnosis and therapeutic issues. Outcome was good for the two patients following an early identification of the bacteria. Stereotactic biopsy was performed in one case and craniotomy with excision of the abscess in the other case. In both cases, complete identification of the bacteria could be achieved, followed by prolonged antibiotic therapy. Exposure to the germ (mainly telluric) is often difficult to suspect from the past medical history of the patient. Diagnosis is also unexpected. Despite the typically and characteristic aspect on CT and MRI, specific identification and anti-microbial sensitivity profiles are necessary to optimize treatment. In some rare cases, unusual species like Nocardia farcinica, can be resistant to numerous antibiotics requiring adjustments of medical management. Early identification of the bacteria is necessary to achieve good outcome in immunocompetents patients.

[Imaging of syringomyelia]. / L'imagerie des syringomyélies.

This review reports the value of current imaging techniques in the diagnosis of syringomyelia excluding tumoral causes. The value of imaging techniques for evaluation of extension, detection of associated anomalies, and pre- and postoperative evaluation are detailed.

[Spontaneous regression of paraplegia caused by spontaneous cervico-thoracic epidural hematoma]. / Régression spontanée d'une paraplégie par hématome épidural cervico-thoracique spontané

Spontaneous spinal epidural hematoma is a rare condition that usually requires surgical treatment in emergency. We report the unusual and well-documented case of a spontaneous spinal epidural hematoma, extending from C6 to T2, occurring in a 56-year old man and causing paraplegia. Without surgery, the paraplegia spontaneously and completely recovered within the first 24 hours. Serial MRI studies demonstrated the remitting course of the spinal epidural hematoma. Emergency surgical evacuation should still be the standard treatment for patients with disabling and/or persistent neurologic deficit. A conservative approach under close neurologic observation may be recommended for patients with no or mild deficits, for patients who show early and continuous clinical improvement within the first 24 hours and for patients with small and/or non-compressive spinal epidural hematoma. Reported cases of spontaneous remission are very rare.

Regrowth of the rostral spinal axons into the caudal ventral roots through a collagen tube implanted into hemisected adult rat spinal cord.

OBJECTIVE: A collagen tube was used to guide axonal regrowth from the spinal cord to the periphery to contribute to improvement of paralysis after lower thoracic spinal cord injury. METHODS: The spinal cords of adult male Sprague-Dawley rats were lesioned by removing the left hemicord from T12 to 5 mm below this level and additionally sectioning all left lumbar ventral roots. In experimental animals (n = 9), a collagen tube was inserted into this gap, spanning the rostral hemisected cord to the caudal sectioned lumbar ventral roots (gap, 7 mm). In control animals (n = 6), no treatment was performed. RESULTS: Six months after surgery, the return of some tension and resistance of the paralyzed hindlimb muscles was observed in all experimental rats except the untreated controls. Nine months postoperatively, muscle action potentials were recorded from the target muscles of the experimental animals while electrostimulating the tissue continuity within the collagen tube. Horseradish peroxidase retrograde labeling showed that the neurons in the rostral cord near the implantation site regrew into the reconnected lumbar ventral roots. Histological examination indicated numerous myelinated axons in the reconnected root pathways and newly formed endplates in the target muscles. No axonal regeneration was found in the control rats. CONCLUSION: These results indicate that the rostral spinal axons can regrow into the caudal sectioned and reconnected ventral roots through a collagen tube, thus innervating the denervated peripheral targets in adult rats after spinal cord injury. This surgical repair model also provides a means for testing the use of trophic factors that may further promote axonal regeneration.

Use of a collagen-based sealant to prevent in vivo epidural adhesions in an adult rat laminectomy model.

OBJECT: The authors investigated the effect of a collagen-based sealant, Gel Amidon Oxydé (GAO), in the prevention of epidural scar adhesions in an adult rat model of laminectomy. METHODS: Seventy-two adult Sprague-Dawley rats underwent an L5-6 laminectomy, after which the dura mater and the left L-4 and L-5 nerve roots were exposed. In the 36 animals that received GAO, the sealant was applied over the dura and around the nerve roots, and it was used to fill the laminectomy cavity before it polymerized. In 36 control animals, the same surgical treatment was performed, but the rats did not receive GAO. During the early postoperative period, a significant decrease in the occurrence of epidural hematoma was found in the GAO-treated rats. In contrast to findings in control rats, a thin white connective tissue layer was found between the dura and surrounding muscles after GAO had degraded and been absorbed. One month posttreatment, no epidural scar adhesion was found between the tissue layer and the dura in the GAO-treated animals. Three months postoperatively, both gross inspection and histological examination further confirmed that formation of epidural adhesions was significantly inhibited in the rats treated with GAO. No special inflammatory reaction was observed, and the healing of skin and muscle lesions was not affected by either treatment. CONCLUSIONS: The data obtained in this study suggest that the GAO collagen-based sealant may be an effective biomaterial to prevent epidural adhesions in vivo after laminectomy.

Innervation of the caudal denervated ventral roots and their target muscles by the rostral spinal motoneurons after implanting a nerve autograft in spinal cord-injured adult marmosets.

OBJECT: The authors conducted a study to determine the effects of using a nerve autograft (NAG) to promote and guide axonal regrowth from the rostral spinal cord to the caudal lumbar ventral nerve roots to restore hindlimb motor function in adult marmosets after lower thoracic cord injury. METHODS: Nine animals underwent a left-sided hemisection of the spinal cord at T-12 via left-sided T9-L3 hemilaminectomy, with section of all ipsilateral lumbrosacral ventral nerve roots. In the experimental group (five animals), an NAG obtained from the right peroneal nerve was anastomosed with the sectioned and electrophysiologically selected lumbar ventral roots (left L-3 and L-4) controlling the left quadriceps muscle and then implanted into the left ventrolateral T-10 cord. In the control group (four animals), the sectioned/selected lumbar ventral roots were only ligated. After surgery, all marmosets immediately suffered from complete paralysis of their left hindlimb. Five months later, some clinical signs of reinnervation such as tension and resistance began to appear in the paralyzed quadriceps of all experimental animals that received autografts. Nine months postoperatively, three of the five experimental marmosets could maintain their lesioned hindlimb in hip flexion. Muscle action potentials and motor evoked potentials were recorded from the target quadriceps in all experimental marmosets, but these potentials were absent in the control animals. Horseradish peroxidase retrograde labeling from the distal sectioned/reconnected lumbar ventral roots traced 234+/-178 labeled neurons in the ipsilateral T8-10 ventral horn, mainly close to the NAG tip. Histological analysis showed numerous regenerating axons in this denervated/reconnected nerve root pathway, as well as newly formed motor endplates in the denervated/reinnervated quadriceps. No axonal regeneration was detected in the control animals. CONCLUSIONS: These data indicate that the rostral spinal neurons can regrow into the caudal ventral roots through an NAG, thereby innervating the target muscle in adult marmosets after spinal cord injury.

Motoneurons of the adult marmoset can grow axons and reform motor endplates through a peripheral nerve bridge joining the locally injured cervical spinal cord to the denervated biceps brachii muscle.

Reconnection of the injured spinal cord (SC) of the marmoset with the denervated biceps brachii muscle (BB) was obtained by using a peripheral nerve (PN) bridge. In 13 adult males, a 45 mm segment of the peroneal nerve was removed: one end was implanted unilaterally into the cervical SC of the same animal (autograft), determining a local injury, although the other end was either directly inserted into the BB (Group A) or, alternatively, sutured to its transected motor nerve, the musculocutaneous nerve (Group B). From 2-4 months post-surgery, eight out of the 10 surviving animals responded by a contraction of the BB to electrical stimulations of the PN bridge. All ten were then processed for a morphological study. As documented by retrograde axonal tracing studies using horse radish peroxidase or Fast Blue (FB), a mean number of 314 (Group A) or 45 (Group B) spinal neurons, mainly located close to the site of injury and grafting, re-expressed a capacity to grow and extend axons into the PN bridge. Most of these regenerated axons were able to grow up to the BB and form or reform functional motor endplates. Many of the spinal neurons that were retrogradely labeled with FB simultaneously displayed immunoreactivity for choline acetyl-transferase and consequently were assumed to be motoneurons. Reinnervation and regeneration of the BB were documented by methods revealing axon terminals, endplates and myofibrillary ATPase activity. Our results indicate that motoneurons of the focally injured SC of a small-sized primate can, following the example of the adult rat, re-establish a lost motor function by extending new axons all the way through a PN bridge connected to a denervated skeletal muscle.

[Syringomyelia and Chiari abnormality in the adult. Analysis of the results of a cooperative series of 285 cases]. / Syringomyélie et anomalie de Chiari chez l'adulte. Analyse et résultats de la série coopérative de 285 cas.

This chapter discusses the retrospective data found in 285 patients with syringomyelia associated with Chiari abnormality and collected from 18 neurosurgical departments. A pre and postoperative MRI study and a minimum follow up of at least 2 years were required. A scale of severity was fixed and tested before and after treatment. The size of the cyst, the degree of the foraminal obstruction were analyzed. The mean age at diagnosis was about 39 years and the duration of symptoms about 6.7 years. Sensory disorders were present in 91% of cases, pain in 66% and motor deficit in about 60%. According to our functional classification, the majority of our patients were moderately disabled and only 10.8% showed a severe impotence. Results of the two major surgical procedures, foramen magnum decompression (FMD) (88% of cases) and cyst shunting procedures (SP) (32% of cases) were evaluated with a mean follow-up period of 6.7 years (ranged from 2 to 14 years). Better clinical and morphological results (87% of stabilization or improvement for FMD versus 71% for SP) were obtained by FMD procedure comparing to SP, with the same rate of complications.

[Characterization of sensation disorders and neuropathic pain related to syringomyelia. A prospective study]. / Caractérisation des troubles sensitifs et des douleurs neuropathiques liés aux syringomyélies. Etude prospective.

The present prospective study aimed to perform quantitative sensory testing (QST) in patients with painful or painless syringomyelia before and after surgical treatment of their syrinx (at 3 and 9 months). Eighteen consecutive patients with cervical or dorso-lumbar syringomyelia completed the study and 9 underwent surgery. Twelve patients had central neuropathic pain (of whom 6 were followed up). Spontaneous pain and brush-evoked allodynia were assessed. Von Frey hairs, vibrameter and a thermotest device were used to determine the mechanical-, vibratory-, thermal-detection thresholds, and the mechanical and thermal pain thresholds. Results showed evidence of deficits in temperature and pain sensibility in 17 cases, often associated with deficits in vibration and touch sensitivity (11 cases). Magnetic resonance scan, including axial images, demonstrated good correlation between paramedian extension of the syrinx and the laterality of thermal deficits. Somatosensory evoked potentials (11 patients) were abnormal in 9 cases at level, and showed good correlation with deficits in vibration. The magnitude of the thermal and tactile deficit was similar between areas of spontaneous pain and adjacent non painful areas. Surgery induced a significant decrease of tactile deficits, and to a lesser extent, of thermal deficits. Effects on neuropathic pain were positive in 3 patients (total disappearance of pain) and negligible or negative in 3 patients, despite collapse of the syrinx (in 2 cases). These results confirm that QST are useful in clinical practice to quantify the clinical results of surgery in patients with syringomyelia, and allow some hypotheses about the mechanisms of neuropathic pain in these patients.