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Paragangliomas are tumors arising in the paraganglia. Involvement of the spine is less common, and usually takes the form of intradural compression of the cauda equina. We report here a case of a 60-year-old man with recurrent and progressive pain of his sacral and perineal area, accompanied by occasional rod and perineal hypoesthesia on admission. He underwent laminectomies of the vertebral bodies S1 and S2, and an en bloc resection of the tumor. Postoperative histopathological examination revealed a paraganglioma. Postoperative staging showed no pathological abnormalities, and no tumor recurrence after one year. Even though rare, the paraganglioma of the sacral spinal canal should be considered in the differential diagnosis of tumors occurring in the spine.

Background: Supratentorial hemangioblastomas are rare lesions, occurring either sporadically or in von Hippel-Lindau disease., Objective: Following recent advances in our understanding of the natural history of von Hippel-Lindau-associated cerebellar and spinal hemangioblastomas, we conducted a study of the natural history of supratentorial hemangioblastomas in von Hippel-Lindau disease., Methods: We reviewed a series of 18 supratentorial hemangioblastomas in 13 patients with von Hippel-Lindau disease. Clinical, genetic, and serial imaging data and operative records were analyzed., Results: Hemangioblastomas were most commonly seen in the temporal lobe. Only 6 tumors had a cyst at diagnosis or during follow-up, and only 6 patients had associated symptoms at presentation or during follow-up. The most frequent clinical presentations were intracranial hypertension and visual loss. Of 14 tumors with documented serial imaging, 13 demonstrated tumor growth. Rates and patterns of tumor growth were unique to each patient. The mechanism of cyst formation described in other locations was also demonstrated in the supratentorial region. Patterns of peritumoral edema and rate of cyst formation seemed to be influenced by the presence of anatomic barriers. Germline VHL mutation was identified in all patients, but no specific genotype-phenotype correlation was found, although a familial predisposition is suggested., Conclusion: This series illustrates the wide variation in tumor locations, patterns of growth, and edema progression seen in supratentorial hemangioblastomas and adds to our knowledge of the natural history of hemangioblastomas.

Object: In this study, the authors investigated the clinical efficacy of decompressive craniectomy treatments for nontraumatic intracranial hypertension in children., Methods: Seven patients with nontraumatic refractory high intracranial pressure (ICP) were enrolled in the study between 1995 and 2005; there were 2 boys and 5 girls with a mean age of 9 years (range 4-14). Decompressive craniectomy was performed in all patients after standard medical therapy had proven insufficient and ICP remained > 50 mm Hg. All patients had a Glasgow Coma Scale score < 8 at admission and a mean Pediatric Risk of Mortality Scale score of 20 (range 10-27)., Results: One patient died of persistent high ICP and circulatory failure 48 hours after surgery. Six months later, according to their Glasgow Outcome Scale scores, 3 patients had adequate recoveries, 2 patients recovered with moderate disabilities, and 1 patient had severe disabilities. According to the Pediatric Overall Performance Category Scale, 4 patients received a score of 2 (mild disability), 1 a score of 3 (moderate disability), and 1 a score of 4 (severe disability). Five patients returned to school and normal life., Conclusions: The authors found decompressive craniectomy to be an effective and lifesaving technique in children. This procedure should be included in the arsenal of treatments for nontraumatic intracranial hypertension.

Background and Purpose: The corpus callosum is an important predilection site for traumatic axonal injury but may be unevenly affected in head trauma. We hypothesized that there were local differences in axonal injury within the corpus callosum as investigated with diffusion tensor imaging (DTI), varying among patients with differing severity of traumatic brain injury (TBI)., Materials and Methods: Ethics committee approval and informed consent were obtained. Ten control subjects (7 men, 3 women; mean age, 37 +/- 9 years) and 39 patients with TBI (27 men, 12 women; 34 +/- 12 years) were investigated, of whom 24 had mild; 9, moderate; and 6, severe TBI. Regions of interest were selected in the callosal genu, body, and splenium to calculate fractional anisotropy (FA), apparent diffusion coefficient (ADC), and the number of fibers passing through. Statistical comparison was made through analysis of variance with the Scheffé post hoc analysis., Results: Compared with controls, patients with mild TBI investigated <3 months posttrauma (n = 12) had reduced FA (P < .01) and increased ADC (P < .05) in the genu, whereas patients with mild TBI investigated > or =3 months posttrauma (n = 12) showed no significant differences. Patients with moderate and severe TBI, all investigated <3 months posttrauma, had reduced FA (P < .001) and increased ADC (P < .01) in the genu compared with controls and reduced FA in the splenium (P < .001) without significant ADC change., Conclusion: Mild TBI is associated with DTI abnormalities in the genu <3 months posttrauma. In more severe TBI, both the genu and splenium are affected. DTI suggests a larger contribution of vasogenic edema in the genu than in the splenium in TBI.

Introduction: Neurotization of lumbar roots with lower intercostal nerves is a potential way to treat neurological deficits after spinal cord injury. The anatomical feasibility of such neurotizations in humans has already been reported. We propose to assess axonal regrowth after intercostal to lumbar neurotization in a sheep model., Materials and Methods: Ten sheep had a left T11-L2, T12-L3, and T13-L4 neurotization. In 5 sheep, a L1 level left hemisection of the spinal cord was performed. The sheep had clinical and electrophysiological monitoring with a 6 mon follow-up., Results: A flaccid paralysis with clinical asymmetry of the left abdominal wall was noted three months after surgery. This asymmetry improved in all the cases at the 6 mon follow-up. Motor potentials were detected without difficulty for the 3 neurotized nerves (L2, L3, and L4) in 5 sheep. In another sheep, motor potentials of the L3 root remained undetected. Eight sheep had postoperative complications responsible for the animals' death in 5 cases., Conclusions: The current study demonstrates the technical feasibility of intercosto-lumbar neurotizations in a sheep model. We proved in all the animals--except in the case of 1 neurotized root--the ability of motor axon to regenerate through neurotization area down to the muscular effectors; however, we noted a high rate of postoperative complications in this animal model.

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.

Study Design: Descriptive anatomy. OBJECTIVE.: To describe the anatomy associated with the extensive transmuscular paraspinal approach required to perform multiple intercosto-lumbar neurotizations., Summary of Background Data: Neurotization of lumbar roots using lower intercostal nerves is a potential method of treating neurologic deficits after spinal cord injury. It appeared to us that the paraspinal splitting approach was potentially an optimal method to perform intercostal nerve harvesting, rerouting, and intercosto-lumbar neurotizations., Methods: Ninth, 10th, and 11th intercostal nerve harvesting and rerouting down to L2, L3, and L4 roots were performed on 50 cadavers. The descriptive anatomy and topographic landmarks are reported., Results: The mean total length of intercostal nerve harvested was 17.96 (range, 10-27) cm for the 9th intercostal nerve, 17.14 cm (range, 10-20) for the 10th intercostal nerve and 15.94 cm (range, 10-25) for the 11th intercostal nerve. The length of harvested nerve was not correlated to the size of the trunk. The length of harvested nerve was sufficient to perform lumbar roots neurotizations in the 300 cases of nerve harvesting., Conclusion: Multiple lumbar roots neurotizations with lower intercostal nerves already have been proposed by other authors. In this strategy, the use of the spinal cord and intercostal nerves above the spinal cord lesion avoids the axonal regrowth required via the injured central nervous system. Rerouting intercostals nerves down to the lumbar roots at their exit from the intervertebral foraminae is less invasive that the same procedure performed down to the vertebral canal at the level of the cauda equina as we used in previous protocols. Our anatomic study confirms the advantage of the paraspinal sacrospinalis splitting approach in multiple intercosto-lumbar neurotizations. The approach is quick and easy and allows a good exposure of the nerve roots at the thoracic and lumbar levels. The L2, L3, and L4 roots could be satisfactorily neurotized with this procedure.

Objective: Neurofibromatosis Type 1 (NF1) is known to be associated with vascular lesions. Association with an extracranial vertebral artery aneurysm is very rare. We report the case of such an aneurysm mimicking a cervical neurofibroma in NF1., Clinical Presentation: An 18-year-old woman with previously diagnosed NF1 presented with a C6 radiculopathy. There were no clinical features suggesting a vascular origin for the lesion. The computed tomographic and standard magnetic resonance imaging scans showed a C5-C6 contrast-enhancing lesion responsible for bony erosion. Subsequent, magnetic resonance angiography and digital subtraction angiography diagnosed the lesion as a C5-C6 vertebral artery aneurysm., Intervention: The lesion was treated by endovascular occlusion of both the aneurysm and the parent vertebral artery with an initial immediate disappearance of the pain., Conclusion: This case serves as a reminder of the importance of ruling out a vertebral artery aneurysm with angiography when managing cervical lesions in patients with NF1.

Diffusion-weighted imaging and fractional anisotropy may be more sensitive than other conventional magnetic resonance imaging techniques to detect, characterize, and map the extent of spinal cord lesions. Fiber tracking offers the possibility of visualizing the integrity of white matter tracts surrounding some lesions, and this information may help in formulating a differential diagnosis and in planning biopsies or resection. Fractional anisotropy measurements may also play a role in predicting the outcome of patients who have spinal cord lesions. In this article, we address several conditions in which diffusion-weighted imaging and fiber tracking is known to be useful and speculate on others in which we believe these techniques will be useful in the near future.

To investigate the characteristics of motor, sensory and sensory-evoked potentials (SEPs) of thoracic and lumbar roots, and demonstrate the feasibility of assessing axonal regrowth after the neurotization procedure in a sheep model. Six adult sheep were anaesthetized and placed in a sternal position. The thoracic and lumbar roots from T11 to L5 were identified at their emergence from the vertebral foramen and stimulated. Motor and sensory responses were monitored. Thoracic and lumbar roots were easily identified in all cases. Motor potentials were detected for each stimulated nerve without difficulty. The amplitudes were quite variable, ranging from 100 to 5300 microV. Sensory and SEPs were satisfactorily recorded in only three of the six animals. Sensory amplitudes also varied greatly, ranging from 25 to 120 microV. In three cases, SEPs could not be identified due to motor artefacts. The motor pathway after axonal regrowth in neurotized lumbar roots might easily be explored by proximal electric stimulation of the root, close to the sutured area. Detection of sensory and spinal cord evoked potentials might be improved by the use of curve summation techniques. Specific axonal tracing holds promise of being a useful technique for examining sensory and motor pathway recovery after neurotization in the sheep model.

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.

Object: The topographic anatomy of the lower intercostal nerves is less well known than that of the upper ones, except for the 12th intercostal nerve. It is possible to use the lower intercostal nerves to perform a neurotization of the lumbar roots. The authors studied the anatomy of the ninth, 10th, and 11th intercostal nerves to obtain descriptive and topographic anatomical data to aid in establishing optimal conditions for harvesting., Methods: The ninth, 10th, and 11th intercostal nerves of 50 cadavers were dissected. The proximal part of the nerve in the posterior intercostal space (ISC) was exposed through a posterior approach. The lateral ICS was exposed through a lateral approach, under the latissimus dorsi, which made it possible to harvest the intercostal nerves using a stripping technique. A histological study was conducted on 10 pigs to evaluate the risk of nerve lesions during the stripping procedure., Conclusions: The proximal course of the nerve in the posterior ICS was the same in all cases. The mean total length of the intercostal nerves harvested was 17.96 cm for the ninth, 17.14 cm for the 10th, and 15.94 cm for the 11th intercostal nerve. The harvested nerve length was sufficient in 297 of the 300 cases to perform lumbar root neurotization. The histological study showed no difference between the "open" and the "stripping" techniques regarding the risk of histological lesions in harvested nerves.

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.

The topographic anatomy of the lower intercostal nerves is less known than the upper ones except for the twelfth intercostal nerve. It is possible to use the lower intercostal nerves to carry out a neurotization of the lumbar roots. We studied the anatomy of the ninth, tenth, and eleventh intercostal nerves in order to specify the data of descriptive and topographic anatomy allowing to carry out their harvesting under good conditions. Ninth, tenth, and eleventh intercostal nerves of 50 cadavers were dissected. The proximal part of the nerve in the posterior intercostal space was exposed through a posterior approach. The lateral intercostal space was exposed through a lateral approach, under the latissimus dorsi, which made it possible to harvest the intercostals nerve. The proximal course of the nerve in posterior intercostals space was the same in all the cases. The nerve moves obliquely towards the outside to reach the lower border of the rib. The exit of posterior intercostal space is a fibrous strait that marks the entry of a channel between two muscular layers. We describe an aponevrotic channel in which the nerve and the vessels are, immediately at the lower border of the cranial rib. The mean total length of intercostal nerve harvested by our technique was 17.96 cm for the ninth intercostal nerve, 17.14 cm for the tenth intercostal nerve, and 15.94 cm for the eleventh intercostal nerve. The bifurcation of the intercostal nerve in a deep branch and the ramus cutaneus lateralis was found in the majority of the cases, from 9.5 to 21 cm of the emergence of the intercostal nerve in posterior intercostal space. This anatomical study of the ninth, tenth, and eleventh intercostal nerves in posterior intercostal space and lateral intercostal space appears to us to allow the realization of a reliable surgical harvesting., (Copyright 2005 Wiley-Liss, Inc.)

Loss of dorsal root ganglion neuron, or injury to dorsal roots, induces permanent somatosensory defect without therapeutic option. We explored an approach to restoring hind limb somatosensory innervation after elimination of L4, L5 and L6 dorsal root ganglion neurons in rats. Somatosensory pathways were reconstructed by connecting L4, L5 and L6 lumbar dorsal roots to T10, T11 and T12 intercostal nerves, respectively, thus allowing elongation of thoracic ganglion neuron peripheral axons into the sciatic nerve. Connection of thoracic dorsal root ganglion neurons to peripheral tissues was documented 4 and 7 months after injury. Myelinated and unmyelinated fibers regrew in the sciatic nerve. Nerve terminations expressing calcitonin-gene-related-peptide colonized the footpad skin. Retrograde tracing showed that T10, T11 and T12 dorsal root ganglion neurons expressing calcitonin-gene-related-peptide or the neurofilament RT97 projected axons to the sciatic nerve and the footpad skin. Recording of somatosensory evoked potentials in the upper spinal cord indicated connection between the sciatic nerve and the central nervous system. Hind limb retraction in response to nociceptive stimulation of the reinnervated footpads and reversion of skin lesions suggested partial recovery of sensory function. Proprioceptive defects persisted. Delayed somatosensory reinnervation of the hind limb after destruction of lumbar dorsal root neurons in rats indicates potential approaches to reduce chronic disability after severe injury to somatosensory pathways.

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.

Object: Peripheral motor axons can regenerate through motor endoneurial tubes of foreign nerves to reinnervate different target muscles. This regenerative capacity has been brought to clinical applications for restorative surgery after nerve or root injury. In this study the authors explore the extent to which nerve cross-anastomosis between lower intercostal nerves and lumbar ventral roots would be effective in inducing reinnervation of paralyzed hindlimb muscles after spinal cord hemisection at the thoracolumbar boundary in rats., Methods: The proximal extremities of sectioned intercostal nerves T10-12 were surgically connected to the distal extremities of sectioned ipsilateral lumbar ventral roots L3-5, respectively. Motor activity reappeared 2 months postsurgery; however, locomotion was not restored and inappropriate motor patterns persisted at 9 months postsurgery. At that time, data from electrophysiological and histological studies and horseradish peroxidase retrograde labeling demonstrated efficient regrowth of thoracic motor neuron axons that reached hindlimb muscles. They also revealed a persistent maturation defect of regrown fibers, as shown by size heterogeneity and presumable extensive axonal branching. These features are consistent with reduced neural activity subsequent to continuing inappropriate motor patterns., Conclusions: These results indicate that cross-anastomosis of intercostal nerves with lumbar ventral roots allows efficient reinnervation of paralyzed hindlimb muscles after spinal cord hemisection in rats. Stimulating the reorganization of the neuronal circuitry in the central nervous system by locomotion training or other methods would presumably result in both functional and anatomical improvements. This experimental setting provides a convenient animal model to investigate these processes.

Objective: Spinal cord arteriovenous shunts (SCAVSs) are currently classified according to their morphological features. Certain shunts cannot be fully integrated into the predetermined categories that are usually described, however. Can these classifications be reevaluated on the basis of recent anatomic, biological, and genetic advances?, Methods: We reviewed the clinical and radiological files for 155 SCAVSs that were treated at Hôpital Bicêtre between 1981 and 1999. The lesions were examined with respect to their number (single or multiple), their primary architectural type (nidus or fistula), and their possible links with associated metameric lesions., Results: All SCAVSs were either arteriovenous malformations or fistulae, with the latter being either micro- or macrofistulae. All SCAVSs corresponded to three categories, i.e., genetic hereditary lesions (macrofistulae and hereditary hemorrhagic telangiectasia), genetic nonhereditary lesions (all of which were multiple lesions with metameric or myelomeric associations), and single lesions (which could represent incomplete presentations of one of the previous groups). Of the SCAVSs in our series, 81% were single lesions and 19% were multiple; among these, 59% were true intradural shunts with metameric features. Ten cases of Cobb syndrome, three cases of Klippel-Trenaunay syndrome, and two cases of Parkes-Weber syndrome, all with associated cord lesions, were observed. Nineteen percent of SCAVSs were fistulae; 23% of those were macrofistulae, of which 83% were related to Rendu-Osler-Weber disease., Conclusion: It seems legitimate to propose a categorization that takes into consideration a primary malformation (nidus or fistula) that evolves with time and in which angioarchitectural changes occur. Recognition of the factors originally responsible for the shunt (e.g., genetic hereditary or genetic nonhereditary) allows a different classification of SCAVSs.

This study investigated the feasibility of using a peripheral nerve autograft (NAG) to promote and guide regeneration of sensory axons from the caudal lumbar dorsal roots to the rostral dorsal column following a lower thoracic cordotomy in adult rats. After a left hemicordotomy at the T13 vertebra level and ipsilateral L3 and L4 rhizotomies, a peripheral NAG (peroneal nerve) was connected to the distal roots stumps, then implanted into the left dorsal column 10 mm rostral to hemicordotomy site (n = 12). After surgery, all animals of the experimental group experienced complete anesthesia in their left hindlimb. Three months later, a slight response to nociceptive stimulation reappeared in L3 and/or L4 dermatomes in 6 of the 12 experimental animals. None of these animals exhibited self-mutilation. Nine months after surgery, we performed retrograde tracing studies by injecting horseradish peroxidase (HRP) into the left dorsal column 30 mm rostral to the NAG implantation site. In eight animals, we found HRP-stained neurons in the left L3 and/or L4 dorsal root ganglia (DRG). The mean number of HRP-stained neurons per DRG was 71 +/- 92 (range 2-259). In control groups, no HRP-stained neurons were found in L3 or L4 DRG. Histological analysis of the NAG showed evidence of axonal regeneration in all 8 animals with positive retrograde labeling of DRG neurons. However, we did not find a statistical correlation between the number of HRP-stained neurons and the degree of sensory recovery. This study demonstrates that an NAG joining dorsal roots to the dorsal column, thus shunting the original CNS-PNS junction, can support regeneration of central axons from DRG primary sensory neurons into the dorsal column over distances of at least 30 mm despite the inhibitory influence of the CNS white matter., (Copyright 2002 Wiley-Liss, Inc.)

After severe brain trauma, blood-brain barrier disruption and alteration of cerebral arteriolar vasoreactive properties may modify the cerebral response to catecholamines. Therefore, the goal of the present study was to compare the effects of dopamine and norepinephrine in a model of brain injury that consisted of a weight-drop model of injury complicated by a 15-min hypoxic-hypotensive insult (HH). Sprague-Dawley rats (n = 7 in each group) received, after brain injury, an infusion of either norepinephrine (TNE group) or dopamine (TDA group) in order to increase cerebral perfusion pressure (CPP) above 70 mm Hg. In addition, a control group (C group, no trauma) and a trauma group (T group, brain injury, no catecholamine infusion) were studied. Mean arterial pressure (MAP), intracranial pressure (ICP, intraparenchymal fiberoptic device), and local cerebral blood flow (LCBF, extradural laser-Doppler fiber) were measured throughout the protocol. In T group, brain injury and HH induced a decrease in CPP (by an increase of ICP and a decrease of MAP), and a decrease of LCBF. Both norepinephrine and dopamine failed to increase CPP, and ICP was significantly higher in TNE and TDA groups than in T group. Interestingly, norepinephrine was not able to alleviate the decrease in MAP. Neither norepinephrine or dopamine could induce an increase of MAP. LCBF decreased similarly in T, TNE and TDA groups. In conclusion, norepinephrine and dopamine are not able to restore values of CPP above 70 mm Hg in a model of severe brain trauma. Furthermore, their systemic vasopressor properties are altered.

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.

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.

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., (Copyright 2000 Wiley-Liss, Inc.)

Study Aim: In order to improve the results of intraspinal retrograde labeling of post-ganglionic primary sensory axons by horseradish peroxidase (HRP), the authors compared three different intraspinal injection methods of this tracer into the inferior thoracic spinal cord in the rat., Material and Method: 'Open field' method (group 1, N = 8); stereotactic injection, needle tip diameter = 0.72 mm (group 2, N = 8); stereotactic injection, needle tip diameter = 0.24 mm (group 3, N = 8). Histological features of the spinal injection site showed that tissue damages due to injection was more extensive and deeper than expected. HRP transported in retrograde fashion from injection site to sensory body cells located in dorsal root ganglia (DRG) was revealed by the Mesulam histochemical technique., Results: The mean number of labeled neurons per DRG was 652 in group 3, 116 in group 2, and 77 in group 1. Differences were statistically significant, especially between groups 1 and 3 (P = 4.10(-16)) and groups 2 and 3 (P = 2.10(-17))., Conclusion: Retrograde labeling of primary sensory axons by HRP (or another axonal tracer) with fine needle stereotactic intraspinal injection may represent an alternative to anterograde labeling. This reliable and reproducible method may be useful in studies dealing with regeneration of post-ganglionic primary sensory axons.

We conducted a retrospective study of 32 patients treated for syringomyelia associated with non-traumatic arachnoid scarring. We selected the cases with documented history of arachnoiditis with pre and post-operative clinical evaluation of the neurological status and anatomical study on MRI with a minimal follow-up of one year. Extensive arachnoid scarring (Group I) was noted in 18 cases, after spinal meningitis in 15 cases (tuberculosis in 9 cases, listeria in 3 cases, pyogenic meningitis in 3 cases), subarachnoid hemorrhage in 3 cases. Focal arachnoid scarring (Group II) occurred in 10 cases, related to spinal surgery in 5 cases (meningiomas: 2, neurinomas: 2, thoracic discectomy: 1), to peridural anesthesia in 1 case, thoracic disc herniation in 1 case, Pott's disease in 1 case, no obvious cause in 2 cases. Basal arachnoid scarring without hindbrain herniation (Group III) was associated with birth injuries in 4 cases. Shunting of the syrinx to the subarachnoid or peritoneal cavity was associated with a recurrence rate of 60% whereas microsurgical dissection of the arachnoid scar and decompression of the subarachnoid space with a recurrence rate of 33%, with a mean follow-up period of 28 months. Successful long-term management of the syrinx was associated with basal or focal spinal arachnoid scarring, no history of spinal meningitis, microsurgical dissection of the arachnoid scar and decompression of the subarachnoid space.

Clinical and neuroradiological data were recorded in a series of 73 spinal cord injured patients (33 in Nantes, 40 in Paris-Bicêtre) in whom a post traumatic syringomyelia (PTS) developed. These findings and a review of the literature allow to point out some of the main characteristics in such a pathology. Clinical symptoms are frequent, the commonest of them are pain and sensory loss but any alteration of the neurological status after spinal cord injury has to be considered. Magnetic resonance imaging (MRI), sagittal and axial T1 and T2 weighted images, confirms the diagnosis of syrinx (area with the same signal intensity as CSF extending beyond the site of the initial lesion at least on 2 vertebral segments). MRI allows the diagnosis when it is performed in the follow up of asymptomatic patients. So PTS is not infrequent in spinal cord injured patients, for some of them in the first year after the trauma. The highest incidence is found in patients with complete thoracic lesions. Pathophysiology and surgical management have to take into account post traumatic residual stenosis of the vertebral canal.

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.

MRI is the best imaging method to evaluate syringomyelia. It is important to study from the posterior cranial fossa to the sacro-lumbar region and also the supra-tentorial structures. This complete analysis is essential to classify the syringomyelia and to investigate other associated malformations. Radiographs and CT scan are useful to analyze bone structures. For MRI, the new sequences with phased-array coils are also very important to study the entire spinal cord and the posterior fossa. It is essential to study the spinal cord with sagittal and axial spin echo T1 and fast spin echo T2 weighted images with sometimes coronal view, particularly when the patient presents a scoliosis, to have a correct morphological and functional evaluation. MRI gives an excellent study of the spinal cord with an excellent analysis of a primitive or foraminal syringomyelia, but also traumatic, infectious or post arachnoiditis syringomyelia. Spin echo T1 weighted images with injection of gadolinium can be used if an intra-medullary tumor is suspected. MRI is also useful for the post-operative follow up to evaluate the persistence of the medullary cyst and the enlargement of the foramen magnum.

Treatment of syringomyelia utilizes two operative approaches: posterior fossa decompression and syrinx shunting (including subarachnoid, pleural and peritoneal shunting). MRI study is nowadays the indispensable tool for the evaluation of patients with syringomyelia and allows to choose the best therapeutic option. Posterior fossa decompression is regarded as the procedure of choice for syringomyelia with Chiari. After intradural exploration, additional steps may be necessary as excision of the cerebellar tonsils. Other therapeutic alternatives are associated with higher complication rates. Patients with persistent focal syrinxes after PFD respond best to syringoperitoneal shunts. For the management of post-traumatic syringomyelia, a large decompressive laminectomy at the fracture site is recommended; the use of a drain does not offer any long-term therapeutic advantage. Syringoperitoneal shunting is the treatment of post-infection syringomyelia but good long-term result is rare in this type of syrinx.

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.

The cervical anatomy of the different nerve contributions that constitute the phrenic nerve (phrenic nerve roots and accessory phrenic nerve) were studied in rabbits. In 55 dissections, 6 main root arrangement types were observed. The roots that issued from the fourth and fifth cervical nerves (C4 and C5 roots) were constant. The C4 root was either short or long. The C6 root was at times absent, or sometimes double. An accessory phrenic nerve was present in 43% of the right and 28% of the left dissections. The distribution of the phrenic nerve roots often displayed left-right asymmetry. We conclude that a better knowledge of the cervical anatomy of the phrenic nerve is useful both in physiological studies involving diaphragm denervation and in experimental laryngeal reinnervation.

Results of CT and MRI explorations in 8 patients with cerebrospinal fluid (CSF) fistulae are reported and compared with surgical findings in 7. Sensitivity of MRI (CISS and fast T2 spin-echo sequences) was excellent giving perfect correlations with surgical findings in 7/7 cases. CT and MRI were found to provide complementary information suggesting they should be used in combination as first intention explorations of suspected CSF fistulae. Computerized cisternography should be used if MRI is contraindicated or if a clinically and biologically proven CSF fistulae is not visualized by CT or MRI.

Background and Purpose: Cysticercosis is the most common parasitic disease affecting the central nervous system. Although it is still very rare in Europe, the frequency will increase due to the influx of immigrants from the endemic areas and increasing trips in these countries. Spinal intramedullary cysticercosis is an uncommon manifestation of neurocysticercosis., Clinical Presentation: We report a case of pure intramedullary cysticercosis in a young white French girl, presenting as a progressive paraplegia with a cystic lesion in T4 on MRI. The diagnosis was made only after surgery by pathological examination., Conclusions: A preoperative diagnosis of spinal intramedullary cysticercosis must be suspected not only in an endemic area in the presence of multiple soft tissue calcifications and segmental lesions revealed by myelography or MRI studies, but also for all cystic lesion of central nervous system even in no endemic area. Surgery is the unique treatment which can be used for spinal intramedullary cysticercosis and with the use of the microsurgical techniques for medullar surgery the outcome is not as dismal as reported earlier.

We investigated the spatiotemporal GFAP mRNA expression over a period of 11 days following brain injury in rats caused by impact acceleration, which is known to produce diffuse axonal injury (DAI). We observed widespread GFAP mRNA expression throughout the brain, which was more rapid and intense in the hippocampus. This expression was obvious in most animals 2 days after injury and appeared maximal at day 6. Although it decreased by day 11, the level of expression remained high compared with control levels. We noted slight differences in time of onset and the magnitude of the response between hippocampus and white matter structures or cortical areas. The different mechanisms able to trigger this response are discussed in regard to histopathological changes observed in DAI models.

In an attempt at repairing the injured spinal cord of adult mammals (rat, dog and marmoset) and its damaged muscular connections, we are currently using: 1) peripheral nerve autografts (PNG), containing Schwann cells, to trigger and direct axonal regrowth from host and/or transplanted motoneurons towards denervated muscular targets; 2) foetal spinal cord transplants to replace lost neurons. In adult rats and marmosets, a PNG bridge was used to joint the injured cervical spinal cord to a denervated skeletal muscle (longissimus atlantis [rat] or biceps brachii [rat and marmoset]). The spinal lesion was obtained by the implantation procedure of the PNG. After a post-operative delay ranging from 2 to 22 months, the animals were checked electrophysiologically for functional muscular reconnection and processed for a morphological study including retrograde axonal tracing (HRP, Fast Blue, True Blue), histochemistry (AChE, ATPase), immunocytochemistry (ChAT) and EM. It was thus demonstrated that host motoneurons of the cervical enlargement could extend axons all the way through the PNG bridge as: a) in anaesthetized animals, contraction of the reconnected muscle could be obtained by electrical stimulation of the grafted nerve; b) the retrograde axonal tracing studies indicated that a great number of host cervical neurons extended axons into the PNG bridge up to the muscle; c) many of them were assumed to be motoneurons (double labelling with True Blue and an antibody against ChAT); and even alpha-motoneurons (type C axosomatic synapses in HRP labelled neurons seen in EM in the rat); d) numerous ectopic endplates were seen around the intramuscular tip of the PNG. In larger (cavitation) spinal lesions (rat), foetal motoneurons contained in E14 spinal cord transplants could similarly grow axons through PNG bridges up to the reconnected muscle. Taking all these data into account, it can be concluded that neural transplants are interesting tools for evaluating both the plasticity and the repair capacities of the mammalian spinal cord and of its muscular connections.

This study concerned the evaluation of wound healing after extensive skin resections in 18 minipigs, sutured with: continuous intradermal Polyglactin 910 suture or Polyamide, an interrupted intradermal sutures using the same resorbable suture material. Three equivalent groups were studied: 0, 3 and 6 cm skin resections were studied after using a dynamometer to record the tension necessary to join the wound margins. Results were evaluated 1 month later by light and electron microscopy, and were statistically correlated by Pearson's test. The wound tension was correlated with skin resection (r = 0.97, p < 10-4). The scar width was exponentially correlated with tension (r = 0.70, p < 10-3); the fibrous and cellular appearances increased with the skin resection. The absence of any significant statistical results prevents any conclusion concerning the superiority of one suture material or suture technique, but the group with no resection led to homogenous results, regardless of the suture technique, or suture material used. 3 and 6 cm resection the groups led to unpredictable and various results. Granulous reactions were observed in 7 out of 12 cases with resorbable suture, and only 1 of the 8 cases with non resorbable suture, but these results are not significant.

A case of pituitary apoplexy occurring in the context of physical effort is reported. A 47-year-old man presented headache after a foot-race. Secondary visual deficit developed. On admission, bilateral cavernous sinus syndrome with bitemporal hemianopia was observed. The CT scan showed an enlarged sella eroded by an intrasellar soft tissue mass. Magnetic resonance imaging (MRI) confirmed the presence of the mass with peripheral enhancement following gadolinium injection. Decompression was carried out by transsphenoidal surgery. The microscopic study demonstrated infarction of the anterior hypophysis with peripheral tissular scarring. The post-operative outcome was characterized by visual recovery and anterior hypophyseal insufficiency. The possible pathophysiological mechanisms are discussed.

Recovery of neurologic function after traumatic injury to the spinal cord can be significantly improved provided prompt medico-surgical decision is being taken, aiming at limiting post traumatic tissue damages extension. In an effort to optimize the triage of these patients, we set a multicentric emergency network program, involving cooperating staff from first care, surgical and rehabilitation departments. This program has allowed us to reduce substantially the time between trauma and medico-surgical treatment. Our first objective was to obtain spinal cord decompression and spinal stabilization as quickly as possible, the set-time limit being 8 hours at most after trauma. This emergency network being operational, we started a multicentric study to test whether the neurologic recovery following a spinal cord injury could be further improved by adding.

In a series of 60 consecutive patients, 137 multiple aneurysms (An) were discovered after subarachnoid hemorrhage. Multiple An were mostly double (83 % of the patients). The incidence of middle cerebral artery An was 42 %, internal carotid artery An 25.5 %, anterior communicating artery An 15 %. Both angiography (A degree) and CT scan could identify the ruptured An in 56 cases or at least the side of the ruptured An in the remaining 4 cases. Among the routine A degree criteria used to determine which one of the An had bled the most reliable ones appears to be: the existence of vasospasm of the parent artery, the bigger size of the sac, the irregular wall of the sac. The incidence of rupture is the highest in anterior communicating artery An (16/21). When an An located on the polygon of Willis is associated to a distal An, the former ruptures in 17 cases/18. All ruptured An were treated during the first operative session. In 47 patients (78.3%) all the An, ruptured and asymptomatic, were treated during the first procedure or in one or two additional surgical sessions. In 13 patients (22.7%) for several reasons only ruptured An and asymptomatic An that could be reached via the same craniotomy were treated. There was no morbidity or mortality related to the surgical treatment of asymptomatic An.

Sixty patients with ruptured cerebral aneurysms were operated during the first 3 days after the onset of bleeding. In all cases the following investigations were performed: before surgery and 10 days after surgery angiography and CTScan, two months later a control CTScan. The first CTScans have been classified according to the staging defined by Fisher. Vasospasms (VS) were assessed comparing the arteriographies before and after surgery and classified as narrow or moderate; ischemia were assessed on post surgical CTScans. VS were found in any of the Fisher grades but were more frequent in grade 4; they occurred in 50% of cases (30 cases). Narrow VS were found 17 times in any Fisher grade. Ischemia occurred in 7 cases (1 death); following narrow VS in 6 cases. The high incidence of VS demonstration is emphasized: it is probably due to the lag time between bleeding and angiography and to the fact that angiographic controls were systematically performed. On the other hand ischemia occurred in 7 patients: the respective role of normalized intracranial pressure, hypervolemia, drug use and surgical procedure are discussed as candidate factors of this low incidence.