Evidence in peroneal nerve entrapment: A scoping review.

BACKGROUND AND PURPOSE: Daily management of patients with foot drop due to peroneal nerve entrapment varies between a purely conservative treatment and early surgery, with no high-quality evidence to guide current practice. Electrodiagnostic (EDX) prognostic features and the value of imaging in establishing and supplementing the diagnosis have not been clearly established. METHODS: We performed a literature search in the online databases MEDLINE, Embase, and the Cochrane Library. Of the 42 unique articles meeting the eligibility criteria, 10 discussed diagnostic performance of imaging, 11 reported EDX limits for abnormal values and/or the value of EDX in prognostication, and 26 focused on treatment outcome. RESULTS: Studies report high sensitivity and specificity of both ultrasound (varying respectively from 47.1% to 91% and from 53% to 100%) and magnetic resonance imaging (MRI; varying respectively from 31% to 100% and from 73% to 100%). One comparative trial favoured ultrasound over MRI. Variable criteria for a conduction block (>20%-≥50) were reported. A motor conduction block and any baseline compound motor action potential response were identified as predictors of good outcome. Based predominantly on case series, the percentage of patients with good outcome ranged 0%-100% after conservative treatment and 40%-100% after neurolysis. No study compared both treatments. CONCLUSIONS: Ultrasound and MRI have good accuracy, and introducing imaging in the standard diagnostic workup should be considered. Further research should focus on the role of EDX in prognostication. No recommendation on the optimal treatment strategy of peroneal nerve entrapment can be made, warranting future randomized controlled trials.

A randomized controlled trial comparing conservative versus surgical treatment in patients with foot drop due to peroneal nerve entrapment: results of an internal feasibility pilot study.

BACKGROUND: Based on the lack of literature to support any treatment strategy in patients with foot drop due to peroneal nerve entrapment, a prospective study randomizing patients between surgery and conservative treatment is warranted. Since studies comparing surgery to no surgery are often challenging, we first examined the feasibility of such a randomized controlled trial. METHODS/DESIGN: An internal feasibility pilot study was conducted to assess several aspects of process, resource, management, and scientific feasibility. The main objective was the assessment of the recruitment rate. The criterion to embark on a full study was the recruitment of at least 14 patients in 6 participating centers within 6 months. Cross-over rate, blinding measures, training strategies, and trial assessments were evaluated. The trial was entirely funded by the KCE Trials public funding program of the Belgian Health Care Knowledge Centre (ID KCE19-1232). RESULTS: The initial duration was prolonged due to the COVID-19 pandemic. Between April 2021 and October 2022, we included 19 patients of which 15 were randomized. Fourteen patients were treated as randomized. One drop-out occurred after randomization, prior to surgery. We did not document any cross-over or accidental unblinding. Training strategies were successful. Patients perceived the quality of life questionnaire as the least relevant assessment. Assessment of ankle dorsiflexion range of motion was prone to interobserver variability. All other trial assessments were adequate. DISCUSSION: Recruitment of the anticipated 14 patients was feasible although slower than expected. The Short-Form Health Survey (SF-36) and assessment of ankle dorsiflexion range of motion will no longer be included in the full-scale FOOTDROP trial. CONCLUSION: The FOOTDROP study is feasible. TRIAL REGISTRATION: ClinicalTrials.gov, identifier NCT04695834 . Registered 4 January 2021.

Thoracic Outlet Syndrome Part II: Consensus on the Management of Neurogenic Thoracic Outlet Syndrome by the European Association of Neurosurgical Societies' Section of Peripheral Nerve Surgery.

BACKGROUND: In the first part of this report, the European Association of Neurosurgical Societies' section of peripheral nerve surgery presented a systematic literature review and consensus statements on anatomy, classification, and diagnosis of thoracic outlet syndrome (TOS) along with a subclassification system of neurogenic TOS (nTOS). Because of the lack of level 1 evidence, especially regarding the management of nTOS, we now add a consensus statement on nTOS treatment among experienced neurosurgeons. OBJECTIVE: To document consensus and controversy on nTOS management, with emphasis on timing and types of surgical and nonsurgical nTOS treatment, and to support patient counseling and clinical decision-making within the neurosurgical community. METHODS: The literature available on PubMed/MEDLINE was systematically searched on February 13, 2021, and yielded 2853 results. Screening and classification of abstracts was performed. In an online meeting that was held on December 16, 2021, 14 recommendations on nTOS management were developed and refined in a group process according to the Delphi consensus method. RESULTS: Five RCTs reported on management strategies in nTOS. Three prospective observational studies present outcomes after therapeutic interventions. Fourteen statements on nonsurgical nTOS treatment, timing, and type of surgical therapy were developed. Within our expert group, the agreement rate was high with a mean of 97.8% (± 0.04) for each statement, ranging between 86.7% and 100%. CONCLUSION: Our work may help to improve clinical decision-making among the neurosurgical community and may guide nonspecialized or inexperienced neurosurgeons with initial patient management before patient referral to a specialized center.

Rationale and design of the peripheral nerve tumor registry: an observational cohort study.

AIM: Peripheral nerve tumors (PNT) are rare lesions. To date, no systematic multicenter studies on epidemiology, clinical symptoms, treatment strategies and outcomes, genetic and histopathologic features, as well as imaging characteristics of PNT were published. The main goal of our PNT Registry is the systematic multicenter investigation to improve our understanding of PNT and to assist future interventional studies in establishing hypotheses, determining potential endpoints, and assessing treatment efficacy. METHODS: Aims of the PNT registry were set at the 2015 Meeting of the Section of Peripheral Nerve Surgery of the German Society of Neurosurgery. A study protocol was developed by specialists in PNT care. A minimal data set on clinical status, treatment types and outcomes is reported by each participating center at initial contact with the patient and after 1 year, 2 years, and 5 years. Since the study is coordinated by the Charité Berlin, the PNR Registry was approved by the Charité ethics committee (EA4/058/17) and registered with the German Trials Registry (www.drks.de). On a national level, patient inclusion began in June 2016. The registry was rolled out across Europe at the 2019 meeting of the European Association of Neurosurgery in Dublin. RESULTS: Patient recruitment has been initiated at 10 centers throughout Europe and 14 additional centers are currently applying for local ethics approval. CONCLUSION: To date, the PNT registry has grown into an international study group with regular scientific and clinical exchange awaiting the first results of the retrospective study arm.

Post-traumatic thoracic outlet syndrome.

BACKGROUND: To evaluate the clinical presentation, diagnostic and therapeutic management and outcome of 27 cases of post-traumatic thoracic outlet syndrome (PT TOS). METHODS: Retrospective chart analysis. RESULTS: Nineteen women and eight men were included in this study. Involvement in a traffic accident was the most common scenario. Fracture of either the first rib or the clavicle was reported in eight patients at the time of injury; in others, the diagnosis was cervical or shoulder soft tissue trauma. Upon presentation at our clinic at a mean 41 months after injury, four patients had bilateral symptoms and 17 reported decreased function of either the arm or hand. Two patients presented with severe lower trunk deficits including one who had received surgical intervention at both the cervical spine and elbow before diagnosis of TOS was made. Sixteen and 15 patients were suffering from some degree of anxiety and/or depression. Upon diagnosis of neurogenic TOS, the two patients with atrophy of the hand musculature were treated surgically. Conservative treatment was applied to all other patients. Six months after presentation to our clinic, nine patients demonstrated a significant improvement. The remainder that reported incapacitating symptoms were offered surgical treatment. Three patients declined the latter. Fifteen patients received surgical treatment via an anterior supraclavicular approach with resection of the anterior scalene muscles. Eleven patients had resection of the middle scalene muscle while five had resection of an osseous structure (partial claviculectomy, C7 transverse process or a cervical rib). The two patients with atrophy of the hand only slightly improved their motor deficit but had a notable relief of symptoms of pain. Postoperative improvement occurred in 80% of surgically treated patients. CONCLUSIONS: The majority of patients suffering from a post-traumatic TOS present a neurogenic, usually subjective syndrome. Prompt therapeutic management is necessary, addressing both physical and psychological complaints. Most patients are cured or well improved by conservative and/or surgical treatment.

Conservative versus surgical treatment of foot drop in peroneal nerve entrapment: rationale and design of a prospective, multi-centre, randomized parallel-group controlled trial.

BACKGROUND: High-quality evidence is lacking to support one treatment strategy over another in patients with foot drop due to peroneal nerve entrapment. This leads to strong variation in daily practice. METHODS/DESIGN: The FOOTDROP (Follow-up and Outcome of Operative Treatment with Decompressive Release Of The Peroneal nerve) trial is a randomized, multi-centre study in which patients with peroneal nerve entrapment and persistent foot drop, despite initial conservative treatment, will be randomized 10 (± 4) weeks after onset between non-invasive treatment and surgical decompression. The primary endpoint is the difference in distance covered during the 6-min walk test between randomization and 9 months later. Time to recovery is the key secondary endpoint. Other secondary outcome measures encompass ankle dorsiflexion strength (MRC score and isometric dynamometry), gait assessment (10-m walk test, functional ambulation categories, Stanmore questionnaire), patient-reported outcome measures (EQ5D-5L), surgical complications, neurological deficits (sensory changes, motor scores for ankle eversion and hallux extension), health economic assessment (WPAI) and electrodiagnostic assessment. DISCUSSION: The results of this randomized trial may elucidate the role of surgical decompression of the peroneal nerve and aid in clinical decision-making. TRIAL REGISTRATION: ClinicalTrials.gov NCT04695834. Registered on 4 January 2021.

Thoracic Outlet Syndrome Part I: Systematic Review of the Literature and Consensus on Anatomy, Diagnosis, and Classification of Thoracic Outlet Syndrome by the European Association of Neurosurgical Societies' Section of Peripheral Nerve Surgery.

BACKGROUND: Although numerous articles have been published not only on the classification of thoracic outlet syndrome (TOS) but also on diagnostic standards, timing, and type of surgical intervention, there still remains some controversy because of the lack of level 1 evidence. So far, attempts to generate uniform reporting standards have not yielded conclusive results. OBJECTIVE: To systematically review the body of evidence and reach a consensus among neurosurgeons experienced in TOS regarding anatomy, diagnosis, and classification. METHODS: A systematic literature search on PubMed/MEDLINE was performed on February 13, 2021, yielding 2853 results. Abstracts were screened and classified. Recommendations were developed in a meeting held online on February 10, 2021, and refined according to the Delphi consensus method. RESULTS: Six randomized controlled trials (on surgical, conservative, and injection therapies), 4 "guideline" articles (on imaging and reporting standards), 5 observational studies (on diagnostics, hierarchic designs of physiotherapy vs surgery, and quality of life outcomes), and 6 meta-analyses were identified. The European Association of Neurosurgical Societies' section of peripheral nerve surgery established 18 statements regarding anatomy, diagnosis, and classification of TOS with agreement levels of 98.4 % (±3.0). CONCLUSION: Because of the lack of level 1 evidence, consensus statements on anatomy, diagnosis, and classification of TOS from experts of the section of peripheral nerve surgery of the European Association of Neurosurgical Societies were developed with the Delphi method. Further work on reporting standards, prospective data collections, therapy, and long-term outcome is necessary.

Management of benign nerve sheath tumors of the brachial plexus: relevant diagnostic and surgical features. About a series of 17 patients (19 tumors) and review of the literature.

Brachial plexus (BP) tumors are rare, potentially difficult-to-manage lesions. The method is retrospective chart analysis. Among the 17 patients, four had neurofibromatosis and one schwannomatosis (NF +). The latter has bilateral BP tumors that remain stable on MRI at a 6.5 year follow-up. Another NF + patient has bilateral non-operable BP plexiform neurofibromas. The complaints of the 15 operated patients were radiated pain, a mass, local pain, paresthesia, a neurological deficit (n = 15, 12, 7, 10, 7). On MRI, the tumors appeared as nodular or ovoid large masses. Four operated tumors were proximal, reaching the foramen. The FDG-PET scan (n = 4) always showed tumor hypermetabolism. A preoperative percutaneous biopsy was done in three patients before neurosurgical consultation; one of them developed neurogenic pain and a sensory deficit following two percutaneous biopsies for a misinterpreted cervical lymphadenopathy. Surgery was performed using a supra-, infra-, supra- + infra-clavicular or posterior subscapular approach (n = 8, 3, 3, 1). Intraoperative electrophysiology was used in all patients. Complete or gross total resection was achieved in 14 patients. Two patients had fascicle reconstruction with grafts. Pathology revealed 13 schwannomas and two neurofibromas. Neurogenic pain transiently developed or worsened after surgery in five patients. At last follow-up, a mild deficit remained in four patients (preexisting in three). No recurrence had occurred. We conclude that a thorough examination of any patient with a cervical or axillary mass is crucial to avoid misinterpretation as a lymphadenopathy. MRI is the best imaging modality. Most BP benign tumors can be completely and safely resected through the use of microsurgical techniques and intraoperative electrophysiology.

Iatrogenic nerve injuries: a potentially serious medical and medicolegal problem. About a series of 42 patients and review of the literature.

OBJECTIVE: To analyze the management of iatrogenic nerve injuries (iNI) in 42 patients. METHODS: Retrospective analysis of the charts. RESULTS: The iNI occurred mostly during a surgical procedure (n = 39), either on a nerve or plexus (n = 13), on bone, joint, vessel or soft tissue (n = 24) or because of malpositioning (n = 2). The most commonly injured nerves were the brachial plexus, radial, sciatic, femoral, or peroneal nerves. 42.9% of the patients were referred later than 6 months. A neurological deficit was present in 37 patients and neuropathic pain in 17. Two patients were lost to follow-up. Conservative treatment was applied in 23 patients because of good spontaneous recovery or compensation or because of expected bad prognosis whatever the treatment. Surgical treatment was performed in 17 patients because of known nerve section (n = 2), persistent neurological deficit (n = 12) or invalidating neuropathic pain (n = 3); nerve reconstruction with grafts (n = 8) and neurolysis (n = 8) were the most common procedures. Outcome was satisfactory in 50%. Potential reasons of poor outcome were a very proximal injury, placement of very long grafts, delayed referral and predominance of neuropathic pain. According to the literature delayed referral of iNI for treatment is frequent. We provide an illustrative case of a young girl operated on at 6.5 months for femoral nerve reconstruction with grafts while nerve section was obvious from the operative note and pathological tissue analysis. Litigation claims (n = 10) resulted in malpractice (n = 2) or therapeutic alea (n = 5) (3 unavailable conclusions). i CONCLUSIONS: NI can result in considerable disability, pain and litigation. Optimal management is required.

European women in neurosurgery: I - A chronology of trailblazers.

Neurosurgery as a distinct speciality has been around for 100 years. Some of the earliest women neurosurgeons were European, emerging from the 1920's onwards. Here we detail the rise of women in neurosurgery across Europe with a decade by decade account of big events and firsts across the continent. The emerging themes are seen in stories of pioneers with enormous resilience, camaraderie, trailblazing and triumphing in a system with great obstacles and challenges. Our journey through this chronology brings us to the modern day, where most European countries have or have had a woman neurosurgeon and the future for women in neurosurgery in the continent is very bright.

European women in neurosurgery: II - Historical characters and living legends.

A collaborative global working group of women neurosurgeons in multiple countries at different stages of their neurosurgical careers undertook the task of researching the history of European women in neurosurgery. While doing so, we happened upon many remarkable female neurosurgeons who overcame great adversity, made tremendous contributions to society and institutional neurosurgery, and displayed numerous talents beyond the operating room. In the first part of this paper, we recounted a chronology of female neurosurgeons in Europe, highlighting the most remarkable achievements of women in every decade, from the 1920's to 2020. In this paper, we honor fascinating women in European neurosurgery, both historical characters and living legends. These women have overcome great adversity and have also excelled in a huge variety of pursuits. While some were themselves refugees, we also have uncovered noteworthy examples of women who immersed themselves in humanitarian missions and who tried to better the world through political action. There are stories of women beating the odds, taking on biased institutions and proving their worth, in spite of the prevailing system. Most inspirational, we have discovered through our comprehensive research on the history of women in European neurosurgery that the future is increasingly female.

Pseudomalignant Myositis Ossificans of the Neck in a Child: Case Report and Review of the Literature.

BACKGROUND: Myositis ossificans is a benign process of heterotopic bone formation developing in soft tissues that can mimic malignancy. Differential diagnosis can be difficult without a biopsy when it originates in atypical locations. CASE DESCRIPTION: A 5½-year-old boy was admitted for a cervical tumor causing torticollis. The nodular tumor developed at the lateral border of the right C3-4 foramen, had calcification/ossification at its periphery, and was accompanied by a huge edematous reaction of the scalene muscles. The patient underwent an extensive work-up by pediatric oncologists. A biopsy was requested because of high suspicion of malignancy. At surgery, the lesion was benign on frozen sections and was completely resected, allowing the diagnosis of myositis ossificans. The patient made a rapid and complete recovery. CONCLUSIONS: Myositis ossificans circumscripta is rare in children, especially in the neck region. The diagnostic challenge is to differentiate it from bone and soft tissue malignancies. Appropriate management, including surgery if needed, leads to an excellent outcome. Another concern is to exclude fibrodysplasia ossificans progressiva when atraumatic myositis ossificans develops in a young child in the neck or shoulder region.

Classical pituitary tumour apoplexy: clinical features, management and outcomes in a series of 24 patients.

We retrospectively analysed the incidence, clinical presentation, endocrinological and radiological findings, medical and surgical management of pituitary apoplexy in our department (single-centre study), having a large experience in pituitary surgery. Among 1540 pituitary lesions, 24 patients presented with pituitary apoplexy. Their charts were retrospectively reviewed. The symptoms included headache (92%), nausea and vomiting (54%), visual deficit (50%), oculomotor paresis (54%) and/or an altered mental state (42%). Skull X-rays (n = 14) demonstrated an enlarged sella turcica in all cases; CT-scan and/or MRI always revealed a sellar and suprasellar expanding lesion. Panhypopituitarism was present on admission in 70% of the patients. Urgent therapeutic management included high-dose cortisone treatment in all but one patients and CSF drainage in three. Three patients were treated conservatively. Nine patients were operated on rapidly, within hours or a few days because of severe visual deficit and/or altered level of consciousness. Nineteen patients were operated by the trans-sphenoidal approach; one of them required a second operation by craniotomy. There were two deaths related to the illness and one to an ill-defined reason at 4 months. Among the other patients 95% made a good recovery. All but two patients required a substitutive treatment with adrenal (83%), thyroid (68%), gonadal (42%) and/or growth (16%) hormones. The preoperative visual deficits recovered in all but one patients (92%) whereas the oculomotor pareses improved in all but two patients (85%). In conclusion, pituitary tumour apoplexy is a rare event, complicating in our series 1.6% of 1540 pituitary adenomas. Even in severe cases, complete recovery is possible if the diagnosis is rapidly obtained and adequate management is initiated in time. Surgical results after trans-sphenoidal approach are in the majority of cases very satisfactory.

Brachial plexus injury: a survey of 100 consecutive cases from a single service.

OBJECTIVE: We analyzed the epidemiology, preoperative management, operative findings, operative treatment, and postoperative results in a group of 99 patients who sustained 100 injuries to the brachial plexus. METHODS: The charts of 100 consecutive surgical patients with brachial plexus injuries were reviewed. RESULTS: The patient group comprised 80 males and 19 females ranging from 5 to 70 years of age. One male patient had bilateral brachial plexus palsy. Causes of injury were largely sudden displacement of head, neck, and shoulder and included 27 motorcycle accidents. There were 23 open wounds, including 8 gunshot wounds, 6 other penetrating wounds, and 9 wounds caused by operative or iatrogenic trauma. Loss was exhibited at C5-C6 in 19 patients, at C5-C7 in 15 patients, and at C5-T1 in 39 patients, and 8 patients had another spinal root pattern of injury. Nineteen patients had injury at the cord or the cord to nerve level. Associated major trauma was present in 59 patients. Emergency surgery for vessel or nerve repair was necessary in 18 patients. Myelography (n = 57) or magnetic resonance imaging (n = 7) revealed at least one root abnormality in 52 patients. The median interval from trauma to operation was 7 months. Operative exposures used included anterior supraclavicular, infraclavicular, combined supra- and infraclavicular, or a posterior approach in 5, 14, 77, and 4 patients, respectively. The surgical procedures performed included neurolysis alone in 12 patients and nerve grafting, end-to-end anastomosis, and/or neurotization in 81, 5, and 47 patients, respectively. Postoperative follow-up of at least 36 months was conducted in 78% of the patients. Grade 3 recovery according to Louisiana State University Medical Center criteria means contraction of proximal muscles against some resistance and of distal muscles against at least gravity. Among the 18 patients with open wounds, 14 (78%) recovered to a Grade 3 or better level, as did 35 (58%) of 60 patients with stretch injuries. In all cases of C5-C6 stretch injuries repaired by nerve grafting (n = 10), the patients recovered useful arm function. CONCLUSION: Brachial plexus injury represents a severe, difficult-to-handle traumatic event. The incidence of such injuries and the indications for surgery have increased during recent years. Graft repair and neurotization procedures play an important role in the treatment of patients with such injuries.

Primary central nervous system lymphoma report of 32 cases and review of the literature.

We retrospectively analyzed 32 cases of primary central nervous system lymphoma (PCNSL). Five cases were diagnosed in the period 1987-1994, for 27 cases in the period 1995-2002. There were 17 men and 15 women whose median age was 69 years. Three patients were immunodeficient. The commonest symptoms were focal deficit (16 patients) and cognitive/behaviour disturbances (14 patients). Radiologically, a total of 47 contrast-enhancing lesions were observed in 32 patients; 18 patients had deep-seated lesions. All but two patients underwent histological diagnosis following craniotomy (11 patients) and/or stereotaxic biopsy (22 patients); diagnosis was obtained on CSF cytology in one patient with a third ventricle tumour. In the last patient, the diagnosis was based on the finding of marked tumour shrinkage under corticotherapy, despite two negative histological examinations. Treatment included surgical resection (10 patients), chemotherapy (25 patients) and/or radiotherapy (12 patients). According to the therapeutic recommendations of the GELA (Groupe d'Etude des Lymphomes de l'Adulte), 19 patients received at least two courses of high-dose methotrexate; intrathecal chemotherapy was used in 20 patients with methotrexate and/or cytosine arabinoside. Radiation therapy consisted of whole brain irradiation followed by a boost on tumour site. Nine patients received a combined treatment of chemotherapy and radiotherapy. Twelve patients showed rapid progression to death. At the time of last contact, 28/32 patients (88%) had died, all from PCNSL disease or from complications due to its treatment. The median survival time was 13.9 months. We conclude that PCNSL is an increasingly frequent tumour. The diagnosis is obtained by stereotactic biopsy in the majority of cases. The prognosis appears dismal despite an intensive multidisciplinary therapeutic approach.

Surgical management of anterior cranial base fractures with cerebrospinal fluid fistulae: a single-institution experience.

OBJECTIVE: The management of cerebrospinal fluid (CSF) fistulae after anterior cranial base fracture remains a surgical challenge. We reviewed our results in the repair of CSF fistulae complicating multiple anterior cranial base fractures via a combined intracranial extradural and intradural approach and describe a treatment algorithm derived from this experience. METHODS: We retrospectively reviewed the files of 209 patients with an anterior cranial base fracture complicated by a CSF fistula who were admitted between 1980 and 2003 to Liège State University Hospital. Among those patients, 109 had a persistent CSF leak or radiological signs of an unhealed dural tear. All underwent the same surgical procedure, with combined extradural and intradural closure of the dural tear. RESULTS: Of the 109 patients, 98 patients (90%) were cured after the first operation. Persistent postoperative CSF rhinorrhea occurred in 11 patients (10%), necessitating an early complementary surgery via a transsphenoidal approach (7 patients) or a second-look intracranial approach (4 patients). No postoperative neurological deterioration attributable to increasing frontocerebral edema occurred. During the mean follow-up period of 36 months, recurrence of CSF fistula was observed in five patients and required an additional surgical repair procedure. CONCLUSION: The closure of CSF fistulae after an anterior cranial base fracture via a combined intracranial extradural and intradural approach, which allows the visualization and repair of the entire anterior base, is safe and effective. It is essentially indicated for patients with extensive bone defects in the cranial base, multiple fractures of the ethmoid bone and the posterior wall of the frontal sinus, cranial nerve involvement, associated lesions necessitating surgery such as intracranial hematomas, and post-traumatic intracranial infection. Rhinorrhea caused by a precisely located small tear may be treated with endoscopy.

Intrasellar arachnoid cysts.

OBJECTIVE: To evaluate the clinical, endocrinological, and radiological presentation of nine cases of surgically verified intrasellar arachnoid cysts and to discuss the physiopathological mechanisms of formation of these cysts. METHODS: Among 1540 patients presenting with pituitary lesions, nine presented with an intrasellar arachnoid cyst. Their charts were retrospectively reviewed. RESULTS: Presenting symptoms included headache (n = 2), visual symptoms (n = 3), menstrual irregularities (n = 2), rapid weight gain (n = 1), vertigo (n = 1), and/or confusion (n = 1). Two cysts were discovered incidentally. T1-weighted magnetic resonance imaging scans showed an intrasellar cystic lesion in all cases, with a huge suprasellar extension in six cases. The cyst was of the same intensity as the cerebrospinal fluid (CSF) in only two patients. A transsphenoidal approach allowed the transdural aspiration of fluid and injection of a water-soluble contrast agent under mild pressure. In three patients, the contrast infiltrated along the pituitary stalk toward the subarachnoid spaces; in the other patients, it remained in the intrasellar compartment. Cyst membranes were removed as completely as possible with fenestration toward the subarachnoid spaces in communicating cysts. In spite of tight packing of the sella and sphenoid sinus, CSF fistulae requiring reoperation developed in two patients. CONCLUSION: The clinical picture of an intrasellar arachnoid cyst resembles that of a nonfunctional pituitary adenoma. Magnetic resonance imaging scans typically show a cystic intrasellar lesion with suprasellar extension, containing isointense or, more often, hyperintense fluid on T1-weighted sequences. In spite of the risk of CSF fistulae, the preferred surgical approach is transsphenoidal. A physiopathological mechanism is proposed according to anatomic variations of the sellar diaphragma allowing penetration of subarachnoid spaces into the sellar compartment and their enlargement by a ball-valve mechanism.

Development of a reconstituted nerve in a three-dimensional collagen gel under tension populated with fibroblasts and Schwann cells.

Our aim is to devise an artificially reconstituted nerve segment made of a three-dimensional collagen gel populated with aligned fibroblasts and Schwann cells. Collagen lattices were prepared by mixing concentrated medium, a type I collagen solution and rat Schwann cells (SC), rat neural fibroblasts (nF) or human dermal fibroblasts (dF) and allowed to polymerize at 37 degrees C. In these free-floating lattices, nF and dF retracted the gel more than SC. All cells appeared to be elongated and oriented at random. Rat cells obtained by enzymatic digestion of nerves undergoing wallerian degeneration retracted the gel at a larger extent than cells from intact nerves. Rectangular lattices restrained at each extremity acquired a paraboloid shape upon retraction by neural or dermal F reflecting the mechanical tension developed by these cells on their support. Adult SC alone produced a faint paraboloid even at high cell density while SC associated with nF developed a paraboloid similar to that obtained with nF alone. The mechanical force developed by dermal F and SC in the restrained lattice was measured by strain gauges and found much higher for F than for SC. In restrained lattices, both types of F were elongated and aligned to the long axis of the gel while SC elongated but not necessarily in a parallel fashion. The central portion of a mixed nF-SC collagen restrained lattice produces a flattened cylindric segment made of longitudinally oriented col-lagen fibrils, F and SC, which could represent a promising material for preparation of nerve grafts. An original plastic mould was devised to allow the preparation of cylindrical segments of free or restrained collagen lattices in view of in vitro and in vivo regeneration studies.