Petroclival Clinoidal Folds and Arachnoidal Membranes of the Anteromedial Incisural Space: Clinical Anatomy for Neuro Critical Care.

A systematic and narrative literature review was performed, focusing attention on the anatomy of the area located at the junction of the sphenoid and the basal portion of the temporal bone (petrous bone, petrous apex, upper petro-clival region) encircled by the free edge of the tentorium, the insertion of the tentorium itself to the petrous apex and the anterior and posterior clinoid processes that give rise to three distinct dural folds or ligaments: the anterior petroclinoid ligament, the posterior petroclinoid ligament and the interclinoid ligament. These dural folds constitute the posterior portion of the roof of the cavernous sinus denominated "the oculomotor triangle". The main purpose of this review study was to describe this anatomical region, particularly in the light of the relationships between the anterior margin of the free edge of the tentorium and the above-mentioned components of the sphenoid and petrous bone.

Anterior cervical corpectomy for the treatment of spondylotic myelopathy: results of a prospective double-armed study with a three-year follow-up.

BACKGROUND: Since the first description in the 1950s, cervical spondylotic myelopathy (CSM) has posed many challenges to neurosurgeons and spine surgeons. Direct comparison among different operative approaches has failed to produce valuable results due to either an insufficient number of enrolled patients or a lack of standardization of baseline conditions. This prospective double-armed non-randomized study with a 3-year follow-up involved 80 patients with degenerative cervical myelopathy surgically and conservatively treated. The primary aim was to determine the efficacy of corpectomy in mild-moderate and severe CSM and to compare the outcomes of conservative and surgical treatment. METHODS: Eighty patients were stratified into two arms, on the basis of the mJOA score: mild-moderate (mJOA ≥12) and severe myelopathy (mJOA score <12). Each arm was subdivided into two treatment groups (operative or conservative): A1, mild-moderate myelopathy treated with corpectomy; A2, mild-moderate myelopathy treated conservatively; B1, severe myelopathy treated with corpectomy; B2, severe cervical myelopathy treated conservatively. The clinical outcome was evaluated with the modified JOA score, timed 10-meter walk, Mehalic grade, motor evoked potentials, the SF-12, and further assessed by external observers blinded to the type of treatment. RESULTS: No significant differences in the recovery rates were found between the A1 and A2 groups at 6 months, although better results were recorded in the surgical groups (A1 and B1) at 12 months and at the final follow-up, as suggested by the significantly higher recovery rates. Multivariate analysis showed an inverse correlation between the duration of symptoms and the recovery rate (P<0.0001). Moreover, the preoperative timed 10-meter walk (P<0.004), the preoperative hypointensity on T1-weighted MR images (P<0.001), a higher Mehalic grade (P<0.02), the pre-treatment MEP (P<0.002), and the preoperative spinal canal diameter (P<0.004) significantly influenced the recovery rate. CONCLUSIONS: This prospective double-armed non-randomized study demonstrates that corpectomy is an effective and safe treatment, especially for severe forms of myelopathy. In mild-moderate conditions, a discrepancy between neurological improvement and expressed level of satisfaction was found. The present results also show that a multiparametric evaluation is crucial for proper patient selection for corpectomy.

The Ipsilateral Interhemispheric Transprecuneal Approach to the Atrium: Technical Considerations and Clinical Outcome on a Series of 7 Patients.

Surgical removal of tumors of the atrium is challenging due to their deep location, vascularization, and to their complex three-dimensional relationships with the highly functional white matter fibers of the region. To assess the feasibility and the effectiveness of the ipsilateral interhemispheric transprecuneus approach (IITA) for tumors involving the atrium and the posterior third of the temporal horn, a retrospective chart review of all patients who had undergone a surgical treatment for intraventricular tumors between January 2008 and January 2017 was performed, and the step-by-step approach is described. Ten patients affected by lesions of the atrium of the lateral ventricle underwent surgical treatment, seven of which were approached through the IITA. The mean age was 42.8 years (range 6-63 years). The symptoms presented included severe, drug-resistant headache (90%), lateral homonymous hemianopsia (50%), seizures (30%), and speech disturbances (30%). Histological examinations revealed seven patients with meningioma (70%), one with a metastasis (10%), one with a choroid plexus papilloma (10%) and one with a cavernoma (10%). In all cases, a gross total removal was obtained. All patients had a significant improvement in their headache. Two patients experienced a worsening of the pre-operative visual disturbances, while two patients had a significant improvement. No patients without pre-operative visual disturbances described a post-operative worsening of visual symptoms. The IITA represents a feasible approach for tumors of the atrium. The three-quarter prone position facilitates the enlargement of the interhemispheric fissure by increasing the working angle and facilitating the exposure of the lateral wall of the atrium.

Microsurgical Anatomy of the Hypoglossal Nerve in the Lateral Approaches to the Craniovertebral Junction: A Study on Fresh Non-Formalin-Fixed Human Specimens.

The aim of this anatomical study is to describe the anatomy of the hypoglossal nerve (HN) from its origin to the extracranial portion as it appears by performing a combined posterolateral and anterolateral approach to the craniovertebral junction (CVJ). Twelve fresh, non-formalin-fixed adult cadaveric heads (24 sides) were analyzed for the simulation of the combined lateral approach to the CVJ. The HN is divided into three main parts: cisternal, intracanalicular, and extracranial The anatomical relationships between the HN and other nerves, muscles, arteries and veins were carefully recorded, and some measurements were made between the HN and related structures. Thus, various landmarks were determined for the easy identification of the HN. Understanding the detailed anatomy of the HN and its relationships with the surrounding structures is crucial to prevent some complications during CVJ surgery.

Hybrid implants in anterior cervical decompressive surgery for degenerative disease.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) still represent the mainstream surgical approach in the treatment of degenerative cervical Degenerative Disc Disease (DDD), being a loss of mobility at the treated segment and adjacent segment diseases well-known complications. To overcome those complications, hybrid surgery (HS) incorporating ACDF and cervical disk arthroplasty is increasingly performed for DDD. METHODS: We retrospectively reviewed the clinical, surgical, and outcome data of 62 consecutive patients (male/female, 29/37) harboring cervical disk herniation with or without osteophytes, with radiculopathy with or without myelopathy, who underwent a cervical discectomy on two or more levels with the anterior approach with at least one disk prosthesis along with cage and plate or O Profile screwed plate. RESULTS: All the patients improved regardless of the cervical construct used. No significant relationship between different kind of prostheses as well as their surgical level, the number and the site of the cages (screwed and/or plated) was found out concerning immediate stability, dynamic prosthesis effectiveness, and clinical improvement in all the patients up to the maximum follow-up. CONCLUSIONS: Although the optimal surgical technique for cervical DDD remains controversial, HS represents a safe and effective procedure in selected patients with multilevel cervical DDD, as demonstrated by biomechanical and clinical studies and the present series. Some technical aspects should be considered when dealing with this procedure, like the drilling of the endplate, and some radiological findings have to be detected because potentially predictive of future misplacement.

The ipsilateral interhemispheric transprecuneal approach: microsurgical anatomy, indications, and neurosurgical applications.

Surgical treatment of intraventricular lesions is challenging because of their deep location, vascularization, and their complex relationships with white matter fibers. The authors undertook this study to describe the microsurgical anatomy of the white matter fibers covering the lateral wall of the atrium and temporal horn and to demonstrate how the ipsilateral interhemispheric transprecuneal approach can be safely used to remove lesions of this region sparing the anatomo-functional integrity of the fibers themselves. A detailed description of the approach including operative measurements is also given. The Klingler' technique with progressive identification of white matter fibers covering the lateral wall of the atrium and temporal horn was performed on ten formalin-fixed human hemispheres. Then, ten fresh, non-formalin-fixed non-silicon-injected adult cadaveric heads were analyzed for the simulation of the ipsilateral interhemispheric transprecuneal approach. Three illustrative cases are presented. The simulation of the interhemispheric transprecuneal approach on ten fresh non-formalin-fixed specimens showed that a 10 to 20 mm corticotomy perpendicular to the parieto-occipital sulcus at the junction with the cingulum allows a wide corridor for the exposure of the entire atrial cavity and the posterior third of the temporal horn. The ipsilateral interhemispheric transprecuneus approach represents a safe and effective option for tumors involving the atrium and the posterior third of the temporal horn.

Cervical Spondylotic Myelopathy: When and Why the Cervical Corpectomy?

BACKGROUND: Cervical spondylotic myelopathy (CSM) is a degenerative disease that represents the most common spinal cord disorder in adults. The best treatment option has remained controversial. We performed a prospective study to evaluate the clinical, radiographic, and neurophysiologic outcomes for anterior cervical corpectomy in the treatment of CSM. METHODS: From January 2011 to January 2017, 60 patients with CSM were prospectively enrolled in the present study. The patients were divided according to the modified Japanese Orthopaedic Association scale (mJOA) score into 2 groups: group A, patients with mild to moderate CSM (mJOA score ≥13); and group B, patients with severe myelopathy (mJOA score <13). Data were collected for each participating subject, including demographic information, symptoms, medical history, radiologic and neurophysiologic features, and functional impairment. RESULTS: Of the 60 patients, 35 were men (58.3%) and 25 were women (41.7%). Their average age was 57.48 ± 10.60 years. The mean symptom duration was 25.33 ± 16.00 months; range, 3-57 months). Of the 60 patients, 22 had undergone single-level corpectomy and 36 multilevel corpectomy. A significant improvement in the motor evoked potentials was observed in both groups. CONCLUSIONS: Single- and multilevel corpectomy are valid and safe options in the treatment of CSM. In the present prospective study, a statistically significant improvement in the mJOA score and neurophysiologic parameters was observed for both moderate and severe forms of CSM.

Combined transoral exoscope and OArm-assisted approach for craniovertebral junction surgery: Light and shadows in single-center experience with improving technologies.

BACKGROUND: The introduction of recent innovations in the field of intraoperative imaging and neuronavigation, such as OArm Stealth Station, allows to obtain crucial intraoperative data by performing safer and controlled surgical procedures. As part of the improvement of surgical visual magnification and wide expansion of surgical corridors, the 3D-4K exoscope (EX) represents nowadays an interesting and useful tool. Transoral approach (TOA) represents the historical gold standard direct microsurgical route to ventral craniovertebral junction (CVJ). METHODS: We herein report a preliminary experience on 6 cases of 33 patients operated by TOA concerning the simultaneous application of OArm with Stealth Navigation system (Medtronic, Memphis, TN) and imaging system along with the 3D-4K EXs in TOA for the treatment of CVJ pathologies. RESULTS: Neither intraoperative neurophysiological changes nor postoperative infections occurred, but a neurological improvement was evident in all the patients. A complete decompression along with stable instrumentation and fusion of the CVJ was accomplished in all cases at the maximum follow-up (mean: 16.8 months). CONCLUSIONS: With EX, the role of surgeon become self-sufficient with a better individual surgical freedom compared to endoscopic surgery and excellent 3D vision and magnification. OArm allows an absolutely reliable intraoperative support for a more effective CVJ decompression. Nevertheless, with OArm-assisted neuronavigation, it can be difficult to navigate C1 lateral masses and C2 isthmi, and to convert 3D into 2D real-time navigation, it can become quite complicate. Finally, the association of EX and OArm appears more time consuming compared to the old fashion one.

Schwalbe's Triangular Fossa: Normal and Pathologic Anatomy on Frozen Cadavers. Anatomo-Magnetic Resonance Imaging Comparison and Surgical Implications in Colloid Cyst Surgery.

BACKGROUND: The fornix is a region of greatest neurosurgical interest in regards to its complex anatomy and surgical approaches to this area. The objective of this study was to evaluate the morphology of the triangular recess (TR) and its role in the growth pattern of the colloid cysts (CC) within the third ventricle and in the choice of the surgical approach for their removal. Furthermore, to compare the results of the dissections with measurements performed on a magnetic resonance imaging scan. METHODS: In the anatomic study, 20 cadaveric specimens were dissected and analyzed. In the radiologic study, a magnetic resonance imaging scan was performed in 20 healthy volunteers. In the clinical study, a retrospective analysis of all the patients affected with CCs microsurgically removed at our institute between 2010 and 2018 was conducted. RESULTS: In the anatomic study, the width, height, and the area of the TR were respectively 0.31 cm, 0.33cm, and 0.051 cm2. In the radiologic study, 3 different typologies of TR were identified: open recess in ventriculomegaly (7 patients); open recess in physiologic ventricular system (3 patients); closed or blind recess (10 patients). Three different growth patterns of CCs were identified: type 1) CCs localized at the foramen of Monro growing behind the fornix and below the third ventricular roof; type 2) CCs growing rostrally between the column of fornix; and type 3) CCs growing above the plane of the third ventricular roof. CONCLUSIONS: The anatomy of the TR influences the growth pattern of CC within the ventricular cavity and determines the surgical strategy for their removal.

Meckel's Cave Meningiomas: New Classification System Focalized on Dumbbell Lesions Deriving from the Morphometric Analysis of the Posterior Petrous Apicectomy on Fresh Non-Formalin-Fixed Specimens. A Correlative Anatomoclinical Study.

BACKGROUND: The Meckel's cave (MC) is commonly affected by neoplastic lesions that often require neurosurgical treatment. We simulated the posterior petrous apicectomy (PPA) on fresh cadavers to verify the in vivo feasibility of the approach. We proposed a new classification system of MC meningioma based on the extent of middle cranial fossa (MCF) involvement. METHODS: Ten fresh, non-formalin-fixed specimens were used in this study. Through a retrosigmoid approach, 20 PPAs were performed. Subsequently, the cerebral hemispheres were removed to quantify the MCF exposure and dimensions of the suprameatal tubercle. Twenty-four patients operated on for MC meningioma were classified as follows: group 1, tumor <3 cm; group 2, tumor >3 cm. Group 2 was subdivided into to 5 subtypes: 2A, tumor of the MCF; 2B, tumor of the posterior cranial fossa; 2C, tumor of MCF and posterior cranial fossa; 2C type I, MCF <15 mm; and 2C type II, MCF >15 mm. RESULTS: The extent of MCF exposure through the PPA is 13 mm. Mean suprameatal tubercle dimensions were 10.4 mm × 3.8 mm. Mean extent of bony removal for the PPA was 10.2 mm. PPA was successfully performed in 3 patients without major neurologic sequelae. CONCLUSIONS: Preliminary results obtained with the PPA in 2C type I meningiomas are encouraging. The new classification system proposed can be useful in clinical practice, especially in the choice of the most suitable surgical approach for dumbbell meningiomas.

Anatomic Dissection of Arachnoid Membranes Encircling the Pituitary Stalk on Fresh, Non-Formalin-Fixed Specimens: Anatomoradiologic Correlations and Clinical Applications in Craniopharyngioma Surgery.

BACKGROUND: The anatomy of the arachnoid membranes and cisternal spaces around the pituitary stalk has not been yet exhaustively described and understood. In this study, we performed a detailed anatomic study on fresh, non-formalin-fixed cadavers of the arachnoid membranes encircling the pituitary stalk and correlate our anatomic findings with magnetic resonance imaging (MRI). METHODS: Ten fresh, non-formalin-fixed, non-silicon-injected adult cadaveric heads were analyzed in this study. The membrane and cisterns that were studied for our study were as follows: 1) the diaphragma sellae and its dural components; 2) the basal arachnoid membrane; 3) the Liliequist membrane with its diencephalic and mesencephalic portion; 4) the medial carotid membrane; 5) the chiasmatic cistern; and 6) the pituitary stalk. MRI examinations of the sellar region were performed in 15 healthy volunteers (9 men, mean age 40 years; and 6 women mean age, 37 years) to visualize the arachnoid membrane encircling the pituitary stalk. MRI examinations were performed with a 3-T unit. A 3-dimensional constructive interference in steady state pulse magnetic resonance sequence was used. RESULTS: All the membranes examined were visualized clearly in all the dissections performed. Their 3-dimensional organization around the pituitary stalk was clarified and confirmed by MRI. CONCLUSIONS: Our study gives a detailed description of the pituitary stalk arachnoid sheets on fresh, non-formalin-fixed cadavers. This technique allowed us to clearly identify a funnel-shaped arachnoid collar encircling the pituitary stalk and delimiting a distinct cisternal space belonging to the stalk itself.

Post-traumatic Collet-Sicard syndrome: personal observation and review of the pertinent literature with clinical, radiologic and anatomic considerations.

STUDY DESIGN: The lesion of the lower four cranial nerves, commonly called Collet-Sicard syndrome, can be caused by a blunt head and neck trauma. It may be associated to an isolated fracture of the occipital condyle or of the atlas. OBJECTIVE: The aim of this report is to assess the modality of the trauma, the type of fracture, the anatomic characteristics, the treatment and clinical results of this syndrome. We discuss 14 cases of fracture of occipital condyle and of atlas and 1 personal case. METHODS: We analyzed 14 cases collected from the literature between 1925 and 2013, reported a further personal case and performed an anatomical study of the paracondylar, atlas and styloid process region. The anatomical dissection was performed to assess the anatomic relationships in the site of transit in which the nerves IX, X, XI and XII are injured. RESULTS: A total of 14 cases of p-CSS were collected: 9 caused by a condyle fracture and 5 by an atlas fracture. The patients were 13 males and only 1 female, 10 of them had a blunt trauma due to the result of axial loading (force directed through the top of the head and through the spine) falling on the head. The nine cases with a condyle fracture were associated to the dislocation of part of it, while those with atlas fractures showed the fracture and/or disjunction of the articular mass. The anatomical evaluations reveal that the lower four cranial nerves, at their emergency, pass through a close osteo-ligamentous space in relationship to the condyle. Below they run through a little wider channel between the articular mass of C1 and the styloid process. Two cases underwent surgical procedure. All the other cases were treated conservatively with immobilization of the cervical spine. During follow-up three cases with condylar fractures were found to be clinically unchanged and six showed modest improvements while one case with atlas fracture had a complete recovery and four improved significantly. CONCLUSIONS: The p-CSS is caused by force directed through the top of the head. We suppose that the nerve injuries are due to their laceration caused by a displacement of a condyle fragment or to their compression and stretching when they pass between the lateral mass of the atlas and the styloid process. These modalities of trauma explain the better clinical results in patients affected by C1 fractures. Conservative treatment is the option of choice. Surgical option, when choosed, is not considered to fix nerve damages.

Preservation of the temporal muscle during the frontotemporoparietal approach for decompressive craniectomy: technical note.

BACKGROUND: In patients undergoing decompressive craniectomy, resection and detachment of the temporal muscle produces esthetic and functional damage, due to atrophy of the frontal portion of the temporal muscle in the temporal fossa. We have performed en-block temporal muscle detachment in decompressive craniectomy patients to avoid esthetic and functional damage to the temporal muscle. METHODS: Twenty-one patients underwent decompressive craniectomy using a frontotemporoparietal approach. Through a three-leaf clover flap skin incision, the temporal muscle was detached en-block and overturned antero-inferiorly conjoined with the frontal myocutaneous flap. A decompressive craniectomy and duraplasty were performed. A polyethylene sheet was added to prevent adherence of the temporal muscle to the dura mater. RESULTS: The decompressive craniectomy was effective in all patients. When subsequent cranioplasty was performed, the temporal muscle was easily repositioned. No complications resulted from the en-block temporal muscle detachment or the use of the polyethylene sheet. In 18 patients eligible for clinical and radiological follow-up, excellent (n = 4) or good (n = 14) esthetic results were detected. Chewing ability is considered normal by all patients. CONCLUSION: Although it requires that the patient undergo two surgical procedures, en-block detachment of the temporal muscle during decompressive craniectomy allows good esthetic and functional results.

Spine surgery in neurological lesions of the cervicothoracic junction: multicentric experience on 33 consecutive cases.

Surgical treatment of the cervico-thoracic junction (CTJ) in the spine require special evaluation due to the anatomical and biomechanical characteristics of this spinal section. The transitional zone between the mobile cervical and the relatively rigid thoracic spine can be the site of serious unstable traumas or neoplastic lesions. Frequently, injury is associated with neurological impairment due to the small caliber of the spinal canal and/or spinal cord vascular insufficiency. The authors considered 33 neurologic lesions of the CTJ (21 traumas, 10 tumors, 2 infections) treated by means of decompression, fixation, and fusion by different type of instrumentation. Surgical procedure was posterior in 26 cases, anterior in 1 and combined in 6. Major general complications were not found in patients undergoing anterior approach. Biomechanical failure was found in two patients operated by T1 body replacement and C7-T2 anterior plate. Serious cardio-respiratory complications were related to 2 polytrauma patients who underwent posterior surgery. Follow-up evaluation showed spinal stability and fusion in 88% of cases, improvement of the neurological deficits in 42% (19% improved to ASIA E), no or only occasional pain in 75% of patients. In the experience, recovery of spinal realignment and stability is essential to avoid disability due to back pain in trauma patients. In spinal tumors, back pain was related to local recurrence. Neurological outcomes can be unsatisfactory due to the initial serious impairment. There is no type of instrumentation more effective than other. In each single lesion, the most suitable type of instrumentation should be employed, considering morphology, biomechanics, and familiarity of the spinal surgeon with different implants and constructs. Therefore, we prefer to use posterior cervicothoracic fixation in T1 lesions with involvement of the vertebral body and subsequently replace the body with cage without anterior stabilization.

Intramedullary solitary fibrous tumor of dorsal spinal cord.

Solitary fibrous tumors (SFT) are rare neoplasms of mesenchymal origin involving soft tissues, mainly serosal sites; the spinal cord location is uncommon. We report a case of SFT occurring in the thoracic spinal cord, discussing histological, ultrastructural and molecular aspects. A 75-year-old woman with an MRI suggesting a dorsal intracanalar lesion was admitted to our institution. T5-T7 laminectomies were performed and an intramedullary tumor was discovered. The tumor arose within the spinal cord and was completely removed. Tumor samples were processed for histological, ultrastructural and molecular analysis (comparative genomic hybridization [CGH], methylation status of O6-methylguanine-DNA methyltransferase [MGMT], p16, deleted in colorectal cancer [DCC] and death-associated protein kinase 1 [DAPK1]). The histological examination demonstrated a proliferation of spindle-shaped cells with a collagen-matrix background. Immunohistochemical staining was positive for vimentin and CD34 and negative for S-100 and epithelial membrane antigen. A histological diagnosis of SFT was made. The ultrastructural examination showed undifferentiated cells within a collagenous matrix and sparse extravascular basement membrane. CGH analysis revealed deletion of 9p21 and losses on 2q, 3p, 16q and 19q and gains on 7q; furthermore, no aberrant methylation pattern was found in the promoter region of MGMT, p16, DCC and DAPK1 genes. On the second-year follow-up, the patient was neurologically intact. The occurrence of SFT within the spinal cord parenchyma and its histological characteristics demonstrate that SFTs are not restricted to serosal surfaces. The course of spinal cord SFT is unknown and long-term follow-up is necessary. The histological, ultrastructural and molecular findings are important for the diagnosis and the authors provide a literature review of these aspects.

Giant cell angiitis of the central nervous system with atypical presentation.

Giant cell angiitis of the CNS is an uncommon form of vasculitis. Neurological manifestations, both of the peripheral and CNS, are common. The most frequent manifestations are visual loss and stroke. Hemorrhagic onset is uncommon. Most cases have a fatal outcome and a tissue diagnosis is rarely established in life. We describe an unusual case of giant cell angiitis beginning as a hemorrhagic tumoral-like lesion. The results of the histological and ultrastructural analysis have also been reported. Our case illustrates that giant cell angiitis should be considered as a cause of intracerebral hemorrhage, particularly when associated with a relapsing and remitting disease of the CNS.

Gliomatosis cerebri type II: two case reports.

INTRODUCTION: TWO TYPES OF GLIOMATOSIS CEREBRI EXIST: Type I and Type II. We report the results of a histological and genetic study of two cases of gliomatosis cerebri Type II, correlating these results with therapy and prognosis. CASE PRESENTATION: Two patients, a 52-year-old man (Patient 1) and a 76-year-old man (Patient 2) with gliomatosis cerebri II were admitted to our institution; they underwent surgical treatment and received radiotherapy and chemotherapy. At the 24-month follow-up, Patient 1 was still alive, while Patient 2 had died. The poor prognosis of Patient 2 was underlined by molecular analysis which showed that the angiogenesis related genes VCAM1 and VEGF were overexpressed, reflecting the high degree of neovascularization. CONCLUSION: Genes involved in drug resistance and metallothioneins were highly expressed in Patient 2 and this, associated with unmethylated O6-methylguanine methyltransferase, can explain the lack of response to chemotherapy.

Correlative analysis of gene expression profile and prognosis in patients with gliomatosis cerebri.

BACKGROUND: In modern clinical neuro-oncology, the pathologic diagnoses are very challenging, creating significant clinical confusion and affecting therapeutic decisions and prognosis. METHODS: TP53 and PTEN gene sequences were analyzed, and microarray expression profiling was also performed. The authors investigated whether gene expression profiling, coupled with class prediction methodology, could be used to determine the prognosis of gliomatosis cerebri in a more consistent manner than standard pathology. RESULTS: The authors reported the results of a molecular study in 59 cases of gliomatosis cerebri, correlating these results with prognosis. The well-known prognostic factors of gliomas (ie, age, Karnofsky performance status, histology [grade 2 vs 3], and contrast enhancement) were found to be predictive of response or outcome in only a percentage of patients but not in all patients. The authors identified a 23-gene signature that was able to predict patient prognosis with microarray gene expression profiling. With the aim of producing a prognosis tool that is useful in clinical investigation, the authors studied the expression of this 23-gene signature by real-time quantitative polymerase chain reaction. Real-time expression values relative to these 23 gene features were used to build a prediction method able to distinguish patients with a good prognosis (those more likely to be responsive to therapy) from patients with a poor prognosis (those less likely to be responsive to therapy). CONCLUSIONS: The results of the current study demonstrated not only a strong association between gene expression patterns and patient survival, but also a robust replicability of these gene expression-based predictors.

Cervicothoracic postarachnoiditic hydrosyringomyelia secondary to pedicular hook dislocation: case report.

BACKGROUND: Pedicular hook dislocation is a rare complication of spinal instrumentation. We report on the first case of hydrosyringomyelia secondary to intracanalar hook displacement after scoliosis surgery. CASE DESCRIPTION: A 15-year-old girl presented to our institution with a 7-month history of persistent neck and occipital pain as well as numbness of the lower extremities and previous dorsolumbar instrumentation with dorsal pedicular hooks and lumbar screws. Magnetic resonance imaging showed intramedullary cystic cavity from C5 to T7, isointense to cerebrospinal fluid (CSF) on T1- and T2-weighted images. Computed tomographic scan showed intracanalar displacement of the left hook. On admission, the patient presented with mild weakness of the lower extremities, hypalgesia below the level of T4, and urinary disturbance. The patient underwent surgical hook removal, T4 laminectomy, and midline dural opening: the arachnoid membrane was found to be thick and adhered to the dura and dorsolateral spinal cord. The arachnoid scarring was dissected, and the cord was untethered. A small posterior-median myelotomy was performed, and a syringosubarachnoid catheter was placed into the subarachnoid space to restore CSF flow. CONCLUSIONS: Late intracanalar displacement of spinal devices is an event that may complicate spinal instrumentation for scoliosis. This case highlights the importance of correct spinal device positioning and that of careful follow-up after instrumentation to detect complications early. We also discuss the pathogenetic pathway of the postarachnoiditic syringomyelia in this case.