Neuroembolization may expose patients to radiation doses previously linked to tumor induction.

OBJECTIVE: Epidemiological studies indicate a link between low-dose irradiation (<10,000 mGy) to the head and the local occurrence of tumors after decades of delay. Comparable radiation doses can be reached during neuro-endovascular procedures (NEP), but the incidence of similar exposures has not been completely delineated. We compared the levels of radiation to the head measured during NEP to those reported for patients developing radiation-induced cancers. METHODS: In our prospective study we determined the cumulative maximum entrance skin doses (MESD) and the incidence of epilation in 107 consecutive patients submitted to NEP between 2003 and 2007. We also extensively searched the literature and compared our results with the data we found. RESULTS: The cumulative MESD due to NEP was above 3,000 mGy (range 3,101-5,421 mGy) in 18 patients. In 22 we observed partial epilation within 10 weeks from the initial NEP. Sixty cases of epilation after NEP have been previously reported in the literature. The average of the reported MESD was 4,241 mGy (range 2,000-6,640 mGy). CONCLUSION: Physical dosimetry and the incidence of partial epilation indicate that about one fifth of the patients submitted to NEP received radiation doses comparable to those linked to the occurrence of tumors. The potential risks of developing tumors after a long delay, when compared to the immediate benefits of endovascular treatment of aneurysm and arteriovenous malformations (AVM) of the brain, do not counterindicate NEP, but increased awareness of the risk should help physicians and patients to make a fully informed decision when other treatments are available.

Adjuvant temozolomide chemotherapy for treatment of papillary tumor of the pineal region.

BACKGROUND: We present a personal case of papillary pineocytoma in a 42-year-old woman. METHODS: The lesion was first treated surgically both for diagnostic aims and for resolution of the mass effect causing hydrocephalus and correlated neurological disturbances. Because the tumor recurred after surgery and radiotherapy, we decided to further treat the patient with chemotherapy, in particular with temozolomide. RESULTS: Currently, almost 9 years after the first treatment, the patient is symptom-free and follow-up magnetic resonance imaging shows no tumor recurrence. CONCLUSION: Although surgery should be considered the first-choice therapy, we think that temozolomide can be a valid option in case of recurrence of these rare tumors.

Central and peripheral components of writing critically depend on a defined area of the dominant superior parietal gyrus.

Classical neuropsychological models of writing separate central (linguistic) processes common to oral spelling, writing and typing from peripheral (motor) processes that are modality specific. Damage to the left superior parietal gyrus, an area of the cortex involved in peripheral processes specific to handwriting, should generate distorted graphemes but not misspelled words, while damage to other areas of the cortex like the frontal lobe should produce alterations in written and oral spelling without distorted graphemes. We describe the clinical and neuropsychological features of a patient with combined agraphia for handwriting and typewriting bearing a small glioblastoma in the left parietal lobe. His agraphia resolved after antiedema therapy and we tested by bipolar cortical stimulation his handwriting abilities during an awake neurosurgical procedure. We found that we could reversibly re-induce the same defects of writing by stimulating during surgery a limited area of the superior parietal gyrus in the same patient and in an independent patient that was never agraphic before the operation. In those patients stimulation caused spelling errors, poorly formed letters and in some cases a complete cessation of writing with minimal or no effects on oral spelling. Our results suggest that stimulating a specific area in the superior parietal gyrus we can generate different patterns of agraphia. Moreover, our findings also suggest that some of the central processes specific for typing and handwriting converge with motor processes at least in the limited portion of the superior parietal gyrus we mapped in our patients.

EDG3 and SHC3 on chromosome 9q22 are co-amplified in human ependymomas.

By qPCR we found that EDG3 and SHC3 were amplified in 60% of ependymomas but none in choroid plexus papillomas. In ependymomas EDG3 and SHC3 amplification increased Shc3 protein levels while EDG3 was less affected. Both proteins were co-immunoprecipitated from ependymoma and Shc3 was tyrosine phosphorylated thus presumably active. We showed by digestion with N-glycosidase-F that EDG3 was glycosylated indicating that EDG3 protein was not retained in the endoplasmic reticulum. The co-immunoprecipitation of Shc3 and EDG3 proteins from ependymomas with amplification of SHC3 and EDG3 genes suggests that the two proteins co-operate and are important for ependymomas in vivo.

Endoscope-assisted infratentorial-supracerebellar approach to the third ventricle: an anatomical study.

OBJECT: The authors studied the microsurgical anatomy and endoscopic features of the pineal region and third ventricle to describe a combined microsurgical-endoscopic infratentorial-supracerebellar approach to the posterior third ventricle. Such an approach exposes the pineal gland and its complex neurovascular structures so that the third ventricle can be reached through a minimally invasive parapineal incision. METHODS: The approach was studied in 10 adult cadaveric heads, six fresh and four formalin fixed, by using an operative microscope with a magnification level of 6 to 40 and the assistance of an endoscope. The endoscope-assisted infratentorial-supracerebellar approach affords a complete view of the third ventricle from a posterior perspective. The third ventricle is entered through a parapineal incision using the natural space between the internal cerebral vein and the vein of Rosenthal located above the superior colliculi. CONCLUSIONS: The infratentorial-supracerebellar approach to the third ventricle follows a natural corridor and requires minimal retraction and resection of critical neural structures. With the use of the endoscope, an unsurpassed view into the third ventricle from a posterior perspective is obtained.

Shc3 affects human high-grade astrocytomas survival.

A selective switch from expression of Shc1 gene to Shc3 occurs with maturation of neuronal precursors into postmitotic neurons. Previous studies showed that in the embryo, Shc1 is maximally expressed in dividing CNS stem cells while it is silenced in mature neurons, where it is replaced by Shc3. Under normal conditions Shc3 is never expressed by glial cells. We now show that in human astrocytomas and glioblastomas, the normal pattern of expression of Shc1/Shc3 is totally subverted, both proteins being present at the same time and in the same cells. Our data indicate that Shc3 is maximally expressed, together with Shc1, in glioblastoma, a highly proliferative tumor with little, if any, indication of neuronal differentiation. In primary cultures of glioblastoma, tumor cells maintain Shc1 expression but downregulate Shc3. Analysis of the phosphorylation status of Shc3 in human glioblastoma tumor samples in vivo indicates that it is tyrosine phosphorylated. Finally, we found that the expression of truncated variants of Shc3 with dominant-negative effects in human high-grade glioma cells that maintain Shc3 expression in vitro leads to a decreased Akt posphorylation and increased apoptosis, thus resulting in impaired survival of the transfected cells. These data suggest that Shc molecules play an important role in glioblastoma cell growth and survival.

Acute brainstem dissection of syringomyelia associated with cervical intramedullary neurinoma.

Intramedullary tumors and syringomyelia typically present with slowly progressing deficits. More rarely, they are characterized by acute presentation or worsening, at times mimicking other more common etiologies. The acute onset of syringomyelia is most likely attributable to an acute increase in cerebrospinal fluid and epidural venous pressure that results in impulsive fluid movement and, ultimately, in the rupture of the syrinx and dissection into the spinal cord or brainstem. Reported here is a case of acute presentation of a small cervical intramedullary neurinoma due to the upward dissection of its associated syrinx. Critical questions are: (1) how can a small tumor produce a large syrinx? and (2) in the absence of craniospinal interferences, which mechanism underlies the acute expansion of the cavity, resulting in a rapid onset? The authors examined the pathophysiology of syrinx formation and enlargement in intramedullary tumors and reviewed the literature, emphasizing the relationship between spinal cord movements and intramedullary pressure. On the basis of current pathogenetic concepts, the authors concluded that tumor-related syringomyelia might be caused by an association of mechanisms, both from within (obstruction of perivascular spaces; increase in extracellular fluid viscosity due to the tumor itself; intramedullary pressure gradients among different cord levels and between the cord and the subarachnoid space) and from without (the cerebrospinal fluid entering the tissue). All these factors may be amplified, as in the reported case, by a tumor located dorsally at the cervical level. Abnormal postures of the spine, such as a prolonged and excessive flexed neck position, may ultimately contribute to the acute dissection of the syrinx.

Surgery for intracranial meningiomas in the elderly: a clinical-radiological grading system as a predictor of outcome.

OBJECT: A grading system, called the Clinical-Radiological Grading System (CRGS), has been developed to standardize surgical indications in elderly patients harboring intracranial meningiomas. Patients with a score lower than 10 had a bad prognosis regardless of surgical treatment, those with a score between 10 and 12 had a prognosis positively influenced by surgery, and those with a score higher than 12 had a good prognosis regardless of surgical treatment. The authors performed a prospective cross-sectional study to validate further the use of the CRGS as a clinical tool to orientate surgical decision making in elderly patients and to explore prognostic factors of survival. METHODS: From 1990 to 2000 the authors consecutively recruited and surgically treated 90 patients 70 years of age or older with neuroimaging findings of intracranial meningiomas and a preoperative evaluation based on the CRGS. The surgical mortality rate, which covers deaths within 3 months after surgical intervention, was 7.8%, and the 1-year mortality rate was 15.6%. Female sex and a higher CRGS score were associated with a higher probability of survival. Among the different subset items of the CRGS score, no peritumoral edema for surgical survival and no concomitant diseases for 1-year survival provide the strongest predictive contribution, even if not at a statistically significant level. CONCLUSIONS: The CRGS score is a useful and practical tool for the selection of elderly patients affected by intracranial meningiomas as surgical candidates. A CRGS score higher than 10 and female sex are good prognostic factors of survival. whereas age is not a contraindication to surgery.

Two-level anterior cervical discectomy and cage-assisted fusion without plates.

OBJECT: Anterior cervical discectomy (ACD) is an effective and safe treatment for nerve root or spinal cord compression caused by disc herniation or spondylosis. Cervical interbody fusion allows preservation of the physiological lordosis and stability of the cervical spine. Based on data reported in the literature, fusion rates decrease significantly when more than one level undergoes surgery, and some authors recommend the addition of a plate system to improve results. At the authors' institution cervical carbon fiber cages (CFCs) are routinely used after ACD. They describe their experience in the treatment of 24 patients with two-level disease treated with CFCs alone. METHODS: Twenty-one patients with cervical radiculopathy and three with radiculomyelopathy underwent ACD. Surgery was performed at C5-6 and C6-7 in 18, at C4-5 and C5-6 in four, and at C3-4 and C5-6 in two patients. All the patients underwent magnetic resonance imaging and 15 also underwent computerized tomography (CT) to assess the results of surgery. Radiculopathy improved after surgery in all the cases, whereas myelopathy resolved in only one patient. At 1 year fusion was achieved in 96% of the surgically treated discs; this was verified on cervical spine x-ray films in all patients and on CT scans in three patients. Cervical lordosis was restored in eight of the nine patients in whom it was lost preoperatively. No complications related to cage extrusion and no cases of symptomatic pseudarthrosis were observed. CONCLUSIONS: Interbody fusion cages have a load-sharing function and stabilize the spine to increase segmental stiffness, thus achieving fusion rates similar to those associated with bone grafts, even in multilevel disease.