Oligodendrogliomas Lacking O6-Methylguanine-DNA-Methyltransferase Expression

O6-Methylguanine-DNA-Methyltransferase (MGMT) is a DNA repair protein considered to be a chemosensitivity predictor. We evaluated the immunohistochemical MGMT expression in 28 consecutive oligodendroglial tumors (21 oligodendrogliomas, 5 mixed oligoastrocytomas, and 2 glioblastomas with prominent oligodendroglial features; 13 treated with CCNU) and compared it with that of 13 glioblastomas. Twenty-six (93%) oligodendroglial tumors were MGMT-negative, 2 (7%) were MGMT-positive. Twelve (92%) patients treated with CCNU had MGMT-negative lesions and their median survival was 73 months; 1 patient had an MGMT-positive oligodendroglioma and is alive at 28 months. Three (23%) glioblastomas were MGMT-negative and 10 (77%) MGMT-positive. The lower MGMT expression in oligodendroglial tumors compared to glioblastomas (P < 0.05), which have different chemosensitivity, suggests a possible role of MGMT in the determination of chemoresistance. Nevertheless, the heterogeneous outcome of our MGMT-negative oligodendroglial tumors treated with CCNU, indicates that MGMT expression alone is insufficient to predict the response to alkylating drugs, presumably because of the numerous mechanisms involved.

Effects of hyper-early (<12 hours) endovascular treatment of ruptured intracranial aneurysms on clinical outcome

Despite the encouraging results obtained with the endovascular treatment of ruptured intracranial aneurysms, few data are available on the effects of the timing of this approach on clinical outcome. The aim of our study was to evaluate the effects of the hyper-early timing of treatment and of pre-treatment and treatment-related variables on the clinical outcome of patients with ruptured intracranial aneurysms. Five hundred and ten patients (167 M, 343 F; mean age 56.45 years) with 557 ruptured intracranial aneurysms were treated at our institution from 2000 to 2011 immediately after their admission. The total population was divided into three groups: patients treated within 12 hours (hyper-early, group A), between 12-48 hours (early, group B) and after 48 hours (delayed, group C). A statistical analysis was carried out for global population and subgroups. Two hundred and thirty-four patients (46%) were included in group A, 172 (34%) in group B and 104 (20%) in group C. Pre-treatment variables (Hunt&Hess, Fisher grades, older age) and procedure-related variable (ischaemic/haemorrhagic complications) showed a significant correlation with worse clinical outcomes. The hyper-early treatment showed no correlation with good clinical outcomes. The incidence of intra-procedural complications was not significantly different between the three groups; 1.2% of pre-treatment rebleedings were observed. The hyper-early endovascular treatment of ruptured intracranial aneurysm does not seem to be statistically correlated with good clinical outcomes although it may reduce the incidence of pre-treatment spontaneous rebleedings without being associated with a higher risk of intra-procedural complications. However, since no significant differences in terms of clinical outcome and pre-treatment rebleeding rate were observed, a hyper-early treatment is not be supported by our data.

Five to ten years follow-up after coiling of 241 patients with acutely ruptured aneurysms. A single centre experience

Endovascular treatment has assumed a role of first choice in the management of ruptured intracranial aneurysms. We describe the clinical and morphological data after the treatment of 258 ruptured intracranial aneurysms in 241 patients, in order to evaluate the safety and the efficacy of the endovascular treatment. Two hundred and forty-one patients with saccular ruptured aneurysms were treated at our institution between 2000 and 2005. After the endovascular treatment a clinical and angiographic follow-up was conducted. The clinical follow-up was carried out with a medical examination and telephonic interviews and mRS was used for evaluation. Two hundred and forty-nine acutely ruptured aneurysms were successfully treated and immediately after the endovascular procedure 81.9% of the aneurysms resulted completely occluded, 12.1% had a residual neck and 6% revealed a residual sac. The evolution of each grade was evaluated at six months and two years. During the follow-up we observed five early and one late re-bleedings. Twenty-four patients underwent a second procedure. After the discharge and up to ten years 73.1% of patients had a good clinical outcome (mRS0-1), 8.9% died and the remainder showed moderate-severe disability (mRS2-3). The long-term stability of the anatomical result is a critic-al issue of this approach because eventual re-bleedings may occur even after several months or years. A careful clinical and radiological follow-up for up to two years after the embolization may prevent recurrences but may not be sufficient.

Evaluation of the anterior pituitary function in the acute phase after spontaneous subarachnoid hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is a potential cause of hypopituitarism. Most of the studies regarding the relationship between SAH and anterior pituitary function were retrospective and hormonal assessment was performed several months after SAH.

AIM

To prospectively evaluate the prevalence of anterior pituitary hormone deficiencies in the acute phase after spontaneous SAH and their possible correlation with clinical and radiological parameters.

METHODS

Pituitary function was tested in 60 patients within 72 h after spontaneous SAH.

RESULTS

56.9% of the patients showed at least one anterior pituitary hormone deficiency: gonadotropin and GH secretion failure represented the most prevalent hormonal deficiencies (33.3 and 22.0%, respectively), whereas ACTH and TSH deficiency was less frequent (7.1 and 1.8%, respectively). With the exception of secondary hypogonadism, the prevalence of other pituitary hormone deficiencies is in agreement with previous studies, which evaluated pituitary function on longterm follow up after SAH. No correlation was found between hypopituitarism and clinical status, as assessed with Hunt-Hess and Glascow Coma Scales. Moreover, no correlation was found between hypopituitarism and bleeding severity evaluated with Fisher's scale.

CONCLUSIONS

We demonstrated a high prevalence of anterior pituitary hormone deficiencies acutely after SAH. Although part of GH and gonadotropin deficiencies might be a consequence of functional alteration due to SAH itself, the finding of low cortisol levels in this stressful condition strongly suggests the presence of true hypocortisolism. Therefore, an evaluation of pituitary function shortly after SAH might be useful to identify a subset of patients who deserve a more accurate follow-up.

A single-institution restrospective experience of brachytherapy in the treatment of pituitary tumors: transsphenoidal approach combined with (192)Ir-afterloading catheters

BACKGROUND AND AIM

Radiotherapy may be used as an adjuvant treatment of pituitary adenomas. The aim of our study was to present our experience of multimodal treatment of pituitary adenomas, consisting in temporary implantation of (192)Ir-labeled wires following transphenoidal surgery.

SUBJECTS AND METHODS

An observational investigation was performed on a series of 80 patients undergoing surgery (S) for pituitary adenomas between 1982 and 2000, some of whom received post-operative external beam radiotherapy (EBRT) (no.=19 between 1982 and 1990), brachytherapy (B) (no.=35, all after 1991), or both irradiation modalities (EBRT+B) (no.=14). The different treatments were compared in terms of hormonal normalization in the subgroup of patients with hypersecreting adenomas, tumor control, and side effects.

RESULTS

Hormonal normalization was obtained in 84% of S+B patients and in 61% of S+EBRT patients. Tumor control was obtained in 74.3% of S+B patients and in 63.1% of S+EBRT patients. Anterior pituitary hormones deficits ranged from 8.6-34% in S+B patients and from 15.8-47.4% in S+EBRT patients, after a mean follow-up of 14 yr. The latter group also showed a higher rate of multiple deficits (42.1% vs 22.8%). Diabetes insipidus and other major complications were rare events in all groups.

CONCLUSIONS

We presented one original experience regarding brachytherapy in the management of pituitary tumors, which turned out to be effective and safe. Additional prospective, and possibly randomized, studies should clarify whether in the era of 3-dimensional conformal radiotherapy and stereotactic radiotherapy this treatment modality may still have a role.

Multi-step approach in a complex case of Cushing's syndrome and medullary thyroid carcinoma

The diagnosis of Cushing's syndrome (CS) may sometimes be cumbersome. In particular, in ACTH-dependent CS it may be difficult to distinguish between the presence of an ACTH-secreting pituitary adenoma and ectopic ACTH and/or CRH secretion. In such instances, the etiology of CS may remain unknown despite extensive diagnostic workout, and the best therapeutic option for each patient has to be determined. We report here the case of a 54-yr-old man affected by ACTH-dependent CS in association with a left adrenal adenoma and medullary thyroid carcinoma (MTC). He presented with clinical features and laboratory indexes of hypercortisolism associated with elevated levels of calcitonin. Ectopic CS due to MTC was reported previously. In our case hypercortisolism persisted after surgical treatment of MTC. Thorough diagnostic assessment was performed, in order to define the aetiology of CS. He was subjected to basal and dynamic hormonal evaluation, including bilateral inferior petrosal sinus sampling. Extensive imaging evaluation was also performed. Overall, the laboratory data together with the results of radiological procedures suggested that CS might be due to inappropriate CRH secretion. However, the source of CRH secretion in this patient remained unknown. It was then decided to remove the left adenomatous adrenal gland. Cortisol level fell and has remained within the normal range nine months after surgery. This case well depicts the complexity of the diagnostic workout, which is needed sometimes to correctly diagnose and treat CS, and suggests that monolateral adrenalectomy may represent, at least temporarily, a reasonable therapeutic option in occult ACTH-dependent hypercortisolism.

Endovascular Coiling of Aneurysm Remnants after Clipping in Patients with Follow-up. A Single Center Experience

SUMMARY

The vast majority of intracranial aneurysms can be obliterated completely with surgical clipping. However, postoperative remnants occur in about 4 to 8% of patients who undergo postoperative angiography. Endovascular embolization has been successfully performed in patients with postoperative aneurysm remnant and it may represent a therapeutic alternative to surgical reintervention. Twelve aneurysm remnants after surgical clipping were treated with endovascular embolization using GDC. All aneurysms were located in the anterior circulation. Our experience confirms the feasibility and relative safety of this treatment strategy that may be considered a valid alternative to reintervention.

Pregnancy and subarachnoid hemorrhage: a case report

Cerebrovascular diseases are rare in pregnancy and mostly caused by rupture of an arterial aneurysm. We present the case of a pregnant woman at 36 weeks of gestation who had a subarachnoid hemorrhage resulting from rupture of an unknown aneurysm, and who underwent a Cesarean section and an endovascular treatment to embolize the aneurysm.

Atypical onset of antiphospholipid syndrome in pregnancy

BACKGROUND

We present a case of an atypical onset of antiphospholipid syndrome (APS).

CASE

A woman in her 15th week gestation had a thrombosis of an unknown cerebral cavernoma, which was successfully removed. Twenty-six days after, she was admitted for a severe pain in right hypochondrium and a second class HELLP syndrome was diagnosed. Two days after, she had a fetal loss. After 1 month, laboratory tests revealed high level of antiphospholipid antibodies. At the same time, she developed a spontaneous thrombosis at her right arm. After 6 weeks, antiphospholipid antibodies, tested again, result positive.

CONCLUSION

Antiphospholipid antibodies often cause pregnancy complications, but, to our knowledge, this is the first report of an association of antiphospholipid antibodies, with cerebral cavernoma thrombosis and early onset HELLP syndrome.

[BCL-2 in primary central nervous system lymphomas. Immunohistochemistry and molecular biology]

BCL-2 is a membrane protein known to be an apoptosis inhibitor. It is the product of the bcl-2 gene located on chromosome 18. Several different tumors show BCL-2 over-expression as result of a translocation or independently from it. More than 85% of follicular lymphomas and a smaller number of diffuse large cell B lymphomas contain t(14;18) (q32;q21). The aim of this study was to investigate the immunohistochemical expression of the BCL-2 protein and to ascertain, by means of traditional PCR (Polimerase Chain Reaction), its possible dependence from t(14;18) (q32;q21) in 9 primary central nervous system lymphomas. Six cases (67%) shoved immunohistochemical BCL-2 over-expression and 3 cases (33%) had t(14;18). Precisely: 2 cases (22%) had immunohistochemical BCL-2 over-expression and t(14;18) (q32;q21); 4 cases (44%) had BCL-2 over-expression without translocation; 1 case (11%) did not show diffuse BCL-2 over-expression in presence of the traslocation; the remaining 2 cases (22%) did not demonstrate BCL-2 over-expression or t(14;18) (q32;q21). In conclusion, our results indicate primary central nervous system lymphomas frequently show BCL-2 over-expression that in some case may be related to t(14;18) (q32;q21). Nevertheless, t(14;18) (q32;q21), as evaluated by traditional PCR, may not correspond to diffuse immunohistochemical BCL-2 positivity.

Results of surgical and endovascular treatment of intracranial micro-arteriovenous malformations with emphasis on superselective angiography

BACKGROUND

The authors retrospectively reviewed the results of two different treatment modalities (surgery and endovascular approach) in patients with intracranial micro-arteriovenous malformations (micro-AVMs). The goal of this study is to evaluate the respective role of surgical treatment and superselective acrylic embolization in the management of micro-AVMs.

METHOD

Fourteen patients with micro-AVMs who had been treated by surgical resection or endovascular acrylic embolization during a 6-year period were analyzed. The average age at presentation was 44.6 years (range, 24-65 yr) with no sex dominance. All patients presented with an intracranial haemorrhage, which was superficial in twelve patients and in eloquent brain areas in seven patients. Severe neurological deficits were observed in eleven patients.

FINDINGS

Digital subtraction angiography (DSA) demonstrated micro-AVMs in eleven patients (78.5%) while in three patients (21.5%) the micro-AVM was detected only by superselective angiography (SA). Eight patients underwent surgical intervention which led to definitive resection in seven with no peri-operative morbidity. SA was performed in nine patients and followed by successful acrylic embolization of the micro-AVM in seven with haemorrhagic complications in two patients. All fourteen lesions were completely obliterated as demonstrated angiographically. Outcomes were classified according to the Modified Rankin Scale. With a mean long term clinical follow-up of 33 months (range, 8-75 mo), seven patients were Grade 0, six patients were Grade I and one patient was Grade IV.

CONCLUSIONS

SA is deemed necessary to visualize micro-AVMs in case of questionable or negative findings also at delayed DSA in young healthy patients with otherwise unexplained intracranial haemorrhage. Obliteration of micro-AVM can be accomplished either surgically or endovascularly; however, the endovascular approach is associated with a defined procedural risk for haemorrhagic complications and long term angiographic follow-up is necessary.

Spontaneous petrous carotid artery occlusive dissection treated by local fibrinolysis and stent deployment

SUMMARY

This paper reports a case of local thrombolytic therapy followed by stenting of the petrous carotid in a young woman with recurrent transient ischemic attacks from spontaneous dissection. A total of four overlapping balloon-expandable stents were delivered in two different sessions one month apart. The procedure resulted in a potentially efficacious treatment for the prevention or reduction of cerebral damages from ischemia. At followup three months later the patient was symptomfree and DSA revealed a delayed proximal small pseudoaneurysm and a carotid-cavernous fistula. At one year follow-up the patient was still symptom-free with unmodified findings at cerebral angiography.

Disappearance of cerebral arteriovenous malformations after partial endovascular embolisation: four cases with follow-up

We report four patients with late angiographic follow-up of spontaneous occlusion of residual cerebral arteriovenous malformation after partial embolisation. Discussion is focused on the possible mechanisms leading to obliteration according to the latest concepts on angioarchitectural remodelling, malformation development and evolution with a brief review of the literature.

[Atypical, aplastic, and unusual meningiomas. Morphology and incidence in 300 consecutive cases]

We morphologically studied 300 consecutive and primitive meningiomas surgically treated between march 1997 and april 2002 in order to evaluate the incidence of atypical, anaplastic, and morphologically unusual meningiomas. Two hundred and fifty-five meningiomas (85%) were WHO I, 33 (11%) were WHO II, 9 (3%) were WHO III; the remaining 3 meningiomas (1%) showed clear and diffuse oncocytic differentiation without cytologic or architectural atypia (oncocytic meningiomas). Forty-five of 255 WHO I meningiomas (18%) were infrequent histological subtypes: 18 (7%) psammomatous, 9 (4%) metaplastic, 9 (4%) secretory, 6 (2%) angiomatous, and 3 (1%) microcystic. Thirty of 33 WHO II meningiomas (91%) were atypical, 2 (6%) were clear cell meningiomas, and 1 (3%) was chordoid meningioma. Seven of 9 WHO III meningiomas (78%) were anaplastic and 2 (22%) were papillary. We evidenced the high morphological variability and the discrete occurrence of WHO I and WHO II meningiomas.

Utility of balloon-assisted guglielmi detachable coiling in the treatment of cerebral aneurysms. A single center retrospective study

SUMMARY

Balloon-assisted Guglielmi detachable coiling (BAGDC) is a new technical option developed to allow endovascular treatment of wide-necked aneurysms. Aim of the following work is to report a single center experience of BADGC of aneurysms with assessment of its efficacy and safety. BAGDC of wide-necked aneurysms (SNR close to 1) was retrospectively evaluated in 37 patients (28 females, nine males, mean age: 56.6 yrs, range: 27-81 yrs) who underwent the procedure between january 1999 and january 2002 for a total of 45 procedures on 41 aneurysms.Twenty- nine patients presented with SAH from an acutely ruptured aneurysm. In two patients BAGDC failed whereas 35 patients successfully underwent BADGC (39 aneurysms). Twenty-nine patients (31 aneurysms) were available for angiographic follow- up (mean: 10 mo, range: 3-24 mo). At the last angiographic follow-up 29/33 aneurysms (87%) resulted stable and occluded (22 aneurysms with dense and seven with loose packing of the sac and the neck), two aneurysms showed regrowth, one aneurysm showed a neck remnant and another one a sac and neck remnant. Complications directly related to the procedure occurred in five patients (three perforations, one thromboembolism, one femoral AV) with a mortality and morbility rate of 2.7 and 5.4 respectively. BAGDC is a promising adjunct to treatment of wide-necked aneurysms broadening the spectrum of indications for endovascular treament of challenging aneurysms.

Percutaneous transluminal cerebral angioplasty and stenting in acute vertebrobasilar ischemic stroke. Report of two cases

SUMMARY

Reports of cerebral transluminal angioplasty and stenting in patients with vertebrobasilar ischemic stroke are scanty. Herein we report on the use of "monorail" coronary balloon angioplasty and stent balloon mounted catheters in two patients with acute vertebrobasilar ischemic stroke, focussing on the differences and possible advantages of the "monorail" technique in comparison with the "over-the-wire" technique. In both patients, the clinical picture was characterized by progressive brainstem symptoms followed by acute loss of consciousness related to an atherothrombotic occlusion and subocclusion of the dominant intracranial vertebral artery, respectively. In one patient, superselective thrombolytic therapy and balloon angioplasty resulted in a dissection flap at the vertebrobasilar junction. The latter was treated by successful deployment of a coronary stent. In the other patient, the subocclusive lesion was directly treated by angioplasty and stenting without thrombolytic therapy. The clinical outcome was poor for one patient ("locked in" syndrome) while the other had a complete clinical recovery. In acute atherothrombotic vertebrobasilar stroke transluminal cerebral angioplasty and stenting may be successfully performed allowing vessel recanalization.

Disappearance of a cerebral arteriovenous malformation after partial endovascular embolisation

SUMMARY

The authors report the observation of a patient with a Spetzler-Martin grade 3, symptomatic, sulcal cerebral arteriovenous malformation (cAVM) of the left precuneus that after partial, uncomplicated, endovascular embolisation disappeared at 4, 6 and 12 months follow-up. Discussion focuses on the angioarchitectural remodelling of the cAVM over time according to the latest concepts on AVM development and evolution.

Which target for DBS in Parkinson's disease? Subthalamic nucleus versus globus pallidus internus

We selected 14 patients with advanced idiopathic Parkinson's disease (PD) and examined the clinical effects of STN DBS versus GPi DBS. Nine patients underwent bilateral STN DBS and five underwent bilateral GPi patients. All patients were followed for at least 12 months. The evaluation was performed on and off drug before surgery; on-drug/on-DBS and off-drug/on-DBS at 1, 3, 6 and 12 months after stereotactic surgery. At 1 and 3 months after surgery in off-drug/on-DBS condition, both groups showed an improvement in motor score (UPDRS III). Nevertheless, the results changed after long-term stimulation in the two groups. Chronic STN DBS is superior to GPi DBS in the amelioration of the clinical features and in the decrease of time spent in the off state. The efficacy in reduction of LID was comparable at 1 and 3 months after surgery, but the results were better in STN DBS after chronic stimulation. The L-dopa dose was reduced only in the STN group.

Neurofibromatosis type 2 attributable to gonosomal mosaicism in a clinically normal mother, and identification of seven novel mutations in the NF2 gene

Neurofibromatosis type 2 (NF2) is an autosomal dominant cancer syndrome that predisposes to the development of bilateral vestibular schwannomas sometimes associated with schwannomas at other locations, meningiomas, ependymomas and juvenile posterior subcapsular lenticular opacities. This disease is caused by inactivating mutations in the NF2 tumour-suppressor gene, located in 22q12. Recently, somatic mosaicism has been demonstrated in some "de novo" NF2 patients. We here report the genetic study of 33 NF2 patients from 33 unrelated Italian families. Twelve mutations were characterised, including seven newly identified mutations and five recurrent ones. Furthermore, we describe one patient with an inactivating mutation that lies in exon 13 but that is present in only a portion of the lymphocytes and, more importantly, a clinically normal individual carrying a somatic/germinal mosaicism for a nonsense mutation in exon 10 of the NF2 gene. Our results confirm the relatively high percentage of mosaicism for mutations in the NF2 gene and establish the importance of evaluating genomic DNA from several tissues, in addition to lymphocytes, so as to identify mosaicism in "de novo" NF2 patients and their relatives. In addition, the demonstration of somatic and/or gonadal mosaicism is an important tool for accurate genetic counselling in families with sporadic cases of NF2.

Surgical treatment of intracranial aneurysms in patients aged over 70: 25 years of experience

Many references and communications regarding neurosurgical topics in elderly patients underline the interest of our Unit for this subject. We already presented in 1978 a series of 75 patients over 60 years of age operated on for intracranial aneurysms; we reported a 90% of success in all the cases operated with clinical grade 1 or 2 according to Botterel grading system on admission. In 1986, during the XXXV Congress of the Italian Neurosurgical Society, we presented other 15 cases operated for intracranial aneurysm over 70 years of age. We present an upgrading of our casistic.

Two-step development of a pituitary adenoma: from hyperprolactinemic syndrome to Cushing's disease

In this report we describe the case of a young female patient with amenorrhea-galactorrhea syndrome apparently due to pituitary PRL-secreting adenoma who, after three years of dopaminergic therapy without any shrinkage of the tumor, developed true Cushing's disease. Progression from hyperprolactinemia to hypersecretion of ACTH has been rarely described and it may be due to different possibilities. However, histopathological and immunohistochemical studies of the adenoma showed a pattern of PRL negative and ACTH positive cells, excluding mixed pituitary tumor. In order to explain the progression from hyperprolactinemia with amenorrhea-galactorrhea to an ACTH hypersecretion syndrome, it must be hypothesized either pituitary stalk compression or the influence of paracrine regulation factor(s) (such as Galanine) due to an "initially silent" corticotropinoma. This case confirms that the presence of hyperprolactinemia in a patient with pituitary tumor and amenorrhea-galactorrhea syndrome is insufficient to confidently conclude for prolactinoma. Furthermore, it underlines the importance both of clinically monitoring the patient with prolactin pituitary adenoma if dopaminergic therapy does not reduce tumor volume, and of accurately and repeatedly measuring the other pituitary hormonal secretions.

Screening for mutations in the neurofibromatosis type 2 (NF2) gene in sporadic meningiomas

Meningiomas are benign tumors of the central nervous system. They are usually sporadic but can also occur associated with the neurofibromatosis type 2 (NF2) syndrome. The gene responsible for NF2, recently isolated from chromosome 22, encodes a membrane-organizing protein that shows high sequence homology to a protein family thought to link the cytoskeleton with membrane proteins. Mutations of the NF2gene have been described in sporadic meningiomas, exclusively in tumors that show loss of heterozygosity (LOH) of 22q. These preliminary results indicate that the NF2 gene is involved in the pathogenesis of at least a subset of meningiomas, where it does indeed behave as a tumor suppressor gene. In order to characterize better the role of the NF2 gene in the genesis of meningiomas we have examined the entire coding sequence of the gene in 125 meningiomas by single-strand conformational polymorphism analysis; furthermore, LOH analysis for markers of 22q has been carried out. Inactivating mutations were identified in 30% of our samples, all of which also showed LOH of 22q. The majority of mutations identified were frameshifts and nonsense mutations, which are predicted to produce a truncated or nonfunctional protein. We also found two missense and three in-frame deletions that may pinpoint specific regions of the protein critical to its function. Furthermore, the distribution of mutations throughout the gene, suggested that exons 2, 3, 5, 11 and 13 are more frequently involved. Our results reconfirm the importance of the NF2 gene in the pathogenesis of meningiomas and also suggest that there may be a nonrandom clustering of mutations throughout the gene.

Analysis of the neurofibromatosis type 2 gene in different human tumors of neuroectodermal origin

The autosomal dominant syndrome neurofibromatosis type 2 (NF2) is characterized by the development of bilateral vestibular schwannomas, meningiomas, ependymomas and gliomas. The NF2 gene, recently isolated from chromosome 22, is mutated in both sporadic and NF2 tumors such as schwannomas, meningiomas and ependymomas. Mutations of the gene have been described not only in the neoplasms usually associated with NF2, but also in 30% of the melanomas and 41 % of the mesotheliomas analyzed. In particular, the finding of mutations in melanomas supports the hypothesis that the NF2 gene is involved in the genesis of several tumor types that arise from the embryonic neural crest. In this study we examined, by single-strand conformational polymorphism (SSCP) analysis, 41 tumors of the central nervous system (11 schwannomas and 30 gliomas), 19 melanomas and 15 Merkel cell carcinoma specimens for mutations in the coding sequence of the NF2 gene. We found three inactivating mutations of the NF2 gene in schwannomas. No alterations of the gene were detected by SSCP analysis of the other tumors. These results confirm the role of NF2 in pathogenesis of schwannomas, but do not define its significance in the genesis of the other neuroectodermal tumors studied.

Somatic mutations in the neurofibromatosis type 2 gene in sporadic meningiomas

Meningiomas are benign tumors of the central nervous system. Although usually sporadic, they can occur in patients affected by the autosomal dominant syndrome, neurofibromatosis type 2 (NF2). The NF2 gene has recently been isolated from chromosome 22. The presence of germline mutations in NF2 patients and the loss of heterozygosity (LOH) on 22q in NF2 tumors support the hypothesis that the NF2 gene acts as a tumor suppressor. Cytogenetic and LOH studies have suggested that the gene responsible for the development of meningiomas is located in the region of 22q in which the NF2 gene maps. The meningiomas gene could therefore be the NF2 gene itself. Recently, somatic mutations of the NF2 gene have been identified in sporadic meningiomas, thus supporting the hypothesis that the NF2 gene is also important in meningioma pathogenesis. In this study, we analyzed sixty-one sporadic meningiomas for LOH of 22q and for mutations in the NF2 gene. LOH was detected in 36 of the 60 informative tumors. Single-strand conformational polymorphism analysis was used to identify nine mutations in five of the eight exons of the NF2 gene studied. The nine tumors with an altered NF2 gene also showed LOH for 22q markers. These results further support the hypothesis that mutations in the NF2 gene are a critical pathogenetic event in at least some meningiomas.

A further case of giant intrasellar carotid aneurysm mimicking a pituitary adenoma: the relevance of a multivariate approach in differential diagnosis

We describe a 53 year old woman who progressively showed a left extrinsic oculomotor paresis, at first suggesting ocular myasthenia, which was ruled out by a negative Tensilon test. A CT scan of the brain revealed a pituitary mass consistent with an adenoma which was confirmed by endocrinological investigation and standard MRI. Carotid angiography, performed the day before the scheduled trans-sphenoidal surgery, clearly showed a giant intrasellar aneurysm of the left carotid syphon. An extra-intracranial by-pass with occlusion of the internal carotid artery was successfully executed.

Cytogenetic studies in sporadic and multiple endocrine neoplasia type 1-associated pituitary adenomas

Four sporadic and two multiple endocrine neoplasia type 1-associated pituitary adenomas were studied. A t(1;21)(q32;22) was discovered in one of the two hereditary tumors.

Computed tomographic determination of coordinates for stereotaxis

A visual, a computer-assisted and a trigonometric method for obtaining coordinates for stereotaxis are compared. Each method had its own deficiencies and produced comparable results.

Cerebrospinal fluid rhinorrhea and unilateral nasal polyposis: a case report

We report a case of cerebrospinal fluid (CSF) rhinorrhea and unilateral polyposis in a 53-year-old woman. The clinical features, tomograms, and CT scan with Metrizamide infusion are examined. The analysis of this case evidences that: 1) A CSF can occur also after a long time (3 years) following a head injury; 2) CT cisternography with Metrizamide can demonstrate a leakage, but not always the fluid egress from the intracranial cavity; and 3) A CSF rhinorrhea may be the primary cause and not an occasional association or complication of a reactive phlogistic nasal disease.

[Computer tomography-guided stereotaxic biopsy of intracranial lesions. Simple technic for the calculation of coordinates; method for the reduction of operative risk in the critical areas of the brain]

The authors describe an original technique to calculate the coordinates for CT-guided stereotactic biopsies of brain lesions. On the basis of simple trigonometric formulas it is possible to get an accuracy of +/- 1 mm. By means of the standard software of a high precision CT and with a CT-compatible stereotactic apparatus the x, y, and z coordinates are obtained in a quick and reliable way. A further development of the trigonometric approach to the stereotactic calculations is the "double target technique". It allows to preset the path of the biopsy-device through a selected point, to reach the final target: in this way a valuable reduction of the surgical risk is afforded especially in critical areas of the brain (brain stem, pineal region etc.).

Parkinsonism caused by chronic subdural hematoma. A case report

A 48 year-old man with chronic subdural hematoma presented with a parkinsonian syndrome. Removal of the hematoma was followed by gradual disappearance of the extrapyramidal symptoms, as in other, rare, published cases.

Frequency of echocardiographic abnormalities in patients with ischemia of the carotid territory--a preliminary report

Eighty-eight consecutive patients referred to a neurosurgical Department (63 men and 25 women) aged from 14 to 68 years, with cerebral ischemia in the carotid territory were subjected to M-mode and two-dimensional echocardiography, carotid angiography and assessment of risk factors. There were 27 patients (average age 54 years) in whom carotid angiography demonstrated a probable source for the ischemia. Carotid angiography was normal in 51 of the remaining 61 (average age 39 years) while 10 revealed distant emboli. Although the incidence of "abnormal echocardiograms" was similar in the two groups (56% and 54% respectively) the spectrum of abnormalities were different. Only 5 (18%) of the 27 patients with abnormal angiograms had a potential cardiac source of emboli while 24 (39%) out of the remaining 61 patients had a potential cardiac source demonstrated at echocardiography. There was a high incidence of mitral valve prolapse (34%) in this latter group of patients. Mitral valve prolapse was not seen in the present series in patients with a probable carotid source on angiography.

Pseudoperiodic paroxysmal discharge in a case of hemorrhagic shock

We report a case of hemorrhagic shock associated with an EEG pattern resembling pseudoperiodic lateralized paroxysmal discharges, repeated focal motor seizures on the opposite side of the prevalent EEG abnormalities and consciousness disturbances in the absence of a demonstrable cerebral lesion occurring in a 45 year-old woman without a personal or familial history of epilepsy. This unusual electroclinical picture appeared inexplicably several days after the hemorrhagic shock when the laboratory data had already normalized. The only cause of this picture seemed to be brain hypoxia and the metabolic disorders consequent upon hemorrhagic shock.

Visual suppression test and ocular dysmetria: some electronystagmographic findings relevant to the assessment of size of cerebellopontine angle tumors

Patients with cerebellopontine angle tumors underwent vestibular examination, testing of voluntary fast and slow conjugate eye movements and of visual-vestibular interaction (visual suppression test--VST) by electronystagmography (ENG). Both spontaneous and evoked nystagmus (Ny) and dysmetric alterations of the voluntary conjugate eye movements are relevant to cerebellopontine pathology. This study shows that ENG may reveal damage to the vestibular brain-stem and archicerebellar structures, the ENG signs of which very often precede the clinical signs of compression. In cranial nerve VIII neuromas vestibular and oculomotor instrumental investigations yield valuable clues for early diagnosis of tumor transition from the otological to the neurosurgical stage.

[Continuous partial epilepsy in a case of cerebral abscess of long duration]

A patient affected by continuous clonus of the right half of his tongue and face with dysphasia and right hemiparesis is described. Partial continuous epilepsy of Kojewnikow was diagnosed. The CT scan showed a spreading lesion surrounded by intense oedema in the left central region, as well as a longstanding subdural hematoma complicated by osteitis. This finding lead to a diagnosis of cerebral abscess which was confirmed by surgery. In this paper it is also analyzed the cortical and/or subcortical origin of this peculiar type of epilepsia.