Factors affecting formation and rupture of intracranial saccular aneurysms.

Unruptured intracranial aneurysms represent a decisional challenge. Treatment risks have to be balanced against an unknown probability of rupture. A better understanding of the physiopathology is the basis for a better prediction of the natural history of an individual patient. Knowledge about the possible determining factors arises from a careful comparison between ruptured versus unruptured aneurysms and from the prospective observation and analysis of unbiased series with untreated, unruptured aneurysms. The key point is the correct identification of the determining variables for the fate of a specific aneurysm in a given individual. Thus, the increased knowledge of mechanisms of formation and eventual rupture of aneurysms should provide significant clues to the identification of rupture-prone aneurysms. Factors like structural vessel wall defects, local hemodynamic stress determined also by peculiar geometric configurations, and inflammation as trigger of a wall remodeling are crucial. In this sense the study of genetic modifiers of inflammatory responses together with the computational study of the vessel tree might contribute to identify aneurysms prone to rupture. The aim of this article is to underline the value of a unifying hypothesis that merges the role of geometry, with that of hemodynamics and of genetics as concerns vessel wall structure and inflammatory pathways.

The trans-sphenoidal resection of pituitary adenomas in elderly patients and surgical risk.

In western countries, the process of "ageing of the population" is increasingly forcing clinical medicine to find answers for pathologies affecting the elder segments of our community. In this respect, pituitary adenomas often raise difficult questions on surgical indications, since little is known about postoperative morbidity and mortality in elderly patients. The transsphenoidal endonasal approach (TNS), which is considered the gold standard for surgical resection of the majority of functioning and non-functioning pituitary adenomas, is supposed to be a low morbidity and mortality procedure in adult patients. However, only a few contradicting data are available in the literature about elderly patients. In this paper we retrospectively analyze a cohort of 43 consecutive patients aged more than 65 years, operated on for pituitary adenomas at our Institution in the years 1998-2007. These patients were treated by transsphenoidal endonasal approach (TNS) for resection of non-functioning pituitary adenomas (n = 31), GH-secreting adenomas (n = 4) and ACTH-secreting adenomas (n = 8). Clinical records reported a macroadenoma with tumour-related mass symptoms in about 80 % of patients; single or multiple pituitary deficits were present in 44 % of patients. Regarding comorbidities, cardiac disease was the most frequently observed (86 %); assessment of anaesthesiological risk indicated a moderate to severe ASA score in most patients, 11 % showing a 4-5 score. On the basis of current criteria, our retrospective analysis revealed that cure was achieved in 54 % of patients. The outcome was similar to that observed in the general population of patients undergoing transphenoidal surgery in our centre, without differences in the rate of surgical and endocrinological cure, minor and major surgical complications and hospitalization duration. In particular, no significant anaesthesiological complications were observed and no patient developed either permanent diabetes insipidus or cerebrospinal fluid rhinorrhea. In conclusion, in specialized centres the surgical treatment of pituitary adenomas via the transsphenoidal route can be a safe and effective procedure even in elderly patients.

Vertebral artery dissection in a child. Is "spontaneous" still an appropriate definition?

Though a rare cause of stroke in the general population, in almost one quarter of young patients affected by stroke cervical artery dissection (CAD) is the underlying cause. Among these cases "spontaneous" dissections, intended as non-traumatic, represent about 34% of posterior circulation arterial dissection in patients aged less than 18 years. We here describe the case of a seven-year-old boy who developed a spontaneous vertebral artery dissection (VAD) leading to occipito-mesial, thalamo-capsular and cerebellar infarction. Once a traumatic origin was excluded, clinical history and laboratory findings were further analysed: fever associated with tonsillitis during the previous week, raised inflammatory indices, a throat culture positive for beta haemolysing Streptococcus group A and high titres of streptococcal antibodies were found. This case suggests that patients with CAD referred as spontaneous deserve extensive analysis. Subjects presenting with a dissection and an underlying infection are likely to have a hyperinflammatory response (although further experience is needed). In these patients immediate start of antibiotic therapy, treatment with anti-inflammatory drugs and further a lifelong prophylaxis with antibiotics before any invasive procedure are strongly recommended.

Intracranial metastasis of testicular seminoma in an HIV-positive. Case report and review.

We present what appears to be the first case of an intracranial metastasis from testicular seminoma in an HIV-positive patient. The computed tomography and magnetic resonance imaging appearance of the lesion mimicked meningioma or lymphoma. A significant increase in the risk of testicular seminoma has been reported in AIDS patients. Whenever there is lymph-node involvement upon diagnosis of testicular seminoma, intracranial metastases may appear. After surgical removal of an intracranial metastasis from testicular seminoma, radiotherapy should be considered. Chemotherapy is to be included in the treatment of intracranial metastases from testicular seminoma with systemic involvement.

Cerebellar mature teratoma in adulthood.

Mature teratoma of the posterior cranial fossa in adults is extremely rare. We report a particularly rare case of medio-lateral cerebellar mature teratoma that became symptomatic in a middle-aged man. The CT revealed the lesion of heterogeneous density with calcifications in the solid medial portion. Only the MRI could reliably define the borders of the cystic component extending into the left cerebellar lobe. Histologically the presence of fully matured representative tissues of the 3 germ layers ensured the diagnosis of mature teratoma. We suggest that the cyst formation from progressive latent hemorrhage and/or secretion from the gland cells of the tumor, may be responsible for the clinical decompensation even in adulthood.

Isolated cervical juvenile xanthogranuloma in childhood.

STUDY DESIGN: This is a report of an exceptional case of isolated cervical juvenile xanthogranuloma in a child. OBJECTIVES: This case report draws attention to the fact that isolated xanthogranuloma of the central nervous system should be considered among possible diagnosis of subdural extramedullary spinal masses in children and young adults. SUMMARY AND BACKGROUND DATA: Isolated juvenile xanthogranuloma of the central nervous system is extremely rare. When located in the spinal canal it behaves like any extramedullary mass-occupying lesion. MRI depicts the tumor's association with adjacent structures. In cases in which a subtotal surgical removal was possible, radiotherapy has been indicated. METHODS: A three-year-old girl presented severe pain in the right shoulder and spastic tetraparesis. The MRI showed an intradural extramedullary mass homogeneously enhancing after DTPA-gadolinium infusion. Complete surgical removal of the tumor was performed through open-door laminoplasty. RESULTS: The child was pain free immediately after the surgical removal of the tumor. A gradual complete recovery of the neurologic deficits followed. Open-door laminoplasty provided sufficient operative space, and it minimized the impact on the growing spinal column. CONCLUSIONS: Isolated juvenile xanthogranuloma does not show any predilections of localization inside the central nervous system. Both intracranial and spinal juvenile xanthogranulomas appear isointense in MRI and enhance homogeneously with gadolinium. Whenever possible, total surgical removal alone seems to be curative. Otherwise, a subtotal removal of the tumor might be followed by radiotherapy. Immunohistochemical tests ensure the diagnosis.

Percutaneous treatment of gas-containing lumbar disc herniation. Report of two cases.

A limited number of cases have been reported in which gas-containing lumbar disc herniation caused compression of nerve roots. The authors describe two patients in whom computerized tomography scanning revealed a large intraspinal gas collection that appeared to be causing nerve root compression and that was successfully evacuated by percutaneous needle aspiration.

Stereotactically guided endoscopy for the treatment of arachnoid cysts.

Arachnoid cysts are well known to the neurosurgeon, and the evolution of their surgical treatment has followed technological advances in neurosurgical procedures and techniques. With the recent mastering of neuroendoscopy by the neurosurgeons, it is becoming the modality of choice for the treatment of arachnoid cysts. A neonate harboring a middle parasagittal arachnoid cyst benefited from stereotactically guided endoscopy. We report this case because of its peculiarities and introduce technical details about the procedure which are not found in the literature.

[Giant aneurysms]. / Aneurismi giganti.

Giant aneurysms (> 2.5 cm) represent only 5-7% of all aneurysms. Nevertheless, their management is rather difficult due to their atypical natural history and peculiar treatment. Clinical history of giant aneurysms does not differ from that of the smaller ones regarding the incidence of subarachnoid hemorrhage, but it is complicated by much more neurologic deficits and by the occurrence of chronic intracranial hypertension syndrome. Diagnosis is essentially based upon CT scan and MR imaging in order to detect the morphological mass features and anatomical relationships, and upon angiography to appreciate characteristics regarding arterial flow and vascular relationships. The goal of treatment lies in the exclusion of the aneurysmal sac from the blood-stream and in the reduction of the mass effect. The treatment may be either surgical, endovascular or both. The most common surgical techniques consist in the direct occlusion of the neck of the aneurysm by means of metallic clips, or by fastening or trapping the carrier vessel or by removing the aneurysmal sac with the reconstruction of the arterial aspect when severe mass effect is detectable. The use of endovascular techniques goes for occlusion of the carrier vessel with balloons or for dynamic study of the collateral vascular districts with temporary occlusions.

Localization accuracy of AC-PC line and functional pallidal target using BRW stereotactic implementation system and axial CT scanning. An experimental study.

BACKGROUND: Ventriculography is still considered an unavoidable step for functional target localization, even though this method is invasive and requires stereotactic rooms, orthogonal frames, and parallax-free X-ray equipment. In this experimental study, the authors investigated the feasibility of performing stereotactic lesions using a conventional, widely employed frame, such as the Brown-Roberts-Wells (BRW) apparatus, and computerized axial tomography (CAT) imaging. METHODS: Five ex vivo models consisting of cadaveric brains enclose in a plastic shell were fixed in a BRW frame. A simple BRW implementation was used to ensure more symmetrical placement of the basal ring. Two-millimeter plastic balls were inserted at the level of the anterior (AC) and posterior commissures (PC) and at the target in the pallidus. Their final position was measured on the anatomical specimens and compared with Schaltenbrand Atlas maps. RESULTS: The error in estimating the length of the intercommissural line ranged from 0.5 mm to 2.0 mm, with a maximum backward angulation of four degrees in predicting the AC-PC plane. Upon dissection, in four out of five cases, the balls were found within the area of the pallidus defined by Laitinen for posteroventral pallidotomy. CONCLUSIONS: The authors conclude that anatomical identification of the AC-PC line and the pallidus target, using the BRW stereotactic system and CAT axial images alone offers sufficient accuracy. They suggest that functional neurosurgery for movement disorders could be safely and successfully carried out without ventriculography if neurophysiological monitoring is also employed.

Low-cost self-irrigating bipolar forceps.

A low cost method for providing continuous saline drip in bipolar diathermy is described, which use is adaptable to any type of standard bipolar forceps. The advantages of this system versus commercially available self-irrigating forceps are reported.

Primary traumatic benign midbrain haematoma in hyperextension injuries of the head.

Primary traumatic brain stem injury occurring in isolation is not universally recognized as a distinct pathological entity which may follow a head injury. We describe two patients with clinical and radiological evidence of primary posttraumatic midbrain haemorrhage occurring in isolation associated with good recoveries. It is suggested that paramedian midbrain syndromes associated with midbrain haemorrhages should be recognized as a distinct, although unusual, complication of hyperextension injury to the head which may have a benign course.

A cervico-dorsal intramedullary epidermoid cyst. Case report and review of the literature.

Intramedullary epidermoid cysts are rarely observed. Only a little more than 30 cases have been reported in the literature. The authors have treated a 51 year-old woman with a cervico-dorsal intramedullary epidermoid tumor associated with a syringomyelia. The frequency of this lesion, its CT and MRI appearance and the possibility of a preoperative diagnosis are discussed.

Traumatic fractures of the craniovertebral junction. Management of 23 cases.

Twenty-three consecutive cases of traumatic C1-C2 fractures treated at the Department of Neurosurgery, University of Milano, are reported. Of these there were 13 cases of odontoid fractures, 6 hangman fractures, 2 anterior inferior corner fractures, 2 atlas-axis combination fractures and 2 Jefferson fractures. Almost all the patients were young people involved in motor vehicle accidents. Nineteen patients were treated with external immobilization (halo vest, Minerva) for 3-6 months while 4 odontoid fractures underwent early surgical posterior stabilization. At follow-up, 20 patients had a good fusion while 3, aged over 75 years, died due to cardiopulmonary or septic complications. The appropriate management of this type of lesion is still a matter of discussion. In our opinion the Halo device allows good stabilization after correct fracture reduction.

Treatment of non-neoplastic stenosis of the aqueduct of Sylvius with extrathecal CSF shunts.

A series of 185 patients operated on with extrathecal shunts for non-neoplastic aqueductal stenosis has been reviewed. The longterm results of 84 of them, followed-up for 2 to 20 years after primary surgery, are illustrated and critically analyzed. This study indicates that a normal mental development or normalization of mental and neurological conditions can be expected in a high percentage of patients after the CSF diversional procedure which nonetheless is still associated with a high percentage of even serious complications.

[Radiotherapy of brain tumors in childhood]. / Radioterapia dei tumori cerebrali nell'infanzia.

External radiotherapy with high energy photons in children's brain tumors improves results of surgical treatment according to their histology. Radiotherapy treatment is a decisive factor in survival time and quality of life. Undifferentiated tumors with high radiosensitivity are treated when radiotherapy is the only means for recovery; tumors presenting histologically low malignancy in which effective radiotherapy treatment is uncertain and the risk of radiotherapy damage is the predominant factor. Radiotherapists who treat children's brains which in many cases are not yet totally myelinized , must have good technical ability. Literature and personal experience show that in medulloblastomas irradiation of the entire central nervous system associated with chemotherapy gives a survival time of 5 years in 50% of the cases; in glioblastomas and anaplastic astrocytomas, fortunately rare in children, results are poor; in brainstem tumors the association of the extracranial shunt to radiotherapy has improved results of survival time at 5 years to 50%. A good quality of life is frequent and radiological effects are rare. It is clear that radiotherapy has reached its maximum. Progress is still to be made thanks to discoveries of more effective radiosensitizer or radioprotector compounds.

[Neuroradiology in cerebral gliomas]. / Neuroradiologia dei gliomi cerebrali.

CT Scan has greatly helped preoperative diagnosis in brain tumors. CT Scan alterations are found in about 95% of brain tumors and the most modern instruments can pick-up even small alterations, locate them precisely and, in 80% to 90% of the cases can give their exact extension. But precise CT-scan diagnosis in brain tumors can be done in only 80% of the cases when in a supratentorial site; about 90% in infratentorial localizations. Differential diagnosis difficulties occur with metastasis, abscesses, infarction, meningiomas, and vessel malformations. Angiography does not always solve these diagnostic problems left uncovered by CT Scan and not infrequently surgical proof is necessary.

[Radiotherapy of primary and secondary spinal tumors]. / La radioterapia dei tumori spinali primitivi e metastatici.

Radiotherapy in primary and metastatic spinal cord tumors following surgical treatment, or even without surgery, is very effective. The Authors analyse the different types of spinal tumors giving the survival time for every one. The results are related to the possible medullary damage before radiotherapy and to the sensibility of the tumor itself. The Authors emphasize the importance of two factors: 1) early diagnosis (myelography); 2) immediate therapy (high dose steroids, surgical decompression and/or radiotherapy).

Intraventricular hemorrhage: role of early ventricular drainage.

Intraventricular hemorrhage (IVH) is usually the result of life-threatening intracranial bleedings eventually leading to death. Early ventricular drainage is suggested as a possible means of reducing fatalities. The retrospective analysis of 80 patients with CT diagnosed IVHs has indeed shown that early drainage prolongs significantly survival before death but does not influence mortality. Clinical and CT grading still remain fundamental prognostic indexes accounting for the irreversible hemorrhagic lesion. Thus ICP monitoring and ventricular drainage may be useful only in selected patients with alterations of consciousness of intermediate severity and sluggish evolution.