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Questo testo è scaturito dall’idea di raccogliere in un unico volume le nozioni della patologia del sistema nervoso utili agli studenti per la loro formazione professionale. La patologia del sistema nervoso, branca assai affascinante della medicina, ha avuto negli ultimi anni un notevole impulso grazie soprattutto ai miglioramenti sia in campo diagnostico che terapeutico. Il presente testo tratta, oltre alle nozioni fondamentali di fisiopatologia, semeiologia e clinica, anche le più recenti tecniche di diagnostica neuroradiologica e neurofisiologica ed i moderni approcci terapeutici, sia medici che chirurgici. Esso è corredato da numerose immagini anatomiche e neuroradiologiche e da una selezione della più significativa e recente bibliografia. Riteniamo che il testo sia utile, oltre che agli studenti, anche a tutti coloro che esercitano la professione nel campo delle scienze neurologiche, come neurologi, neurochirurghi, neurofisiopatologi, neuroradiologi. Ringraziamo tutti coloro che hanno proficuamente collaborato nella realizzazione di questo testo che ci auguriamo abbia ampia diffusione.

Malignant brain tumours are one of the most relevant causes of morbidity and mortality across a wide range of individuals. Malignant glioma is the most common intra axial tumor in the adult. Many researches on this theme brought advances in the knowledge of gliomas biology and pathogenesis and to the development of new agents for targeted molecular therapy. Recent studies focused on either tumor metabolism analysis or epigenetic regulation in the pathogenesis or maintenance of brain tumors. This Review summarizes these developments analyzing molecular pathology and possible further developments for targeted therapies.

The transsphenoidal approach has specific indications in the management of craniopharyngiomas. Usually, it is best reserved for patients with preferably cystic extra-arachnoid-infradiaphragmatic tumors with small suprasellar extension. Moreover, it is definitely less traumatic than transcranial approaches and it has been proven to be feasible also in paediatric patients. When possible, radical removal of these tumours must be the goal of surgery, but this attitude, which reduces but not eliminates the risk of relapse, has to be counterbalanced by heavy morbidity and even mortality, especially in children. In this view, many neurosurgeons favour a more 'conservative' approach with subtotal removal followed by radiotherapy whose dramatic efficacy on craniopharyngiomas is well known. With these premises, a transsphenoidal approach is realistically applicable to a greater number of large cystic craniopharyngiomas if the aim is not radical removal, but is to drain them into the sphenoid sinus to relieve mass effect symptoms (cystosphenoidostomy), and delay radiotherapy and its detrimental effects on visual and pituitary function, especially in younger patients, to a more suitable time after surgery.

Small nodules of neoplastic cells protruding from the arachnoidal layer surrounding an intracranial meningioma, completely independent from the tumor mass, have been observed in three patients who underwent primary surgery. The high rate of recurrence for meningiomas after a seemingly total excision has been many times reported, and related to histological subtypes, tumor site, and hormonal influence. In the past meningotheliomatous cell aggregates protruding from the inner surface of the dura mater at a distance of 3 cm from the insertion of globoid meningiomas have been described, and the concept of "localized dural multifocality" emphasized. Probably this concept has to be enlarged to consider meningioma as a "neoplastic disease" with different grade of expression. The presence of unidentified macroscopic or microscopic clusters of neoplastic cells, lying around, more or less close to, the line of insertion of lesion, could render any attempt to gain a "radical" excision useless.

A case is reported of successful occlusion of a dural carotid-cavernous fistula (type D) by means of a transvenous anterior approach. Through the left angular vein, the distal superior ophthalmic vein (SOV) and the cavernous sinus were cannulated and three Gianturco coils were delivered close to the fistulous communications. Obliteration of the carotid-cavernous communication was achieved sparing the internal carotid artery and its branches. The major advantage of entering the sinus from the venous route is to preclude any damage to the artery, distal migration of the detachable balloon or of thrombi, intracavernous pseudoaneurysm formation. The trans-orbital approach may be considered chiefly when the openings are in the antero inferior compartment and the SOV is enlarged. Its applications, quite sporadic until now, probably will become more popular, mainly in treating D type fistulas, thanks to the good results achieved and to its safety.

Somatostatin is an endogenous inhibitor of hormone secretion and cell proliferation. Treatment with somatostatin analogues in humans causes a reduction in size and secretory activity of endocrine tumours, including GH-secreting pituitary adenomas. This study was aimed to characterize the intracellular mechanisms mediating the in vitro antiproliferative and antisecretory effects of somatostatin and its analogue lanreotide, on primary cultures of GH-secreting pituitary adenoma cells.Thirteen GH-secreting pituitary adenoma postsurgical specimens were analysed for somatostatin receptor (SSTR) mRNA expression and a subset of them was analysed in vitro for the effect of somatostatin on cell proliferation, assessed by means of [3H]-thymidine uptake, and GH release, using an immunoradiometric assay. Moreover, the intracellular signalling involved in such effects has been studied.All the adenomas analysed expressed at least one somatostatin receptor subtype mRNA. SSTR2 mRNA was identified in 77% of the adenomas, SSTR1 and SSTR3 in 69% and SSTR5 in 60%. Somatostatin and lanreotide inhibited cell proliferation in phorbol ester (PMA)-stimulated conditions (10/13 adenomas), as well as after fetal calf serum (3/3 adenomas) or IGF-I stimulation (2/2 adenomas). Conversely, GHRH or forskolin treatments did not significantly affect DNA synthesis in adenoma cells in the presence or absence of somatostatin (2/2 and 4/4 adenomas, respectively). Vanadate pretreatment reversed somatostatin inhibition of PMA-induced DNA synthesis suggesting an involvement of tyrosine phosphatase in this effect (2/2 adenomas); this was confirmed by the direct induction of tyrosine phosphatase activity in two adenomas after somatostatin treatment. Somatostatin and also lanreotide caused significant inhibition of phorbol ester, forskolin, GHRH and KCl-dependent increase of GH secretion in the culture medium. Moreover, voltage-sensitive calcium channel activity induced by 40 mm KCl depolarization in microfluorimetric analysis, was significantly reduced (5/5 adenomas).These data show that somatostatin and lanreotide inhibit human GH-secreting pituitary adenoma cell proliferation and hormone release in vitro, and suggest that the activation of tyrosine phosphatases may represent intracellular signals mediating the antiproliferative effects and that the inhibition of the voltage-dependent calcium channels and adenylyl cyclase activities may control GH secretion.

An experimental trial has been realized in rabbits interposing a polytetra fluoroethylene (PTFE) graft through the left carotid artery. Patency has been compared to one obtained by utilization of vein grafts in identical conditions.

Percutaneous retrogasserian glycerol rhizolysis (PRGR) became a diffuse and valuable method for treatment of trigeminal neuralgia, following its introduction by Hakanson in 1981. Its main advantages are: a) mild postoperative facial sensory loss, b) simplification of the technique, c) reduction of costs. Our results in a series of 191 patients treated between September 1983 and September 1990 are reported. The procedure was performed according to Hakanson's method with minor modifications. In 11 cases (5.7%) we failed to pierce the foramen ovale; the procedure was successfully repeated a week or two later. In 17 cases it was impossible to obtain CSF from the needle. Complete relief of pain was achieved in 177 patients (92.7%), in 124 (64.9%) immediately, in 53 (27.8%) within 6 days; the operation was unsuccessful in 14 (7.3%). Postoperative sensory evaluation showed: no sensory loss in 33 cases (17.3%); hypalgesia in 8 (4.2%); mild hypesthesia in 88 cases (46.1%), confined to the affected divisions in 45 (23.6%), exceeding it in 43 (22.5%); moderate hypesthesia in 62 cases (32.4%), restricted to the target divisions in 36 (18.8%), exceeding them in 26 (13.6%). No case of anesthesia occurred. Complications of PRGR were: circum-oral ipsilateral herpetic eruption (herpes simplex type), spontaneously and completely regressing: 63 cases (33%); minor dysesthesia, seldom reported as painful: 33 cases (17.3%); impairment of corneal reflex: 19 cases (9.9%), the first branch being the target of the treatment in 11; regressive masticatory weakness; 11 patients (5.7%); aseptic meningitis, promptly regressed: 2 cases (1.0%). Follow-up ranges from 1 to 7 years (Sept. 1983-Sept. 1990). A recurrence was observed in 44 cases (23%): in 15 patients (7.8%) a partial relapse occurred, well controlled by drug therapy and not requiring further surgical treatment; in 29 cases (15.2%) a new percutaneous procedure was required. The mean time of recurrence was 30.5 months. The recurrence rate in the patients of our series at the end of the follow-up period was 23%. Glycerol produces a weak neurolytic lesion, that generates minor post-operative facial deafferentation; it is the best technique, in our opinion, for treatment of tic douloreux.

Trans-sphenoidal surgery has a very low rate of complications despite a series of apparently negative anatomo-topographical factors. Complications may be either mechanical or functional, transitory or permanent. The most important complications are: hematoma of the focus, sub-arachnoid hemorrhage, empty sella, liquoral fistula, opto-chiasmatic lesions, arterial lesions, lesions of the cavernous sinus, parenchymal damage, nasal and paranasal mechanical lesions, insipid diabetes, hypopituitarism. The overall mortality rate is 0.4-1% and is always associated with predisposing factors, such as previous treatment, voluminous extrasellar growth, concomitant causes of disease; the most frequent causes of death are: hemorrhagic phenomena in the extrasellar portion of large size adenomas; vascular lesions involving the intracavernous carotid artery; and hypothalamic lesions. The frequency of major complications is in the region of 2.3%. Predisposing factors are: volume, consistency, invasiveness, previous treatment, intratumoral necrotic-hemorrhagic phenomena, age. Surgery is only indicated for some of the above complications, including hematoma of the focus, acute postoperative empty sella, rhinoliquorrhea resistent to conservative treatment, excessive filling of the sellar cavity. All the other possible complications are results or functional alterations which must be treated medically, even if a specific therapy only exists for some (such as early hypotonic polyuria). The series of patients reported here refers to the period 1978-1989 and accounts for a total of 259 trans-sphenoidal operations performed in 245 patients. Of the secondary operations, 6 were due to postoperative complications (hematoma of the focus in 2 cases, rhinoliquorrhea in 2 cases; empty sella and hemorrhagic infarction of a large suprasellar site in the 2 remaining cases). There were 2 deaths related to direct mechanical complications (both caused by hemorrhagic infarction of large tumoural residues and the surrounding cerebral parenchyma). Complications which did not require re-operating were observed in 11 further cases: 6 cases of persistent rhinoliquorrhea which required protracted spinal drainage; 2 cases of deterioration of previous visual deficits unrelated to either hematoma of the focus or empty sella but caused by trauma to optic structures, either directly or on a vascular basis; 3 cases of dyplopia due to oculomotory deficiency. In terms of hypophyseal function, the ex-novo onset of postoperative pan-hypopituitarism and insipid diabetes was only observed in one case.(ABSTRACT TRUNCATED AT 400 WORDS)

To examine the reliability of the diagnoses reached on multiple small fragments of cerebral glial tumors obtained via stereotactic biopsy, samples obtained from 100 consecutive glial tumors (during real or simulated biopsy) were studied by cytology and histology. In comparison to the definitive diagnosis made on the whole tumor, a correct positive diagnosis on the biopsy sample was made by histology in 96% of cases and by cytology in 93% of the cases (with 96% correct results when combining both methods). A correct identification of the tumor type and grade was achieved by histology in 82% of cases and by cytology in 80% of the cases (with 85% correct results when combining both methods). The limits of stereotactic biopsy are related to the difficulty of identifying all of the typical tumor features on tiny tissue fragments of a pleomorphic neoplasm, such as a glioma. This study demonstrates that better results may be obtained by using both cytology and histology to study multiple stereotactic biopsy samples from glial tumors.