First-line stereotactic treatment of thalamic abscesses: report of three cases and review of the literature.

Solitary pyogenic thalamic and basal ganglia abscesses are relatively uncommon. Even if widespread antibiotic therapy and modern imaging technologies combined with minimally invasive techniques have improved the outcome in patients with brain abscesses, this is counterbalanced by an increasing population of immunocompromised patients. Basal ganglia, thalamic, brainstem or multiple abscesses are usually of hematogenous origin with an underlying source of infection which can include congenital heart disease, thoracic sepsis or, less frequently, an odontogenic or otogenic source. However, no evident foci of sepsis or predisposing factors may be found. Only a few studies are reported in the literature, because midline abscesses are usually included in studies dealing on the treatment of abscesses in general. Different treatment options and the timing of treatment are described. We report our experience in 3 consecutive cases of thalamic abscess, treated by stereotactic puncture as the first step, followed by histological analysis, external drainage and targeted intrathecal and systemic antibiotic therapy. Deep-seated abscesses seem to behave differently as they are associated with an increased risk of intraventricular rupture and antibiotic resistance, a fact which justifies a more aggressive and immediate surgical treatment. We review the literature on this topic in the last 20 years.

Is it appropriate to redefine the indication for stereotactic brain biopsy in the MRI Era? Correlation with final histological diagnosis in supratentorial gliomas.

BACKGROUND: The aim of this study was to evaluate the advisability of modifying the indications for stereotactic brain biopsy (SBB) in high- and low-grade supratentorial glial tumors in correlation with the diagnostic accuracy of magnetic resonance imaging (MRI). MATERIALS AND METHODS: We analyzed 174 cases of supratentorial glial lesions diagnosed by MRI before biopsy. On the basis of the MRI findings the patients were divided into two groups: high-grade (n=107) and low-grade (n=67) gliomas. All patients underwent CT-guided biopsy. Only one preoperative diagnosis was allowed. RESULTS: A final histological diagnosis was achieved in 95% of the 174 cases. In the group of high-grade gliomas (HGG) there was diagnostic coincidence in 87% of cases, reaching 100% in lesions of the corpus callosum. In 11 cases (10%) the histological analysis changed the presumptive diagnosis and the consequent management. In the group of low-grade gliomas (LGG) there was diagnostic coincidence in 63% (42 cases), whereas there was discordance in 30%: 10 cases were upgraded to anaplastic astrocytoma, and in 10 cases no tumors were observed at all. CONCLUSIONS: In the future, the histological diagnosis of glial tumors will include molecular genetic definition, thus making it crucial for management using the new therapeutic options. Today, the indications for biopsy in lesions mimicking high-grade gliomas are mainly linked to the site of the tumor, coexisting differential diagnoses or more than one treatment option. In lesions of the corpus callosum, histological analysis seems not to be required in order to proceed to complementary therapies. On the contrary, in lesions where MRI findings indicate low-grade gliomas, grading is crucial also in order to avoid treatment inappropriate in non-neoplastic lesions.

Acoustic intrameatal meningiomas.

BACKGROUND: The sporadic finding of an acoustic intrameatal meningioma stimulated the authors to the present study. An analysis of the cases previously reported in the literature aimed to outline a preliminary account about biological, radiological and surgical specific hallmarks of these tumours. METHODS: Eight previous cases of meningiomas, meeting the prerequisite of origin and situation within the internal acoustic canal, have been discovered in the known literature since 1975. A further case was recently observed in our experience. The cases in the series showed no sex prevalence and in most of them the age of incidence was comprised between the fifth and sixth decade of life. Hearing loss was the prevalent symptom, lasting 1 month to 7 years before presentation. Myelocisternography, myelo-CT or high resolution CT/MR revealed no specific radiological features to distinguish small intrameatal meningiomas from the more frequently occurring vestibular schwannomas, while CT scan with bone algorithm could point out valuable indirect details for differential diagnosis. Various surgical approaches, i.e. middle fossa, translabyrinthine and retromastoid, were utilized by the different authors. RESULTS: Basing on apparent individual surgical preference, one of three different surgical routes (translabyrinthine, middle fossa, retromastoid) was chosen for 10 procedures in 9 patients. In all, except two cases the impression at surgery was of complete tumour removal. CONCLUSIONS: The possibility for meningiomas to recur and invade the surrounding bone requires a differential diagnosis from vestibular schwannomas. In the absence of intrinsic distinctive signs, radiological evaluation of peritumoral bone alterations could help diagnosis. Although the various surgical routes have often proved effective, temporal bone invasion justifies more extensive approach even in small tumours.

Conservative management of C5-C6 fracture-luxation in the elderly. Case report.

The case of a 86-year-old female victim of cervical trauma with C5-C6 fracture-luxation and bilateral locked facets is hereinafter described. The case was reputed representative of the complexity in deciding between conservative and surgical treatment in spine surgery. Conservative management would have been dictated by the additional risks linked to the age of the patient, whereas the surgical treatment would have been favored by the easy access to the anterior cervical spine for reduction and fixation. On the way to plan the definitive treatment, the patient died by pulmonary embolism. The controversial aspects and the indication to anticoagulant therapy in spinal surgery, frequently faced in the treatment of spine trauma in patients of this age group, are discussed in this case report.

Stereotactic-guided microsurgical removal of lesions without cortical appearance planned by three-dimensional CT reconstruction: limits and advantages of the frame-based technique.

Intraoperative positioning still constitutes a basic problem in the microsurgical removal of intracerebral lesions, either deep-seated or without cortical appearance. We treated different types of lesions (cavernous angiomas, intraventricular tumors, gliomas, and metastases), by combining stereotactic targeting with the standard microsurgical technique. The dedicated software for the three-dimensional reconstruction of stereotactic CT images allowed us to determine the least traumatic surgical trajectory and the exact location of the lesion intraoperatively, with minimum manipulation of healthy cerebral tissue. We believe that the main indication for this technique is the removal of small, encapsulated or well-defined lesions without cortical appearance or in critical areas, while a direct inspection of the area is still essential in order to evaluate surgical removal in the case of infiltrating tumors.

Treatment of the failed back surgery syndrome due to lumbo-sacral epidural fibrosis.

The failed back surgery syndrome (FBSS) is a severe, long-lasting, disabling and relatively frequent (5-10%) complication of lumbosacral spine surgery. Wrong level of surgery, inadequate surgical techniques, vertebral instability, recurrent disc herniation, and lumbo-sacral fibrosis are the most frequent causes of FBSS. The results after repeated surgery on recurrent disc herniations are comparable to those after the first intervention, whereas repeated surgery for fibrosis gives only 30-35% success rate, and 15-20% of the patients report worsening of the symptoms. Computerized tomography (CT) with contrast medium and, in particular, Gd-DPTA enhanced MRI have recently allowed a differentiation between these two pathologies permitting us to adopt different therapies. In 1982-92 we applied spinal cord stimulation (SCS) as a first therapy of FBSS with proven lumbo-sacral fibrosis. Fifty-five patients underwent percutaneous trial SCS with a mono/multipolar electrode placed at the level of Th9-12. In the 36 patients who had a positive response to the trial stimulation, the electrode was connected to an implantable neurostimulator. On January '94 a third party, not involved in the treatment of the patients, controlled 34 of the 36 patients with a mean follow-up of 55 months. We classified the patients reporting at least 50% pain relief and satisfaction with result as successful, and 56% of the patients fell in that category. 10 out of 34 patients were able to resume their work. The success rate was significantly higher in females (73%) than in males, and in radicular rather than axial pain. Our data have led us to consider SCS as a first choice treatment in FBSS due to lumbo-sacral fibrosis.

Therapeutic approach to the Pancoast pain syndrome.

The incidence of the Pancoast syndrome ranges from 2 to 5% of patients with lung cancer. We treated 20 cases between 1979 and 1984 with 29 procedures including percutaneous cordotomy, selective posterior radiculotomy, decompressive laminectomy, central administration of opiates, and TENS. Selective posterior radiculotomy gave the best pain relief.

Therapeutic protocol in the treatment of trigeminal neuralgia.

The ideal treatment of trigeminal neuralgia is still an open question. A recent large series reporting the results from the three available percutaneous techniques has been reviewed. Fifty consecutive cases, treated from January 1984 to January 1985, are reported. Microcompression was performed as the first approach in all cases. The other techniques were adopted only in case of failure of microcompression.

Primary intracranial esthesioneuroblastoma. Case report.

Esthesioneuroblastoma or olfactory neuroblastoma is a rare tumor of the nasal cavities and paranasal sinuses. In the majority of cases the cerebral involvement is secondary. Only ten cases have been reported in which the tumor was primarily intracranial. An eleventh case is reported and literature reviewed.