Francesco Maiuri

Spondylodiscitis. Clinical and magnetic resonance diagnosis.

Study Design. This study reviews 65 patients with spondylodiscitis, both spontaneous and postoperative and of different etiology, studied by magnetic resonance imaging. Objectives. To define the magnetic resonance imaging characteristics of infections of the spine in acute and chronic stages and to evaluate the role of magnetic resonance imaging in defining their etiology. Background Data. Early diagnosis of spondylodiscitis is often difficult because of the long latent period. Radiographs of the spine, bone scan, and computed tomography scan provide insufficient data. Methods. Among 65 patients with spondylodiscitis studied by magnetic resonance imaging, 24 were examined in the acute stage (clinical evolution between 7 days and 20 days), and 41 were examined in the chronic stage (3‐6 weeks). The etiologic agent was staphylococcus in eight cases, Brucella in 13, Mycobacterium tuberculosis in 29, Salmonella in four, and unknown in 11. Results. In cases observed in the acute stage, the disc and the vertebral bodies were hypointense in T1 and hyperintense in T2; this relatively constant finding was not correlated with the etiologic agent. In the chronic stage, cases caused by Brucella or of unknown etiology showed long T1 and T2 relaxation times, with precocious contrast enhancement of the disc; in cases of tubercular etiology there was slight shortening of T1, with inhomogeneous enhancement of the involved vertebral bodies and late disc enhancement. Conclusions. Magnetic resonance imaging is the investigation method of choice in diagnosing spondylodiscitis, especially in very early stages of the disorder, when other investigations still yield negative results. In chronic stages, magnetic resonance imaging also allows tubercular spondylodiscitis to be distinguished from cases of different etiology.

Endoscopic third ventriculostomy in idiopathic normal pressure hydrocephalus.

OBJECTIVE:To define the role and indications for an endoscopic third ventriculostomy (ETV) in patients with idiopathic normal pressure hydrocephalus (INPH). A series of 25 patients treated by endoscopic technique was analyzed, and the results were compared with those of 14 studies reporting patients treated by shunting. METHODS:Twenty-five patients with INPH were treated by ETV from January 1994 through December 2000. All were younger than 75 years of age, had a preoperative clinical history of 1 year or less, had prevalence of gait disturbance with scarce or mild dementia, had marked ventricular enlargement on magnetic resonance imaging (MRI), and had intracranial pressure values ranging from 8 to 12 mm Hg. All were studied by a phase-contrast MRI flow study 1 month after ETV. The 14 reviewed series of patients treated by shunting (all published after 1980) each include more than 25 patients, for a total of 777 patients. RESULTS:The overall rate of neurological improvement after ETV in our series was 72% (including two patients reoperated on because of absence of flow in the MRI scan); this percentage is slightly higher than that found in the 14 series of shunted patients (66%). Gait disturbance showed a high rate of improvement when compared with other symptoms, both in our ETV study and in other shunting series. Postoperative complications occurred only in one patient (4%) with an intracerebral frontal hemorrhage and in 37.9% of patients from the series including shunted patients. CONCLUSION:In patients with INPH showing short duration of symptoms, prevalence of gait disturbance, and slight mental impairment, ETV provides similar results to those of shunting. We suggest performing ETV in these patients and reserving shunting only for those who do not improve after ETV, despite the presence of cerebrospinal fluid flow through the ventriculostomy on MRI flow studies. The good results after ETV in our series indirectly confirm that the cerebrospinal fluid absorption is good or at least sufficient in selected patients with INPH.

Supratentorial cavernous malformations and epilepsy: seizure outcome after lesionectomy on a series of 35 patients

Epilepsy is the most frequent presenting sign in patients with cavernous angiomas and is the major cause of morbility. Persistence of seizures after surgical treatment prompted many authors to examine the possibility of removing the cavernoma and the surrounding tissue. In our series of 53 cavernous angiomas, all the 35 patients with preoperative seizures underwent surgery by means of lesionectomy alone. One hundred percent of patients with less than five preoperative seizures and/or an history under 12 months was seizure free, while only 62.5% of patients with more than five seizures and/or an history longer than 12 months was seizure free. Number and duration of seizures before surgery seems to be the most important factor in the seizure outcome after surgical treatment.

Recurrences of meningiomas: predictive value of pathological features and hormonal and growth factors

SummaryObjectiveRecurrence of apparently completely resected benign meningiomas is a rather frequent event, the mechanisms of which are still unclear. The aim of this study is to define the pathological features, proliferation indexes, growth factors and hormone receptor expression in predicting the meningioma recurrence.MethodsTwo groups of 50 completely resected benign WHO I meningiomas, with and without recurrence respectively, have been reviewed. Tumor location, consistency, vascularity, and histological types have been considered. Immunohistological studies include mitotic index (MI), Ki-67 LI, estrogen and progesterone receptors (ER and PR), Vascular Endothelial Growth Factor (VEGF), Epidermal Growth Factor (EGF), and Bcl-2. All these factors have been correlated with the recurrence.ResultsThe tumor recurrence was not correlated with the patient age, tumor location, consistency, vascularity and histology. There was not difference in the histological pattern between local and diffuse recurrences. M.I. and Ki-67 LI were significantly correlated with the recurrence (P<0.0001). PR negativity had a strong predictive value of recurrence (P<0.0001), whereas the ER status was not relevant. VEGF and EGF-R were not correlated with the recurrence of meningiomas, whereas the Bcl-2 protein positivity showed a tendency to the significativity (P=0.0294). The negative association between Bcl-2 and PR is an interesting finding of our study.ConclusionsHigher MI and Ki-67 LI and PR negativity are predictive factors of recurrence of benign (WHO I) completely resected meningiomas, particularly when Bcl-2 positivity is associated.

Posterior fossa hemangioblastomas

The authors report 40 personal cases of infratentorial hemangioblastomas and review 36 series from the literature for a total number of 1023 patients. The clinical, pathological, and surgical features of these tumors are discussed, with particular consideration of localizations outside the nervous system, multicentric tumors, recurrences, and long-term results. Although hemangioblastomas are benign tumors, their high growth potential makes their long-term development unpredictable in some cases.

Endoscopic third ventriculostomy in idiopathic normal pressure hydrocephalus: An Italian multicenter study

OBJECTIVES The aim of the report is to define the indications and results of endoscopic third ventriculostomy (ETV) in idiopathic normal pressure hydrocephalus and to discuss the physiopathological mechanism of this procedure. METHODS The cases of 110 patients with idiopathic normal pressure hydrocephalus who underwent ETV in four Italian neurosurgical centers were retrospectively reviewed. The postoperative outcome was correlated with patient age, length of clinical history, preoperative clinical score, symptoms of clinical onset, type of hydrocephalus, and intraoperative findings. RESULTS The follow-up period ranged from 2 to 12 years (average, 6.5 yr). The outcome evaluation was made 2 years after the procedure. Postoperative clinical improvement occurred in 76 (69.1%) of 110 patients. There was no correlation between success rate and patient age or type of ventricular enlargement (normal or enlarged fourth ventricle). Conversely, the rate of neurological improvement was higher in patients with shorter clinical history, better preoperative neurological score, and clinical onset with gait disturbances. Moreover, the intraoperative finding of the sudden reappearance of normal cerebral pulsations and significant downward and upward movements of the third ventricular floor after ETV was also correlated with a good outcome. CONCLUSION ETV results in a relatively high rate of clinical improvement and a low complication rate in patients with idiopathic normal pressure hydrocephalus. Therefore, it may be easily performed with the same approach used for intracranial pressure monitoring with low morbidity. However, our data must be confirmed by additional studies.

Intracranial meningiomas: correlations between MR imaging and histology

The authors have examined the relationship between magnetic resonance imaging (MRI) and histopathological features in 35 surgically verified intracranial meningiomas. Tumor signals on T1-weighted images were rather similar regardless of the histologic subtype of the tumors. On T2-weighted images, hypointense meningiomas were mainly fibroblastic and hyperintense tumors were mainly syncytial and angioblastic, and partly transitional. Isointense tumors were mainly transitional and partly fibroblastic and syncytial. The authors conclude that the signal intensity of the MRI may be useful in the preoperative characterization of intracranial meningiomas. T1-weighted images may predict the presence of cysts and intratumoral blood vessels; whereas T2-weighted images can give information about histological subtype, vascularity and consistency. Meningiomas hyperintense to the cortex on T2 are usually soft, more vascular and more frequently of syncytial or angioblastic subtype; tumors hypointense or hypo-isointense on T2 tend to have a more hard consistency and are more often of fibroblastic or transitional subtype.

Cerebral gliosarcomas: correlation of computed tomographic findings, surgical aspect, pathological features, and prognosis.

The cases of 5 patients with cerebral gliosarcomas examined by computed tomography are reported and the correlations among the computed tomographic (CT) findings, the surgical and histological aspects, and the prognosis are discussed. In some patients, these tumors appear on CT scan as intracerebral lesions, with large necrotic areas and peripheral contrast enhancement; this CT aspect, similar to that of glioblastomas, corresponds to a diffusely infiltrating growth of the tumor and the prevalence of a gliomatous component. In other patients, the tumor appears on the CT scan as a hyperdense mass with well-defined margins and homogenous contrast enhancement; this CT finding, which may mimic that of a meningioma, corresponds to a rather well-demarcated surgical aspect and the prevalence of sarcomatous component. In our series, we have also noticed a more prolonged survival in a patient with a CT aspect that suggested a meningioma and prevalence of the sarcomatous component.

Cerebral edema associated with meningiomas.

Fifty patients with intracranial meningiomas have been retrospectively examined, and the cerebral edema on computed tomography scan has been correlated with the clinical evolution, size, location, and histological features of the tumor. The degree of brain edema was found to be related to the clinical evolution and the size of the tumor, whereas the histological features were less significant. These results are discussed after reviewing the data of five other series in the literature of this subject. A correlation between the tumor steroid receptors and edema is suggested.

Anomalies of the lumbosacral nerve roots.

The congenital anomalies of the lumbosacral nerve roots have frequently been found in the past as operative findings during surgery for protruded disc and are today diagnosed preoperatively with increasing frequency. They include the more cranial or more caudal origin of a nerve root, the conjoined structure of two roots and the anastomoses between two or more roots. This study reviews the large amount of literature on these anomalies and discusses their incidence, classification and embryological origin, the anatomical structure of the anomalous roots, their clinical presentation and radiological diagnosis. Anomalous nerve roots are often asymptomatic; radicular symptoms may appear in the presence of a protruded disc or lumbar stenosis, as a result of the compression or traction of the anomalous root. Myelography with water-soluble contrast media allows a good visualization of the root sheaths and thus a good diagnostic definition of these anomalies. In symptomatic cases, the surgical treatment consists of the removal of the disc hernia, associated with hemilaminectomy and foraminotomy, to obtain a good mobilization of the anomalous root; it usually results in the remission of the radicular symptoms.