Benedicto Oscar Colli

Chordoma and chondrosarcoma: Similar, but quite different, skull base tumors

Chordoma and chondrosarcoma of the skull base are frequently amalgamated because of similar anatomic location, clinical presentation, and radiologic findings. The chondroid chordoma variant has been reported to carry a better prognosis. The objective of the current study was to investigate the distinctions between these 3 entities.

Cysticercosis of the central nervous system: I. Surgical treatment of cerebral cysticercosis. A 23 years experience in the hospital das clínicas of Ribeirão Preto Medical School

Cysticercosis is the most frequent parasitosis of the nervous system and nowadays it is widespread through the world. Despite the development of anticysticercal drugs (praziquantel and albendazole), their efficacy is more marked in cases with parenchymal active cysts and they do not prevent complications such as hydrocephalus. Thus, many patients with neurocysticercosis require surgical intervention, generally of palliative nature, but that may occasionally produce a cure. The clinical outcome of 180 patients with cerebral cysticercosis who underwent surgical treatment form 1970 to 1993 was analyzed. Surgical treatment was performed to control increased ICP in 177 patients and due to local compression of cranial nerves or brainstem in five. Some patients had more than one surgical procedure, totalizing 287 interventions. Increased intracranial pressure (ICP) was caused by hydrocephalus in 91%, by intracranial mass lesion (tumoral form) in 6.2% and by pseudotumor cerebri (pseudotumoral form) in 2.8% of the case. Based on the pathophysiological mechanisms of intracranial hypertension identified through conventional CT-scan, ventriculography, cysternotomography, ventriculotomography and MRI, different surgical approaches were indicated. Patients with tumoral form were submitted to direct approach and cyst removal and generally they had benefits from this procedure. Patients with pseudotumoral form whose clinical treatment failure underwent decompressive craniectomies and had a poor outcome (40% of good results). Direct removal of ventricular/cisternal cysts and/or ventriculoatrial/peritoneal shunting (VA/VPS) was performed in patients with hydrocephalus. Removal of free ventricular cysts in patients who had no ependimitis/arachnoiditis generally allowed a good outcome. Patients with adherent cysts and inflammatory process needed a VA/VPS posteriorly and the outcome was not so good. One hundred thirty-two patients were submitted to VA/VPS (109 as the first procedure and 23 after another surgical treatment). The VA/VPS was effective to control increased ICP, despite many complications observed mainly during the two first postoperative years. After this period the surviving patients generally had a better outcome. The patients submitted to cyst removal due to local compression of cranial nerves/brainstem generally had good results. Based on the experience acquired with the management of these patients we present our recent policy for the treatment of patients with neurocisticercosis.

Surgical management of glomus jugulare tumors: a proposal for approach selection based on tumor relationships with the facial nerve

OBJECT The goal of this paper is to analyze the extension and relationships of glomus jugulare tumor with the temporal bone and the results of its surgical treatment aiming at preservation of the facial nerve. Based on the tumor extension and its relationships with the facial nerve, new criteria to be used in the selection of different surgical approaches are proposed. METHODS Between December 1997 and December 2007, 34 patients (22 female and 12 male) with glomus jugulare tumors were treated. Their mean age was 48 years. The mean follow-up was 52.5 months. Clinical findings included hearing loss in 88%, swallowing disturbance in 50%, and facial nerve palsy in 41%. Magnetic resonance imaging demonstrated a mass in the jugular foramen in all cases, a mass in the middle ear in 97%, a cervical mass in 85%, and an intradural mass in 41%. The tumor was supplied by the external carotid artery in all cases, the internal carotid artery in 44%, and the vertebral artery in 32%. Preoperative embolization was performed in 15 cases. The approach was tailored to each patient, and 4 types of approaches were designed. The infralabyrinthine retrofacial approach (Type A) was used in 32.5%; infralabyrinthine pre- and retrofacial approach without occlusion of the external acoustic meatus (Type B) in 20.5%; infralabyrinthine pre- and retrofacial approach with occlusion of the external acoustic meatus (Type C) in 41%; and the infralabyrinthine approach with transposition of the facial nerve and removal of the middle ear structures (Type D) in 6% of the patients. RESULTS Radical removal was achieved in 91% of the cases and partial removal in 9%. Among 20 patients without preoperative facial nerve dysfunction, the nerve was kept in anatomical position in 19 (95%), and facial nerve function was normal during the immediate postoperative period in 17 (85%). Six patients (17.6%) had a new lower cranial nerve deficit, but recovery of swallowing function was adequate in all cases. Voice disturbance remained in all 6 cases. Cerebrospinal fluid leakage occurred in 6 patients (17.6%), with no need for reoperation in any of them. One patient died in the postoperative period due to pulmonary complications. The global recovery, based on the Karnofsky Performance Scale (KPS), was 100% in 15% of the patients, 90% in 45%, 80% in 33%, and 70% in 6%. CONCLUSIONS Radical removal of glomus jugulare tumor can be achieved without anterior transposition of the facial nerve. The extension of dissection, however, should be tailored to each case based on tumor blood supply, preoperative symptoms, and tumor extension. The operative field provided by the retrofacial infralabyrinthine approach, or the pre- and retrofacial approaches, with or without closure of the external acoustic meatus, allows a wide exposure of the jugular foramen area. Global functional recovery based on the KPS is acceptable in 94% of the patients.

Galectin-3 as an Immunohistochemical Tool to Distinguish Pilocytic Astrocytomas from Diffuse Astrocytomas, and Glioblastomas from Anaplastic Oligodendrogliomas

The distinction of astrocytomas and oligodendrogliomas, mainly pilocytic astrocytomas (PILOs) from infiltrating astrocytomas and oligodendrogliomas (ODs), and high‐grade oligodendrogliomas from glioblastomas (GBMs), poses a serious clinical problem. There is no useful immunohistochemical (IHC) marker to differentiate these gliomas, and sometimes the differential diagnosis between them is arbitrary. We identified galectin‐3 (Gal‐3) as a possible tool to differentiate them based on gene expression profiles of GBMs. We confirmed the differential expression in 45 surgical samples (thirteen GBMs; seven PILOs; 5 grade II ODs; 5 anaplastic oligodendrogliomas [AODs], including 2 Oligo‐astrocytomas; 8 diffuse astrocytomas [ASTs], and 7 non‐neoplastic samples) by quantification of Gal‐3 gene expression by real‐time quantitative PCR (rt‐PCR). Higher expression of Gal‐3 was observed in GBMs and PILOs than in OD, AODs and ASTs. The IHC expression of Gal‐3 was evaluated in 90 specimens (fifteen PILOs, fourteen ASTs, 10 anaplastic astrocytomas, fifteen GBMs, eleven ODs, fifteen AODs, and 10 dysembryoplastic neuroepithelial tumors). The mean labeling score for Gal‐3 determined according to the percentage of labeled cells in the tumor bulk was significantly different in GBMs versus AODs and in PILOs versus ASTs. Hence, Gal‐3 is differentially expressed in central nervous system tumors, making IHC detection of Gal‐3 a useful tool in distinguishing between these gliomas.

Cysticercosis of the central nervous system: II. Spinal cysticercosis

The compromising of the spinal canal by cysticercus is considered infrequent, varying from 16 to 20% in relation to the brain involvement. In the spinal canal the cysticercus predominantly places in the subarachnoid space. Clinical signs in spinal cysticercosis can be caused by direct compression of the spinal cord/roots by cysticerci and by local or at distance inflammatory reactions (arachnoiditis). Another mechanism of lesion is degeneration of the spinal cord due to pachymeningitis or circulatory insufficiency. The most frequent clinical features are signs of spinal cord and/or cauda equina compression. The diagnosis of spinal cysticercosis is based on evidence of cerebral cysticercosis and on neuroradiological examinations (myelography and myelo-CT) that show signs of arachnoiditis and images of cysts in the subarachnoid space and sometimes, signs of intramedullary lesions, but the confirmation can only be made through immunological reactions in the CSF or during surgery. The clinical course of 10 patients with diagnosis of spinal cysticercosis observed among 182 patients submitted to surgical treatment due to this disease are analyzed. The clinical pictures in all cases were signs of spinal cord or roots compression. All but two presented previously signs of brain cysticercosis. Neuroradiological examinations showed signs of arachnoiditis in 4 patients, images of cysts in the subarachnoid space in 5, and signs of arachnoiditis and images of cysts in one. The 6 patients that presented intraspinal cysts were submitted to exeresis of the cysts and 2 patients with total blockage of the spinal canal underwent surgery for diagnosis. The 2 remaining patients with arachnoiditis and blockage of the spinal canal were clinically treated. All of the six patients submitted to cyst exeresis had initial improvement but 4 of them later developed arachnoiditis and recurrence of the clinical signs and only 2 remained well for long-term. The 2 non operated patients had no improvement of their clinical signs. Two patients died later due to complications of cerebral cysticercosis. Based on the experience acquired in the management of these patients we indicate surgical treatment for patients that present free cyst in subarachnoid space. For those who present arachnoiditis, surgery is indicated only when there is doubt in the diagnosis. Intramedullary cysts should also be surgically treated.

Clear cell meningioma of the fourth ventricle

Clear cell meningioma (CCM) has been identified and included in the World Health Organization classification of CNS tumors recently. CCMs are histologically characterized by sheets of polygonal cells with clear cytoplasm, which is the expression of high glycogen concentration. Compared with other variants of meningiomas, CCMs occur in younger patients and usually are located in the spinal canal and posterior fossa, the last ones mainly in the cerebellopontine angle. Some reports suggest that CCMs have high recurrence rate and potentially aggressive behavior. Poor outcome has been shown in intracranial and spinal tumor location, but indicators that predict outcome have not been established. The authors present two cases of intracranial CCMs, with excellent outcome in patients harboring tumor location (restricted to the fourth ventricle) and some clinical particular features (young age, gender, obesity, and moderate impairment of intellectual capacity). To the best of our knowledge, these are the two first reported cases of clear cell meningioma located primarily in the fourth ventricle.

Isolated fourth ventricle in neurocysticercosis : pathophysiology, diagnosis, and treatment

Four cases of isolated fourth ventricle in neurocysticerocosis are reported (three after ventriculoperitoneal shunting, and one after hydrocephalus without shunting). Diagnosis was made based on computed tomography (CT) and/or CT cisternogram/ventriculogram. Three patients underwent fourth ventricle drainage (two died and the third remains well). The fourth patient refused surgical treatment and continues to have severe ataxia. Diagnosis, pathophysiology, and treatment of this entity in neurocysticercosis are discussed.

Intramedullary spinal cord paracoccidioidomycosis: report of two cases

Two cases of intramedullary paracoccidioidomycosis are reported. Paracoccidioidomycosis is a systemic disease that involves the buccopharyngeal mucosa, lungs lymph nodes and viscera and infrequently the central nervous system. Localization in the spinal cord is rare. Case 1: a 55-year old male admitted with crural pararesis, tactile/painful hypesthesia and sphincter disturbances of 15 days duration. Cutaneous-pulmonary blastomycosis was diagnosed 17 years ago. Myelotomography showed a blockade of T3-T4 (intramedullary lesion). The lesion surgically removed was a Paracoccidioides brasiliensis granuloma. Treatment with sulfadiazine was started after the surgery. Follow-up of 15 month showed an improvement of the clinical signs. Case 2: a 57-year old male was admitted elsewhere 6 months ago and, with a radiologic diagnosis of pulmonary paracoccidioidomycosis, was treated with amphotericin B. He progressively developer paresthesia and tactile/pain anaesthesia on the left side, sphincter disturbances and tetraparesis with bilateral extensor plantar response and clonus of the feet. Myelotomography showed a blockade of C4-C6 (intramedullary lesion). The lesion was not found during surgical exploration and the patient deteriorated and died. Post-mortem examination revealed an intramedullary tumor above the site of the mielotomy (Paracoccidioides brasiliensis granuloma). The preoperative diagnosis of intramedullary paracoccidioidomycotic granulomas is difficult because the clinical and radiologic manifestations are uncharacteristic. Clinical suspicion was possible in our cases based on the history of previous systemic disease. Contrary to intracranial localizations, paracoccidioidomycotic granulomas causing progressive spinal cord compression may require early surgery because response to clinical treatment is slow and the reversibility of neurological deficits depends on the promptness of the decompression.

Avaliação da isquemia cerebral pela respiração mitocondrial: modelo experimental

Brain ischemia occurs in several diseases. One of the critical factors for recovery of patients is the duration of the ischemic process. Brain activity depends on the energetic supply, it suggests that the study of mitochondrial function can be useful for evaluation of neuronal damage. The purpose of the present research was to study the mitochondrial respiration by occlusion of the left middle cerebral artery by intraluminal suture technique. Adults Wistar rats were subdivided in 4 groups: control, 15, 30 and 60 minutes of occlusion. Results showed that there was no significant difference between the group of 15 minutes and the control group. The group of 30 minutes had significant decrease of state III of mitochondrial respiration compared with control group. The group of 60 minutes had significant decrease in state III and IV of mitochondrial respiration compared with control group. Mitochondrial respiration allowed an early and effective evaluation of focal ischemic process of the rat brain.

Amygdala gene expression of NMDA and GABAA receptors in patients with mesial temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is the most common form of partial epilepsy and affects 40% of the patients. Seizures arising from the mesial temporal lobe structures (i.e., amygdala and hippocampus) are common, whereas neocortical seizures are rare. In recent years, many studies aimed to identify the pattern of gene expression of neurotransmitters involved in molecular mechanisms of epilepsy. We used real‐time PCR to quantify the expression of GABAA (subunits α1, β1, β2) and NMDA (subunits NR1, NR2A, and NR2B) receptor genes in amygdalae of 27 patients with TLE and 14 amygdalae from autopsy controls. The NR1 subunit was increased in patients with epilepsy when compared with controls. No differences were found in expression of NMDA subunits NR2A and NR2B or in α1, β1, and β2 subunits of GABAA receptors. Our results suggest that the NR1 subunit of NMDA receptors is involved in the amygdala hyperexcitability in some of the patients with TLE.