Microscopic mild focal cortical dysplasia in temporal lobe dual pathology: an electrocorticography study.

BACKGROUND: Associations between electrophysiological and histological findings might provide an insight into the epileptogenicity of mild focal cortical dysplasia (FCD) in patients with temporal lobe epilepsy (TLE) and a dual pathology. SUBJECTS AND METHODS: A total of 22 patients with pharmacoresistant TLE were included in the study, 16 of them with histologically confirmed hippocampal sclerosis (HS) associated with neocortical temporal mild Palmini Type-I FCD subtypes and 6 with HS. Intraoperative electrocorticography (ECoG) recordings were analysed for epileptiform discharge frequency and morphology. Associations between histological, and electrocorticography pattern findings in these patients were analysed. Electroclinical outcomes in these patients were also evaluated. RESULTS: Neocortical areas with mild Palmini Type-I FCD showed a significantly higher spike frequency (SF) recorded in the inferior temporal gyrus than those neocortical areas in patients with HS. There was a tendency to higher spike frequency and lower amplitude in neocortical areas with histopathologic subtype IB FCD in relation with IA during intraoperative ECoG. Post-SF excision and amplitude were significantly lower during neocortical post-excision intraoperative ECoG than during neocortical pre-excision recording. There was no difference found in the clinical outcome between patients with and without FCD. CONCLUSIONS: Intraoperative electrocorticographic interictal spike frequency recorded in the neocortical inferior temporal gyrus may help to characterize the histopathologic subtypes of mild Palmini Type-I FCD in patients with temporal lobe epilepsy (TLE) and a dual pathology. Our data support the epileptogenicity of neocortical mild FCD in TLE and assessments of ECoG patterns are relevant to determine the extent of the resection in these patients which can influence the electroclinical outcome.

[Pathological neocortical findings in patients with medication-resistant medial temporal lobe epilepsy submitted to surgery]. / Hallazgos patológicos neocorticales en pacientes con epilepsia del lóbulo temporal medial farmacorresistente sometidos a cirugía.

INTRODUCTION: The dual pathology consisting of hippocampal sclerosis plus focal cortical dysplasia (FCD) is often reported in patients with medication-resistant medial temporal lobe epilepsy (MTLE). AIMS: To determine the histopathological changes that take place in the neocortex of patients with medication-resistant MTLE submitted to surgery and to evaluate the relation between the histopathological changes, pathological background and the clinical course of patients who had received surgical treatment. MATERIALS AND METHODS: Tissue obtained by en bloc resection from the neocortex of 18 patients with MTLE refractory to medical treatment was processed histologically and a tailored temporal lobectomy was performed with electrocorticography. RESULTS: Dual pathology was diagnosed in 13 patients (72.2%). Imaging studies confirmed the existence of mesial sclerosis of the temporal in 100% of cases and there was no evidence of neocortical lesions. Histologically, 46.15% and 38.46% of the patients were diagnosed as belonging to FCD type 1a and FCD type 1b, respectively. Only one patient presented FCD type 2a. A statistically significant relation was found between the presence of dual pathology and the existence of an early precipitating injury (p = 0.04). One year after surgery, 72.7% (8/11) patients with dual pathology were classified as belonging to Engel class I. CONCLUSIONS: In patients with MTLE there are microscopic FCD-type alterations in the neocortex. There is an association between these alterations and the existence of an initial precipitating injury. Complete resection of the epileptogenic area, which is guaranteed by the lobectomy tailored by electrocorticography, allows patients to enjoy a favourable post-surgical progression one year after surgery.

[Video-EEG evaluation complemented by spectral and EEG source analysis in patients with medication-resistant medial temporal lobe epilepsy]. / Evaluación videoelectroencefalográfica complementada con análisis espectral y de las fuentes generadoras del electroencefalograma en pacientes con epilepsia del lóbulo temporal medial resistente a los fármacos.

AIM: To evaluate the value of prolonged video-electroencephalographic (video-EEG) monitoring complemented with spectral and EEG source analysis in identifying the epileptogenic area in patients with medial temporal lobe epilepsy who are candidates for non-lesional resective surgery. PATIENTS AND METHODS: The electrographic patterns during the onset of seizures were evaluated in over 667 seizures from 41 patients with a clinical diagnosis of medication-resistant partial epilepsy. Analyses were performed using Harmonie software and variable resolution electrical tomography (VARETA). RESULTS: Video-EEG was used to determine that 53.6% of the patients evaluated suffered complex partial seizures of a temporal origin; these were characterised by having an average frequency of 5.56 +/- 1.56 Hz, while the non-temporal seizures displayed a frequency within the range 9.17 +/- 3.32 Hz. The topographic location of the dominant ictal frequency during the period of maximum spectral energy in patients with temporal lobe epilepsy enabled us to draw a distinction between a group of patients with mesial seizures and those with non-mesial seizures that exceeded the number that was determined by visual inspection of the EEG, that is, 78.9 versus 47.3%, respectively. There was a 100% coincidence between the area where the seizures began as defined by surface EEG complemented with spectral analysis, the generator of this activity as defined by VARETA and the epileptogenic region. CONCLUSIONS: The localising information provided by video-EEG complemented with spectral and EEG source analysis allows for non-invasive location of the epileptogenic region in patients with medial temporal lobe epilepsy even when structural imaging studies show an absence or bilaterality of abnormalities.

[Penetrating head injury from harpoon. Case report]. / Trauma craneoencefálico perforante por arpón. Precentación de un caso y revisión de la literatura.

The harpoon presence as aggressor weapon is unusual in the neurosurgical practice. Most cases are associated with diving or sport activities as result of imprudence. A 31 year old patient who sustained a penetrating craniocerebral injury with a fishing harpoon is presented and complementary exams, neurosurgical procedure and postoperative evolution are detailed. We discuss the management of this unusual injury and review the current literature on craniocerebral injuries caused by similar objects.

[Presentation of distal saccular aneurysm as a subdural haematoma]. / Aneurisma sacular distal presentándose como hematoma subdural.

INTRODUCTION: Intracranial aneurysms are one of the most frequent vascular diseases. Nevertheless, saccular aneurysms that are not due to an inflammatory aetiology, which are located in the peripheral segment of the posterior circulation, are extremely rare. They are most frequently located in the thickest arterial branches within the region of the anterior brain circulation, as is the case of the complex made up of the anterior cerebral artery posterior communicating artery, middle cerebral artery and posterior communicating artery. No clinical manifestations are produced in many of these aneurysms, and their rupture and the subsequent development of a subarachnoid haemorrhage is the cause of the most intense neurological damage, which on occasions can lead to fatal consequences. CASE REPORT: We report the case of a patient who was a carrier of distal aneurysm, located in the posterior region of the brain circulation, and also the neuroradiological findings, the form of clinical presentation and surgical treatment carried out, which allowed us to identify and close the afferent vessel and the resection of the aneurysmatic sac. CONCLUSION: From the presentation of the symptoms of this patient in the form of a subarachnoid haemorrhage, accompanied by a subdural haematoma, it could be inferred that these clinical and imagenological findings point to the rupture of a distal aneurysm. Application of the stereotactic approach would be one of the first choice treatments for aneurysms in the distal region if we bear in mind the characteristics of the afferent vessel, the size of the neck and the morphology of the sac

[Complications of stereotaxic surgery for cerebral tumors. Minimal access neurosurgery]. / Complicaciones de la cirugía estereotáxica de los tumores cerebrales. Neurocirugía de mínimo acceso.

INTRODUCTION: Complications of neurosurgery include the clinical, neurological and neurosurgical aspects. Their prevention and correction depend on satisfactory preoperative assessment and close postoperative follow-up. Although minimum access neurosurgery reduces some problems, the complexity and depth of many cerebral lesions cause problems. Therefore it is important to adhere to the above principles to obtain good results. OBJECTIVES: To determine the clinical complications, their early detection and course to be followed when they occur. PATIENTS AND METHODS: We studied 29 patients with intracranial tumors operated on using stereotaxic surgery during a period of two years. They were evaluated before and after surgery and the complications recorded. RESULTS: We discuss the most significant clinical aspects of peri-operative management. The main complications found were lower respiratory tract infection and hyperglycemia. CONCLUSIONS: These results show the need for suitable management, even in minimum access surgery, in patients with cerebral tumors operated on using stereotaxis and underline the most significant complications.

[Stereotaxic microsurgical resection of intracranial tumors guided by imaging and assisted by computer]. / Resección microquirúrgica estereotáxica de tumores intracraneales guiada por imagen y asistida por computadora.

INTRODUCTION: The microsurgical techniques for resection of intracranial lesions are limited where anatomical references do not exist or cannot be used as guides in the dissection of deeply located lesions or in more superficial eloquent areas. The stereotaxic guide, guided by imaging gives precise volumetric and geometric definition in intracranial lesions. Its application in the resection of intracranial tumors has special characteristics due to their biological condition and varied localization. OBJECTIVES: Spatial orientation during surgery is essential. We show this application of stereotaxic surgery in the Centro Internacional de Restauración Neurológica (CIREN) in La Havana, Cuba, between May 1994 and February 1988, describing 65 microsurgical operations done using stereotaxis in 62 patients with intracranial cerebral tumors. PATIENTS AND METHODS: The procedure was divided into three stages: acquiring an image, computerized axial tomography and surgical planning, with the STASSIS planning system and microsurgical procedures, including systems of stereotaxis: Leksell, Micromar and Estereoflex. RESULTS: Of the total, 27 of these patients had glial tumors, 33 non-glial tumors and only 2 had non-neoplastic lesions of different sites and sizes. A total of 30 resections were done. Surgical morbidity was minimal and there was no surgical mortality. CONCLUSIONS: The main advantages of this method are: exact localization of the site for craniotomy, easy spatial orientation and ease in distinguishing the delimitation between the tumour and the healthy tissue. It has been shown that Estereoflex may be used in cerebral microsurgery.

[Sepsis and antibiotic prophylaxis in stereotaxic neurosurgery]. / Sepsis y profilaxis antibiótica en neurocirugía estereotáxica.

INTRODUCTION: Stereotaxic surgery is becoming increasingly important because of the possibility of approaching the deep zones of the brain with less risk. It is in daily use in cerebral tumours and in the functional surgery of Parkinson's disease. The use of antibiotic prophylaxis in neurosurgery is controversial, although in many centres, including ours, all patients receive it. OBJECTIVE: To study the pre-operative clinical characteristics analysing the antibiotic prophylaxis used, septic complications seen and their management. PATIENTS AND METHODS: In this study we included 93 patients with neurosurgical disorders operated on using a stereotaxic approach in the Neurosurgical Department of the Centro Internacional de Restauración Neurologica (Cuba) during 1997 and 1998, in which antibiotic prophylaxis was used and septic patients detected. The variables studied included age, sex, neurological disorders, surgical operations done and the antibiotic used for prophylaxis. We analysed the test of clinical criteria for sepsis in all patients. RESULTS: We found that a greater number of patients operated on had had functional surgery, which showed its importance as an alternative surgical method in Parkinson's disease. There was satisfactory use of antibiotic prophylaxis with a reduction in the rate of nosocomial infection; most infections were seen in the lower respiratory tract. CONCLUSION: These results support the hypothesis of use of antibiotic prophylaxis in stereotaxic surgery to achieve a reduction in intra-hospital infections in surgical patients.

[Central neurocytoma]. / Neurocitoma central.

INTRODUCTION: A central neurocytoma (CN) is a rare tumor, of neuronal origin, well-differentiated and found intraventricularly. It mainly affects young adults. Firm diagnosis is made on immunohistochemical (IHQ) and ultrastructural studies, since on optic microscopy it is similar in appearance to an oligodendroglioma or to an ependymoma. PATIENTS AND METHODS: We studied 4 cases, three after surgical resection and one on autopsy. The average age was 29, ranging from 3 to 63. Both sexes were equally affected. In all cases IHQ techniques were used (GFAP, neurofilament, synaptophysin and specific neuronal enolase) and they were studied by electron microscopy. RESULTS: IHQ was negative for GFAP and neurofilament, but intensely positive for synaptophysin and specific neuronal enolase. On ultrastructural study there were few neurofilaments, microtubules and dense central granules typical of neural differentiation. CONCLUSIONS: The findings in our cases lead to diagnosis of NC and confirm that this tumor is a distinct clinicopathological entity.

Neurocitoma central / Central neurocitoma

Introducción. El neurocitoma central (NC) es un tumor raro, de origen neuronal, bien diferenciado y de localización intraventricular; afecta preferentemente a adultos jóvenes. El diagnóstico definitivo se establece por el estudio inmunohistoquímico (IHQ) y ultraestructural debido a su semejanza con el oligodendroglioma y el ependimoma al microscopio óptico. Pacientes y métodos. Se procesaron 4 casos, 3 procedentes de resección quirúrgica y 1 de autopsia. La edad media fue de 29 años, con un rango entre 3 y 63 años; ambos sexos se afectaron por igual. A todos los casos se les realizó técnicas de IHQ (GFAP, neurofilamento, sinaptofisina y enolasa neuronal específica) y se estudiaron por microscopía electrónica. Resultados. La IHQ resultó negativa para la GFAP y para el neurofilamento, y fue intensamente positiva para la sinaptofisina y la enolasa neuronal específica. El aspecto ultraestructural evidenció escasos neurofilamentos, microtúbulos y gránulos de centro denso propios de la diferenciación neural. Conclusiones. Los hallazgos encontrados en nuestros casos permitieron realizar el diagnóstico de NC y confirmaron a este tumor como una entidad clinicopatológica distintiva