NEUROZONE: on-line recognition of brain structures in stereotactic surgery--application to Parkinson's disease.

The success of stereotactic surgery for Deep Brain Stimulation depends critically on the exact positioning of a microelectrode recording in a target area of the brain. This paper presents the software system NEUROZONE composed of two main applications: first, it allows online recognition of brain structures by the analysis of signals from microelectrode recordings (MER), and second, it processes and analyses off-line databases allowing the inclusion of new trained classifiers for automatic identification. The software serves as a support to the analysis done by a medical specialist during surgery, and seeks to reduce the adverse side effects that may occur because of inadequate identification of the target areas. The software also allows the specialists to label recordings obtained during surgery, in order to generate a new off-line database or increase the amount of records in an already existing off-line database. NEUROZONE has been tested for Deep Brain Stimulation performed at the Institute for Epilepsy and Parkinson of the Eje Cafetero (Colombia), achieving positive identifications of the Subthalamic Nucleus (STN) over to 85% using a naive Bayes classifier.

Focal cortical dysplasias: surgical outcome in 67 patients in relation to histological subtypes and dual pathology.

The purpose of this study was to assess whether the histological subtype of focal cortical dysplasia and dual pathology affect surgical outcome in patients with medically intractable epilepsy due to focal cortical dysplasia (FCD). We retrospectively analysed the outcome of 67 patients from 2 to 66 years of age at follow-up periods of 6 to 48 months after epilepsy surgery. Histological subtypes were classified according to Palmini and included a few cases with mild histological abnormalities corresponding to the definition of mild malformations of cortical development. The seizure outcome was classified according to Engel and evaluated at the last follow-up visit as well as at follow-up periods of 12 and 24 months after surgery. The outcome in patients with FCD and additional hippocampal pathology (dual pathology) was analysed separately. Distribution of histological subtypes differed in temporal and extratemporal localization, with a significantly higher extratemporal prevalence of FCD type 2. There was a tendency towards better postsurgical outcome related to the last follow-up visit in patients with more subtle abnormalities classified as mild malformations of cortical development (mMCD) (63% Engel Ia), FCD type 1a (67% Engel Ia) and FCD type 1b (55% Engel Ia) compared with patients with FCD type 2a (43% Engel Ia) and FCD type 2b (Taylor type) (50% Engel Ia). Considering the outcome at follow-up periods over 12 and 24 months, complete seizure-freedom was achieved significantly more often in patients with FCD type 1 and mMCD than with FCD type 2, and seizure reduction by less than 75% (Engel IV) occurred in more patients with FCD type 2a compared with the other subgroups. This tendency was seen in the whole patient group and in the extratemporal subgroup. Patients with dual pathology almost always had temporal lobe epilepsy; the outcome in this patient group was generally favourable (66% complete seizure-freedom at the last follow-up visit). The outcome remained almost constant with longer periods of follow-up. We conclude that patients with FCD type 1 and mMCD had a better outcome compared with those with more severe forms of cortical dysplasia. A higher incidence of FCD type 1 in temporal localization did not allow the effects of histological subtype and localization to be separated. A subanalysis of extratemporal FCDs, however, revealed a similar tendency for a better outcome with FCD type 1, suggesting that the histological subtype itself seems to be at least a relevant cofactor influencing postsurgical outcome.

[Chronic subdural hematoma: a disease of elderly people]. / Hematoma subdural crónico: una enfermedad del adulto mayor.

BACKGROUND: The lack of specificity and heterogeneity of the clinical picture of chronic subdural hematoma, hampers its diagnosis. AIM: To report the experience of a Neurosurgical Service in chronic subdural hematoma. PATIENTS AND METHODS: One hundred patients (77 male, mean age 77 +/- 13 years) with chronic subdural hematoma were analyzed. RESULTS: The main clinical presentations were mental status changes (50%) and progressive focal neurological deficit (46%). Five cases presented as a transient neurological deficit. All patients were treated with burr hole drainage. Thirteen had recurrence of the hematoma and they were reoperated. The surgical mortality was 3%. Eighty seven patients were followed for a mean of 66 months. Eighty one of these had a complete recovery, 6 had permanent neurological deficit and 2 of these were unable to care for themselves. Bad prognosis was associated with the absence of a previous trauma to explain the hematoma and symptoms of dementia as the clinical presentation. CONCLUSIONS: Most patients with chronic subdural hematoma treated with burr hole drainage have a good outcome.

Cerebellar hemorrhage arising postoperatively as a complication of supratentorial surgery: a retrospective study.

OBJECT: Postoperative cerebellar hemorrhage as a complication of supratentorial surgery is an increasingly recognized clinical entity. So far, it has remained unclear whether this complication constitutes an intraoperative or postoperative event. The observation of such cases prompted the authors to analyze retrospectively their series of supratentorial craniotomies. The aim of this study was to determine the incidence of cerebellar hemorrhage and its temporal relationship to supratentorial surgery. METHODS: The authors reviewed discharge notes and reports on postoperative computerized tomography (CT) scans for 1650 patients who had undergone supratentorial craniotomy between January 1998 and February 2001. The retrospective study led to the identification of 10 patients who had sustained cerebellar hemorrhage as a complication of supratentorial surgery. Because it was routine to perform CT scanning following craniotomy, an early CT scan obtained within the 1st postoperative hour (mean 24 minutes after wound closure) was available in eight of the 10 patients. In seven of these patients no hemorrhage was found immediately after surgery, and in only one patient was there the suspicion of cerebellar hemorrhage. In the whole series of 10 patients, cerebellar hemorrhage was detected during the later postoperative course, after a mean interval of 7 hours and 35 minutes (range 1 hour and 49 minutes-144 hours) following surgery. The incidence of cerebellar hemorrhage was 0.6% of all patients who underwent supratentorial surgery. Among patients suffering from epilepsy the incidence was 4.6%, and in those patients who underwent temporal lobe resection it was 12.9%. CONCLUSIONS: The authors have demonstrated that cerebellar hemorrhage as a complication of supratentorial surgery arises not as an intraoperative event, but as a postoperative event. Resective nontumorous temporal lobe procedures place patients at particular risk for this complication. Evidence suggests that the complication might be precipitated by postoperative suction drainage.

Quistes sinoviales de columna lumbar: una causa de compresión radicular / Synovial cysts of the lumbar spine: a cause of radicular compression

Los quistes sinoviales (QS) de columna lumbar son lesiones infrecuentes pero deben considerarse frente a casos de compresión radicular. Existe controversia acerca de su patogenia y se describen múltiples opciones terapéuticas. Se presenta una serie clínica retrospectiva de siete pacientes tratados en un período de ocho años. En general fueron pacientes mayores de 60 años, con un cuadro de dolor radicular unilateral, que se presentó 3 meses antes del diagnótico. Sólo dos pacientes tuvieron déficit de la raíz correspodiente. Todos los QS se localizaron en el nivel L4-L5, realizándose hemilaminectomía y resección total del quiste. Seis casos tuvieron desaparición completa del dolor. Un paciente presentó sólo alivio moderado, constatándose espondilolistesis, por lo que fue sometido posteriormente a una fusión vertebral, mejorando su sintomatología. La cirugía es un tratamiento seguro y eficaz para la resolución de esta patología. La literatura acerca de esta importante patología fue revisada

Criterios quirúrgicos de neurocirujanos de latinoamérica en hematomas intracerebrales espontáneos / Surgical criteria of latinamerican neurosurgeons in spontaneous intracerebral hematomas

La cirugía en hematomas intracerebrales espontáneos es aún un tema de gran controversia pese a los numerosos estudios publicados en la literatura. Se realizó una encuesta en el XXVII Congreso Latinoamericano de Neurocirugía, realizado en Honduras en el mes de octubre de 1996, en donde se preguntó sobre criterios empleados en la indicación de cirugía por los encuestados. Fueron analizadas las siguientes variables: localización, lateralidad, tamaño, nivel de conciencia y desviación de línea media en la tomografía computada (TC). La encuesta fue respondida por 118 neurocirujanos pertenecientes a 18 países latinoamericanos, 82 por ciento titulados y 18 por ciento residentes. Se encontraron algunas tendencias como operar los hematomas talámicos, controvertida la cirugía en hematomas putaminales, operar a los pacientes en sopor con volumen del hematoma con volumen del hematoma entre 20 y 80 cc y con desviación de la línea media en la TC mayor de 5 mm. Pese a tales tendencias generales no se encontró uniformidad de criterios entre los encuestados