Gonzalo Torrealba

Cysticercosis of the central nervous system: clinical and therapeutic considerations.

In a group of forty cases of cysticercosis of the central nervous system, 59% presented with intracranial hypertension due to obstructive hydrocephalus. Ventricular or cisternal cysts, and chronic cysticercus meningitis were the most common causes of hydrocephalus. Seizures occurred in 40% of the patients, in one-half of them in association with CT-detected parenchymatous cysts. In 20% of the cases progressive mental deterioration was the main clinical feature, at times associated with hydrocephalus. CT scan provided the highest diagnostic yield, being abnormal in 90% of cases. Long term prognosis was poor, with a mortality rate of 38% over a 40-month follow-up period. The most common cause of death (60%) was meningitis. CSF shunting is the treatment of choice for hydrocephalus, irrespective of its mechanism. Surgical resection is indicated in some cases with a single superficial (cortical) or posterior fossa cyst. Supratentorial cysts carry a relatively benign prognosis.

Intracranial metastasis or meningioma? An uncommon clinical diagnostic dilemma.

BACKGROUND Cerebral metastases are the most frequent brain tumors in adults and they may occasionally present as an isolated meningeal mass, suggesting a meningioma. Because of the prognostic relevance in discriminating both tumors, we review the literature and analyze four patients in whom the diagnosis of meningioma was initially made. CASE DESCRIPTION Four cases of isolated meningeal metastases are presented and in all of them a meningioma was considered as the main preoperative diagnosis. Only one patient had a history of previous cancer. The primary tumors found after pathological testing of the lesions were thyroid carcinoma, prostate adenocarcinoma, breast adenocarcinoma, and hypernephroma. The clinical and neuroimaging features as well as the differential diagnoses are discussed. The literature regarding these forms of meningeal metastases was reviewed. CONCLUSIONS Although they are uncommon, dural metastases can be mistaken for meningiomas. Our experience in these cases has led us to consider ordinary metastases as a differential diagnosis even when a meningioma is suspected. The definitive diagnosis of a meningioma should be established only after the histopathological report has been analyzed.

A novel, inexpensive method of image coregistration for applications in image-guided surgery using augmented reality

OBJECTIVE Augmented reality (AR) is a technique in which an overlay of a virtual image to a live picture is performed to create a new image in which both original images coexist as a single image. This results in the visualization of internal structures through overlying tissues. The objective was to describe an easy, inexpensive, and successful method to coregister with AR in an image-guided surgery setting using the resources at hand. METHODS Cortical information was obtained with a volumetric acquisition of 200 0.8-mm thick, cerebral magnetic resonance imaging scans in an axial T1-weighted sequence. For the venous anatomy, a contrast phase at 7 mm/s velocity was used. This data was reconstructed in a three-dimensional fashion using MRIcro software (v. 1.37, freeware, courtesy of Chris Rorden) and was overlaid to a digital image of the cerebral cortex either pre- or intraoperatively. RESULTS Eight patients were studied. There was an adequate coregistration in seven of the patients as confirmed by intraoperative ultrasound, frame-based stereotaxy, or obvious anatomic homology between the three-dimensional magnetic resonance imaging scan virtual reconstruction and the live image obtained during surgery. AR was not possible in one case of a cerebellar lesion. CONCLUSION AR coregistration capabilities are adequate when revised by other intraoperative guidance devices. When performed with “freeware” software and conventional digital cameras, it is relatively inexpensive, which makes it a potential tool for surgical planning and noncontinuous intraoperative guidance in neurosurgery. Its largest drawbacks are the inability to function in deep-seated lesions and its lack of tracking devices, which gives it a noncontinuous coregistration nature.

Temporal lobe epilepsy surgery with limited resources: results and economic considerations.

Summary: This study evaluates the surgical outcome of patients with medically refractory temporal lobe epilepsy (TLE) who underwent anterior temporal lobe lobectomy (ATL) based on data derived from noninvasive studies and assesses the economic costs entailed at a newly created epilepsy program in Chile. Seventeen ATL candidates underwent a presurgical evaluation. This included outpatient brain MRI and neuropsychological testing and inpatient scalp/sphenoidal prolonged video‐EEG monitoring. There were 10 females and 7 males, with a mean age of 23.8 years and a mean duration of seizure disorder of 12 years. Patients with congruent data localizing the seizure focus to one anterotemporal region underwent ATL. Seven patients underwent a left‐side ATL and 10 patients a right‐side ATL. The histopathological findings showed a lowgrade tumor in six patients, hippocampal sclerosis in five, neuronal migration disorder in four, and cavernous angiomas in two patients. The mean follow‐up period was 29·1 months. Seizure outcome was assessed with Engels classification: class I, no seizures or only auras; class II, rare seizures; class III, >90% seizure reduction; class IV, <90% seizure reduction. Fifteen patients are now in class I, one patient in class II, and one in class IV. The total cost, including evaluation and surgery, was equivalent to US

Surgery for high-grade gliomas in a developing country: survival estimation using a simple stratification system

5,020. Thus, well‐selected TLE patients can derive maximal benefit from ATL after a noninvasive presurgical evaluation. This finding is of great significance for the creation of epilepsy surgery programs in developing countries.

Quistes sinoviales de columna lumbar: una causa de compresión radicular

BACKGROUND In spite of great technological advances in diagnostic and therapeutic tools, survival in patients with HGG has not changed significantly in the last years. Judicious management in each case needs survival estimation after surgery. We used a simple stratification system evaluating the histology, patients age, and the KPS. METHODS We retrospectively made an analysis of survival in 103 patients with HGG operated in a 10-year period (1990--1999). Three significant prognostic variables were studied: histology, patients age, and KPS. The BS-MG was calculated, adding the partial score (0 or 1) obtained for each variable. This score ranges from 0 (worse condition) to 3 (best condition). RESULTS Overall, MS was 12 months. For glioblastoma multiforme, AA, and ODS, it was 10, 20, and 19 months, respectively (P = .0001). Patients 44 years old or younger had an MS of 28 months, higher than 10 months for patients older than 45 years (P < .0001). Median survival was 20 months for patients with KPS 80 or higher, and 9 months for those with KPS 70 or lower (P = .02). It was 3.5 months in patients with BS-MG = 0, 9 months for BS-MG = 1, 22 months for BS-MG = 2, and 55 months for BS-MG = 3 (P < .0001.). CONCLUSIONS Survival presented here is comparable with those previously reported despite lacking the most sophisticated surgical technique. The stratification score that includes the 3 most important variables for survival seems to be simple and reliable for survival estimation.

Trombosis carotidea en el lactante

Los quistes sinoviales (QS) de columna lumbar son lesiones infrecuentes pero deben considerarse frente a casos de compresion radicular. Existe controversia acerca de su patogenia y se describen multiples opciones terapeuticas. Se presenta una serie clinica retrospectiva de siete pacientes tratados en un periodo de ocho anos. En general fueron pacientes mayores de 60 anos, con un cuadro de dolor radicular unilateral, que se presento 3 meses antes del diagnostico. Solo dos pacientes tuvieron deficit de la raiz correspondiente. Todos los QS se localizaron en el nivel L4-L5, realizandose hemilaminectomia y reseccion total del quiste. Seis casos tuvieron desaparicion completa del dolor. Un paciente presento solo alivio moderado, constatandose espondilolistesis, por lo que fue sometido posteriormente a una fusion vertebral, mejorando su sintomatologia. La cirugia es un tratamiento seguro y eficaz para la resolucion de esta patologia. La literatura acerca de esta importante patologia fue revisada

Hematoma de fosa posterior no traumático: consideraciones clínicas y terapéuticas

INTRODUCTION. Los Accidentes Vasculares En-falicos (A. V. E.) oclusivos del adulto tienenuna frecuencia alta, habiendose discutido exten-samente su etiopatogenia, cuadro clinico y trata-miento. Conocido es tambien el papel que juegaen ellos la oclusion (total o parcial) de la arteriacarotida a nivel del cuello. (7-8).Problema aparte, lo constituyen los A. V. E.oclusivos en el nino, los cuales son poco conocidosy estudiados, quedando a menudo la etiologia pococlara.Ademas de la escasa frecuencia con que se des-criben estos casos, mas excepcional aim resulta elcompromise de la arteria carotida a nivel del cue-llo, a diferencia del adulto.Nuestro proposito es el presentar a un lactan-te, con una trombosis de carotida cervical y exten-dernos en algunas consideraciones a proposito dela etiologia de estas oclusiones, considerando queno hemos encontrado referencias nacionales so-bre el tema.

Protracted vomiting as the presenting sign of posterior fossa mass lesions.

Fifty two patients (28 male and 24 female) with non-traumatic posteriorfossa hematomas were analyzed. Average age of the patients was 60 yearsold. In ten cases (19.2%), the hematomas were secondary to arteriovenousmalformations (5), cavernomas (3), venous angiomas (1) and hemangioblastoma (1). Forty two (80.7%) wereconsidered primary, with a history of high blood pressure in 31 patients and coagulation disorders in 5. Six caseshad no predisposing factors. Most subjects also had intercraneal hypertension (84%). Computerized tomographyshowed hematomas in all cases, of which four were under 2 cm in size, 24 were between 2 and 3 cm, and 24were larger than 3 cm. Hydrocephalus was present in 22 cases (42.3%). Twelve patients underwent digitalangiography, with favorable results in seven (5 arteriovenous malformations, 1 venous angioma and 1hemangioblastoma). Magnetic resonance imaging was done with two patients, and showed one cavernousangioma. Thirty-one patients underwent surgery; the hematoma was drained in 24 cases, 14 of which involvedLCR draining. The remaining cases were treated for hydrocephalus only. Favorable results were seen in 67.3% ofthe cases, and the overall mortality rate was 9.6%. Surgical mortality was 12.5%. The initial state ofconsciousness and size had a bearing on results. We believe that treatment must be evaluated on a case-by-casebasis, since no single factor has an absolute effect on a patients outcome.