The TIGR triangle of the pineal region: a virtual reality anatomic study.

BACKGROUND: In this morphometric study, we describe the anatomy of the TIGR triangle, which is bordered by the tentorial surface of the cerebellum, the internal cerebral vein and vein of Galen complex, and the vein of Rosenthal. These structures define the window, or deep keyhole, to access the pineal region in non-midline supracerebellar infratentorial approaches. METHODS: The posterior fossa anatomy of 16 patients was studied in virtual reality (VR), and the TIGR triangles were defined and measured with special attention on its angular orientation in the posterior fossa. The angular expanse of the posterior fossa was measured and recorded as the transverse-sigmoid junction (TSJ) angle. Because a perpendicular corridor through an anatomic aperture provides the best exposure, we studied the starting point along the TSJ angle that offers the best exposure of TIGR. RESULTS: In the 31 posterior fossa sides included in the study, the perpendicular trajectory through the TIGR triangle was on average 27.13° CI 95% (range: 5.97°-48.53°) from the midline. When comparing the SCIT variants, both the paramedian and lateral approaches provided near-perpendicular trajectory through the TIGR triangle in a majority of specimens. However, the modified paramedian approach, with starting point defined as TSJ angle/3, provided the most perpendicular path through the TIGR triangle. CONCLUSION: We studied the size, spatial orientation, and morphology of the TIGR triangle. Our data indicated that the best exposure of TIGR is through a modified paramedian SCIT approach, in which the starting point one third of the way from midline to the TSJ.

Symptomatic obstructive hydrocephalus caused by choroid plexus hyperplasia in a pediatric patient: illustrative case.

BACKGROUND: Choroid plexus hyperplasia has been described as a rare cause of communicating hydrocephalus due to cerebrospinal fluid (CSF) overproduction. However, this is the first report of symptomatic obstructive hydrocephalus caused by mechanical obstruction of the aqueduct by a hyperplastic choroid plexus. OBSERVATIONS: A 4-year-old male presented with headaches and intermittent emesis. Magnetic resonance imaging (MRI) of the brain showed abnormal enlargement of the choroid plexus in the lateral ventricles with extension into the third ventricle, resulting in obstruction of the aqueduct of Sylvius, leading to obstructive hydrocephalus. Endoscopic third ventriculostomy (ETV) was chosen as the surgical treatment. During the procedure, high pressure flow of clear CSF was noted. Normal intraventricular anatomy was identified, and no cyst or tumor was found. The postoperative MRI showed a patent third ventriculostomy, without complication, and a significant decrease in supratentorial ventricular size. The patient was discharged 3 days after surgery with a complete resolution of symptoms. LESSONS: Choroid plexus hyperplasia has the potential to cause obstructive hydrocephalus, and it can be effectively treated with ETV. Our hypothesis is that the change in pressure caused by the procedure may have led to an uncorking of the aqueduct by the hyperplastic choroid plexus, contributing to the observed improvement.

Refractory anorexia nervosa in adulthood and nucleus accumbens deep brain stimulation.

Background: Anorexia Nervosa is a life-threatening mental illness with numerous consequences. Some cases are chronic and refractory to multiple treatments. Consequently, there is great interest in therapeutic alternatives that may improve severe patients. We present an adult patient with anorexia nervosa that underwent to bilateral nucleus accumbens deep brain stimulation (NAc-DBS). Case description: The patient was a healthy 46-year-old woman with higher education and an adequate premorbid socio-labour situation. Her disease had a late onset (25 years). The patient never presented clinical remission or weight stability. In recent years, the patient's body mass index (BMI) was 13.16 (32kg). The case was evaluated with multiple neuropsychological tests as well as the BMI before and after surgery. The clinical follow-up was 50 months. After bilateral NAc-DBS the patient experienced an important clinical benefit and significant improvement in neuropsychological tests and weight (BMI 17.28, 42 kg; 50th month) Programming: 4,5V, 130Hz, 210 µs. Conclusion: Despite the patient´s age and the long duration of the disease, our results suggest that bilateral nucleus accumbens stimulation may be a useful and effective therapeutic strategy for cases such as the one presented. Additionally, this case presents a surgical midlife patient with both the latest disease onset and the longest follow-up after treatment in the literature.

Gastric balloon: A rare cause of lumbar radiculopathy.

BACKGROUND: Factors that are known to cause lumbar epidural venous plexus (EVP) engorgement include inferior vena cava (IVC) obstruction, portal hypertension, vascular agenesis, morbid obesity, and/or hypercoagulable states. Here, we present a 32-year-old female admitted with the new onset of lumbar radiculopathy attributed to a gastric balloon causing compression of the IVC and engorgement of the EVP. CASE DESCRIPTION: A 32-year-old female was admitted with a left L5 radiculopathy. She had a history of morbid obesity and had undergone intragastric balloon insertion 4 months ago. The abdominal/pelvic CT documented an intragastric balloon producing a voluminous gastric mass with resultant compression of the IVC. The lumbar MRI showed the resultant marked multilevel engorgement of the lumbar EVP. Here, following balloon removal, the patient was immediately symptom free and remained asymptomatic over the next postoperative year. CONCLUSION: An intragastric balloon can produce a voluminous gastric mass that can result in IVC occlusion and engorgement of the EVP, leading to lumbar radiculopathy. Removal of the balloon results in immediate and permanent resolution of the compressive symptoms.