Journal of neurosurgery
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Journal of neurosurgery · May 2017
Case ReportsPrimary pituitary diffuse large B-cell lymphoma with somatotroph hyperplasia and acromegaly: case report.
Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma and comprises approximately 30% of all lymphomas. Patients typically present with a nonpainful mass in the neck, groin, or abdomen associated with constitutional symptoms. In this report, however, the authors describe a rare case of a 61-year-old woman with hyperprolactinemia, hypothyroidism, and acromegaly (elevation of insulin-like growth factor-1 [IGF-1]) with elevated growth hormone-releasing hormone (GHRH) in whom an MRI demonstrated diffuse enlargement of the pituitary gland. ⋯ She underwent a transsphenoidal biopsy, which yielded a diagnosis of DLBCL with an activated B-cell immunophenotype with somatotroph hyperplasia. After stereo-tactic radiation therapy in combination with chemotherapy, she is currently in remission from her lymphoma and has normalized IGF-1 levels without medical therapy, 8 months after her histopathological diagnosis. This is the only reported case of its kind and displays the importance of a broad differential diagnosis, multidisciplinary evaluation, and critical intraoperative decision-making when treating atypical sellar lesions.
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Journal of neurosurgery · May 2017
CommentExternal validation of the Practical Risk Chart for the prediction of delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage.
OBJECTIVE Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) occurs in approximately 30% of patients. The Practical Risk Chart was developed to predict DCI based on admission characteristics; the authors seek to externally validate and critically appraise this prediction tool. METHODS A prospective cohort of aSAH patients was used to externally validate the previously published Practical Risk Chart. ⋯ The best-fit model used a combination of the Hunt and Hess grade and the modified Fisher scale to yield an AUC of 0.76 (95% CI 0.675-0.85) and 0.70 (95% CI 0.602-0.8) for the prediction of DCI and clinical vasospasm, respectively. CONCLUSIONS The Practical Risk Chart adequately predicts the risk of DCI following aSAH. However, the best-fit model represents a simpler stratification scheme, using only the Hunt and Hess grade and the modified Fisher scale, and produces a comparable AUC.
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Journal of neurosurgery · May 2017
CommentLow flow velocity in the middle cerebral artery predicting infarction after bypass surgery in adult moyamoya disease.
OBJECTIVE Direct and indirect bypass surgeries are recognized as the most effective treatments for preventing further stroke in adults with moyamoya disease (MMD). However, the risk factors for postoperative infarction after bypass surgery for MMD are not well established. Therefore, the objective of this study was to investigate the risk factors for postoperative infarction. ⋯ CONCLUSIONS A low MFV in the ipsilateral MCA may predict postrevascularization infarction. Bypass surgery for MMD appears to be safe in early-stage MMD. Results of TCD ultrasonography provide clinical data on the hemodynamics in MMD patients before and after revascularization.
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Journal of neurosurgery · May 2017
Comparative StudyProbabilistic versus deterministic tractography for delineation of the cortico-subthalamic hyperdirect pathway in patients with Parkinson disease selected for deep brain stimulation.
OBJECTIVE Diffusion-weighted MRI (DWI) and tractography allows noninvasive mapping of the structural connections of the brain, and may provide important information for neurosurgical planning. The hyperdirect pathway, connecting the subthalamic nucleus (STN) with the motor cortex, is assumed to play a key role in mediating the effects of deep brain stimulation (DBS), which is an effective but poorly understood treatment for Parkinson disease. This study aimed to apply recent methodological advances in DWI acquisition and analysis to the delineation of the hyperdirect pathway in patients with Parkinson disease selected for surgery. ⋯ CONCLUSIONS These data provide a strong impetus for the use of a robust probabilistic tractography framework based on constrained spherical deconvolution, or similar advanced DWI models, in clinical settings. The inherent limitations and demonstrated inaccuracy of the tensor-based method leave it questionable for use in high-precision stereotactic DBS surgery. The authors have also described a straightforward method for importing tractography-derived information into any clinical neuronavigation system, based on the generation of track-density images.
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Journal of neurosurgery · May 2017
Microelectrode recording findings within the tractography-defined ventral intermediate nucleus.
OBJECTIVE The ventral intermediate nucleus (VIM) of the thalamus is not visible on structural MRI. Therefore, direct VIM targeting methods for stereotactic tremor surgery are desirable. The authors previously described a direct targeting method for visualizing the VIM and its structural connectivity using deterministic tractography. ⋯ Significant local field potential beta power was identified within the T-VIM (area under the curve for 13-30 Hz = 6.6 ± 7.7) with a trend toward higher beta power in the dorsal T-VIM. The most significant reduction in tremor was also observed in the dorsal T-VIM. CONCLUSIONS The electrophysiological findings within the VIM thalamus defined by tractography, or T-VIM, correspond with the known microelectrode recording characteristics of the VIM in patients with tremor.