Magnetic Resonance-Guided Focused Ultrasound (MRgFUS)-Thalamotomy for Essential Tremor: Lesion Location and Clinical Outcomes.

BACKGROUND: Factors predicting clinical outcomes after MR-guided focused ultrasound (MRgFUS)-thalamotomy in patients with essential tremor (ET) are not well known. OBJECTIVE: To examine the clinical outcomes and their relationship with patients' baseline demographic and clinical features and lesion characteristics at 6-month follow-up in ET patients. METHODS: A total of 127 patients were prospectively evaluated at 1 (n = 122), 3 (n = 102), and 6 months (n = 78) after MRgFUS-thalamotomy. Magnetic resonance imaging (MRI) was obtained at 6 months (n = 60). Primary outcomes included: (1) change in the Clinical Rating Scale of Tremor (CRST)-A+B score in the treated hand and (2) frequency and severity of adverse events (AEs) at 6 months. Secondary outcomes included changes in all subitems of the CRST scale in the treated hand, CRST-C, axial tremor (face, head, voice, tongue), AEs, and correlation of primary outcomes at 6 months with lesion characteristics. Statistical analysis included linear mixed, standard, and logistic regression models. RESULTS: Scores for CRST-A+B, CRST-A, CRST-B in the treated hand, CRST-C, and axial tremor were improved at each evaluation (P < 0.001). Five patients had severe AEs at 1 month that became mild throughout the follow-up. Mild AEs occurred in 71%, 45%, and 34% of patients at 1, 3, and 6 months, respectively. Lesion volume was associated with the reduction in the CRST-A (P = 0.003) and its overlapping with the ventralis intermedius nucleus (Vim) nucleus with the reduction in CRST-A+B (P = 0.02) and CRST-B (P = 0.008) at 6 months. CONCLUSIONS: MRgFUS-thalamotomy improves hand and axial tremor in ET patients. Transient and mild AEs are frequent. Lesion volume and location are associated with tremor reduction. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Posterior reversible encephalopathy syndrome (PRES): a rare condition after resection of posterior fossa tumors: two new cases and review of the literature.

INTRODUCTION: In 1996, Hinchey and colleagues coined the term "Posterior reversible encephalopathy syndrome" (PRES) to describe a condition seen in patients with acute neurological symptoms and reversible subcortical vasogenic edema predominantly involving parieto-occipital areas demonstrated in brain MRI. The occurrence of this phenomenon after surgical resection of CNS tumors is typically linked to pediatric cases. MATERIAL AND METHODS: Two new cases of PRES after posterior fossa surgery are reported. A thorough review of the literature is carried out with the purpose of updating and summarizing the main features regarding PRES in similar cases. Seven cases of PRES after resection of a posterior fossa tumor have been hitherto reported (4 patients were <20 years old). There is another pediatric case described after a ventriculoperitoneal shunting procedure in a patient with fourth ventricle ependymoma. Two resected tumors were ependymomas, 2 hemangiopericytomas in one patient, 1 pilocyticastrocytoma, 1 vestibular schwannoma, and 1 of the reported cases did not describe the final pathology diagnosis. CASE REPORTS: We present 2 new cases of PRES after surgical resection of a posterior fossa tumor (medulloblastoma in case 1 and ependymoma in case 2) in pediatric patients. Case 1 developed delayed seizures and altered mental status(10 days after surgical resection) after receiving treatment with bromocriptine for cerebellar mutism. Case 2 presented with generalized seizures and altered mental status within the first 48 postoperative hours followed by right hemiparesis. Both patients fully recovered and returned to neurological baseline status. A thorough review of the literature was carried out with the purpose of updating and summarizing the main features regarding PRES in similar cases. CONCLUSIONS: We report 2 new pediatric cases of posterior reversible encephalopathy syndrome (PRES) that developed after surgical resection of a posterior fossa tumor. Appropriate management includes supportive measures, antihypertensive agents, and antiepileptic drugs, if needed. Full recovery is the most likely outcome in line with previous articles.

Revisiting Forel Field Surgery.

BACKGROUND: Lesioning the Forel field or the subthalamic region is considered a possible treatment for tremoric patients with Parkinson disease, essential tremor, and other diseases. This surgical treatment was performed in the 1960s to 1970s and was an alternative to thalamotomy. Recently, there has been increasing interest in the reappraisal of stimulating and/or lesioning these targets, partly as a result of innovations in imaging and noninvasive ablative technologies, such as magnetic resonance-guided focused ultrasonography. OBJECTIVE: We wanted to perform a thorough review of the subthalamic region, both from an anatomic and a surgical standpoint, to offer a comprehensive and updated analysis of the techniques and results reported for patients with tremor treated with different techniques. METHODS: We performed a systematic review of the literature, gathering articles that included patients who underwent ablative or stimulation surgical techniques, targeting the pallidothalamic pathways (pallidothalamic tractotomy), cerebellothalamic pathway (cerebellothalamic tractotomy), or subthalamic area. RESULTS: Pallidothalamic tractotomy consists of a reduced area that includes pallidofugal pathways. It may be considered an interesting target, given the benefit/risk ratio and the clinical effect, which, compared with pallidotomy, involves a lower risk of injury or involvement of vital structures such as the internal capsule or optic tract. Cerebellothalamic tractotomy and/or posterior subthalamic area are other alternative targets to thalamic stimulation or ablative surgery. CONCLUSIONS: Based on the significant breakthrough that magnetic resonance-guided focused ultrasonography has meant in the neurosurgical world, some classic targets such as the pallidothalamic tract, Forel field, and posterior subthalamic area may be reconsidered as surgical alternatives for patients with movement disorders.

Imaging and Radiologic-Pathologic Correlation in Granular Cell Astrocytomas: Report of 2 Cases.

BACKGROUND: Granular cell astrocytoma is a rare and aggressive subtype of astrocytoma that is histopathologically well defined in the literature. It is formed by polygonal cells with granular cytoplasm mixed with neoplastic astrocytes and usually a perivascular infiltrate of lymphocytes. Despite its unusual histologic appearance, relevant radiologic features have not yet been described. CASE DESCRIPTION: We report 2 middle-aged patients with neurologic symptoms secondary to a newly diagnosed brain tumor. The absence of central tumor necrosis as well as the presence of an atypical pattern of enhancement and areas of intense diffusion restriction on magnetic resonance imaging in both cases led to the diagnosis of primary central nervous system lymphoma. Histopathologic findings in both tumors showed an aggressive astrocytoma with a prominent granular cell population and perivascular lymphocytic cuffing in tissue, corresponding to a granular cell astrocytoma. Despite the favorable prognostic factors, including World Health Organization grades II and III astrocytomas and IDH mutations, the outcome was poor. CONCLUSIONS: Granular cell astrocytomas can show unusual aggressive radiologic features that do not correspond to their histopathologic grade of malignancy. The presence of perivascular lymphocytic infiltrate may alter the typical radiologic appearance of common astrocytomas.

Misdiagnosis of posterior sequestered lumbar disc herniation: report of three cases and review of the literature.

INTRODUCTION: Posterior migration of sequestered disc is an extremely rare event that mimics more common spinal lesions as spinal tumors, making difficult its preoperative diagnosis and appropriate management. We retrospectively reviewed all lumbar disc herniations treated by surgery at our institution from 2006 to 2016 to identify cases with posterior sequestered disc fragments and possible misdiagnosis for other spinal lesions. Complementarily, a literature review of misdiagnosed cases of posterior migrated discs was undertaken. CASE REPORT: Three posterior sequestered lumbar disc cases (one intradural), were found among the 1153 reviewed surgeries. Two of them, presenting with progressive neurological deficit, were respectively misdiagnosed as pseudotumoral lesion and meningioma/neurogenic tumor on MRI. After intraoperative diagnosis and emergent resection, histology confirmed intervertebral disc tissue. The remaining case had an accurate preoperative diagnosis and after an initial conservative management finally underwent surgery because of refractory pain. Full recovery was achieved months after surgical treatment in all cases. DISCUSSION: Non-tumoral lesions are the most frequent misdiagnosis of posterior sequestered lumbar disc described in the literature. Early surgical treatment is the standard management due to high incidence of cauda equine syndrome (CES); however, spontaneous regression of posterior sequestered lumbar disc herniations has been recently reported. In conclusion low incidence and similar clinical and radiological features with other more common posterior spinal lesions like hematomas, synovial cyst or abscess turns posterior sequestered disc herniations a diagnosis challenge. Despite high incidence of CES, an initial conservative management should be evaluated in selected patients without neurological deficit and well-controlled pain.

Multinodular and vacuolating neuronal tumor of the cerebrum. A rare entity. New case and review of the literature.

BACKGROUND: Multinodular and vacuolating neuronal tumor has been recently described and included in the World Health Organization Classification of Tumors of The Central Nervous System, even though its consideration as a true tumor is controversial. Patients with these lesions usually present with refractory seizures and inconclusive imaging findings that may be confused with other more common diagnoses such as dysembryoplastic neuroepithelial tumors or low-grade gliomas. Therefore, surgical resection is warranted to reach a pathologic diagnosis and seizure control. To the best of our knowledge, only 16 cases have been published in the English literature. CASE DESCRIPTION: We present the case of a 52-year-old male who presented at our institution with a 2-year-history of absence of seizures. Brain MRI showed a T2-hyperintense lesion with no contrast enhancement affecting his temporal lobe. Temporal craniotomy and microsurgical resection was scheduled. The procedure was uneventful and a grayish, gluey mass was sent for pathologic analysis. The tumor was formed by immature neuronal cells organized in nodules with a vacuolated matrix. A thorough immunohistochemical analysis showed positivity for: Protein Gene Product 9.5. ATRX. OLIG2. SOX10. p16. Nestin. Synaptophysin. The findings were consistent with multinodular and vacuolating neuronal tumor. The patient has been seizure-free after surgery and with no signs of tumor progression. CONCLUSION: We present a thorough review addressing this uncommon tumor along with a description of the 17th reported case of MVNT, a tumor that was described for the first time in 2013. Further studies and case studies are necessary to establish a well-defined morphological and immunohistochemical profile along with knowledge about its natural history.

Microvascular Decompression for Trigeminal Neuralgia Using a Novel Fenestrated Clip and Tentorial Flap Technique.

BACKGROUND: Microvascular decompression (MVD) for neurovascular compression syndromes, such as trigeminal neuralgia and hemifacial spasm, has been traditionally described as an interposing technique using Teflon. Some alternative interposing materials have been proposed. In addition, transposing techniques have been increasingly reported as an alternative with a potentially lower recurrence rate and fewer complications. OBJECTIVE: To describe our experience with a technique consisting of transposition of the superior cerebellar artery using a fenestrated clip and a tentorial flap in patients with trigeminal neuralgia. METHODS: We describe a novel transposing technique using a fenestrated clip and a tentorial flap in patients with neurovascular compression. An illustrative case is provided of an 83-year-old female patient who complained of a 4-year history of left trigeminal neuralgia caused by compression by the superior cerebellar artery who was treated with this technique. Furthermore, a thorough review of the literature is presented. RESULTS: The patient underwent the procedure with the proposed technique without complication. Both the surgery and the postoperative course were uneventful. The patient remains asymptomatic 1 year after the procedure. CONCLUSION: We propose a novel technique for the treatment of trigeminal neuralgia, eliminating the need for padding the vessel with a foreign body. This technique can be applied successfully in selected cases of neurovascular compression syndromes.

Angiocentric Glioma in an Elderly Patient: Case Report and Review of the Literature.

BACKGROUND: Angiocentric glioma is a very uncommon low-grade tumor, predominantly occurring in pediatric patients, that was first described in 2005 and was codified 2 years later as a new central nervous system primary tumor. We herein report an exceptionally rare case of an elderly patient with angiocentric glioma. Only one additional case of angiocentric glioma in a patient older than 65 years has been hitherto reported. CASE DESCRIPTION: An 83-year-old male patient presented at our institution complaining of a 1-month history of progressive weakness of his right hand and difficulty performing fine movements. Magnetic resonance imaging of the brain was performed, and fluid-attenuated inversion recovery and T2-hyperintense diffuse cortico-subcortical lesion were reported. A neuronavigation-guided frontal craniotomy was performed to expose the premotor cortex, motor cortex, Rolandic sulcus, and postcentral gyrus. Intraoperative mapping showed that the tumor was close to the shoulder area. Therefore, only partial resection was safely feasible. Pathology report described astrocytic neoplastic cells affecting mainly the cortex and piamater with the classic finding of subpial palisading, with no endothelial invasion or atypia. Neoplastic cells were positive for glial fibrillary acidic protein, epithelial membrane antigen, Wilms tumor protein-1, P16, and P53. Low proliferative activity was seen (Ki-67 < 2%). Abundant gliovascular structures were also reported. CONCLUSIONS: Considering the morphologic and immunohistochemical data, the final pathologic diagnosis was angiocentric glioma. Furthermore, a thorough review of the literature was performed with the purpose of updating and summarizing the main clinical, radiologic, and pathologic features of this rare tumor.

Hypoglossal nerve paresis secondary to anterior approach of upper cervical spine followed by spontaneous recovery.

We describe an exceptional complication of cervical spine surgery in a 63-year-old male. He suffered the impact of a beam to the top of his head. During evaluation in the emergency room he reported intense neck pain with no other neurological symptoms or findings on physical examination. Spine computed tomography (CT) showed C3 vertebral body fracture that required surgical stabilization. A right side anterior approach to upper cervical spine with C3 corpectomy and placement of iliac bone autograft was performed. After surgery the patient presented dysphagia, dysarthria and limitation tongue mobility to the right side. These findings were consistent with hypoglossal neuropraxia probably related to soft tissue traction generated by the upper part of the self-retaining retractor. After discharge the patient experienced spontaneous improvement of hypoglossal paresis.

Expanded Endoscopic Transclival Approach for Resection of a Chordoid Meningioma without Dural Attachment (MWODA) Located in the Prepontine Cistern.

BACKGROUND: Meningiomas without dural attachment (MWODA) located in the posterior fossa are an unfrequent entity. They are usually located in the fourth ventricle, and their occurrence outside of this anatomic structure is an even more uncommon finding. Chordoid meningiomas are a rare subtype of meningioma, and they have been reported to account for 0.5%-1% of all meningiomas. CASE DESCRIPTION: We report the unusual case of a 36-year-old female patient, with unremarkable past medical history, who presented at our institution complaining of acute binocular diplopia. Right cranial nerve VI paresis was observed on physical examination. Imaging studies revealed an intradural retroclival solid mass that enhanced homogeneously after contrast administration. Interestingly, no dural tail was present. Expanded endonasal endoscopic resection of her retroclival lesion was performed. We used a 4-hand technique with 0 and 30 degrees endoscopes, with intradural pituitary transposition. Gross total resection was achieved and the pathology report described findings consistent with chordoid meningioma. The patient is recurrence-free and in good condition at 1-year follow-up. CONCLUSIONS: We performed a thorough review of the literature, and we found 10 reported cases describing extraventricular MWODA in the posterior fossa. To our knowledge, this is the first reported case of retroclival MWODA with pathologic findings consistent with chordoid meningioma.