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Background: Surgical decompression for the treatment of chronic subdural hematomas (cSDHs) is irrefutably effective; however, its utility in managing cSDH in patients with comorbid coagulopathy remains controversial. The optimal threshold for platelet transfusion in cSDH management is <100,000/mm³, according to guidelines from the American Association of Blood Banks GRADE framework. This threshold may be unachievable in refractory thrombocytopenia, though surgical intervention may still be warranted. We present a patient with symptomatic cSDH and transfusion-refractory thrombocytopenia successfully treated with middle meningeal artery embolization (eMMA). We also review the literature to identify management approaches for cSDH with severe thrombocytopenia. Case Description: A 74-year-old male with acute myeloid leukemia presented to the emergency department with persistent headache and emesis following fall without head trauma. Computed tomography (CT) revealed a 12 mm right-sided, mixed density SDH. Platelets were <2000/mm3 initially, which stabilized to 20,000 following platelet transfusions. He then underwent right eMMA without surgical evacuation. He received intermittent platelet transfusions with platelet goal >20,000 and was discharged on hospital day 24 with resolving SDH on CT. Conclusion: High-risk surgical patients with refractory thrombocytopenia and symptomatic cSDH may be successfully treated with eMMA without surgical evacuation. A platelet goal of 20,000/mm3 before and following surgical intervention proved beneficial for our patient. Similarly, a literature review of seven cases of cSDH with comorbid thrombocytopenia revealed five patients undergoing surgical evacuation following initial medical management. Three cases reported a platelet goal of 20,000. All seven cases resulted in stable or resolving SDH with platelets >20,000 at discharge. [ABSTRACT FROM AUTHOR]

Background: Craniovertebral junction (CVJ) schwannomas are rare, with surgery and stereotactic radiosurgery (SRS) being effective yet challenging options. We systematically reviewed the literature on CVJ schwannomas. Methods: PubMed, Scopus, Web-of-Science, and Cochrane were searched following the PRISMA statement to include studies reporting CVJ schwannomas. Clinical features, management, and outcomes were analyzed. Results: We collected 353 patients from 101 included articles. Presenting symptoms were mostly neck pain (30.3%) and headache (26.3%), with most cranial neuropathies involving the XII (31.2%) and X (24.4%) nerves. Most tumors originated from C2 (30.9%) and XII (29.4%) nerves, being extracranial (45.1%) and intradural-extradural (44.2%). Erosion of C1–C2 vertebrae (37.1%), the hypoglossal canal (28.3%), and/or jugular foramen (20.1%) were noted. All tumors were operated, preferably with the retrosigmoid approach (36.5%), with the far-lateral approach (29.7%) or with the posterior approach and cervical laminectomy (26.9%), far-lateral approaches (14.2%), or suboccipital craniotomy with concurrent cervical laminectomy (14.2%). Complete tumor resection was obtained most frequently (61.5%). Adjuvant post-surgery stereotactic radiosurgery was delivered in 5.9% patients. Median follow-up was 27 months (range, 12–252). Symptom improvement was noted in 88.1% of cases, and cranial neuropathies showed improvement in 10.2%. Post-surgical complications occurred in 83 patients (23.5%), mostly dysphagia (7.4%), new cranial neuropathies (6.2%), and cerebrospinal fluid leak (5.9%). A total of 16 patients (4.5%) had tumor recurrence and 7 died (2%), with median overall survival of 2.7 months (range, 0.1–252). Conclusions: Microsurgical resection is safe and effective for CVJ schwannomas. Data on SRS efficacy and indications are still lacking, and its role deserves further evaluation. [ABSTRACT FROM AUTHOR]

Simple Summary: [68Ga]Ga-DOTA-SSTR PET imaging has recently been introduced in the management of patients with brain tumors, mostly meningiomas and pituitary adenomas or carcinomas. The current literature demonstrated the superior diagnostic accuracy of this imaging modality, especially for lesions difficult to be detected or characterized on conventional imaging protocols, such as skull base or transosseous meningiomas. [68Ga]Ga-DOTA-SSTR PET tracers also seem to provide superior volume contouring for radiotherapy planning and may also be used to evaluate the tumor's overexpression of somatostatin receptors for devising patient-tailored peptide receptor radionuclide therapy. In this review, we comprehensively analyzed the current literature discussing the implementation of [68Ga]Ga-DOTA-SSTR PET imaging in brain tumors, further presenting ongoing clinical trials and suggesting potential future applications. Background: The development of [68Ga]Ga-DOTA-SSTR PET tracers has garnered interest in neuro-oncology, to increase accuracy in diagnostic, radiation planning, and neurotheranostics protocols. We systematically reviewed the literature on the current uses of [68Ga]Ga-DOTA-SSTR PET in brain tumors. Methods: PubMed, Scopus, Web of Science, and Cochrane were searched in accordance with the PRISMA guidelines to include published studies and ongoing trials utilizing [68Ga]Ga-DOTA-SSTR PET in patients with brain tumors. Results: We included 63 published studies comprising 1030 patients with 1277 lesions, and 4 ongoing trials. [68Ga]Ga-DOTA-SSTR PET was mostly used for diagnostic purposes (62.5%), followed by treatment planning (32.7%), and neurotheranostics (4.8%). Most lesions were meningiomas (93.6%), followed by pituitary adenomas (2.8%), and the DOTATOC tracer (53.2%) was used more frequently than DOTATATE (39.1%) and DOTANOC (5.7%), except for diagnostic purposes (DOTATATE 51.1%). [68Ga]Ga-DOTA-SSTR PET studies were mostly required to confirm the diagnosis of meningiomas (owing to their high SSTR2 expression and tracer uptake) or evaluate their extent of bone invasion, and improve volume contouring for better radiotherapy planning. Some studies reported the uncommon occurrence of SSTR2-positive brain pathology challenging the diagnostic accuracy of [68Ga]Ga-DOTA-SSTR PET for meningiomas. Pre-treatment assessment of tracer uptake rates has been used to confirm patient eligibility (high somatostatin receptor-2 expression) for peptide receptor radionuclide therapy (PRRT) (i.e., neurotheranostics) for recurrent meningiomas and pituitary carcinomas. Conclusion: [68Ga]Ga-DOTA-SSTR PET studies may revolutionize the routine neuro-oncology practice, especially in meningiomas, by improving diagnostic accuracy, delineation of radiotherapy targets, and patient eligibility for radionuclide therapies. [ABSTRACT FROM AUTHOR]

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a negative regulator of AKT/mTOR signaling pathway. Mutations in PTEN are found in patients with autism, epilepsy, or macrocephaly. In mouse models, Pten loss results in neuronal hypertrophy, hyperexcitability, seizures, and ASD-like behaviors. The underlying molecular mechanisms of these phenotypes are not well delineated. We determined which of the Pten loss-driven aberrations in neuronal form and function are orchestrated by downstream mTOR complex 1 (mTORC1). Rapamycin-mediated inhibition of mTORC1 prevented increase in soma size, migration, spine density, and dendritic overgrowth in Pten knockout dentate gyrus granule neurons. Genetic knockout of Raptor to disrupt mTORC1 complex formation blocked Pten loss-mediated neuronal hypertrophy. Electrophysiological recordings revealed that genetic disruption of mTORC1 rescued Pten loss-mediated increase in excitatory synaptic transmission. We have identified an essential role for mTORC1 in orchestrating Pten loss-driven neuronal hypertrophy and synapse formation. [Display omitted] • Pten KO results in increased neuronal growth and excitatory synapse function • Pharmacological inhibition of mTOR prevents morphological changes in Pten KO • Raptor KO rescues morphological and synaptic phenotypes of Pten KO • Downstream mTORC1 function is necessary for neuronal growth and synapse formation PTEN negatively regulates growth factor signaling through PI3K. Tariq et al. show that Pten loss in neurons causes overgrowth and increased excitatory synapse formation and function. Double knockout of Raptor and Pten normalizes neuronal growth, synapse number, and function. Neuronal hypertrophy and synapse formation downstream of PI3K requires mTORC1. [ABSTRACT FROM AUTHOR]

Cerebral cavernous malformations (CCM) in deep eloquent areas present a surgical challenge. Laser interstitial thermal therapy (LITT) may present itself as a safe minimally invasive treatment option. To systematically review the indications, safety, and outcomes of LITT for CCM. Electronic databases were searched from inception to October 7, 2021 for articles with CCM and LITT keywords. Studies describing CCMs treated with LITT were included. A total of 32 patients with CCMs in lobar (79%), basal ganglia (12%), and brainstem (9%) locations were treated with LITT. Indications for LITT included drug-resistant seizures (75%), unacceptable surgical risk (22%), recurrent hemorrhage (16%), and early intervention to discontinue antiepileptic drugs (3%). No death or CCM-associated intracranial hemorrhage occurred intraoperatively or postoperatively, and most patients experienced no adverse effects or transient effects that resolved at follow-up (84%). Of those treated for CCM-associated epilepsy, 83% experienced Engel class I seizure freedom and most were class IA (61%). Most patients experienced symptomatic improvement (93%), and a decrease in antiepileptic drugs was reported in more than half of patients (56%), with 28% able to discontinue all antiepilepsy medications after LITT. LITT seems to be a safe treatment for CCMs located in deep eloquent areas and in lesions presenting with medically refractory seizures or recurrent hemorrhages. Randomized studies are needed to further elucidate its efficacy in treating CCM. [ABSTRACT FROM AUTHOR]

Objective: To understand trends in neuronavigation we employed machine learning methods to perform a broad literature review which would be impractical by manual inspection., Methods: PubMed was queried for articles with "Neuronavigation" in any field from inception-2020. Articles were designated neuronavigation-focused (NF) if "Neuronavigation" was a major MeSH. The latent dirichlet allocation topic modeling technique was used to identify themes of NF research., Results: There were 3896 articles of which 1727 (44%) were designated as NF. Between 1999-2009 and 2010-2020, the number of NF publications experienced 80% growth. Between 2009-2014 and 2015-2020, there was a 0.3% decline. Eleven themes covered 1367 (86%) NF articles. "Resection of Eloquent Lesions" comprised the highest number of articles (243), followed by "Accuracy and Registration" (242), "Patient Outcomes" (156), "Stimulation and Mapping" (126), "Planning and Visualization" (123), "Intraoperative Tools" (104), "Placement of Ventricular Catheters" (86), "Spine Surgery" (85), "New Systems" (80), "Guided Biopsies" (61), and "Surgical Approach" (61). All topics except for "Planning and Visualization", "Intraoperative Tools", and "New Systems" exhibited a monotonic positive trend. When analyzing subcategories, there were a greater number of clinical assessments or usage of existing neuronavigation systems (77%) rather than modification or development of new apparatuses (18%)., Conclusion: NF research appears to focus on the clinical assessment of neuronavigation and to a lesser extent on the development of new systems. Although neuronavigation has made significant strides, NF research output appears to have plateaued in the last decade.