UNASSIGNED: Advancements in minimally invasive spinal surgery have led to an expansion of targeted pathologies as well as improvements in surgical outcomes compared to their conventional counterparts through open laminectomy; however, this technique is rarely mentioned in the literature for intrinsic cord lesions. The authors present a novel minimally invasive, dorsolateral, and expandable tubular approach for the resection of an intradural, intramedullary thoracic cavernous malformation (CM).
UNASSIGNED: A 52-year-old male patient presented with rapidly progressive myelopathy and loss of ambulatory capabilities, with which magnetic resonance imaging revealed a hemorrhagic CM within the thoracic spinal cord. The CM was successfully resected through a minimally invasive tubular approach utilizing a dorsal root entry zone myelotomy. Postoperative imaging confirmed gross resection. His motor examination rapidly recovered, and he remains ambulatory with the use of a cane at a 2-year follow-up.
UNASSIGNED: This novel minimally invasive approach is a promising technique for well-selected cases of symptomatic spinal CMs. Further exploration and potentially randomized studies are necessary to fully affirm the tubular approach\'s suitability for the treatment of intradural intramedullary CMs compared to conventional techniques.

Cavernous malformations surrounding the fourth ventricle are challenging lesions to access and treat surgically owing to the complexity and eloquence of adjacent neural tissue [1] Long-standing practice included tissue transgression through the overlying cerebellar cortical surface of the hemisphere or vermis [1-3]. Using natural corridors such as tonsillobiventral fissure, cerebellomedullary fissure, and tonsillouvular fissure (TUF) offers elegant access to the fourth ventricle, avoiding traversing of neural tissue [4-7]. A 32-year-old male presented with headache, nausea, vomiting, double vision, and vertigo. Neuroimaging demonstrated a 17-mm diameter cavernous malformation protruding into the left lateral recess of the fourth ventricle. The patient consented for the procedure and underwent a middline suboccipital craniotomy in a prone position. TUF approach was performed by dissecting the arachnoid to the depth of the fissure, and after identifying the tonsillomedullary segment of the posterior inferior cerebellar artery, minimal white matter transgression was used to reach cavernous malformation. Complete removal of the lesion was achieved and confirmed on postoperative imaging. The postoperative course was uneventful. TUF approach with manipulation by ipsilateral and contralateral retraction of tonsills allows the widening of the surgical corridor and better exposure of lesions of the lateral recess of the fourth ventricle [1]. TUF approach is a valuable alternative to transvermian and transcerebellar approaches that minimize the division of neural tissue [6]. To the best of our knowledge this is the first case describing the TUF approach to exophytic cavernoma presenting in the lateral recess of the fourth ventricle. Under our institutional ethical review board regulations, approval was not necessary.

BACKGROUND: Stereotactic radiosurgery (SRS) for cerebral cavernous malformations has been used for more than 30 years. However, indications for this method and outcomes are still discussable.
OBJECTIVE: To analyze available literature data on SRS for cerebral cavernous malformations with assessment of indications for treatment, radiation parameters, radiological and clinical complications and outcomes.
RESULTS: The final analysis included 20 reports describing post-SRS outcomes in 1834 patients with cerebral cavernous malformations. The main radiation parameter was mean radiation dose to the edge of cavernous malformation (prescribed dose, 13.25±2.16 Gy). In natural course of malformation, mean incidence of hemorrhages from cavernous malformation when counted after the second hemorrhage was 25.9±14.6%, after the patient\'s birth - 2.59±0.44%. Mean follow-up period after SRS was 66.7±24.1 months. Incidence of hemorrhages from cavernous malformation after SRS for the first 2 years of follow-up was assessed in 14 studies (4.67±3.51%). Incidence of hemorrhages ≥2 years after SRS was analyzed in 12 studies (1.55±0.8%).
CONCLUSIONS: Despite significant global experience in SRS for cerebral cavernous malformations and many studies devoted to this problem, clear patient selection criteria have not yet been formulated. Modern selection principles have insufficient evidence base.
Стереотаксическая радиохирургия (СРХ) кавернозных мальформаций (КМ) головного мозга применяется уже более 30 лет. Тем не менее вопросы показаний к этому виду лечения и оценки его результатов продолжают оставаться предметом обсуждения.
UNASSIGNED: Анализ данных литературы по проблеме радиохирургического лечения КМ головного мозга различной локализации с оценкой показаний к лечению, параметров облучения, рентгенологических и клинических осложнений и исходов лечения.
UNASSIGNED: В итоговый анализ было включено 20 публикаций, в которых описываются результаты СРХ 1834 пациентов с КМ головного мозга. Основным приводимым параметром облучения являлась средняя доза облучения на край КМ (предписанная доза), средний показатель которой составил 13,25±2,16 Гр. При естественном течении КМ средняя частота кровоизлияний из КМ при подсчете от второго кровоизлияния составила 25,9±14,6%, при подсчете от рождения пациента — 2,59±0,44%. Средний срок наблюдения после СРХ составил 66,±24,1 мес. Частота кровоизлияний из КМ после СРХ за первые 2 года наблюдения оценивалась в 14 исследованиях — средний показатель составил 4,67±3,51%. В 12 исследованиях рассчитана частота кровоизлияний через 2 года и более после РХ, средний показатель составил 1,55±0,8%.
UNASSIGNED: Несмотря на значительный мировой опыт применения СРХ при КМ различных отделов головного мозга и наличие множества научных работ, посвященных данной проблеме, четкие критерии отбора пациентов для данного вида лечения до сих пор не сформулированы, а имеющиеся принципы отбора имеют низкую степень доказательности.

BACKGROUND: Craniotomy is required for the removal of brainstem cavernous malformations (CMs) with repeated hemorrhage, and this condition is often complicated by an accompanying developmental venous anomaly (DVA). However, a DVA of the brainstem or cerebellum with drainage penetrating the pons is an exceptional finding.
METHODS: A 57-year-old man presented with double vision. Computed tomography revealed progressive enlargement of the hemorrhage in the dorsal pons. Contrast-enhanced magnetic resonance angiography revealed an expanded transverse vessel penetrating the center of the pons in contact with the CM. Digital subtraction angiography revealed that the DVA, comprising the expanded transpontine vein and some cerebellar medullary veins acting as normal venous drainage, coexisted with the CM. By utilizing the angioarchitecture and intraoperative neuronavigation system data, electrophysiological mapping, and indocyanine green videoangiography, complete removal of the CM was accomplished while preserving the DVA and brain function.
CONCLUSIONS: This study presents the intraoperative images of an expanded transpontine vein as a DVA, which has never been depicted in a live patient before, accompanied by a CM in the dorsal portion of the pons. https://thejns.org/doi/10.3171/CASE24314.

Immune thrombocytopenia (ITP) is an autoimmune disease resulting in a fall in platelet count, causing ecchymoses and bleeding manifestations. The most prevalent acquired bleeding disorder in children is ITP. Intracranial hemorrhage (ICH) is a rare but most devastating complication of ITP which can cause neurological sequelae. We report the case of a four-year-old male child who presented with a history of seizures, headache, multiple ecchymoses, and bruising. Blood counts and bone marrow examination were suggestive of ITP. Magnetic resonance imaging (MRI) of the brain showed ICH with multiple cerebral cavernous malformations. ICH as the first presentation of ITP is extremely rare. ICH in a case of ITP secondary to arteriovenous malformation has been scarcely reported, establishing the rarity of the currently presented case. Morbidity and mortality of ICH occurring as a consequence of ITP can be reduced by recognizing the symptoms, diagnosing promptly, and treating aggressively.

OBJECTIVE: The objective was to demonstrate the surgical steps and outcomes of the sublabial transmaxillary microsurgical approach with endoscopic assistance to treat lesions in the inferior aspect of the orbit, as well as to describe the use of patient-specific 3D models to facilitate surgical preparation and improve experience with the technique.
METHODS: The authors\' study evaluated data from patients who underwent an endoscope-assisted sublabial transmaxillary approach for inferior orbital lesions. For 2 patients, 3D models were created for preoperative planning and assessment of the approach. Surgical steps comprised osteotomy to access the maxillary sinus, bony resection of the orbital floor, opening of the periorbital fascia, and dissecting and removing the lesion, followed by closure. The neuroendoscope was used to inspect the surgical cavity between each step.
RESULTS: The study included 5 patients with varying visual field defects and proptosis who underwent the sublabial transmaxillary microsurgical approach with endoscopic assistance. Complete resection was achieved in all, and all patients reported improvement in visual field defects and proptosis after the procedure. No complications were observed except for transient unilateral maxillary edema noted around the incision site in 3 patients during the early postoperative period, which resolved within a few days. Histopathological examination confirmed the diagnosis of cavernous malformation in all patients.
CONCLUSIONS: The sublabial transmaxillary approach is a direct and safe method to resect cavernous malformations at the inferior aspect of the orbit. It reduces the risk of complications associated with lateral, transcranial, and transnasal approaches that may cross critical structures. The microsurgical approach provides the benefit of two-handed dissection for lesions embedded in orbital fat, which can be challenging because of adhesions to surrounding tissues. The use of 3D models can facilitate surgical planning and enhance familiarity with the approach.

BACKGROUND: Understanding the intricate relationship between consciousness and the midbrain\'s structures remains a significant challenge in neuroscience. Transient lesions are perfect examples of the physiological functioning mechanism of these structures.
METHODS: The authors present the case of a 49-year-old female who experienced a transient disorder of consciousness due to a midbrain hematoma following surgical interventions to remove a cavernous malformation in the midbrain. This case explores the interplay between the ascending reticular activating system (ARAS) and the thalamic centers, highlighting the role of structural disruptions in influencing consciousness levels. Notably, the patient\'s recovery correlated with the resolution of midbrain edema, reinstating normal ARAS function and consciousness.
CONCLUSIONS: In patients affected by midbrain lesions, edema can lead to a fluctuating neurological status, which can be difficult to diagnose. This case highlights the midbrain\'s crucial role in the consciousness network and the need to comprehend the intricate connections between subcortical and cortical structures for a comprehensive understanding of human consciousness. https://thejns.org/doi/10.3171/CASE2411.

Cerebral cavernomas belong to a group of vascular lesions characterized by varying structural properties and presentations. Clinical manifestations vary among patients and are particularly influenced by age, posing challenges in diagnosis and treatment. Here, we present a pediatric case of a cerebral cavernoma, which is very rare. We further aim to emphasize the importance of a good physical examination.

BACKGROUND: Familial cerebral cavernous malformation (CCM) syndrome is characterized by multiple, non-contiguous cavernous malformations. The lesion burden may affect morbidity. Our aim was to identify risk factors for high lesion burden in these patients.
METHODS: Patients with radiologically confirmed CCM were screened between 2015 and 2023. Only familial or presumed familial CCM patients were included. Demographic information and medical history at the time of diagnosis were evaluated. The first diagnostic MRI was used to determine T2 total and T2 large lesion (≥5 mm) count. Chi-square was used to determine risk factors for total T2 large lesion count ≥5.
RESULTS: Of 107 patients with familial or presumed familial CCM (55.1 % female, age 42.4 years), the median total T2 lesion count and large lesion count was 4 (range: 1-109) and 2 (range: 0-50) respectively. Current tobacco use was a risk factor for T2 large lesion count ≥5.
CONCLUSIONS: Further studies combining familial cohorts and assessing length of exposure may be useful to confirm tobacco as a risk factor for T2 large lesion formation in familial CCM.

BACKGROUND: Cavernous malformations (CMs) originating from spinal nerve roots are rare but can present with rapidly progressing neurological deficits. Therefore, quick identification and treatment are essential.
METHODS: The authors present the case of a 52-year-old male presenting with headaches and gait disturbance, found to have a CM of the C1 nerve root. The patient underwent successful suboccipital craniectomy and C1 laminectomy, with complete resection of the lesion, preservation of the cervical spinal nerve roots, and symptomatic improvement postoperatively.
CONCLUSIONS: This is the first presentation in the literature of a CM originating from the C1 nerve root. The authors show complete resection of the lesion with preservation of the C1 nerve root. Nerve root lesions usually show insidious symptomatic onset. Quick identification and resection are recommended to prevent permanent neurological disability. https://thejns.org/doi/10.3171/CASE2456.