National multicentered retrospective review of clinical and intraoperative factors associated with the development of cerebellar mutism after pediatric posterior fossa tumor resection.

BACKGROUND: Cerebellar mutism (CM) is characterized by a significant loss of speech in children following posterior fossa (PF) surgery. The biological origin of CM remains unclear and is the subject of ongoing debate. Significant recovery from CM is less likely than previously described despite rigorous multidisciplinary neuro-rehabilitational efforts. METHODS: A national multi-centered retrospective review of all children undergoing PF resection in four midsized Canadian academic pediatric institutions was undertaken. Patient, tumor and surgical factors associated with the post-operative development of CM were reviewed. Retrospective identification of PF surgery patients including those developing and those that did not (internal control). RESULTS: The study identified 258 patients across the 4 centers between 2010 and 2020 (mean age 6.73 years; 42.2% female). Overall, CM was experienced in 19.5% of patients (N = 50). Amongst children who developed CM histopathology included medulloblastoma (35.7%), pilocytic astrocytoma (32.6%) and ependymoma (17.1%). Intraoperative impression of adherence to the floor of the 4th ventricle was positive in 36.8%. Intraoperative abrupt changes in blood pressure and/or heart rate were identified in 19.4% and 17.8% of cases. The clinical resolution of CM was rated to be complete, significant resolution, slight improvement, no improvement and deterioration in 56.0%, 8.0%, 20.0%, 14.0% and 2.0%, respectively. In the cohort of children who experienced post-operative CM as compared to their no-CM counterpart, proportionally more tumors were felt to be adherent to the floor of the 4th ventricle (56.0% vs 49.5%), intraoperative extent of resection was a GTR (74% vs 68.8%) and changes in heart rate were noted (≥ 20% from baseline) (26.0% vs 15.9%). However, a multiple regression analysis identified only abrupt changes in HR (OR 5.97, CI (1.53, 23.1), p = 0.01) to be significantly associated with the development of post-operative CM. CONCLUSION: As a devastating surgical complication after posterior fossa tumor surgery with variable clinical course, identifying and understanding the operative cues and revising intraoperative plans that optimizes the child's neurooncological and clinical outcome are essential.

Undifferentiated presentation of unilateral agenesis of a cervical pedicle and a contiguous vertebral hemangioma: illustrative case.

BACKGROUND: Unilateral agenesis of a cervical pedicle is a known rare entity that has been well described over the past 70 years. It is usually an incidental or minimally symptomatic presentation with no significant clinical repercussion. No previous report has described concurrent non-osseous developmental abnormalities alongside this unique pathology. OBSERVATIONS: This case reported a cervical hemangioma with associated unilateral pedicle agenesis and an incidental finding of callosal dysgenesis and lipoma. The initial presentation consisted solely of persistent neck pain, with cervical radiography illustrating significant kyphotic deformity secondary to apparent anterolisthesis of C3-C4. The patient underwent a combined approach: anterior cervical corpectomy at C4-C5 with supplemental posterior fusion. The authors provided a review of the literature concerning developmental pedicle abnormalities and vertebral hemangioma. Pedicle agenesis is known to be associated with multiple pathologies, but the authors have not found evidence of a clinical paradigm consisting of a vertebral hemangioma in the presence of cervical pedicle agenesis, callosal dysgenesis, or callosal lipoma. LESSONS: Careful evaluation of radiographs with appropriate subsequent multimodal imaging is key to identifying unique pathologies in the spine that complement a patient's history and clinical findings. If multiple abnormalities are noted, a novel clinical etiology or syndrome must be considered.