Posterior fossa syndrome and increased mean diffusivity in the olivary bodies.

OBJECTIVE: Posterior fossa syndrome (PFS) is a common postoperative complication following resection of posterior fossa tumors in children. It typically presents 1 to 2 days after surgery with mutism, ataxia, emotional lability, and other behavioral symptoms. Recent structural MRI studies have found an association between PFS and hypertrophic olivary degeneration, which is detectable as T2 hyperintensity in the inferior olivary nuclei (IONs) months after surgery. In this study, the authors investigated whether immediate postoperative diffusion tensor imaging (DTI) of the ION can serve as an early imaging marker of PFS. METHODS: The authors retrospectively reviewed pediatric brain tumor patients treated at their institution, Lucile Packard Children's Hospital at Stanford, from 2004 to 2016. They compared the immediate postoperative DTI studies obtained in 6 medulloblastoma patients who developed PFS to those of 6 age-matched controls. RESULTS: Patients with PFS had statistically significant increased mean diffusivity (MD) in the left ION (1085.17 ± 215.51 vs 860.17 ± 102.64, p = 0.044) and variably increased MD in the right ION (923.17 ± 119.2 vs 873.67 ± 60.16, p = 0.385) compared with age-matched controls. Patients with PFS had downward trending fractional anisotropy (FA) in both the left (0.28 ± 0.06 vs 0.23 ± 0.03, p = 0.085) and right (0.29 ± 0.06 vs 0.25 ± 0.02, p = 0.164) IONs compared with age-matched controls, although neither of these values reached statistical significance. CONCLUSIONS: Increased MD in the ION is associated with development of PFS. ION MD changes may represent an early imaging marker of PFS.

Common Conditions Requiring Long-Term Anticoagulation in Neurosurgical Patients.

Long-term anticoagulant therapy prevents thrombosis. Management of neurosurgical patients with conditions such as atrial fibrillation, mechanical heart valves, and other prothrombotic states necessitates application of a strategy to mitigate hemorrhagic complications of anticoagulation. Development of direct oral anticoagulants, which include the direct thrombin and factor X inhibitors, yields new considerations to be had, in particular, the introduction of reversal agents. This article reviews the more common chronic clinical entities that require the use of prolonged anticoagulant therapy with special consideration for neurosurgical patients. It also includes a discussion of established treatment strategies across available treatment options.