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Early postnatal anesthesia causes long-lasting learning and memory impairment in rodents, however, evidence for a specific neurotoxic effect on early synaptogenesis has not been demonstrated. Drebrin A is an actin binding protein whose localization in dendritic protrusions serves an important role in dendritic spine morphogenesis, and is a marker for early synaptogenesis. We therefore set out to investigate whether clinically-relevant concentrations of anesthetic sevoflurane, widely- used in infants and children, alters dendritic morphology in cultured fetal day 16 mouse hippocampal neurons. After 7 days in vitro, mouse hippocampal neurons were exposed to four hours of 3% sevoflurane in 95% air/5% CO2 or control condition (95% air/5% CO2). Neurons were fixed in 4% paraformaldehyde and stained with Alexa Fluor555-Phalloidin, and/or rabbit anti-mouse drebrin A/E antibodies which permitted subcellular localization of filamentous (F)-actin and/or drebrin immunoreactivity, respectively. Sevoflurane caused acute significant length-shortening in filopodia and thin dendritic spines in days-in-vitro 7 neurons, an effect which was completely rescued by co-incubating neurons with ten micromolar concentrations of the selective Rho kinase inhibitor Y27632. Filopodia and thin spine recovered in length two days after sevoflurane exposure. Yet cluster-type filopodia (a precursor to synaptic filopodia) were persistently significantly decreased in number on day-in-vitro 9, in part owing to preferential localization of drebrin immunoreactivity to dendritic shafts versus filopodial stalks. These data suggest that sevoflurane induces F-actin depolymerization leading to acute, reversible length-shortening in dendritic protrusions through a mechanism involving (in part) activation of RhoA/Rho kinase signaling and impairs localization of drebrin A to filopodia required for early excitatory synapse formation. [ABSTRACT FROM AUTHOR]

Background: Cervical laminoplasty is an established and effective surgical treatment for neurologic dysfunction associated with cervical myelopathy. "Dome laminotomies" involve undercutting the laminae adjacent to the laminoplasty levels to decompress and prevent spinal cord kinking on the lamina edges. The technique allows for a decrease in the number of instrumented laminae, smaller surgical exposure, and preservation of muscular attachments at the top of C2 and C7. We investigated whether dome laminotomies are associated with satisfactory neurologic and pain outcome., Methods: This study involved a retrospective review of consecutive patients treated at a single institution between November 2015 and September 2018. The patients underwent a C3-C6 laminoplasty with dome laminotomies of the caudal edge of C2 and the cranial edge of C7 lamina. Postoperative evaluations of pain, myelopathy symptoms, and complications occurred at early (mean, ∼2 months) and late (mean, ∼15 months) time points., Results: Twenty-one patients were enrolled (mean age, 62 years). Mean axial pain score improved significantly at both the early ( P = .02) and late ( P = .045) postoperative evaluations compared with the mean baseline pain score. A total of 92% of patients experienced resolution of baseline hand dysfunction at the early postoperative follow-up, and 84% maintained it at the late follow-up. Two-thirds of patients experienced (late) significant improvement ( P < 0.05) in baseline balance impairment. Postoperative response rates for urinary dysfunction were 58% (early) and 42% (late). There were no wound complications, late neurologic deterioration, kyphosis, or C5 palsy., Conclusions: C3-C6 laminoplasty with C2 and C7 dome laminotomies was safe, well tolerated, and associated with satisfactory early and late improved neurologic function and decreased pain., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2021 ISASS.)

The aim of the present paper is to report undiagnosed sporadic neurofibromatosis type 2 presenting with symptomatic compressive spinal tumors following pregnancy. A 36-year-old woman experienced progressive, severe lumbar radicular pain in the second trimester of pregnancy which became intractable soon after delivery. Magnetic resonance imaging revealed a complex heterogeneous hypointense mass lesion around the conus. There were two small punctate lesions in the cauda equina suggestive of myxopapillary ependymoma with 'drop metastases.' The patient underwent surgical resection of two cystic compressive conus masses. Her low back pain improved after surgery. The masses were consistent with cystic/cellular schwannomas. An incidental finding was of a small, low-grade spinal ependymoma which lacked the characteristic histologic features of myxopapillary ependymoma. Multiple, large cystic schwannomas are not uncommon in schwannomatosis, however, the co-occurrence of low-grade ependymoma strongly suggests a clinical diagnosis of new, sporadic neurofibromatosis type 2. Although cranial nerve schwannomas (orbital, auditory) have been reported to enlarge during pregnancy, to our knowledge, this is the first report of multiple cystic/cellular schwannomas causing severe pain (due to conus compression) during and immediately after pregnancy., Competing Interests: Conflicts of interest The authors declare that no conflicts of interest exist. Disclosure The authors report no conflict(s) of interest related to the work presented.