Faculty Bibliography

Background/UNASSIGNED:The diagnosis of a lumbar herniated disc, stenosis, and other degenerative findings are typically established preoperatively with MR scans, supplemented with non-contrast CT studies. Here, a 77-year-old female, diagnosed as having L2-S1 stenosis and a large left-sided L2-L3 herniated disc was found at surgery to have a massive left-sided L2-L3 synovial cyst. Case Description/UNASSIGNED:A 77-year-old female was followed by pain management for 6-months with proximal left lower extremity weakness. The lumbar MR at that time was read as demonstrating a large left L2-L3 disc herniation with inferior migration to the L3 mid pedicle level, accompanied by L2-S1 lumbar stenosis. When she finally consulted neurosurgery, she exhibited severe left iliopsoas and quadriceps weakness (2/5), absent lower extremity reflexes, and profound decreased pin appreciation in the left L2-L3 distributions. The repeat MR and new CT studies confimred a large left L2-L3 disc accompanied by moderate/marked L2-S1 stenosis. However, at surgery, consisting of a laminectomy L2-S1, the supposed left L2-L3 disc proved to be a massive synovial cyst. Postoperatively, the patient regained normal function, and remained neurologically intact 6 months later. Conclusion/UNASSIGNED:In this 77 year-old female, the preoperative MR and CT scans were interpreted as showing a "typical" large left L2-L3 herniated disc. This proved at surgery to be a massive left L2-L3 synovial cyst. As demonstrated in this case, older patients with degenerative lumbar disease/stenosis, may have synovial cysts that mimic disc herniations both clinically and on preoperative diagnostic studies.

Background/UNASSIGNED:Reviewing the neurosurgical literature demonstrated that spinal neurosurgeons rarely (0.78%) diagnose chiari-1 malformation (CM-1) in adults on magnetic resonance (MR) studies defined by tonsillar descent >5 mm below the foramen magnum (FM). Children, averaging 10 years of age, exhibit CM-1 in 96/100,000 cases. According to the literature, fewer spinal neurosurgeons additionally recognize and treat the low lying cerebellar tonsil (LLCT) syndrome. Methods/UNASSIGNED:The normal location of the cerebellar tonsils on cranial/cervical MR averages 2.9 mm ± 3.4 mm above or up to 3 mm below the FM. The neurosurgical literature revealed that most neurosurgeons diagnose and treat CM-1 where the tonsils are >5 mm to an average of 12 mm below the FM. Fewer spinal neurosurgeons additionally diagnose and treat the LLCT syndrome defined by <5 mm of tonsillar descent below the FM. Results/UNASSIGNED:According to the neurosurgical literature, many neurosurgeons perform cranial/spinal decompression with/without fusion and/or duraplasty for CM-1. Fewer neurosurgeons perform these procedures for CM-1 and the LLCT syndrome, for which they additionally perform preoperative cervical traction under anesthesia, and the postoperative placement of occipital neurostimulators (ONS) for intractable headaches following chiari-1/LLCT surgery. Conclusion/UNASSIGNED:Reviewing the literature revealed that spinal neurosurgeons rarely diagnose CM-1, and treat them with decompressions with/without fusions and/or duraplasty. Fewer spinal neurosurgeons diagnose/treat both the CM-1 and LLCT syndromes, perform preoperative traction under anesthesia, and place ONS for persistent headaches following CM-1 surgery.

Background/UNASSIGNED:Prior to spine surgery (SS), we ask whether and when to stop low-dose aspirin (LD-ASA), particularly in patients with significant cardiovascular disease (CAD). Although platelets typically regenerate in 10 days, it can take longer in older patients. Methods/UNASSIGNED:Here we reviewed several studies regarding the perioperative risks/complications [e.g. hemorrhagic complications, estimated blood loss (EBL), continued postoperative drainage] for continuing vs. stopping LD-ASA at various intervals prior to lumbar SS. Results/UNASSIGNED:Multiple studies confirmed the increased perioperative risks for continuing LD-ASA throughout SS, or when stopping it for just 3-7 preoperative days; however, there were no increased risks if stopped between 7 to 10 days postoperatively. Other studies documented no increased perioperative risk for continuing LD-ASA throughout SS, although some indicated increased morbidity (e.g., one patient developed a postoperative hematoma resulting in irreversible paralysis). Conclusions/UNASSIGNED:Several studies demonstrated more hemorrhagic complications if LD-ASA was continued throughout or stopped just 3 to up to 7 days prior to SS. However, there were no adverse bleeding events if stopped from 7-10 days preoperatively. As a spine surgeon who wishes to avoid a postoperative epidural hematoma/paralysis, I would recommend stopping LD-ASA 10 days or longer prior to SS. Nevertheless, each spine surgeon must determine what is in the "best interest" of their individual patient. Certainly, we need future randomized controlled trials to better answer: when and if to stop LD-ASA before spine surgery.

Background/UNASSIGNED:The tethered cord syndrome (TCS) accompanying Chiari-1 (CM-1) malformations and the occult tethered cord syndrome (OTCS) syndrome accompanying the low lying cerebellar tonsil (LLCT) syndrome may be treated with sectioning of the filum terminale (SFT). Methods/UNASSIGNED:Utilizing PubMed, we reviewed the neurosurgical literature to determine how frequently spinal neurosurgeons diagnosed the TCS (e.g., conus terminating below the normal L1-L2 disc level) on lumbar magnetic resonance (MR) studies in patients with CM-1 malformations [e.g. tonsils >5-12 mm below the foramen magnum (FM) warranting SFT]. In addition, we assessed how frequently spinal neurosurgeons encountered the OTCS (e.g., conus normally located at L1-L2 on MR) accompanying the LLCT (e.g., tonsils herniated <5 mm below the FM) also requiring SFT. Results/UNASSIGNED:According to the neurosurgical literature, the incidence of TCS accompanying CM-1 requiring SFT ranged from 2.2% to < 6%, and up to 14%. Few studies additionally highly correlated the OCTS accompanying the LLCT syndrome warranting SFT. Conclusions/UNASSIGNED:Given the differences in the literature, more studies are needed to assess the risks (complications) vs. benefits (improved neurological outcomes) of SFT surgery for TCS with CM-1 and SFT for OCTS with LLCT.