Longitudinal scoliosis behavior in Chiari malformation with and without syringomyelia.

OBJECTIVE: The objective of this study was to understand the natural history of scoliosis in patients with Chiari malformation type I (CM-I) with and without syringomyelia. METHODS: A retrospective review of data was conducted. Patients with CM-I were identified from a cohort of 14,118 individuals age 18 years or younger who had undergone MRI over an 11-year period at the University of Michigan. Patients eligible for study inclusion had a coronal curve ≥ 10° on radiography, associated CM-I with or without syringomyelia, and at least 1 year of clinical follow-up prior to any surgery. Curve magnitude at initial diagnosis, prior to posterior fossa decompression (PFD; if applicable), and at the last follow-up (prior to any surgical correction of scoliosis) was recorded, and clinical and radiographic characteristics were noted. The change in curve magnitude by 10° was defined as curve progression (increase by 10°) or regression (decrease by 10°). RESULTS: Forty-three patients met the study inclusion criteria and were analyzed. About one-third (35%) of the patients presented with symptoms attributed to their CM-I. The mean degree of scoliosis at presentation was 32.6° ± 17.7°. Twenty-one patients (49%) had an associated syrinx. The mean tonsil position below the level of the foramen magnum was 9.8 ± 5.8 mm. Patients with a syrinx were more likely to have a curve > 20° (86% vs 41%, p = 0.002). Curve magnitude remained stable (≤ ±10°) in 77% of patients (33/43), progressed in 16% (7/43), and regressed in 7% (3/43). Mean age was higher (14.8 ± 0.59 years) among patients with regressed curves (p = 0.026). All regressed curves initially measured ≤ 20° (mean 14° ± 5.3°), and none of the patients with regressed curves had a syrinx. The change in curve magnitude was statistically similar in patients with (7.32° ± 17.7°) and without (5.32° ± 15.8°) a syrinx (p = 0.67). After a mean follow-up of 3.13 ± 2.04 years prior to surgery, 27 patients (63%) ultimately underwent posterior fossa or scoliosis correction surgery. For those who eventually underwent PFD only, the rate of change in curve magnitude prior to surgery was 0.054° ± 0.79°. The rate of change in curve magnitude was statistically similar before (0.054° ± 0.79°) and after (0.042° ± 0.33°) surgery (p = 0.45) for patients who underwent PFD surgery only. CONCLUSIONS: The natural history of scoliosis in the presence of CM-I is variable, though most curves remained stable. All curves that regressed were ≤ 20° at initial diagnosis, and most patients in such cases were older at scoliosis diagnosis. Patients who underwent no surgery or PFD only had similar profiles for the change in curve magnitude, which remained relatively stable overall, as compared to patients who underwent PFD and subsequent fusion, who demonstrated curve progression. Among the patients with a syrinx, no curves regressed, most remained stable, and some progressed. Understanding this variability is a first step toward building a prediction model for outcomes for these patients.

Subdural hematoma from an acquired dural arteriovenous fistula following external ventricular drain placement for subarachnoid hemorrhage.

Objective: Intracranial dural arteriovenous fistulas represent pathological connections between dural arteries and dural veins, dural sinuses or meningeal veins in the absence of an intervening capillary bed. They are thought to be acquired secondary to trauma, surgery, sinus thrombosis, venous hypertension or arterial dysplasia. Methods: A 66-year-old Asian female presented with subarachnoid hemorrhage secondary to ruptured 2-mm saccular aneurysm of the left middle cerebral artery associated with fusiform dilatation. It was successfully treated with endovascular coiling. A right frontal external ventricular drain was also placed to treat her hydrocephalus. On post-bleed day 10, she became acutely unresponsive with a fixed and dilated right pupil. Head CT was obtained and revealed an acute right subdural hematoma which was emergently evacuated. Results: No obvious bleeders were identified during surgery. Patient improved and repeat catheter angiography a week later showed a new dural arteriovenous fistula fed by the anterior falcine artery and the middle meningeal artery to a cortical vein draining into the superior sagittal sinus. Conclusion: We hope that the present report will raise awareness to treating physicians to be cognizant of this unusual complication in their differential diagnosis when treating patients with an EVD in place.

Does the Coexistence of Multiple Segmental Rib Fractures in Polytrauma Patients Presenting With "Major" Vertebral Fracture Affect Care and Acute Outcomes?

OBJECTIVE: To determine whether operating on "major" vertebral fractures leads to premature abortion of surgery and/or other acute cardiopulmonary complications. DESIGN: Retrospective review. CLINICAL SETTING: Level 1 trauma center. PATIENTS/PARTICIPANTS AND INTERVENTION: We retrospectively queried our institutional Trauma Rregistry for all cases presenting with concomitant rib fractures and surgically managed vertebral fractures. MAIN OUTCOME MEASUREMENTS: The main outcomes included the surgical outcome (aborted vs. successfully performed), total and Intensive Care Unit length of stay (LOS), adverse discharge, mortality, and functional outcomes. RESULTS: We found 57 cases with concomitant segmental rib fractures and surgically managed vertebral fractures. Seven patients (12%) received a rib fixation, of which 1 received before vertebral fixation and 6 after. Importantly, 4 vertebral fixation cases (7.02%) had to be aborted intraoperatively because of the inability to tolerate prone positioning for surgery. For case-control analysis, we performed propensity score matching to obtain matched controls, that is, cases of vertebral fixation but no rib fractures. On matched case-control analysis, patients with concomitant segmental rib fractures and vertebral fractures were found to have higher Intensive Care Unit LOS [median = 3 days (Inter-Quartile Range = 0-9) versus. 8.4 days, P = 0.003], whereas total LOS, frequency of complete, incomplete or functional spinal cord injury, discharge to rehab, and discharge to nursing home were found to be similar between the 2 groups. CONCLUSION: Our findings demonstrate that segmental rib fractures with concomitant vertebral fractures undergoing surgical treatment represent a subset of patients that may be at increased risk of intraoperative cardio-pulmonary complications and rib fixation before prone spine surgery for cases in which the neurological status is stable is reasonable. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Pediatric and adolescent injury in motocross.

Motocross is a competitive outdoor extreme sport in which motorcyclists race across vast courses of jumps, berms and long straightaways of unpredictable terrain. While the sport has gained notoriety in adult popular culture through contests like the X Games, motocross is also increasingly popular among youth in the Unites States and beyond. In the setting of contemporary discussions on traumatic brain injury, this poses an obvious challenge to those advising children and parents on the risks of motocross to the developing brain and spine. The available literature demonstrates that even when practiced with appropriate protective equipment, motocross poses an increased risk for acquiring major trauma to the brain, spine and limbs for which the long-term consequences have been poorly studied. Riders and parents should be counseled about the risks of these injuries prior to participation and in accordance with state laws. Furthermore, formal return-to-play guidelines following concussions should be developed.

Temporal Lobe Gliosarcoma After Gamma Knife Radiosurgery for Vestibular Schwannoma.

OBJECTIVE: Secondary tumorigenesis after exposure to ionizing radiation is a well-described phenomenon. The probability of developing a malignancy after stereotactic radiosurgery (SRS) is theoretically less than conventional external beam radiation therapy; however, the exact risk remains unknown. Such information is important for patient counseling when considering treatment of benign conditions such as vestibular schwannoma (VS). The objective of the current report is to describe a case of a temporal lobe gliosarcoma developing 3 years after radiosurgical treatment of a sporadic VS. SETTING: Tertiary academic referral center. PATIENT: A 54-year-old man was diagnosed with a left-sided 1.6 cm cerebellopontine angle mass, consistent with VS. After reviewing treatment options, the patient proceeded with radiosurgery, and a tumor volume of 2.4 cm was treated with a marginal dose of 12.5 Gy prescribed to the 50% isodose line. RESULTS: Serial magnetic resonance imaging (MRI) revealed good treatment response, demonstrated by central necrosis and tumor shrinkage. However, 3 years after treatment, the patient presented to the emergency department for a month long history of progressive word finding difficulties. Imaging revealed a 5 cm temporal lobe mass consistent with a high-grade glial neoplasm. He subsequently underwent stereotactic resection and final pathology confirmed World Health Organization Grade IV gliosarcoma. CONCLUSION: De novo malignancy after radiosurgery for VS is rare. We present only the second case of a gliosarcoma arising within the low-dose radiation field of the radiosurgery treatment plan. Some of the challenges of establishing causality between radiation treatment and secondary tumor development are discussed. The reporting of malignancy after radiation therapy, and even microsurgery, warrants continued vigilance.

Syrinx location and size according to etiology: identification of Chiari-associated syrinx.

OBJECT Syrinx size and location within the spinal cord may differ based on etiology or associated conditions of the brain and spine. These differences have not been clearly defined. METHODS All patients with a syrinx were identified from 14,118 patients undergoing brain or cervical spine imaging at a single institution over an 11-year interval. Syrinx width, length, and location in the spinal cord were recorded. Patients were grouped according to associated brain and spine conditions including Chiari malformation Type I (CM-I), secondary CM (2°CM), Chiari malformation Type 0 (CM-0), tethered cord, other closed dysraphism, and spinal tumors. Syringes not associated with any known brain or spinal cord condition were considered idiopathic. Syrinx characteristics were compared between groups. RESULTS A total of 271 patients with a syrinx were identified. The most common associated condition was CM-I (occurring in 117 patients [43.2%]), followed by spinal dysraphism (20 [7.4%]), tumor (15 [5.5%]), and tethered cord (13 [4.8%]). Eighty-three patients (30.6%) did not have any associated condition of the brain or spinal cord and their syringes were considered idiopathic. Syringes in patients with CM-I were wide (7.8 ± 3.9 mm) compared with idiopathic syringes (3.9 ± 1.0, p < 0.0001) and those associated with tethered cord (4.2 ± 0.9, p < 0.01). When considering CM-I-associated and idiopathic syringes, the authors found that CM-I-associated syringes were more likely to have their cranial extent in the cervical spine (88%), compared with idiopathic syringes (43%; p < 0.0001). The combination of syrinx width greater than 5 mm and cranial extent in the cervical spine had 99% specificity (95% CI 0.92-0.99) for CM-I-associated syrinx. CONCLUSIONS Syrinx morphology differs according to syrinx etiology. The combination of width greater than 5 mm and cranial extent in the cervical spine is highly specific for CM-I-associated syringes. This may have relevance when determining the clinical significance of syringes in patients with low cerebellar tonsil position.