External validation of the Chicago Chiari Outcome Scale in adults with Chiari malformation type I

OBJECTIVE

The Chicago Chiari Outcome Scale (CCOS) serves as a standardized clinical outcome evaluation tool among patients with Chiari malformation type I (CM-I). While the reliability of this scale has been proven for pediatric patients, the literature lacks CCOS validation when used solely in adults. Therefore, this study aimed to determine the validity of the CCOS in an external cohort of adult patients.

METHODS

The authors retrospectively analyzed the medical records of symptomatic patients with CM-I who underwent posterior fossa decompression between 2010 and 2018 in six neurosurgical departments. Each patient was clinically assessed at the latest available follow-up. Gestalt outcome was determined as improved, unchanged, or worsened compared with the preoperative clinical state. Additionally, the CCOS score was calculated for each patient based on the detailed clinical data. To verify the ability of the CCOS to determine clinical improvement, the area under the receiver operating characteristic (AUROC) curve was evaluated. A logistic regression analysis using all four components of the CCOS (pain symptoms, nonpain symptoms, functionality, and complications) was performed to establish predictors of the improved outcome.

RESULTS

Seventy-five individuals with a mean age of 42 ± 15.32 years were included in the study. The mean follow-up duration was 52 ± 33.83 months. Considering gestalt outcome evaluation, 41 patients (54.7%) were classified as improved, 24 (32%) as unchanged, and 10 (13.3%) as worsened. All patients with a CCOS score of 14 or higher improved, while all those with a CCOS score of 8 or lower worsened. The AUROC was 0.986, suggesting almost perfect accuracy of the CCOS in delineating clinical improvement. A CCOS score of 13 showed high sensitivity (0.93) and specificity (0.97) for identifying patients with clinical improvement. Additionally, a meaningful correlation was found between higher CCOS scores in each component and better outcomes. Patient stratification by total CCOS score showed that those categorized as improved, unchanged, and worsened scored prevalently between 13 and 16 points, 10 and 12 points, and 4 and 9 points, respectively.

CONCLUSIONS

In this adult cohort, the CCOS was found to be almost perfectly accurate in reflecting postoperative clinical improvement. Moreover, all four CCOS components (pain symptoms, nonpain symptoms, functionality, and complications) significantly correlated with patient clinical outcomes.

Comparative Assessment of Three Posterior Fossa Decompression Techniques and Evaluation of the Evidence Supporting the Efficacy of Syrinx Shunting and Filum Terminale Sectioning in Chiari Malformation Type I. A Systematic Review and Network Meta-Analysis

BACKGROUND

This study aimed to compare the effectiveness of posterior fossa decompression (PFD), posterior fossa decompression with duraplasty (PFDD), and posterior fossa decompression with resection of tonsils (PFDRT) in Chiari malformation type I (CMI). Furthermore, we aimed to evaluate the evidence supporting the efficacy of filum terminale sectioning (FTS), syringosubarachnoid shunting (SSS), and syringoperitoneal shunting (SPS) in CMI.

METHODS

PubMed, Cochrane, and Embase databases were screened for English-language studies published from inception until August 11, 2020. A total of 3593 studies were identified through the searching process. Fifteen cohort studies were included in the systematic review and network meta-analysis.

RESULTS

No studies concerning FTS, SSS, and SPS were found eligible. Therefore, only PFD, PFDD, and PFDRT were compared. PFDD showed significantly higher incidence of complications (relative risk [RR], 3.79; 95% confidence interval [CI], 2.54-5.64) cerebrospinal fluid leak (RR, 9.74; 95% CI, 2.33-40.78) and neurologic deficit (RR, 8.76; 95% CI, 2.08-36.90) than did PFD. Both PFDD and PFDRT achieved higher syringomyelia improvement (RR, 1.23, 95% CI, 1.09-1.39 and RR, 1.32, 95% CI, 1.15-1.51, respectively) and greater clinical improvement (RR, 1.24, 95% CI, 1.10-1.39 and RR, 1.24, 95% CI, 1.08-1.44, respectively) than did PFD. No differences were found between PFDD and PFDRT.

CONCLUSIONS

PFDD and PFDRT are superior to PFD, especially in patients with syringomyelia-Chiari complex, because of greater syringomyelia reduction and better clinical improvement. However, PFDD and PFDRT can be considered equally efficient. There is no evidence pleading in favor of SFT, SSS, and SPS over any PFD technique.

Navigated neuroendoscopy combined with intraoperative magnetic resonance cysternography for treatment of arachnoid cysts

Endoscopic cystocysternostomy or cystoventriculostomy is the treatment of choice in patients with symptomatic intracranial arachnoid cysts. There are no objective diagnostic tests for reliable intraoperative evaluation of the effectiveness of performed stomies. The aim of this prospective open-label study is to demonstrate for the first time the usefulness of intraoperative cysternography performed with the low-field 0.15-T magnetic resonance imager Polestar N20 during endoscopic cysternostomies. The study was performed in patients operated for middle fossa arachnoid cysts (n = 10), suprasellar cysts (n = 4), paraventricular or intraventricular cysts (n = 6), and a pineal cyst (n = 1). The operations were performed with use of a navigated neuroendoscope. Intraoperative magnetic resonance (iMR) cysternography was performed before and after the cystostomy. In each case, iMR cysternography was safe and could show clearly the cyst morphology and the effectiveness of performed endoscopic cystostomies. In six cases, iMR cysternography had a significant influence of the surgical decision (p = 0.027). The rate of inconsistency between the intraoperative observations and iMR imaging–based findings was 29%. A good contrast flow through the fenestrated cyst walls correlated with a good long-term clinical outcome (ρ = 0.54, p < 0.05) and good long-term radiological outcome (ρ = 0.72, p < 0.05). Intraoperative low-field MR cysternography is a safe and reliable method for assessment of the efficacy of performed endoscopic cystostomies and has significant influence on the surgical decision. It may be reliably used for prediction of the long-term clinical and radiological outcome.

Partial Recovery of Proprioception in Rats with Dorsal Root Injury after Human Olfactory Bulb Cell Transplantation

Transplanted human olfactory ensheathing cells (hOECs) were mixed with collagen into a unilateral transection of four dorsal roots (C6-T1) in a rat model. By mixing with collagen, the limited numbers of hOEC were maximized from an olfactory bulb biopsy and optimize cavity filling. Cyclosporine was administered daily to prevent immune rejection. Forelimb proprioception was assessed weekly in a vertical climb task. Half of the rats receiving hOEC transplants showed some functional improvement ("responders") over six weeks of the study while the other half did not ("nonresponders") and performed similarly to "injured only" rats. Transplanted cells were seen at both one week and six weeks after the surgical procedure; many were concentrated within the lesion cavity, but others were found with elongated processes in the overlying connective tissue. There were some fibers in the injury area associated with transplanted cells that were immunostained for neurofilament and TUJ1. Responder and nonresponder rats were compared with regard to microglial activation within the deep dorsal horn of cervical levels C7, C8 and also axon loss within the cuneate fasciculus at cervical level C3. Little difference was seen in microglial activation or axonal loss that could account for the improved proprioception in the responders group. This preliminary study is the first to transplant human olfactory bulb cells into a rat model of dorsal root injury; by refining each component part of the procedure, the repair potential of OECs can be maximized in a clinical setting.

Comparison of Olfactory Bulbar and Mucosal Cultures in a Rat Rhizotomy Model

In an ongoing clinical trial, a spinal injured patient who received a transplant of autologous cells cultured from the olfactory bulb is showing greater functional benefit than three previous patients with transplants of mucosal origin. Previous laboratory studies of transplantation into rat spinal cord injuries show that the superior reparative benefits of bulbar over mucosal cultures are associated with regeneration of severed corticospinal tract fibers over a bridge of olfactory ensheathing cells (OECs) formed across the injury site. In a rat rhizotomy paradigm, we reported that transplantation of bulbar cell cultures also enables severed axons of the C6–T1 dorsal roots to regenerate across a bridge of OECs into the spinal cord and restore electrophysiological transmission and forepaw grasping during a climbing test. We now report a repeat of the same rhizotomy procedure in 25 rats receiving cells cultured from olfactory mucosal biopsies. In no case did the transplanted cells form a bridging pathway. No axons crossed from the severed roots to the spinal cord, and there was no restoration of forepaw grasping. This suggests that the superior clinical benefit in the patient receiving bulbar cell transplants is due to regeneration of severed fibers across the injury site, and this correlates with imaging and the pattern of functional recovery. Using present culture protocols, the yield of OECs from bulbar biopsies is around 50%, but that from mucosal biopsies is less than 5%. Improving the yield of OECs from mucosal biopsies might avoid the necessity for the intracranial approach to obtain bulbar cells.

Functional regeneration of supraspinal connections in a patient with transected spinal cord following transplantation of bulbar olfactory ensheathing cells with peripheral nerve bridging

Treatment of patients sustaining a complete spinal cord injury remains an unsolved clinical problem because of the lack of spontaneous regeneration of injured central axons. A 38-year-old man sustained traumatic transection of the thoracic spinal cord at upper vertebral level Th9. At 21 months after injury, the patient presented symptoms of a clinically complete spinal cord injury (American Spinal Injury Association class A-ASIA A). One of the patient's olfactory bulbs was removed and used to derive a culture containing olfactory ensheathing cells and olfactory nerve fibroblasts. Following resection of the glial scar, the cultured cells were transplanted into the spinal cord stumps above and below the injury and the 8-mm gap bridged by four strips of autologous sural nerve. The patient underwent an intense pre- and postoperative neurorehabilitation program. No adverse effects were seen at 19 months postoperatively, and unexpectedly, the removal of the olfactory bulb did not lead to persistent unilateral anosmia. The patient improved from ASIA A to ASIA C. There was improved trunk stability, partial recovery of the voluntary movements of the lower extremities, and an increase of the muscle mass in the left thigh, as well as partial recovery of superficial and deep sensation. There was also some indication of improved visceral sensation and improved vascular autoregulation in the left lower limb. The pattern of recovery suggests functional regeneration of both efferent and afferent long-distance fibers. Imaging confirmed that the grafts had bridged the left side of the spinal cord, where the majority of the nerve grafts were implanted, and neurophysiological examinations confirmed the restitution of the integrity of the corticospinal tracts and the voluntary character of recorded muscle contractions. To our knowledge, this is the first clinical indication of the beneficial effects of transplanted autologous bulbar cells.

Transplantation of autologous olfactory ensheathing cells in complete human spinal cord injury

Numerous studies in animals have shown the unique property of olfactory ensheathing cells to stimulate regeneration of lesioned axons in the spinal cord. In a Phase I clinical trial, we assessed the safety and feasibility of transplantation of autologous mucosal olfactory ensheathing cells and olfactory nerve fibroblasts in patients with complete spinal cord injury. Six patients with chronic thoracic paraplegia (American Spinal Injury Association class A-ASIA A) were enrolled for the study. Three patients were operated, and three served as a control group. The trial protocol consisted of pre- and postoperative neurorehabilitation, olfactory mucosal biopsy, culture of olfactory ensheathing cells, and intraspinal cell grafting. Patient's clinical state was evaluated by clinical, neurophysiological, and radiological tests. There were no adverse findings related to olfactory mucosa biopsy or transplantation of olfactory ensheathing cells at 1 year after surgery. There was no evidence of neurological deterioration, neuropathic pain, neuroinfection, or tumorigenesis. In one cell-grafted patient, an asymptomatic syringomyelia was observed. Neurological improvement was observed only in transplant recipients. The first two operated patients improved from ASIA A to ASIA C and ASIA B. Diffusion tensor imaging showed restitution of continuity of some white matter tracts throughout the focus of spinal cord injury in these patients. The third operated patient, although remaining ASIA A, showed improved motor and sensory function of the first spinal cords segments below the level of injury. Neurophysiological examinations showed improvement in spinal cord transmission and activity of lower extremity muscles in surgically treated patients but not in patients receiving only neurorehabilitation. Observations at 1 year indicate that the obtaining, culture, and intraspinal transplantation of autologous olfactory ensheathing cells were safe and feasible. The significance of the neurological improvement in the transplant recipients and the extent to which the cell transplants contributed to it will require larger numbers of patients.

Usefulness of intraoperative magnetic resonance ventriculography during endoscopic third ventriculostomy

BACKGROUND

Endoscopic third ventriculostomy (ETV) is the preferred method for the treatment of noncommunicating hydrocephalus. The different success rates of ETV indicate the difficulties in predicting the success of this procedure.

OBJECTIVE

To show the usefulness of intraoperative ventriculography performed by the low-field 0.15-T magnetic resonance imager Polestar N20 during ETV.

METHODS

The study was conducted in 11 patients with noncommunicating hydrocephalus caused by tumors or cysts of the third ventricle (n = 5), nontumoral stenosis of the sylvian aqueduct (n = 3), and fourth ventricle outlet obstruction (n = 3). Intraoperative magnetic resonance (iMR) ventriculography was performed before and after the ETV.

RESULTS

In each case, iMR-ventriculography was a safe procedure and determined the exact site of obstruction of cerebrospinal fluid flow. In all cases, iMR-ventriculography performed after ETV showed with the greatest accuracy the patency of the performed fenestrations, demonstrating in 9 patients good flow of the contrast from the third ventricle to the basal cisterns, restricted flow in 1 patient, and no flow in 1 patient. The results of ventriculography were consistent with the postoperative neurological status of operated-on patients. In 3 patients, the opinion of the surgeons about the patency of endoscopic fenestration, based on intraoperative observation of the third ventricle floor, was inconsistent with the results from iMR-ventriculography.

CONCLUSION

Low-field iMR-ventriculography is a safe procedure that can be successfully applied during ETV to determine the site of obstruction in hydrocephalus and the patency of performed ventricle fenestration.

The olfactory bulb and olfactory mucosa obtained from human cadaver donors as a source of olfactory ensheathing cells

During the last decade, olfactory ensheathing cells (OECs) have been successfully applied in multiple experimental approaches aimed to repair damaged mammalian spinal cord. Some of these experiments have consequently been translated into clinical trials. Finding a reliable source of human OECs that is easily accessible and can ensure a sufficient number of cells is a major prerequisite for conducting studies on OEC-mediated spinal cord regeneration. Here, we present a procedure for obtaining olfactory bulbs (OBs) and olfactory mucosa (OM) simultaneously from adult cadaver heart-beating donors for OEC isolation and analyze some of the factors that may condition successful OEC culture. We show that the results of OEC culture from OBs (10 cases) correlated significantly with warm ischemia time (WIT) as well as the initial viability of the isolated cells. Efficient OEC culture was possible when the WIT for the OB was up to 20 min. Brain damage, assessed by determination of S100B serum level, was not related to the success of OEC culture from the OB. Cadaver OM (7 cases) was shown to be a more reliable source of human OECs than the OB. In most of the examined cases the efficacy of culturing OECs from cadaver OM obtained even 180 min after cardiac arrest was comparable to that of living patients. The method of obtaining OBs and OM from cadavers enables the use of an alternative source of primary adult human OECs for further preclinical and clinical studies on their neurotrophic properties.