Cerebrospinal fluid levels of GFAP and pNF-H are elevated in patients with chronic spinal cord injury and neurological deterioration.

BACKGROUND: Years after a traumatic spinal cord injury (SCI), a subset of patients may develop progressive clinical deterioration due to intradural scar formation and spinal cord tethering, with or without an associated syringomyelia. Meningitis, intradural hemorrhages, or intradural tumor surgery may also trigger glial scar formation and spinal cord tethering, leading to neurological worsening. Surgery is the treatment of choice in these chronic SCI patients. OBJECTIVE: We hypothesized that cerebrospinal fluid (CSF) and plasma biomarkers could track ongoing neuronal loss and scar formation in patients with spinal cord tethering and are associated with clinical symptoms. METHODS: We prospectively enrolled 12 patients with spinal cord tethering and measured glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase L1 (UCH-L1), and phosphorylated Neurofilament-heavy (pNF-H) in CSF and blood. Seven patients with benign lumbar intradural tumors and 7 patients with cervical radiculopathy without spinal cord involvement served as controls. RESULTS: All evaluated biomarker levels were markedly higher in CSF than in plasma, without any correlation between the two compartments. When compared with radiculopathy controls, CSF GFAP and pNF-H levels were higher in patients with spinal cord tethering (p ≤ 0.05). In contrast, CSF UCH-L1 levels were not altered in chronic SCI patients when compared with either control groups. CONCLUSIONS: The present findings suggest that in patients with spinal cord tethering, CSF GFAP and pNF-H levels might reflect ongoing scar formation and neuronal injury potentially responsible for progressive neurological deterioration.

Neurosurgical untethering with or without syrinx drainage results in high patient satisfaction and favorable clinical outcome in post-traumatic myelopathy patients.

STUDY DESIGN: Retrospective data collection and patient-reported outcome measures. OBJECTIVES: To investigate surgical outcome, complications, and patient satisfaction in patients with chronic SCI and symptomatic post-traumatic progressive myelopathy (PPM) who underwent neurosurgical untethering and/or spinal cord cyst drainage with the aim of preventing further neurological deterioration. SETTING: Single-center study at an academic neurosurgery department. METHODS: All SCI patients who underwent neurosurgery between 1996 and 2013 were retrospectively included. All medical charts and the treating surgeon's operative reports were reviewed to identify surgical indications, surgical technique, and post-operative complications. A questionnaire and an EQ-5D-instrument were used to assess patient's self-described health status and satisfaction at long-term follow-up. RESULTS: Fifty-two patients (43 men, 9 women) were identified, of whom five were dead and one was lost to follow-up. Main indications for surgery were pain (54%), motor (37%), or sensory (8%) impairment, and spasticity (2.0%). Overall complications were rare (8%). At follow-up, the subjectively perceived outcome was improved in 24 and remained unchanged in 21 patients. Thus, the surgical aim was met in 87% of patients. Of the 46 eligible patients, 38 responded to the questionnaire of whom 65% were satisfied with the surgical results. Patients with cervical lesions were more satisfied with the surgical treatment than patients with thoracic/thoracolumbar lesions (p = 0.05). CONCLUSIONS: Neurosurgical untethering and/or cyst drainage in chronic SCI patients and PPM resulted in a high degree of patient satisfaction, particularly in cervical SCI patients with minimal complications.

Gait training after spinal cord injury: safety, feasibility and gait function following 8 weeks of training with the exoskeletons from Ekso Bionics.

STUDY DESIGN: Prospective quasi-experimental study, pre- and post-design. OBJECTIVES: Assess safety, feasibility, training characteristics and changes in gait function for persons with spinal cord injury (SCI) using the robotic exoskeletons from Ekso Bionics. SETTING: Nine European rehabilitation centres. METHODS: Robotic exoskeleton gait training, three times weekly over 8 weeks. Time upright, time walking and steps in the device (training characteristics) were recorded longitudinally. Gait and neurological function were measured by 10 Metre Walk Test (10 MWT), Timed Up and Go (TUG), Berg Balance Scale (BBS), Walking Index for Spinal Cord Injury (WISCI) II and Lower Extremity Motor Score (LEMS). RESULTS: Fifty-two participants completed the training protocol. Median age: 35.8 years (IQR 27.5-52.5), men/women: N = 36/16, neurological level of injury: C1-L2 and severity: AIS A-D (American Spinal Injury Association Impairment Scale). Time since injury (TSI) < 1 year, N = 25; > 1 year, N = 27. No serious adverse events occurred. Three participants dropped out following ankle swelling (overuse injury). Four participants sustained a Category II pressure ulcer at contact points with the device but completed the study and skin normalized. Training characteristics increased significantly for all subgroups. The number of participants with TSI < 1 year and gait function increased from 20 to 56% (P = 0.004) and 10MWT, TUG, BBS and LEMS results improved (P < 0.05). The number of participants with TSI > 1 year and gait function, increased from 41 to 44% and TUG and BBS results improved (P < 0.05). CONCLUSIONS: Exoskeleton training was generally safe and feasible in a heterogeneous sample of persons with SCI. Results indicate potential benefits on gait function and balance.

Cerebrospinal fluid biomarkers of white matter injury and astrogliosis are associated with the severity and surgical outcome of degenerative cervical spondylotic myelopathy.

BACKGROUND CONTEXT: Degenerative cervical spondylotic myelopathy (DCM) is the commonest form of spinal cord injury in adults. However, a limited number of clinical reports have assessed the role of biomarkers in DCM. PURPOSE: We evaluated cerebrospinal fluid (CSF) biomarkers in patients scheduled for DCM surgery and hypothesized that CSF biomarkers levels (1) would reflect the severity of preoperative neurological status; and (2) correlate with radiological appearance; and (3) correlate with clinical outcome. STUDY DESIGN/SETTING: Prospective clinical and laboratory study. PATIENT SAMPLE: Twenty-three DCM patients, aged 66.4±12.8 years and seven controls aged 45.4±5.3 years were included. OUTCOME MEASURES: The American Spinal Injury Association Impairment Scale, the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire and EuroQol 5-dimensions were assessed preoperatively and at 3 months post-surgery. METHODS: We measured preoperative biomarkers (glial fibrillary acidic protein [GFAP], neurofilament light [NFL], phosphorylated neurofilament-H [pNF-H] and Ubiquitin C-terminal hydrolase L1) in CSF samples collected from patients with progressive clinical DCM who underwent surgical treatment. Biomarker concentrations in DCM patients were compared with those of cervical radiculopathy controls. RESULTS: The median symptom duration was 10 (interquartile range 6) months. The levels of GFAP, NFL, pNF-H, Ubiquitin C-terminal hydrolase L1 were significantly higher in the DCM group compared to controls (p=.044, p=.002, p=.016, and p=.006, respectively). Higher pNF-H levels were found in patients with low signal on T1 Magnetic Resonance Imaging sequence compared to those without (p=.022, area under the receiver operating characteristic curve [AUC] 0.780, 95% Confidence Interval: 0.59-0.98). Clinical improvement following surgery correlated mainly with NFL and GFAP levels (p<.05). CONCLUSIONS: Our results suggest that CSF biomarkers of white matter injury and astrogliosis may be a useful tool to assess myelopathy severity and predict outcome after surgery, while providing valuable information on the underlying pathophysiology.

Cerebrospinal fluid biomarkers of glial and axonal injury in cervical spondylotic myelopathy.

OBJECTIVE: Degenerative cervical spondylotic myelopathy (CSM) is a major cause of spinal cord dysfunction with an unpredictable prognosis. Βiomarkers reflecting pathophysiological processes in CSM have been insufficiently investigated. It was hypothesized that preoperative cerebrospinal fluid (CSF) biomarker levels are altered in patients with CSM and correlate with neurological status and outcome. METHODS: CSF biomarkers from patients with CSM and controls were analyzed with immunoassays. Spinal cord changes were evaluated with MRI. The American Spinal Cord Injury Association Impairment Scale, the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and the EQ-5D questionnaire were applied prior to and 3 months after surgery. A p value < 0.05 was considered statistically significant. RESULTS: Twenty consecutive CSM patients with a mean age of 67.7 ± 13 years and 63 controls with a mean age of 65.2 ± 14.5 years (p > 0.05) were included in the study. In the CSM subjects, CSF neurofilament light subunit (NF-L) and glial fibrillary acidic protein (GFAP) concentrations were higher (p < 0.05), whereas fatty acid-binding protein 3 (FABP3), soluble amyloid precursor proteins (sAPPα and sAPPß), and amyloid ß (Aß) peptide (Aß38, Aß40, and Aß42) concentrations were lower than in controls (p < 0.05). Aß peptide levels correlated positively with symptom duration. Preoperative JOACMEQ lower extremity function and CSF NF-L levels correlated positively, and the JOACMEQ bladder function correlated negatively with sAPPα and sAPPß (p < 0.05). CSF NF-L and FABP3 levels were higher in patients with improved outcome (EQ-5D visual analog scale difference > 20). CONCLUSIONS: CSF biomarkers of glial and axonal damage, inflammation, and synaptic changes are altered in symptomatic CSM patients, indicating that axonal injury, astroglial activation, and Aß dysmetabolism may be present in these individuals. These findings reflect CSM pathophysiology and may aid in prognostication. However, future studies including larger patient cohorts, postoperative biomarker data and imaging, and longer follow-up times are required to validate the present findings.

Exoskeleton gait training after spinal cord injury: An exploratory study on secondary health conditions.

OBJECTIVE: To explore changes in pain, spasticity, range of motion, activities of daily living, bowel and lower urinary tract function and quality of life of individuals with spinal cord injury following robotic exoskeleton gait training. DESIGN: Prospective, observational, open-label multicentre study. METHODS: Three training sessions per week for 8 weeks using an Ekso™ GT robotic exoskeleton (EKSO Bionics). Included were individuals with recent (<1 year) or chronic (>1 year) injury, paraplegia and tetraplegia, complete and incomplete injury, men and women. RESULTS: Fifty-two participants completed the training protocol. Pain was reported by 52% of participants during the week prior to training and 17% during training, but no change occurred longitudinally. Spasticity decreased after a training session compared with before the training session (p <0.001), but not longitudinally. Chronically injured participants increased Spinal Cord Independence Measure (SCIM III) from 73 to 74 (p = 0.008) and improved life satisfaction (p = 0.036) over 8 weeks of training. Recently injured participants increased SCIM III from 62 to 70 (p < 0.001), but no significant change occurred in life satisfaction. Range of motion, bowel and lower urinary function did not change over time. CONCLUSION: Training seemed not to provoke new pain. Spasticity decreased after a single training session. SCIM III and quality of life increased longitudinally for subsets of participants.