Parmenion P. Tsitsopoulos, Ulrika Holmström, Kaj Blennow, Henrik Zetterberg, and Niklas Marklund
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.
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.
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 sAPPβ), and amyloid β (Aβ) peptide (Aβ38, Aβ40, and Aβ42) concentrations were lower than in controls (p < 0.05). Aβ 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 sAPPβ (p < 0.05). CSF NF-L and FABP3 levels were higher in patients with improved outcome (EQ-5D visual analog scale difference > 20).
CSF biomarkers of glial and axonal damage, inflammation, and synaptic changes are altered in symptomatic CSM patients, indicating that axonal injury, astroglial activation, and Aβ 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.
Odysseas Paxinos, Parmenion P. Tsitsopoulos, Michael R. Zindrick, Leonard I. Voronov, Mark A. Lorenz, Robert M. Havey, and Avinash G. Patwardhan
There is limited data on the pullout strength of spinal fixation devices in the thoracic spine among individuals with different bone quality. An in vitro biomechanical study on the thoracic spine was performed to compare the pullout strength and the mechanism of failure of 4 posterior fixation thoracic constructs in relation to bone mineral density (BMD).
A total of 80 vertebrae from 11 fresh-frozen thoracic spines (T2–12) were used. Based on the results from peripheral quantitative CT, specimens were divided into 2 groups (normal and osteopenic) according to their BMD. They were then randomly assigned to 1 of 4 different instrumentation systems (sublaminar wires, pedicle screws, lamina claw hooks, or pedicle screws with wires). The construct was completed with 2 titanium rods and 2 transverse connectors, creating a stable frame. The pullout force to failure perpendicular to the rods as well as the pattern of fixation failure was recorded.
Mean pullout force in the osteopenic Group A (36 vertebrae) was 473.2 ± 179.2 N and in the normal BMD Group B (44 vertebrae) was 1414.5 ± 554.8 N. In Group A, no significant difference in pullout strength was encountered among the different implants (p = 0.96). In Group B, the hook system failed because of dislocation with significantly less force than the other 3 constructs (931.9 ± 345.1 N vs an average of 1538.6 ± 532.7 N; p = 0.02). In the osteopenic group, larger screws demonstrated greater resistance to pullout (p = 0.011). The most common failure mechanism in both groups was through pedicle base fracture.
Bone quality is an important factor that influences stability of posterior thoracic implants. Fixation strength in the osteopenic group was one-fourth of the value measured in vertebrae with good bone quality, irrespective of the instrumentation used. However, in normal bone quality vertebrae, the lamina hook claw system dislocated with significantly less force when compared with other spinal implants. Further studies are needed to investigate the impact of different transpedicular screw designs on the pullout strength in normal and osteopenic thoracic spines.
Andreas Fahlström, Henrietta Nittby Redebrandt, Hugo Zeberg, Jiri Bartek Jr., Andreas Bartley, Lovisa Tobieson, Maria Erkki, Amel Hessington, Ebba Troberg, Sadia Mirza, Parmenion P. Tsitsopoulos, and Niklas Marklund
The authors aimed to develop the first clinical grading scale for patients with surgically treated spontaneous supratentorial intracerebral hemorrhage (ICH).
A nationwide multicenter study including 401 ICH patients surgically treated by craniotomy and evacuation of a spontaneous supratentorial ICH was conducted between January 1, 2011, and December 31, 2015. All neurosurgical centers in Sweden were included. All medical records and neuroimaging studies were retrospectively reviewed. Independent predictors of 30-day mortality were identified by logistic regression. A risk stratification scale (the Surgical Swedish ICH [SwICH] Score) was developed using weighting of independent predictors based on strength of association.
Factors independently associated with 30-day mortality were Glasgow Coma Scale (GCS) score (p = 0.00015), ICH volume ≥ 50 mL (p = 0.031), patient age ≥ 75 years (p = 0.0056), prior myocardial infarction (MI) (p = 0.00081), and type 2 diabetes (p = 0.0093). The Surgical SwICH Score was the sum of individual points assigned as follows: GCS score 15–13 (0 points), 12–5 (1 point), 4–3 (2 points); age ≥ 75 years (1 point); ICH volume ≥ 50 mL (1 point); type 2 diabetes (1 point); prior MI (1 point). Each increase in the Surgical SwICH Score was associated with a progressively increased 30-day mortality (p = 0.0002). No patient with a Surgical SwICH Score of 0 died, whereas the 30-day mortality rates for patients with Surgical SwICH Scores of 1, 2, 3, and 4 were 5%, 12%, 31%, and 58%, respectively.
The Surgical SwICH Score is a predictor of 30-day mortality in patients treated surgically for spontaneous supratentorial ICH. External validation is needed to assess the predictive value as well as the generalizability of the Surgical SwICH Score.