Cervical spondylotic myelopathy: Changes of fractional anisotropy in the spinal cord and magnetic resonance spectroscopy of the primary motor cortex in relation to clinical symptoms and their duration.

OBJECTIVE: To determine the changes in fractional anisotropy (FA) at the proximal spinal cord and in magnetic resonance spectroscopy (MRS) of the precentral gyrus in patients with cervical spondylotic myelopathy (CSM) with respect to clinical symptoms and their duration. MATERIAL AND METHODS: 20 patients with CSM (7 female; mean age 64.6 ± 10.5 years) and 18 age/sex matched healthy controls (9 female; mean age 63.5 ± 6.6 years) were prospectively included. Clinical data (modified Japanese Orthopaedic Association Score (mJOA) and Neck Disability Index (NDI)) and 3T MR measurements including DTI at the spinal cord (level C2/3) with FA and MRS of the left and right precentral gyrus were taken. Clinical correlations and regression analyses were performed. RESULTS: Mean clinical scores of patients were significantly different to controls (mJOA; CSM: 10.2 ± 2.9; controls: 18.0 ± 0.0, p < 0.001; NDI; CSM: 41.4±23.5; controls: 4.4±6.6, p<0.001); FA was significantly lower in patients (CSM: 0.645 ± 0.067; controls: 0.699 ± 0.037, p = 0.005). MRS showed significantly lower metabolite concentrations between both groups: creatine (Cr) (CSM: 46.46±7.64; controls: 51.36±5.76, p = 0.03) and N-acetylaspartate (NAA) (CSM: 93.94±19.22; controls: 107.24±20.20, p = 0.05). Duration of symptoms ≤6 months was associated with increased myo-inositol (Ins) (61.58±17.76; 44.44±10.79; p = 0.02) and Ins/Cr ratio (1.36±0.47; 0.96±0.18; p = 0.014) compared to symptoms >6 months. CONCLUSION: Metabolic profiles of the precentral gyrus and FA in the uppermost spinal cord differ significantly between patients and healthy controls. Ins, thought to be a marker of endogenous neuroinflammatory response, is high in the early course of CSM and normalizes over time.

Remote motor system metabolic profile and surgery outcome in cervical spondylotic myelopathy.

OBJECTIVE In patients with cervical spondylotic myelopathy (CSM), the motor system may undergo progressive functional/structural changes rostral to the lesion, and these changes may be associated with clinical disability. The extent to which these changes have a prognostic value in the clinical recovery after surgical treatment is not yet known. In this study, magnetic resonance spectroscopy (MRS) was used to test 2 primary hypotheses. 1) Based on evidence of corticospinal and spinocerebellar, rubro-, or reticulospinal tract degeneration/dysfunction during chronic spinal cord compression, the authors hypothesized that the metabolic profile of the primary motor cortices (M1s) and cerebellum, respectively, would be altered in patients with CSM, and these alterations would be associated with the extent of the neurological disabilities. 2) Considering that damage and/or plasticity in the remote motor system may contribute to clinical recovery, they hypothesized that M1 and cerebellar metabolic profiles would predict, at least in part, surgical outcome. METHODS The metabolic profile, consisting of N-acetylaspartate (NAA; marker of neuronal integrity), myoinositol (glial marker), choline (cell membrane synthesis and turnover), and glutamate-glutamine (glutamatergic system), of the M1 hand/arm territory in each hemisphere and the cerebellum vermis was investigated prior to surgery in 21 patients exhibiting weakness of the upper extremities and/or gait abnormalities. Age- and sex-matched controls (n = 16) were also evaluated to estimate the pre-CSM metabolic profile of these areas. Correlation and regression analyses were performed between preoperative metabolite levels and clinical status 6 months after surgery. RESULTS Relative to controls, patients exhibited significantly higher levels of choline but no difference in the levels of other metabolites across M1s. Cerebellar metabolite levels were indistinguishable from control levels. Certain metabolites-myo-inositol and choline across M1s, NAA and glutamate-glutamine in the left M1, and myo-inositol and glutamate-glutamine in the cerebellum-were significantly associated with postoperative clinical status. These associations were greatly improved by including preoperative clinical metrics into the models. Likewise, these models improved the predictive value of preoperative clinical metrics alone. CONCLUSIONS These preliminary findings demonstrate relationships between the preoperative metabolic profiles of two remote motor areas and surgical outcome in CSM patients. Including preoperative clinical metrics in the models significantly strengthened the predictive value. Although further studies are needed, this investigation provides an important starting point to understand how the changes upstream from the injury may influence the effect of spinal cord decompression.

Metabolite and functional profile of patients with cervical spondylotic myelopathy.

OBJECTIVE The goal of this study was to compare the recovery of neuronal metabolism and functional reorganization in the primary motor cortex (M1) between mild and moderate cervical spondylotic myelopathy (CSM) following surgical intervention. METHODS Twenty-eight patients with CSM underwent 3-T MRI scans that included spectroscopy and functional MRI, before surgery and 6 months postsurgery. The classification of severity was based on the modified Japanese Orthopaedic Association questionnaire. Mild and moderate myelopathy were defined by modified Japanese Orthopaedic Association scores > 12 of 18 (n = 15) and 9-12 (n = 13), respectively. Ten healthy control subjects underwent 2 MRI scans 6 months apart. Metabolite levels were measured in the M1 contralateral to the greater deficit side in patients with CSM and on both sides in the controls. Motor function was assessed using a right finger-tapping paradigm and analyzed with BrainVoyager QX. RESULTS Patients with mild CSM had a lower preoperative N-acetylaspartate to creatine (NAA/Cr) ratio compared with moderate CSM, suggesting mitochondrial dysfunction. Postsurgery, NAA/Cr in moderate CSM decreased to the levels observed in mild CSM. Preoperatively, patients with mild CSM had a larger volume of activation (VOA) in the M1 than those with moderate CSM. Postoperatively, the VOAs were comparable between the mild and moderate CSM groups and had shifted toward the primary sensory cortex. CONCLUSIONS The NAA/Cr ratio and VOA size in the M1 can be used to discriminate between mild and moderate CSM. Postsurgery, the metabolite profile of the M1 did not recover in either group, despite significant clinical improvement. The authors proposed that metabolic impairment in the M1 may trigger the recruitment of adjacent healthy cortex to achieve functional recovery.

Cervical Spondylotic Myelopathy: Metabolite Changes in the Primary Motor Cortex after Surgery.

Purpose To characterize longitudinal metabolite alterations in the motor cortex of patients with cervical spondylotic myelopathy (CSM) by using proton magnetic resonance (MR) spectroscopy and to evaluate white matter integrity with diffusion-tensor imaging in patients who are recovering neurologic function after decompression surgery. Materials and Methods Informed written consent was obtained for all procedures and the study was approved by Western University's Health Sciences Research Ethics Board. Twenty-eight patients with CSM and 10 healthy control subjects were prospectively recruited and underwent two separate 3-T MR imaging examinations 6 months apart. Patients with CSM underwent surgery after the first examination. N-acetylaspartate (NAA), an indicator of neuronal mitochondrial function, normalized to creatine (Cr) levels were measured from the motor cortex contralateral to the greater functional deficit side in the patient group and on both sides in the control group. Fractional anisotropy and mean diffusivity were measured by means of diffusion-tensor imaging in the white matter adjacent to the motor and sensory cortices of the hand and the entire cerebral white matter. Clinical data were analyzed by using Student t tests. Results In patients with CSM, NAA normalized to Cr (NAA/Cr) levels were significantly lower 6 months after surgery (1.48 ± 0.08; P < .03) compared with preoperative levels (1.73 ± 0.09), despite significant improvement in clinical questionnaire scores. Fractional anisotropy and mean diffusivity were the same (P > .05) between the patient and control groups in all measured regions at all time points. Conclusion NAA/Cr levels decreased in the motor cortex in patients with CSM 6 months after successful surgery. Intact white matter integrity with decreased NAA/Cr levels suggests that mitochondrial metabolic dysfunction persists after surgery. © RSNA, 2016 Online supplemental material is available for this article.

[Effect of acupotomy intervention on cervicomuscular apoptosis in cervical spondylosis rabbits].

OBJECTIVE: To observe the effect of acupotomy therapy on cervicomuscular apoptosis and apoptosis regulator Bax protein expression in cervical spondylosis (CS) rabbits so as to investigate its mechanisms underlying improvement of CS. METHODS: Twenty-four New Zealand rabbits were randomly divided into normal control, model, acupotomy and electroacupuncture (EA) groups, with 6 rabbits in each group. The CS model was made by forced head-bowing for 5 hours in a restrained chamber, once daily for 12 weeks. Acupotomy was performed at the starting point of trapezius, the mastoid process attaching point of sternocleidomastoid, the cerverical vertebrae joint process or the local induration or cord-like mass (2 or 3 points of them were used as the needle-knife entering points), once a week for 3 weeks. For animals of the EA group, EA (2 Hz/100 Hz, 2 mA) was applied to bilateral "Tianzhu" (BL 10), "Jingbailao" (EX-HN 15), "Dazhu" (BL 11) for 20 min, once daily and 3 times a week for 3 weeks. The number of apoptotic cells in the cervical muscle was observed by light microscope after TUNEL staining and muscular Bcl-2 and Bax protein expression was detected by Western blot. RESULTS: In comparison with the control group, the number of cervicomuscular apoptotic cells, and the expression level of cervicomuscular Bax protein were significantly increased, and the Bcl-2/Bax was obviously decreased in the model group (P < 0.01, P < 0.05). Compared to the model group, the number of apoptotic cells and the expression level of muscular Bax protein were notably decreased in the acupotomy group (P < 0.01, P < 0.05), while the ratio of Bcl-2 and Bax was apparently increased in the acupotomy group (P < 0.05). The effects of acupotomy were significantly superior to those of EA in lowering apoptotic cell number and in up-regulating Bcl-2/Bax (P < 0.01, P < 0.05). No significant differences were found between the EA and model groups in the apoptotic cell number and among the four groups in Bcl-2 protein expression levels (P > 0.05). CONCLUSION: Acupotomy therapy can reduce cervicomuscular cellular apoptosis and Bax protein expression in CS rabbits, which may be one of its mechanism underlying improving CS.

[Effects of electroacupuncture on Wnt-ß-catenin signal pathway in annulus fibrosus cells in intervertebral disc in rats with cervical spondylosis].

OBJECTIVE: To observe the effects of electroacupuncture (EA) at "Dazhui" (GV 14) on Wnt-ß-catenin signal pathway in annulus fibrosus cells in intervertebral disc in rats with cervical spondylosis. METHODS: Forty SD rats were randomized into a control group, a model group, an EA group and a medication group, 10 rats in each one. Rats in the control group were treated with sham operation, only incision on local skin; rats in the remaining groups were made into cervical spondylosis models. After model establishment, rats in the control group and model group received fixed treatment under identical condition; rats in the EA group were treated with EA at "Dazhui" (GV 14), 30 min per treatment; rats in the medication group were treated with intragastric administration of meloxicam tablets. Treatments were both given once a day, and 14 days were taken as one session; there was an interval of 2 days between two sessions, and totally two sessions were given. After the treatments, immunohistochemistry was applied to measure the expression of Wnt, glycogen synthase kinase-3ß (GSK-3ß) and Axin in annulus fibrosus cells; western blot was used to test the expression of P-ß-catenin. RESULTS: In the control group, there were more positive cells of Wnt, GSK-3ß and Axin, which were intensively distributed, deeply colored, and strongly positive; In the model group, there were less positive cells of Wnt, GSK-3ß and Axin, which were sparsely distributed and weakly positive. The expression of Wnt, GSK-3ß, Axin and P-ß-catenin in the model group was less than that in the control group (all P < 0.05); expression of Wnt, GSK-3ß, Axin and P-ß-catenin in the EA group and medication group was higher than that in the model group (all P < 0.05); expression of Wnt, GSK-3ß, Axin and P-ß-catenin was not significantly different between EA group and medication group (all P > 0.05). CONCLUSION: EA could delay the degeneration of intervertebral disc, which may be related to EA inhibiting signal pathway of Wnt-ß-catenin.

Electroacupuncture inhibits annulus fibrosis cell apoptosis in vivo via TNF-α-TNFR1-caspase-8 and integrin ß1/Akt signaling pathways.

OBJECTIVE: To examine whether electroacupuncture (EA) treatment inhibited cell apoptosis of intervertebral annulus fibrosis (AF) via tumor necrosis factor-α (TNF-α)-tumor necrosis factor receptor 1 (TNFR1)-caspase-8 and integrin ß1/Akt signaling pathways in a rat model of cervical intervertebral disc degeneration caused by unbalanced dynamic and static forces. METHODS: Thirty-two Sprague-Dawley rats were included in this study, of which 24 rats underwent surgery to induce cervical intervertebral disc degeneration, while eight rats received EA treatment at Dazhui (GV 14). Immunohistochemical staining was used to detect TNF-α, TNFR1, and caspase-8. Apoptosis of AF cells was examined with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining. The mRNA and protein expression levels of integrin ß1 and Akt were evaluated with real-time polymerase chain reaction and western blot analysis, respectively. RESULTS: Treatment with EA decreased TUNEL-positive AF cells and lowered TNF-α, TNFR1 and caspase-8 positive cells compared with control groups. EA treatment also increased integrin ß1 and Akt mRNA and protein levels compared with controls. CONCLUSION: Treatment with EA inhibits AF cell apoptosis through suppression of the TNF-α-TNFR1-caspase-8 signal pathway and increases the expression of integrin ß1 and Akt. EA may be a good alternative therapy for treating cervical spondylosis.