Cervical spinal functional magnetic resonance imaging of the spinal cord injured patient during electrical stimulation.

PURPOSE: To evaluate the spatial distribution and signal intensity changes following spinal cord activation in patients with spinal cord injury. METHODS: This study used spinal functional magnetic resonance imaging (fMRI) based on signal enhancement by extra-vascular water protons (SEEP) to assess elicited responses during subcutaneous electrical stimulation at the right elbow and right thumb in the cervical spinal cord. RESULTS: Seven healthy volunteers and seven patients with cervical spinal cord injury (SCI) were included in this study. Significant functional activation was observed mainly in the right side of the spinal cord at the level of the C5-C6 cervical vertebra in both the axial and sagittal planes. A higher percentage of signal changes (4.66 ± 2.08 % in injured subjects vs. 2.78 ± 1.66 % in normal) and more average activation voxels (4.69 ± 2.59 in injured subjects vs. 2.56 ± 1.13 in normal subject) in axial plane at the C5-C6 cervical vertebra with a statistically significant difference. The same trends were observed in the sagittal plane with higher percentage of signal changes and more average activation voxels, though no statistically significant difference compared with the control group. CONCLUSIONS: Spinal SEEP fMRI is a powerful noninvasive method for the study of local neuronal activation in the human spinal cord, which may be of clinical value for evaluating the effectiveness of interventions aimed at promoting recovery of function using electrical stimulation.

[Correlation study of spinal canal and dural sac dimensions on MRI with therapy of lumbar disc herniation].

OBJECTIVE: To explore the value of spinal canal and dural sac dimensions for the treatment of lumbar disc herniation in MRI. METHODS: The clinical data of 144 patients with single-level lumbar disc herniation underwent nonsurgical or surgical treatment from January 2010 to December 2012 were retrospectively analyzed. There were 91 patients in the nonsurgical group, including 55 males and 36 females, ranging in age from 20 to 68 years old with an average of (43.37±12.48) years; and there were 53 patients in the surgical group, including 28 males and 25 females, ranging in age from 20 to 64 years old with an average of (42.98±12.95) years. JOA scores (29 scores) were used to evaluate clinical manifestation (including subjective symptoms, objective findings, limitation of daily activities and bladder function) and outcomes. The parameters related to spinal canal and dural sac dimensions (including spinal canal midsagittal diameter and available diameter, lateral recess width, spinal canal and dural sac cross-sectional area) in the initial axial T2-weighted MRI were measured, and odds ratio of available diameter to midsagittal diameter, odds ratio of lateral recess width to midsagittal diameter and area ratio of dural sac to spinal canal were calculated. Then, the differences of all parameters between two groups, and the correlations with initial JOA scores were analyzed. RESULTS: (1) All patients were followed up from 1 to 3 years with an average of 2.1 years. JOA scores before treatment were 16.27±2.96 in nonsurgical group and 12.64±3.30 in surgical group, there was statistically significant difference (t=6.319, P<0.01). At final follow-up time, there was no statistically significant difference in JOA scores (25.41±2.22 vs 25.76±2.29), improvement rate [(72.95±12.54)% vs (76.80±9.45)%], and the excellent and good rate (84.91% vs 78.02%) between two groups (P>0.05). But, the relapse rate of nonsurgical group was higher than surgical group (14.29% vs 5.67%). (2) Spinal canal midsagittal diameter and available diameter, lateral recess width, spinal canal and dural sac area, the ratio of available diameter to midsagittal diameter, and the ratio of lateral recess width to midsagittal diameter in surgical group were smaller than that of nonsurgical group, but the area ratio of dural sac to spinal canal was larger, and there were statistically significant differences between two groups (P<0.01). (3) The initial JOA scores showed significantly positive correlation with spinal canal midsagittal diameter and available diameter, lateral recess width, and canal and dural sac area (P<0.01); also presented positive correlation with the ratio of available diameter to midsagittal diameter and the ratio of lateral recess width to midsagittal diameter (P<0.05); but there was a significantly negative correlation between initial JOA scores and the area ratio of dural sac to spinal canal. CONCLUSION: Both nonsurgical and surgical treatment of lumbar disc herniation can obtain good effect, but the recurrence rate of non-surgical treatment is higher. Preoperative MRI measurement parameters of spinal canal and dural sac dimensions has certain value for the treatment selection of lumbar disc herniation, but further refinement and validation is still required.

SSFSE sequence functional MRI of the human cervical spinal cord with complex finger tapping.

PURPOSE: Functional MR imaging of the human cervical spinal cord was carried out on volunteers during alternated rest and a complex finger tapping task, in order to detect image intensity changes arising from neuronal activity. METHODS: Functional MR imaging data using single-shot fast spin-echo sequence (SSFSE) with echo time 42.4 ms on a 1.5 T GE Clinical System were acquired in eight subjects performing a complex finger tapping task. Cervical spinal cord activation was measured both in the sagittal and transverse imaging planes. Postprocessing was performed by AFNI (Analysis of Functional Neuroimages) software system. RESULTS: Intensity changes (5.5-7.6%) were correlated with the time course of stimulation and were consistently detected in both sagittal and transverse imaging planes of the cervical spinal cord. The activated regions localized to the ipsilateral side of the spinal cord in agreement with the neural anatomy. CONCLUSION: Functional MR imaging signals can be reliably detected with finger tapping activity in the human cervical spinal cord using a SSFSE sequence with 42.4 ms echo time. The anatomic location of neural activity correlates with the muscles used in the finger tapping task.

Functional MR imaging of the cervical spinal cord by use of 20Hz functional electrical stimulation to median nerve.

PURPOSE: Functional MR imaging of the human cervical spinal cord was carried out on volunteers by 20Hz functional electrical stimulation to median nerve, in order to detect signal changes arising concomitant to neuronal activity. METHODS: Functional MR imaging data were acquired in six subjects with single-shot fast spin-echo sequence (SSFSE) on a 1.5T GE Clinical System. Cervical spinal cord activation was measured both in the sagittal and transverse imaging planes. Postprocessing was performed by AFNI (Analysis of Functional Neuroimages) software system. RESULTS: Activation correlated with the time course of stimulation was consistently detected in both sagittal and transverse imaging planes of the cervical spinal cord. Regions of the spinal cord associated with motor and pain response were observed by 20Hz functional electrical stimulation to the median nerve. CONCLUSION: The functional MR imaging signal can be detected in the human cervical spinal cord with functional electrical stimulation. Investigating the FES response in the spinal cord using the spinal fMRI will be helpful for the further discussion on the diagnosis and functional recovery to spinal cord diseases.

Interleukin-1 beta induction of neuron apoptosis depends on p38 mitogen-activated protein kinase activity after spinal cord injury.

AIM: Interleukin-1 beta (IL-1beta) has been implicated as an extracellular signal in the initiation of apoptosis in neurons and oligodendrocytes after spinal cord injury (SCI). To further characterize the apoptotic cascade initiated by IL-1beta after SCI, we examined the expression of IL-1beta, p38 mitogen-activated protein kinase (p38 MAPK) and caspase-3 after SCI, and further investigated whether p38 MAPK was involved in neuron apoptosis induced by IL-1beta. METHODS: Adult rats were given contusion SCI at the T-10 vertebrae level with a weight-drop impactor (10 g weight dropped 25.0 mm). The expression levels of IL-1beta, p38 MAPK and caspase-3 after SCI were assessed with Western blots, immunohistochemistry staining, and real time reverse transcription polymerase chain reactions (RT-PCR). Neuron apoptosis was assessed with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) method. RESULTS: Increased levels of IL-1beta and p38 MAPK were observed soon after injury, with a peak in expression levels within 6 h of injury. By 24 h after injury, caspase-3 expression was markedly increased in the injured spinal cord. TUNEL-positive cells were first observed in the lesioned area 6 h after SCI. The largest number of TUNEL-positive cells was observed at 24 h post-SCI. Intrathecal injection of the IL-1 receptor antagonist IL-1Ra significantly reduced expression of p38 MAPK and caspase-3, and reduced the number of TUNEL-positive cells. Moreover, intrathecal injection of an inhibitor of p38 MAPK, SB203580, also significantly reduced the expression of caspase-3, and reduced the number of TUNEL-positive cells in the injured spinal cord. CONCLUSION: The p38MAPK signaling pathway plays an important role in IL-1beta mediated induction of neuron apoptosis following SCI in rats.

Expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis.

AIM: To determine the expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis and its clinical significance. METHODS: A cervical spondylosis model was established in rats by destroying the stability of cervical posterior column, and the cord segments C(4-6) and gastric antrum were collected 3, 4 and 5 mo after the operation. Rats with sham operation were used as controls. c-fos neuronal counter-staining was performed with an immunohistochemistry method. Every third sections from C(4-6) segments were drawn. The 10 most labeled c-fos-immunoreactive (Fos-IR) neurons were counted, and the average number was used for statistical analysis. The mean of Fos-IR neurons in myenteric plexus was calculated after counting Fos-IR neurons in 25 ganglia from each antral preparation, and expressed as a mean count per myenteric ganglion. RESULTS: There were a few c-fos-positive neurons in the cervical cord and antrum in the control group. There was an increased c-fos expression in model group 3, 4 and 5 mo after operation, whereas there was no significant increase in c-fos expression in the control group at 3, 4 and 5 mo. More importantly, there was a significant difference in c-fos expression between rats followed up for 3 mo and those for 5 mo in the model group (11.20+/-2.26 vs 27.68+/-4.36, P<0.05, for the cervical cord; and 11.3+/-2.3 vs 29.3+/-4.6, P<0.05, for the gastric antrum). There was no significant difference between rats followed up for 3 mo and those for 4 mo and between rats followed up for 4 mo and those for 5 mo in the model group. CONCLUSION: c-fos expression in gastric myenteric plexus was dramatically associated with that in the spinal cord in rats with cervical spondylosis, suggesting that the gastrointestinal function may be affected by cervical spondylosis. If this hypothesis is confirmed by further studies, functional gastrointestinal diseases such as functional dyspepsia and irritable bowel syndrome could be explained by neurogastroenterology.