Postoperative changes in spinal cord signal intensity in patients with spinal cord injury without major bone injury: comparison between preoperative and postoperative magnetic resonance images

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  • 1 Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine; and
  • | 2 Department of Orthopedic Surgery, Chubu Rosai Hospital, Japan Organization of Occupational Health and Safety, Nagoya, Japan
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OBJECTIVE

Although increased signal intensity (ISI) on MRI is observed in patients with cervical spinal cord injury (SCI) without major bone injury, alterations in ISI have not been evaluated. The association between postoperative ISI and surgical outcomes remains unclear. This study elucidated whether or not the postoperative classification and alterations in MRI-based ISI of the spinal cord reflected the postoperative symptom severity and surgical outcomes in patients with SCI without major bone injury.

METHODS

One hundred consecutive patients with SCI without major bone injury (79 male and 21 female) with a mean age of 55 years (range 20–87 years) were included. All patients were treated with laminoplasty and underwent MRI pre- and postoperatively (mean 12.5 ± 0.8 months). ISI was classified into three groups on the basis of sagittal T2-weighted MRI: grade 0, none; grade 1, light (obscure); and grade 2, intense (bright). The neurological statuses were evaluated according to the Japanese Orthopaedic Association (JOA) scoring system and the American Spinal Injury Association Impairment Scale (AIS).

RESULTS

Preoperatively, 8 patients had grade 0 ISI, 49 had grade 1, and 43 had grade 2; and postoperatively, 20 patients had grade 0, 24 had grade 1, and 56 had grade 2. The postoperative JOA scores and recovery rate (RR) decreased significantly with increasing postoperative ISI grade. The postoperative ISI grade tended to increase with the postoperative AIS grade. Postoperative grade 2 ISI was observed in severely paralyzed patients. The postoperative ISI grade improved in 23 patients (23%), worsened in 25 (25%), and remained unchanged in 52 (52%). Patients with an improved ISI grade had a better RR than those with a worsened ISI grade.

CONCLUSIONS

Postoperative ISI reflected postoperative symptom severity and surgical outcomes. Alterations in ISI were seen postoperatively in 48 patients (48%) and were associated with surgical outcomes.

ABBREVIATIONS

AIS = American Spinal Injury Association Impairment Scale; CSM = cervical spondylotic myelopathy; ISI = increased signal intensity; JOA = Japanese Orthopaedic Association; RR = recovery rate; SCI = spinal cord injury; T1WI = T1-weighted MRI; T2WI = T2-weighted MRI.

OBJECTIVE

Although increased signal intensity (ISI) on MRI is observed in patients with cervical spinal cord injury (SCI) without major bone injury, alterations in ISI have not been evaluated. The association between postoperative ISI and surgical outcomes remains unclear. This study elucidated whether or not the postoperative classification and alterations in MRI-based ISI of the spinal cord reflected the postoperative symptom severity and surgical outcomes in patients with SCI without major bone injury.

METHODS

One hundred consecutive patients with SCI without major bone injury (79 male and 21 female) with a mean age of 55 years (range 20–87 years) were included. All patients were treated with laminoplasty and underwent MRI pre- and postoperatively (mean 12.5 ± 0.8 months). ISI was classified into three groups on the basis of sagittal T2-weighted MRI: grade 0, none; grade 1, light (obscure); and grade 2, intense (bright). The neurological statuses were evaluated according to the Japanese Orthopaedic Association (JOA) scoring system and the American Spinal Injury Association Impairment Scale (AIS).

RESULTS

Preoperatively, 8 patients had grade 0 ISI, 49 had grade 1, and 43 had grade 2; and postoperatively, 20 patients had grade 0, 24 had grade 1, and 56 had grade 2. The postoperative JOA scores and recovery rate (RR) decreased significantly with increasing postoperative ISI grade. The postoperative ISI grade tended to increase with the postoperative AIS grade. Postoperative grade 2 ISI was observed in severely paralyzed patients. The postoperative ISI grade improved in 23 patients (23%), worsened in 25 (25%), and remained unchanged in 52 (52%). Patients with an improved ISI grade had a better RR than those with a worsened ISI grade.

CONCLUSIONS

Postoperative ISI reflected postoperative symptom severity and surgical outcomes. Alterations in ISI were seen postoperatively in 48 patients (48%) and were associated with surgical outcomes.

In Brief

The authors aimed to elucidate whether postoperative classification and alterations in increased signal intensity (ISI) on spinal cord MRI reflected the postoperative symptom severity and surgical outcomes in spinal cord injury (SCI) patients without major bone injury. The postoperative ISI was classified as grade 0 (no ISI), 1 (obscure ISI), or 2 (bright ISI). Alterations in ISI were observed postoperatively in 48 patients (48%) and were associated with surgical outcomes. The ISI grade was found to be associated with changes of symptoms during the postoperative course of SCI patients without major bone injury.

The incidence of spinal stenosis has been increasing with the aging of the population and has led to an increase in the number of spinal cord injuries (SCIs) without major bone injury caused by minor trauma. SCI without major bone injury involves SCI without evidence of spinal fracture or dislocation on plain radiographs or CT scans.1–3 At present, MRI is the state-of-the-art clinical modality for evaluation of traumatic SCI.4,5 Therefore, MRI is essential for examining patients with SCI without major bone injury because it shows the degree of spinal stenosis and details about the intramedullary spinal cord condition. For diagnosis and prognosis of SCI without major bone injury, MRI has been found to be useful because of its superior contrast resolution, absence of bony artifacts, and multiplanar imaging capability.6,7

There have been few reports on the preoperative MRI features of patients with cervical SCI without major bone injury,8,9 so it would be useful to examine the findings of T2-weighted MRI (T2WI) before surgery. Patients with cervical SCI without major bone injury often exhibit intramedullary high signal intensities (increased signal intensities [ISIs]). With advances in MRI techniques, it is possible to detect two different types of ISI: light (obscure) and intense (bright) signal changes.9–12

In some patients with SCI without major bone injury, resolution or decrease in ISI has been observed after surgery, but few studies to our knowledge have evaluated alterations in ISI between pre- and postoperative MRI sequences.13 However, alterations in ISI have not been evaluated fully, and no relationship between postoperative ISI and surgical outcomes in patients with SCI without major bone injury has been clearly established. The aim of this study was to determine if the postoperative classification of and alterations in ISI on MRI of the spinal cord reflect the postoperative symptom severity and surgical outcomes in patients with SCI without major bone injury.

Methods

Study Population

A total of 100 consecutive patients with SCI without major bone injury who had undergone expansive laminoplasty were included. The participants included 79 males and 21 females, with a mean age of 55.5 ± 13.3 years. All patients underwent preoperative functional radiography in the acute phase, and they were followed up for a minimum of 12 months after surgery. The exclusion criteria were as follows: 1) presence of ossification of the posterior longitudinal ligament; 2) massive disc herniation; 3) history of rheumatoid arthritis, cerebral palsy, or tumors; 4) fracture or traumatic instability, such as dislocation/subluxation; 5) destructive spondylarthritis due to hemodialysis; 6) previous cervical surgery; 7) severe kyphosis (C2–7 kyphosis of more than 15°),14 spinal fusion with instrumentation; 8) thoracic spondylotic myelopathy; and 9) lumbar spinal canal stenosis. All patients presented with symptoms of cervical SCI and MRI findings consistent with symptoms secondary to multisegment cervical spinal canal stenosis. For each patient, SCI was confirmed by physical examination, and cord compression between the C3–4 and C6–7 disc levels was detected by MRI. Patients with profound neurological deficits and persistent spinal cord compression due to cervical spinal canal stenosis were indicated for surgery. This study was approved by our institutional review board, and written informed consent was obtained from each patient prior to study participation or surgery.

All patients underwent high-resolution MRI in the acute phase preoperatively and at 1-year follow-up postoperatively. MRI was performed using a 1.5-T MRI unit (Signa, GE Healthcare). Most patients underwent preoperative MRI within 24 hours after trauma (mean 26.0 ± 45.6 hours [± SD]). The mean period from operation to postoperative MRI was 12.5 ± 0.8 months. Sagittal T1-weighted MRI (T1WI) and T2WI of the cervical cord were obtained using a spin echo sequence system for T1WI and a fast spin echo sequence system for T2WI, with a surface coil. The slice width was 4 mm, and the acquisition matrix was 512 × 256. The sequence parameters included were as follows: TR 400 msec and TE 11 msec for T1WI and TR 4000 msec and TE 126 msec for T2WI. On the sagittal T2WI scans, the ISI of the spinal cord at the narrowest level was classified into three groups on the basis of the reports by Yukawa et al.: grade 0, none; grade 1, light (obscure); and grade 2, intense (bright) (Fig. 1),10,15 where an intense ISI was considered to be similar to the signal from the CSF The classifications were made by two independent spinal surgeons experienced in spinal imaging. For the analysis of the T2WI scans, the level of agreement between the two observers was 0.94 (kappa = 0.85, p < 0.001). The two observers established the final classification by consensus. Interpretation of postoperative MRI by the radiologist confirmed that surgical decompression was successfully achieved in all patients.

FIG. 1.
FIG. 1.

Sagittal T2-weighted MR images showing ISI classification of the spinal cord. The arrows indicate ISI sites.

The following parameters were compared between the groups: age, sex, injury mechanism, time from injury to operation, and period from operation to postoperative MRI. The neurological levels based on ISI or narrowest levels were evaluated on MRI.

Surgical Technique for Modified Double-Door Laminoplasty

A double-door laminoplasty was performed according to the Kurokawa method with some modifications by Machino et al.16,17 The muscles attached to the C2 spinous process were preserved without detachment. Surgical exposure was limited as much as possible. The spinous processes between C3 and C7 were resected at their bases, and the laminae were cut at the center by using a high-speed drill. Bilateral gutters were created as hinges at the border between the laminae and facets in a slightly more medial fashion than originally described, thus minimizing invasion of the facets. After elevating the halves of the laminae similar to opening a French door, the bone graft struts (16–18 mm long) created from the C6 or C7 spinous process were tied to bridge the bilateral edges of the laminae.

Postoperative Considerations

All patients were allowed to sit up and walk on postoperative day 1 while wearing a Philadelphia collar. The collars were fitted for all patients, but they were allowed to remove them at their discretion. The cervical range of motion exercises were performed as soon as possible during the rehabilitation program. The ideal spinal alignment was explained to all patients after surgery.

Clinical Outcome

Postoperative follow-up duration, surgery time, and blood loss were assessed. Symptom severity was investigated according to the scoring system of the Japanese Orthopaedic Association (JOA) for cervical myelopathy17,18 before surgery, 1 year after surgery, and at the final follow-up. The postoperative JOA score was determined at the 1-year follow-up and evaluated at the same time as the MRI investigation. The JOA recovery rate (RR) was calculated using the formula suggested by Hirabayashi et al.:19 RR = (postoperative JOA score − preoperative JOA score)/(17 − preoperative JOA score) × 100%, with 100% corresponding to the best possible postoperative improvement. The American Spinal Injury Association Impairment Scale (AIS) grades were evaluated (grades A–E).8,12 The percentages of AIS improvement of one or more grades were also assessed.8,12

According to the ISI grading system, the alterations were classified into three groups: improved, unchanged, or worsened after decompressive surgery. The clinical features and surgical outcomes associated with the average patient age, sex, pre- and postoperative JOA scores, RR of the JOA score, and improvement in the AIS grade were compared among the three groups of postoperative alterations in ISI.

Statistical Analysis

Data were analyzed using IBM SPSS statistical software (version 25.0, IBM Corp.). Results are presented as the mean ± standard deviation. Differences between two groups were analyzed by performing the Mann-Whitney U-test, whereas differences among three groups were analyzed by performing the Kruskal-Wallis test. Repeated measures within the same group were analyzed by performing the Wilcoxon signed-rank test. The chi-square test was performed to analyze differences between groups; p < 0.05 was considered to be indicative of statistical significance.

Results

All patients underwent expansive laminoplasty, which was performed at C3–7 in 94 patients and C3–6 in 6 patients. The mean period from injury to operation was 17.4 ± 3.3 days. The mean operative time was 94.5 ± 42.9 minutes, and the mean blood loss was 83.9 ± 119.6 ml. All patients were followed up for > 12 months after surgery, and the mean follow-up period was 24.9 ± 18.4 months. The mean pre- and postoperative (1 year after surgery) JOA scores were 8.4 ± 3.6 points and 11.6 ± 3.4 points, respectively, whereas at the final follow-up, the mean score was 11.6 ± 3.5 points. The mean RR was 40.0% ± 25.5% at the 1-year follow-up, and 67% of the patients showed one or more grades of improvement in the AIS grade.

Ninety-two patients (92%) presented with preoperative ISI. The preoperative MRI showed grade 0 in 8 patients, grade 1 in 49 patients, and grade 2 in 43 patients. Eighty patients (80%) had postoperative ISI. Postoperative MRI showed grade 0 in 20 patients, grade 1 in 24, and grade 2 in 56 (Table 1). No differences were found among the three groups regarding age and sex, injury mechanism, time from injury to operation, or period from operation to postoperative MRI (Table 2). The neurological levels based on ISI or narrowest levels were C3–4 in 39 patients, C4–5 in 39 patients, and C5–6 in 22 patients. There were no differences in the neurological levels based on ISI or the narrowest levels among the three groups (Table 2).

TABLE 1.

Number of patients in each of 3 pre- and postoperative grades of ISI

Postop Grade
Preop Grade012
0800
1111325
211131
TABLE 2.

Patient demographics and summary details in each grade of postoperative ISI

Grade 0Grade 1Grade 2p Value
No. of patients202456
Mean age, yrs52.1 ± 15.458.2 ± 10.155.6 ± 13.60.4212
Male/female sex, n14/618/647/90.3628
Injury mechanism, n (%)
 Fall or jump13 (65)15 (62.5)34 (60.7)0.9426
 Motor vehicle collision5 (25)7 (29.2)16 (28.6)0.9443
 Sports accident1 (5)1 (4.2)4 (7.1)0.8572
 Other1 (5)1 (4.2)2 (3.6)0.9605
Neurological level, n (%)
 C3–44 (20)10 (41.7)25 (44.6)0.1454
 C4–58 (40)10 (41.7)21 (37.5)0.9356
 C5–68 (40)4 (16.6)10 (17.9)0.0934
Mean time from injury to operation, days17.2 ± 3.717.4 ± 3.317.6 ± 3.20.8454
Mean time from operation to postop MRI, mos12.6 ± 0.812.5 ± 0.812.5 ± 0.80.9217

Mean values are presented as the mean ± SD.

No significant differences were found among the three groups regarding follow-up period, surgery time, and blood loss. The percentage of patients with one or more grades of AIS improvement decreased significantly with an increasing postoperative ISI grade (Table 3).

TABLE 3.

Clinical and radiographic outcomes in each grade of postoperative ISI

Grade 0Grade 1Grade 2p Value
Follow-up period, mos24.0 ± 16.724.0 ± 21.025.4 ± 23.80.8087
Surgery time, mins81.3 ± 26.096.3 ± 43.498.5 ± 47.00.3305
Estimated blood loss, ml60.4 ± 68.368.8 ± 59.798.9 ± 148.70.7158
Preop JOA score11.6 ± 3.47.4 ± 3.47.7 ± 3.2<0.0001*
Postop JOA score14.3 ± 3.512.0 ± 2.710.5 ± 3.3<0.0001*
JOA score RR, %57.6 ± 28.647.9 ± 20.430.5 ± 23.1<0.0001*
≥1 grade of improvement in AIS grade, n (%)18 (90)21 (87.5)28 (50)0.0002*

Values are presented as the mean ± SD unless stated otherwise.

Statistically significant.

There were significant differences in the pre- and postoperative mean JOA scores among the three groups. The postoperative JOA scores decreased significantly with an increasing postoperative ISI grade. The RR of the JOA score decreased significantly with postoperative ISI grade (Fig. 2). The postoperative ISI grade tended to increase with the postoperative AIS grades. Postoperative ISI grade 2 on MRI was observed in severely paralyzed patients (Fig. 3).

FIG. 2.
FIG. 2.

Pre- and postoperative JOA scores (A) and RR of the JOA scores (B) in each postoperative ISI grade. A significant difference was observed among the three groups, regarding the pre- and postoperative JOA scores and RR of the JOA score, where the postoperative JOA score and RR of the JOA score decreased significantly with an increasing ISI grade. Bars indicate the mean and error bars the SD. *p < 0.0001.

FIG. 3.
FIG. 3.

Pre- and postoperative AIS grades in each postoperative ISI grade. The ISI grade tended to increase with the pre- and postoperative AIS grades. ISI grade 2 on MRI was observed postoperatively in severely paralyzed patients.

The postoperative ISI grade improved in 23 patients (23%), worsened in 25 (25%), and remained unchanged in 52 (52%). The RR of the JOA score was less in the patients with worsened ISI grade than in those with an improved ISI grade. In contrast, improvement in the AIS grade was better in the patients with an improved ISI grade than in those with worse ISI grade (Table 4 and Fig. 4).

TABLE 4.

Clinical features and surgical outcomes according to 3 groups of postoperative alterations in ISI

ImprovedUnchangedWorsenedp Value
No. of patients235225
Mean age, yrs53.7 ± 14.057.1 ± 11.654.0 ± 15.90.6390
Male/female sex, n16/741/1122/30.2528
Mean preop JOA score9.9 ± 4.08.0 ± 3.58.0 ± 3.30.0622
Mean postop JOA score13.4 ± 3.311.0 ± 3.511.0 ± 3.20.0023*
Mean JOA score RR, %54.1 ± 28.437.4 ± 24.632.8 ± 22.50.0137*
≥1 grade of improvement in AIS, n (%)20 (87.0)34 (65.4)13 (52)0.0153*

Mean values are presented as the mean ± SD.

Statistically significant.

FIG. 4.
FIG. 4.

Representative case of a 55-year-old male who presented with an SCI without major bone injury due to a fall. Left: Preoperative sagittal T2-weighted MR image showing an intramedullary high signal intensity suggesting SCI at the C4–5 level. Prevertebral hyperintensity and intense ISI (grade 2 ISI) in the center of obscure ISI with spinal cord edema are seen. Right: One-year postoperative sagittal T2-weighted MR image showing adequate decompression after cervical laminoplasty at C3–7. The image also shows reduced spinal cord edema and clearer intense ISI (grade 2 ISI).

Discussion

Patients with SCI without major bone injury often show ISI of the spinal cord on T2WI, and recent progress in MRI technology and software have enabled identification of various degrees of ISI.20,21 Associations among the postoperative alteration of ISI, severity of symptom, and surgical outcome have not been established.13 The present study elucidated the degree of and alterations in ISI in patients with cervical SCI without major bone injury before and after decompressive surgery and the relationship of postoperative ISI with the severity of postoperative symptoms and surgical outcomes. Our results showed that increased postoperative ISI grade in patients with SCI without major bone injury reflected postoperative symptomatology and surgical outcomes, indicating that postoperative ISI grade 2 was associated with a worse outcome. Alterations of ISI were also associated with surgical outcomes.

SCI without major bone injury is related to hyperextension injury of the cervical spine and is often seen in patients with minor trauma without bony injury, with preexisting pathology (such as cervical spondylosis), and with canal stenosis.22,23 Additionally, a narrow canal is commonly observed in middle-aged and elderly patients, which is important in the context of SCI without major bone injury because the mechanism underlying central cord syndrome perhaps differs from that seen in young patients.24,25 In a hyperextension injury, the cord is compressed between the enfolded ligamentum flavum and the vertebral osteophyte.26,27

A diagnosis of SCI without major bone injury is based on physical symptoms, neurological examination findings, and radiographic imaging. There is no doubt that MRI is the best diagnostic modality to evaluate traumatic SCI in any population.28 MRI provides a detailed view of both the degree of spinal canal stenosis and the intramedullary condition of the spinal cord, which is useful for diagnosing SCI.29,30 MRI has been increasingly used for investigation of posttraumatic myelopathy for both imaging of the injured cord and predicting outcomes.31,32 Significant changes in signal intensity due to hemorrhage, contusion, or edema are often observed on T2WI.13 However, there have been no reports on the association between the grade of postoperative signal change on MRI and functional outcomes in patients with SCI without major bone injury.

The predictive value of abnormal signal intensity on preoperative MRI has been well described in the literature.8,12,21 As an umbrella term, abnormal signal intensity in the spinal cord includes intramedullary hematoma, hemorrhage, and edema.8,12,13 The use of quantitative radiographic measures of SCI was proposed by Fehlings et al., who showed that spinal cord hemorrhage and maximum spinal cord compression were related to poor neurological recovery.33 Other factors, such as age, spasticity, good hand function, and injury type, have been shown to predict final outcomes.7,20,22,32 However, there have been few reports about postoperative MRI features in patients with SCI without major bone injury.13

In the present study, 80 (80%) patients exhibited postoperative ISI. Postoperative MRI showed grade 0 in 20 patients, grade 1 in 24 patients, and grade 2 in 56 patients, and the postoperative MRI classifications were consistent with the symptom severity and surgical outcomes. The postoperative JOA scores decreased significantly with increasing postoperative ISI grade, and a significant relationship was confirmed between the postoperative MRI classification and RR of the JOA score. The ISI grade 2 patients were shown to have the worst surgical outcome.

Light ISI has been suggested to reflect mild neuropathological alterations in the spinal cord and a higher recovery potential, whereas intense ISI has been thought to reflect severe alterations and a lower recovery potential.10,11,34 In SCI without major bone injury, the spinal cord signal intensity alterations that occur with disease progression range from none to light ISI, then from light to intense ISI, and eventually lead to decreased RRs after surgery.9,12

SCI without major bone injury has been shown to cause irreversible paralysis and sensory damage,2,3 and whether or not conservative or surgical treatment strategies are best for patients with SCI without major bone injury remains controversial.22,23 The associated risks in any consideration of surgery should be fully disclosed and explained after the patient’s general state has been thoroughly ascertained. There are surgical indications for patients with ISI grade 2, but the spinal cord should be treated before it loses its recuperative potential.

To date, no consensus on a management protocol for SCI without major bone injury has been reached.23 At our institution, we perform CT scanning to identify cervical spine fractures or dislocations, and when instability is not evident on functional radiography, patients are allowed to sit up and walk while wearing a Philadelphia collar. Rehabilitation is then started immediately after injury. However, the role of surgery is controversial in patients with SCI without major bone injury.35 At our institution, patients with spinal cord compression on delayed MRI are offered cervical laminoplasty to achieve a more favorable outcome and prevent symptom deterioration.

In a previous study of 505 patients with cervical spondylotic myelopathy (CSM) that was recognized as degenerative nontraumatic disease, of 169 patients with preoperative grade 1 ISI, 42 (24.9%) exhibited improvement to grade 0 postoperatively but 57 (33.7%) showed worsening to grade 2 postoperatively.36 Overall, the ISI grade in the entire cohort improved in 66 patients (13.1%), worsened in 57 patients (11.3%), and was unchanged in 382 patients (75.6%). Alterations in ISI were observed postoperatively in 123 patients (24.4%).

In the present study of SCI without major bone injury recognized as traumatic disease, among the 49 patients with grade 1 ISI that had been noted preoperatively, 11 patients (22.4%) improved to grade 0 postoperatively, whereas 25 (51.0%) worsened to grade 2 postoperatively. Overall, the ISI grade improved in 23 patients (23%), worsened in 25 (25%), and remained unchanged in 52 (52%). Alterations in ISI were observed postoperatively in 48 patients (48%). The ISIs of SCI without major bone injury have been found to be twice as likely to change postoperatively as those of CSM. Compared with CSM, SCI without major bone injury was also found to be more easily changed postoperatively.37 In particular, ISI grade 1 was more likely to be worse in SCI without major bone injury than in CSM. Therefore, careful postoperative follow-up is more important.

There were some limitations in this study that should be considered when assessing our classifications. The follow-up duration was relatively brief, and patient-reported outcome measures, such as quality of life determined using the JOA Cervical Myelopathy Evaluation Questionnaire, SF-36, Neck Disability Index, and EQ-5D, were not assessed. Better objectivity could be achieved by combining these tests with clinical observations, such as the JOA score. The use of objective measures should be included in future studies. Because the current study could not address the chronological changes of clinical and MRI investigation after surgery, further study is needed to analyze them. Future large-scale and well-controlled studies are needed to further validate the clinical value of the presented classification system.

Conclusions

Postoperative ISI classification on MRI was found to reflect postoperative symptom severity and surgical outcomes in patients with SCI without major bone injury. Alterations in ISI were observed postoperatively in 48 patients (48%) and were associated with surgical outcomes.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Imagama. Acquisition of data: Machino. Analysis and interpretation of data: Machino, Kanbara, S Ito, Inoue, Yamaguchi, Koshimizu. Drafting the article: Machino. Critically revising the article: Ando, Kobayashi, Nakashima. Reviewed submitted version of manuscript: Imagama. Statistical analysis: Machino. Administrative/technical/material support: K Ito, Kato. Study supervision: Imagama, Ishiguro.

References

  • 1

    Gupta SK, Rajeev K, Khosla VK, et al. Spinal cord injury without radiographic abnormality in adults. Spinal Cord. 1999;37(10):726729.

  • 2

    Kothari P, Freeman B, Grevitt M, Kerslake R. Injury to the spinal cord without radiological abnormality (SCIWORA) in adults. J Bone Joint Surg Br. 2000;82(7):10341037.

    • Search Google Scholar
    • Export Citation
  • 3

    Hendey GW, Wolfson AB, Mower WR, Hoffman JR. Spinal cord injury without radiographic abnormality: results of the National Emergency X-Radiography Utilization Study in blunt cervical trauma. J Trauma. 2002;53(1):14.

    • Search Google Scholar
    • Export Citation
  • 4

    Song J, Mizuno J, Inoue T, Nakagawa H. Clinical evaluation of traumatic central cord syndrome: emphasis on clinical significance of prevertebral hyperintensity, cord compression, and intramedullary high-signal intensity on magnetic resonance imaging. Surg Neurol. 2006;65(2):117123.

    • Search Google Scholar
    • Export Citation
  • 5

    Miyanji F, Furlan JC, Aarabi B, et al. Acute cervical traumatic spinal cord injury: MR imaging findings correlated with neurologic outcome—prospective study with 100 consecutive patients. Radiology. 2007;243(3):820827.

    • Search Google Scholar
    • Export Citation
  • 6

    Tewari MK, Gifti DS, Singh P, et al. Diagnosis and prognostication of adult spinal cord injury without radiographic abnormality using magnetic resonance imaging: analysis of 40 patients. Surg Neurol. 2005;63(3):204209.

    • Search Google Scholar
    • Export Citation
  • 7

    Kasimatis GB, Panagiotopoulos E, Megas P, et al. The adult spinal cord injury without radiographic abnormalities syndrome: magnetic resonance imaging and clinical findings in adults with spinal cord injuries having normal radiographs and computed tomography studies. J Trauma. 2008;65(1):8693.

    • Search Google Scholar
    • Export Citation
  • 8

    Machino M, Yukawa Y, Ito K, et al. Can magnetic resonance imaging reflect the prognosis in patients of cervical spinal cord injury without radiographic abnormality? Spine (Phila Pa 1976). 2011;36(24):E1568E1572.

    • Search Google Scholar
    • Export Citation
  • 9

    Ouchida J, Yukawa Y, Ito K, et al. Delayed magnetic resonance imaging in patients with cervical spinal cord injury without radiographic abnormality. Spine (Phila Pa 1976). 2016;41(16):E981E986.

    • Search Google Scholar
    • Export Citation
  • 10

    Yukawa Y, Kato F, Yoshihara H, et al. MR T2 image classification in cervical compression myelopathy: predictor of surgical outcomes. Spine (Phila Pa 1976). 2007;32(15):16751679.

    • Search Google Scholar
    • Export Citation
  • 11

    Machino M, Imagama S, Ando K, et al. Image diagnostic classification of magnetic resonance T2 increased signal intensity in cervical spondylotic myelopathy: clinical evaluation using quantitative and objective assessment. Spine (Phila Pa 1976). 2018;43(6):420426.

    • Search Google Scholar
    • Export Citation
  • 12

    Machino M, Ando K, Kobayashi K, et al. MR T2 image classification in adult patients of cervical spinal cord injury without radiographic abnormality: a predictor of surgical outcome. Clin Neurol Neurosurg. 2019;177:15.

    • Search Google Scholar
    • Export Citation
  • 13

    Boldin C, Raith J, Fankhauser F, et al. Predicting neurologic recovery in cervical spinal cord injury with postoperative MR imaging. Spine (Phila Pa 1976). 2006;31(5):554559.

    • Search Google Scholar
    • Export Citation
  • 14

    Suda K, Abumi K, Ito M, et al. Local kyphosis reduces surgical outcomes of expansive open-door laminoplasty for cervical spondylotic myelopathy. Spine (Phila Pa 1976). 2003;28(12):12581262.

    • Search Google Scholar
    • Export Citation
  • 15

    Yukawa Y, Kato F, Ito K, et al. Postoperative changes in spinal cord signal intensity in patients with cervical compression myelopathy: comparison between preoperative and postoperative magnetic resonance images. J Neurosurg Spine. 2008;8(6):524528.

    • Search Google Scholar
    • Export Citation
  • 16

    Machino M, Yukawa Y, Hida T, et al. Modified double-door laminoplasty in managing multilevel cervical spondylotic myelopathy: surgical outcome in 520 patients and technique description. J Spinal Disord Tech. 2013;26(3):135140.

    • Search Google Scholar
    • Export Citation
  • 17

    Machino M, Yukawa Y, Imagama S, et al. Surgical treatment assessment of cervical laminoplasty using quantitative performance evaluation in elderly patients: a prospective comparative study in 505 patients with cervical spondylotic myelopathy. Spine (Phila Pa 1976). 2016;41(9):757763.

    • Search Google Scholar
    • Export Citation
  • 18

    Imagama S, Matsuyama Y, Yukawa Y, et al. C5 palsy after cervical laminoplasty: a multicentre study. J Bone Joint Surg Br. 2010;92(3):393400.

    • Search Google Scholar
    • Export Citation
  • 19

    Hirabayashi K, Miyakawa J, Satomi K, et al. Operative results and postoperative progression of ossification among patients with ossification of cervical posterior longitudinal ligament. Spine (Phila Pa 1976). 1981;6(4):354364.

    • Search Google Scholar
    • Export Citation
  • 20

    Talbott JF, Whetstone WD, Readdy WJ, et al. The Brain and Spinal Injury Center score: a novel, simple, and reproducible method for assessing the severity of acute cervical spinal cord injury with axial T2-weighted MRI findings. J Neurosurg Spine. 2015;23(4):495504.

    • Search Google Scholar
    • Export Citation
  • 21

    Matsushita A, Maeda T, Mori E, et al. Can the acute magnetic resonance imaging features reflect neurologic prognosis in patients with cervical spinal cord injury? Spine J. 2017;17(9):13191324.

    • Search Google Scholar
    • Export Citation
  • 22

    Kawano O, Ueta T, Shiba K, Iwamoto Y. Outcome of decompression surgery for cervical spinal cord injury without bone and disc injury in patients with spinal cord compression: a multicenter prospective study. Spinal Cord. 2010;48(7):548553.

    • Search Google Scholar
    • Export Citation
  • 23

    Mazaki T, Ito Y, Sugimoto Y, et al. Does laminoplasty really improve neurological status in patients with cervical spinal cord injury without bone and disc injury? A prospective study about neurological recovery and early complications. Arch Orthop Trauma Surg. 2013;133(10):14011405.

    • Search Google Scholar
    • Export Citation
  • 24

    Dai L, Jia L. Central cord injury complicating acute cervical disc herniation in trauma. Spine (Phila Pa 1976). 2000;25(3):331336.

  • 25

    Hohl JB, Lee JY, Horton JA, Rihn JA. A novel classification system for traumatic central cord syndrome: the central cord injury scale (CCIS). Spine (Phila Pa 1976). 2010;35(7):E238E243.

    • Search Google Scholar
    • Export Citation
  • 26

    Imajo Y, Hiiragi I, Kato Y, Taguchi T. Use of the finite element method to study the mechanism of spinal cord injury without radiological abnormality in the cervical spine. Spine (Phila Pa 1976). 2009;34(2):E83E87.

    • Search Google Scholar
    • Export Citation
  • 27

    Epstein NE, Hollingsworth R. Diagnosis and management of traumatic cervical central spinal cord injury: a review. Surg Neurol Int. 2015;6(suppl 4):S140S153.

    • Search Google Scholar
    • Export Citation
  • 28

    Bozzo A, Marcoux J, Radhakrishna M, et al. The role of magnetic resonance imaging in the management of acute spinal cord injury. J Neurotrauma. 2011;28(8):14011411.

    • Search Google Scholar
    • Export Citation
  • 29

    Kurpad S, Martin AR, Tetreault LA, et al. Impact of baseline magnetic resonance imaging on neurologic, functional, and safety outcomes in patients with acute traumatic spinal cord injury. Global Spine J. 2017;7(3)(suppl):151S174S.

    • Search Google Scholar
    • Export Citation
  • 30

    Farhadi HF, Kukreja S, Minnema A, et al. Impact of admission imaging findings on neurological outcomes in acute cervical traumatic spinal cord injury. J Neurotrauma. 2018;35(12):13981406.

    • Search Google Scholar
    • Export Citation
  • 31

    Selden NR, Quint DJ, Patel N, et al. Emergency magnetic resonance imaging of cervical spinal cord injuries: clinical correlation and prognosis. Neurosurgery. 1999;44(4):785793.

    • Search Google Scholar
    • Export Citation
  • 32

    Aarabi B, Alexander M, Mirvis SE, et al. Predictors of outcome in acute traumatic central cord syndrome due to spinal stenosis. J Neurosurg Spine. 2011;14(1):122130.

    • Search Google Scholar
    • Export Citation
  • 33

    Fehlings MG, Furlan JC, Massicotte EM, et al. Interobserver and intraobserver reliability of maximum canal compromise and spinal cord compression for evaluation of acute traumatic cervical spinal cord injury. Spine (Phila Pa 1976). 2006;31(15):17191725.

    • Search Google Scholar
    • Export Citation
  • 34

    Ohshio I, Hatayama A, Kaneda K, et al. Correlation between histopathologic features and magnetic resonance images of spinal cord lesions. Spine (Phila Pa 1976). 1993;18(9):11401149.

    • Search Google Scholar
    • Export Citation
  • 35

    Stevens EA, Marsh R, Wilson JA, et al. A review of surgical intervention in the setting of traumatic central cord syndrome. Spine J. 2010;10(10):874880.

    • Search Google Scholar
    • Export Citation
  • 36

    Machino M, Ando K, Kobayashi K, et al. Alterations in intramedullary T2-weighted increased signal intensity following laminoplasty in cervical spondylotic myelopathy patients: comparison between pre- and postoperative magnetic resonance images. Spine (Phila Pa 1976). 2018;43(22):15951601.

    • Search Google Scholar
    • Export Citation
  • 37

    Machino M, Ando K, Kobayashi K, et al. Differences in clinical outcomes between traumatic cervical myelopathy and degenerative cervical myelopathy: a comparative study of cervical spinal cord injury without major bone injury and cervical spondylotic myelopathy. J Clin Neurosci. 2019;70:127131.

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    • Export Citation
  • View in gallery

    Sagittal T2-weighted MR images showing ISI classification of the spinal cord. The arrows indicate ISI sites.

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    Pre- and postoperative JOA scores (A) and RR of the JOA scores (B) in each postoperative ISI grade. A significant difference was observed among the three groups, regarding the pre- and postoperative JOA scores and RR of the JOA score, where the postoperative JOA score and RR of the JOA score decreased significantly with an increasing ISI grade. Bars indicate the mean and error bars the SD. *p < 0.0001.

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    Pre- and postoperative AIS grades in each postoperative ISI grade. The ISI grade tended to increase with the pre- and postoperative AIS grades. ISI grade 2 on MRI was observed postoperatively in severely paralyzed patients.

  • View in gallery

    Representative case of a 55-year-old male who presented with an SCI without major bone injury due to a fall. Left: Preoperative sagittal T2-weighted MR image showing an intramedullary high signal intensity suggesting SCI at the C4–5 level. Prevertebral hyperintensity and intense ISI (grade 2 ISI) in the center of obscure ISI with spinal cord edema are seen. Right: One-year postoperative sagittal T2-weighted MR image showing adequate decompression after cervical laminoplasty at C3–7. The image also shows reduced spinal cord edema and clearer intense ISI (grade 2 ISI).

  • 1

    Gupta SK, Rajeev K, Khosla VK, et al. Spinal cord injury without radiographic abnormality in adults. Spinal Cord. 1999;37(10):726729.

  • 2

    Kothari P, Freeman B, Grevitt M, Kerslake R. Injury to the spinal cord without radiological abnormality (SCIWORA) in adults. J Bone Joint Surg Br. 2000;82(7):10341037.

    • Search Google Scholar
    • Export Citation
  • 3

    Hendey GW, Wolfson AB, Mower WR, Hoffman JR. Spinal cord injury without radiographic abnormality: results of the National Emergency X-Radiography Utilization Study in blunt cervical trauma. J Trauma. 2002;53(1):14.

    • Search Google Scholar
    • Export Citation
  • 4

    Song J, Mizuno J, Inoue T, Nakagawa H. Clinical evaluation of traumatic central cord syndrome: emphasis on clinical significance of prevertebral hyperintensity, cord compression, and intramedullary high-signal intensity on magnetic resonance imaging. Surg Neurol. 2006;65(2):117123.

    • Search Google Scholar
    • Export Citation
  • 5

    Miyanji F, Furlan JC, Aarabi B, et al. Acute cervical traumatic spinal cord injury: MR imaging findings correlated with neurologic outcome—prospective study with 100 consecutive patients. Radiology. 2007;243(3):820827.

    • Search Google Scholar
    • Export Citation
  • 6

    Tewari MK, Gifti DS, Singh P, et al. Diagnosis and prognostication of adult spinal cord injury without radiographic abnormality using magnetic resonance imaging: analysis of 40 patients. Surg Neurol. 2005;63(3):204209.

    • Search Google Scholar
    • Export Citation
  • 7

    Kasimatis GB, Panagiotopoulos E, Megas P, et al. The adult spinal cord injury without radiographic abnormalities syndrome: magnetic resonance imaging and clinical findings in adults with spinal cord injuries having normal radiographs and computed tomography studies. J Trauma. 2008;65(1):8693.

    • Search Google Scholar
    • Export Citation
  • 8

    Machino M, Yukawa Y, Ito K, et al. Can magnetic resonance imaging reflect the prognosis in patients of cervical spinal cord injury without radiographic abnormality? Spine (Phila Pa 1976). 2011;36(24):E1568E1572.

    • Search Google Scholar
    • Export Citation
  • 9

    Ouchida J, Yukawa Y, Ito K, et al. Delayed magnetic resonance imaging in patients with cervical spinal cord injury without radiographic abnormality. Spine (Phila Pa 1976). 2016;41(16):E981E986.

    • Search Google Scholar
    • Export Citation
  • 10

    Yukawa Y, Kato F, Yoshihara H, et al. MR T2 image classification in cervical compression myelopathy: predictor of surgical outcomes. Spine (Phila Pa 1976). 2007;32(15):16751679.

    • Search Google Scholar
    • Export Citation
  • 11

    Machino M, Imagama S, Ando K, et al. Image diagnostic classification of magnetic resonance T2 increased signal intensity in cervical spondylotic myelopathy: clinical evaluation using quantitative and objective assessment. Spine (Phila Pa 1976). 2018;43(6):420426.

    • Search Google Scholar
    • Export Citation
  • 12

    Machino M, Ando K, Kobayashi K, et al. MR T2 image classification in adult patients of cervical spinal cord injury without radiographic abnormality: a predictor of surgical outcome. Clin Neurol Neurosurg. 2019;177:15.

    • Search Google Scholar
    • Export Citation
  • 13

    Boldin C, Raith J, Fankhauser F, et al. Predicting neurologic recovery in cervical spinal cord injury with postoperative MR imaging. Spine (Phila Pa 1976). 2006;31(5):554559.

    • Search Google Scholar
    • Export Citation
  • 14

    Suda K, Abumi K, Ito M, et al. Local kyphosis reduces surgical outcomes of expansive open-door laminoplasty for cervical spondylotic myelopathy. Spine (Phila Pa 1976). 2003;28(12):12581262.

    • Search Google Scholar
    • Export Citation
  • 15

    Yukawa Y, Kato F, Ito K, et al. Postoperative changes in spinal cord signal intensity in patients with cervical compression myelopathy: comparison between preoperative and postoperative magnetic resonance images. J Neurosurg Spine. 2008;8(6):524528.

    • Search Google Scholar
    • Export Citation
  • 16

    Machino M, Yukawa Y, Hida T, et al. Modified double-door laminoplasty in managing multilevel cervical spondylotic myelopathy: surgical outcome in 520 patients and technique description. J Spinal Disord Tech. 2013;26(3):135140.

    • Search Google Scholar
    • Export Citation
  • 17

    Machino M, Yukawa Y, Imagama S, et al. Surgical treatment assessment of cervical laminoplasty using quantitative performance evaluation in elderly patients: a prospective comparative study in 505 patients with cervical spondylotic myelopathy. Spine (Phila Pa 1976). 2016;41(9):757763.

    • Search Google Scholar
    • Export Citation
  • 18

    Imagama S, Matsuyama Y, Yukawa Y, et al. C5 palsy after cervical laminoplasty: a multicentre study. J Bone Joint Surg Br. 2010;92(3):393400.

    • Search Google Scholar
    • Export Citation
  • 19

    Hirabayashi K, Miyakawa J, Satomi K, et al. Operative results and postoperative progression of ossification among patients with ossification of cervical posterior longitudinal ligament. Spine (Phila Pa 1976). 1981;6(4):354364.

    • Search Google Scholar
    • Export Citation
  • 20

    Talbott JF, Whetstone WD, Readdy WJ, et al. The Brain and Spinal Injury Center score: a novel, simple, and reproducible method for assessing the severity of acute cervical spinal cord injury with axial T2-weighted MRI findings. J Neurosurg Spine. 2015;23(4):495504.

    • Search Google Scholar
    • Export Citation
  • 21

    Matsushita A, Maeda T, Mori E, et al. Can the acute magnetic resonance imaging features reflect neurologic prognosis in patients with cervical spinal cord injury? Spine J. 2017;17(9):13191324.

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    • Export Citation
  • 22

    Kawano O, Ueta T, Shiba K, Iwamoto Y. Outcome of decompression surgery for cervical spinal cord injury without bone and disc injury in patients with spinal cord compression: a multicenter prospective study. Spinal Cord. 2010;48(7):548553.

    • Search Google Scholar
    • Export Citation
  • 23

    Mazaki T, Ito Y, Sugimoto Y, et al. Does laminoplasty really improve neurological status in patients with cervical spinal cord injury without bone and disc injury? A prospective study about neurological recovery and early complications. Arch Orthop Trauma Surg. 2013;133(10):14011405.

    • Search Google Scholar
    • Export Citation
  • 24

    Dai L, Jia L. Central cord injury complicating acute cervical disc herniation in trauma. Spine (Phila Pa 1976). 2000;25(3):331336.

  • 25

    Hohl JB, Lee JY, Horton JA, Rihn JA. A novel classification system for traumatic central cord syndrome: the central cord injury scale (CCIS). Spine (Phila Pa 1976). 2010;35(7):E238E243.

    • Search Google Scholar
    • Export Citation
  • 26

    Imajo Y, Hiiragi I, Kato Y, Taguchi T. Use of the finite element method to study the mechanism of spinal cord injury without radiological abnormality in the cervical spine. Spine (Phila Pa 1976). 2009;34(2):E83E87.

    • Search Google Scholar
    • Export Citation
  • 27

    Epstein NE, Hollingsworth R. Diagnosis and management of traumatic cervical central spinal cord injury: a review. Surg Neurol Int. 2015;6(suppl 4):S140S153.

    • Search Google Scholar
    • Export Citation
  • 28

    Bozzo A, Marcoux J, Radhakrishna M, et al. The role of magnetic resonance imaging in the management of acute spinal cord injury. J Neurotrauma. 2011;28(8):14011411.

    • Search Google Scholar
    • Export Citation
  • 29

    Kurpad S, Martin AR, Tetreault LA, et al. Impact of baseline magnetic resonance imaging on neurologic, functional, and safety outcomes in patients with acute traumatic spinal cord injury. Global Spine J. 2017;7(3)(suppl):151S174S.

    • Search Google Scholar
    • Export Citation
  • 30

    Farhadi HF, Kukreja S, Minnema A, et al. Impact of admission imaging findings on neurological outcomes in acute cervical traumatic spinal cord injury. J Neurotrauma. 2018;35(12):13981406.

    • Search Google Scholar
    • Export Citation
  • 31

    Selden NR, Quint DJ, Patel N, et al. Emergency magnetic resonance imaging of cervical spinal cord injuries: clinical correlation and prognosis. Neurosurgery. 1999;44(4):785793.

    • Search Google Scholar
    • Export Citation
  • 32

    Aarabi B, Alexander M, Mirvis SE, et al. Predictors of outcome in acute traumatic central cord syndrome due to spinal stenosis. J Neurosurg Spine. 2011;14(1):122130.

    • Search Google Scholar
    • Export Citation
  • 33

    Fehlings MG, Furlan JC, Massicotte EM, et al. Interobserver and intraobserver reliability of maximum canal compromise and spinal cord compression for evaluation of acute traumatic cervical spinal cord injury. Spine (Phila Pa 1976). 2006;31(15):17191725.

    • Search Google Scholar
    • Export Citation
  • 34

    Ohshio I, Hatayama A, Kaneda K, et al. Correlation between histopathologic features and magnetic resonance images of spinal cord lesions. Spine (Phila Pa 1976). 1993;18(9):11401149.

    • Search Google Scholar
    • Export Citation
  • 35

    Stevens EA, Marsh R, Wilson JA, et al. A review of surgical intervention in the setting of traumatic central cord syndrome. Spine J. 2010;10(10):874880.

    • Search Google Scholar
    • Export Citation
  • 36

    Machino M, Ando K, Kobayashi K, et al. Alterations in intramedullary T2-weighted increased signal intensity following laminoplasty in cervical spondylotic myelopathy patients: comparison between pre- and postoperative magnetic resonance images. Spine (Phila Pa 1976). 2018;43(22):15951601.

    • Search Google Scholar
    • Export Citation
  • 37

    Machino M, Ando K, Kobayashi K, et al. Differences in clinical outcomes between traumatic cervical myelopathy and degenerative cervical myelopathy: a comparative study of cervical spinal cord injury without major bone injury and cervical spondylotic myelopathy. J Clin Neurosci. 2019;70:127131.

    • Search Google Scholar
    • Export Citation

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