Table 3.
Summary of 22 publications that have studied the impact of types of T2-weighted increased signal intensity (ISI) on surgical outcome in patients with cervical spondylotic myelopathy
| References | Level of evidencea | Nature of studyb | Number of patients | Mean age (years) | T2W ISI classificationc | Surgeryd | Outcome variablese | Mean follow-up duration (months) | Statistical analysisf | Conclusions |
|---|---|---|---|---|---|---|---|---|---|---|
| Ahn et al. [33] | II | R | 39 | 62.4 | Q1, L1 | P | JOA RR | 19.1 | Correlation | Number of ISI segments, focal ISI and rostral location of ISI were associated with poor prognosis |
| Arvin et al. [36] | II | Pr | 52 | 56.2 | Q2 | C | JOA RR, Nurick grade, SF36, NDI | 12.0 | Multivariate regression | Absence of focal ISI and regression of ISI after surgery were associated with good recovery |
| Avadhani et al. [2] | II | R | 35 | 57.8 | Q3, L2 | P | Nurick grade | 51.3 | Linear regression | T2W ISI alone had no prognostic significance |
| Chatley et al. [4] | II | Pr | 64 | 47.1 | L2 | A | JOA RR | 47.1 | Linear regression | Multisegmental ISI predicted poor outcome |
| Chen et al.g [5] | II | Pr | 64 | 56.6 | Q3 | P | JOA RR | 6.0 | ANCOVA | Type 1 ISI had better surgical outcome compared to type 2 |
| Fernandez de Rota et al. [8] | II | Pr | 67 | 59.5 | L2 | C | JOA RR | 39.0 | Linear regression | Multisegmental T2W ISI had poorer prognosis |
| Kohno et al. [37] | II | Pr | 22 | 60.5 | L2 | P | JOA RR | 61.2 | Mann–Whitney U test | Multisegmental T2W ISI was associated with poorer outcomes |
| Mastronardi et al. [9] | II | Pr | 47 | 54.0 | Q4, L2 | A | JOA, Nurick grade | 40.2 | Correlation | Best results were produced in the absence of T2W ISI. Better outcomes were seen when T2W ISI regressed after surgery |
| Mehalic et al. [28] | IV | R | 19 | 33–85 | Q4 | C | NS | NS | NS | Decreased intensity of T2W ISI in postoperative MR images was associated with improved clinical outcome |
| Mizuno et al. [29] | II | R | 144 | 56.5 | O1 | A | JOARR | NS | NS | Snake-eye appearance of ISI associated with worse functional outcome |
| Papadopoulos et al. [26] | II | Pr | 42 | 57.5 | L2 | C | JOA RR | 6.0-24.0 | Student t test | Type 0 and type 1 ISI had a better prognosis than type 2 ISI |
| Park et al. [25] | II | R | 80 | 62.1 | L2 | C | NCSS | 3.0 | Multivariate regression | Multisegmental ISI was independently associated with poorer NCSS recovery rate |
| Shen et al. [27] | II | R | 64 | 58.5 (median) | O2 | C | JOA RR | 34.0 (median) | Student’s t test and ANOVA | ISI in gray and white matter (Group B) was associated with worse outcomes |
| Shin et al. [34] | I | Pr | 70 | 51.1 | Q3 | A | JOA RR | 32.7 | Multivariate regression | Increased ISI grade was related to poorer neurological outcome |
| Singh et al. [30] | II | Pr | 69 | 57.0 (male), 62.0 (female) | L2 | C | Nurick grade, MDI, Ranawat Scale | 3.0 | Correlation | Presence and number of ISI were associated with clinical severity. However, confounders and lack of strong correlation affected analysis of the impact of ISI on surgical outcome |
| Vedantam et al. [13] | II | R | 197 | 48.8 | Q3 | A | Nurick grade change, cure | 35.2 | Multivariate regression | Type 2 ISI was associated with lower probability of complete recovery (Nurick grade 0 or 1) |
| Wada et al. [31] | II | R | 31 | 60.1 | L2 | C | JOA RR | 1.5 | Mann–Whitney U test | Presence of ISI did not correlate with severity of myelopathy or surgical outcome |
| Wada et al. [3] | II | R | 50 | 61.0 | L2 | P | JOA RR | 35.1 | Multivariate regression | Multisegmental ISI correlated with poorer outcomes, but was not a prognostic factor for surgical outcome |
| Yagi et al. [32] | II | R | 71 | 62.9 | L3 | P | JOA RR | 60.6 | Mann–Whitney U test | Long-term surgical outcome was worse in patients with ISI and postoperative expansion of ISI |
| Yukawa et al. [10] | II | Pr | 104 | 61.0 | Q3 | P | JOA RR | 40.0 | Mann–Whitney U test | T2W ISI correlated with postoperative JOA and JOA RR. Intense ISI had a worse prognosis compared to light ISI |
| Yukawa et al. [35] | II | Pr | 104 | 61.0 | Q3 | P | JOA RR | 39.7 | Mann–Whitney U test | Postoperative expansion of ISI was not associated with outcome |
| Zhang et al. [38] | II | R | 73 | 53.2 | O3 | C | JOA RR | 12.0 | Multivariate regression | Increased signal intensity ratio (SIR) with pyramidal signs is associated with poorer prognosis. SIR correlates with JOA RR and postoperative JOA |
NS not specified
aLevels of evidence as described in Table 2
bR retrospective, Pr prospective
cTypes of T2W ISI classifications: Q1–3- qualitative, based on intensity and margins, L1–3 based on longitudinal extent, O1–2 other classifications (refer Table 1)
dType of surgery: P posterior decompression only, A anterior decompression only, C anterior, posterior or combined approaches
eOutcome variables: JOA Japanese Orthopedic Association score, JOA RR JOA recovery rate, SF36 short form-36, NDI neck disability index, NCSS Neurosurgical Cervical Spine score, MDI myelopathy disability index
fANCOVA analysis of co-variance, ANOVA analysis of variance
gIn the study by Chen et al. [5] although the figures in the report suggested that posterior decompression was performed, the exact surgical procedure was not specified