Conventional structural magnetic resonance imaging in differentiating chronic disorders of consciousness

BACKGROUND: Differential diagnosis of chronic disorders of consciousness remains one of the most difficult problems even for experienced clinicians. AIM: To evaluate the inter-expert consistency and capacity of the researcher-developed structural scale based on magnetic resonance imaging to differentiate chronic disorders of consciousness, named, DOC-MRIDS, on a larger sample of patients. MATERIALS AND METHODS: Sixty patients with a clinically stable status diagnosed with consciousness disorders (vegetative state, n=32; minimally conscious state, n=28) were enrolled. The revised coma recovery scale (CRS-R) was included in the clinical assessment. All patients underwent structural magnetic resonance imaging with 3.0-T Siemens scanners including T2 and T1 sequences. Structural changes were assessed using the DOC-MRIDS scale and included the following features: diffuse cortical atrophy, ventricular enlargement, gyri dilatation, leukoaraiosis, brainstem and/or thalamic degeneration, corpus callosum degeneration, and focal corpus callosum lesions. A total score was calculated. Magnetic resonance imaging data were analyzed by three neuroradiologists, and inter-observer agreement (Krippendorf’s alpha) was assessed. RESULTS: A high inter-examiner agreement of the DOC-MRIDS scale score was found, with α=0.806 (95% confidence interval 0.757–0.849). The vegetative state group had a higher DOC-MRIDS score than the minimally conscious state group (p 0.005). A negative correlation was obtained between CRS-R and DOC-MRIDS scale scores (ρ=–0.457, p 0.0001), individual clinical scale domains, and magnetic resonance imaging features. CONCLUSION: When assessing structural changes in patients with chronic consciousness disorders, the use of the DOC-MRIDS scale helps differentiate the type of such disorders with sufficient specificity, sensitivity, and inter-rater agreement. This scale can be used in clinical practice as an additional differential diagnostic tool.