Prognosis for Recovery from a Vegetative State

Abstract

The prognosis for recovery from a vegetative state (VS) remains underdeveloped.Objective. To determine the feasibility of prognosis for recovery from a vegetative state based on clinical comparison of 18- fluorodeoxyglucose-PET (18FDGPET) and MRI (SCT) data.Materials and methods. We compared and analyzed retrospectively cerebral PET and MRI (SCT) scans and relevant prognostic criteria (including revised coma recovery scale — CRS-R scores) prospectively during 6–84 months of follow-up in a cohort of 39 VS patients. All VS cases were of different etiologies, lasting for more than 2 months after brain damage (including 18 patients in chronic VS).Pairwise comparison of groups was used (significance level P0.05) and multiple comparison for three groups with a Bonferroni correction at P0.017 was employed.Results. Three patterns were identified when comparing 18FDGPET and MRI (SCT) neuro-images: pattern I — the area of functional alterations was larger than the area of structural damage, pattern II — complete matching of areas of structural and functional alterations, III — mixed pattern. Pattern I (69% of cases) was more common than patterns II (18%), and III (13%), P0.001. There were no differences in VS etiology, VC duration, CRS-R scores, patients’ gender and age between the groups of patients each falling into one of patterns. The outcome in a group with pattern I patients (all of them recovered from VS) was better than in other two groups exhibiting patterns II or III, each, P0.001. In a group of patients with pattern III the recovery was better than in pattern II (all patients remained in VS), P=0.018. The increases in the total CRS-R score values were as follows: 12,1±4,46; Me=12 (4–19), N=27 (patients with a pattern I); 0±1,54 (–2–1, Me=0, N=7 (patients with a pattern II); and 5,20±4,09/ Me=4 (1 — 10), N=5 (patients with a pattern III). Significant increases in neurological improvement were revealed in pattern I patients with non-chronic VS versus chronic VS, P=0.003.Conclusion. Clinical comparison of PET/MRI (SCT) data showed certain potential to predict patient’s recovery from VS in 87% of cases. A retrospectively confirmed favorable prognosis in patients with pattern I was established in 69% cases, unfavorable (pattern II patients) was defined in 18% cases, regardless of other prognostic criteria, including chronic VS. Therefore, the data confirms the feasibility and clinical relevance of neurophysiological justification as a candidate approach for evaluating the prospect of recovering patients from VS.

Keywords

• chronic disorders of consciousness
• chronic vegetative state
• recovery from a vegetative state
• prediction
• potential for recovery of consciousness