The metabolic patterns in the brain associated with Parkinson’s disease (PD) can be a powerful neuroimaging biomarker that highlights metabolic changes in the prodromal stage of Parkinson’s, prodromal Lewy bodies, and a prospective phenoconversion in isolated sleep behavior disorder with rapid eye movement (REM) can significantly predict (RBD), according to study results published in Neurology.
A team of researchers in Korea conducted a prospective cohort study (ClinicalTrials.gov Identifier: NCT02984137) to determine whether PD-related metabolic patterns in the brain can be used as biomarkers in isolated RBD and to compare metabolic patterns obtained from long-term and de novo PD. were derived.
Of the 100 people included in the analysis, 24 people were healthy controls, 30 people had isolated RBD, 25 people had de novo PD with prolonged RBD symptoms, and 21 people had long-term PD.
Movement Disorders Society-Unified PD Rating Scale Motor scores were significantly associated with long-term PD (P = 0.013), but not with de novo PD with prolonged RBD (P = 0.076). In a butanol threshold test, de novo PD-related metabolic patterns in the brain were associated with the sense of smell (P = 0.018) in patients with isolated RBD, but not in patients with de novo PD and prolonged RBD (P = 0.21).
In addition to the 30 patients with isolated RBD, 14 additional patients from a separate validation sample were included in a longitudinal follow-up to predict disease conversion; 12 patients developed a neurodegenerative disease (PD, n = 7; multiple system atrophy, n = 1; dementia with Lewy bodies, n = 4).
The mean follow-up time was 3.02 years and there was an estimated phenoconversion rate of 35.5% at 5 years with an overall annual conversion rate of 7.1%. While the values for de novo PD-related brain metabolism patterns as well as for long-term PD were higher in disease converters than in non-disease converters, the greater effect size in de novo PD-related brain metabolism patterns indicated a higher distinguishability from future converters with de novo PD -related metabolic patterns in the brain compared to long-term PD.
In cut-off areas for the 2 metabolic pattern expressions of 1.5 to 3 standard deviations from the normal control value, de novo PD-related metabolic brain patterns predicted the phenoconversion significantly in all cut-off areas (hazard ratio [HR], 5.90 ~ 38.6). Long-term PD significantly predicted phenoconversion for a portion of the cut-off.
“The [de novo PD-related brain metabolic patterns] can be an efficient biomarker, individually applicable in [isolated REM sleep behavior disorder]“, Write the study authors. They concluded: “Validation of the [de novo PD-related brain metabolic patterns] from an independent [de novo PD with prolonged RBD] and [isolated REM sleep behavior disorder] Cohort of different ethnic backgrounds would determine the reliability of the [de novo PD-related brain metabolic patterns]. “
Shin JH, Lee JY, Kim YK et al. Parkinson’s Disease Related Brain Metabolic Patterns and Neurodegeneration in Isolated REM Sleep Behavior Disorder. Neurology. Published online May 19, 2021. doi: 10.1212 / WNL.0000000000012228