Synopsis

Keywords: Neurodegeneration, Alzheimer's Disease

Prediction or prevention of progression to dementia for non-demented patients is critical for management and prevention strategy of dementia. Recent evidences suggest that larger choroid plexus (CP) volume was associated with the severity of cognitive impairment in Alzheimer disease (AD) spectrum. We evaluated clinical data and the volume, permeability and susceptibility of choroid plexus of 62 consecutive non-demented prospective cohorts with follow-up up to 2 years. Dementia converter group showed larger CP volume than that of non-converters. Thus, CP volume could be utilized as a potential imaging marker for patients who are likely to progress to dementia.

INTRODUCTION

Larger choroid plexus (CP) volume has been suggested as an important imaging marker associated with the severity of cognitive impairment in Alzheimer disease (AD) spectrum ¹. However, whether CP imaging features can be a predictor of progression of dementia is not clear. In this study, we investigated whether CP imaging features could be utilized as possible imaging marker for prediction of dementia conversion for non-demented patients by using structural MR imaging, dynamic contrast enhanced (DCE) imaging, and quantitative susceptibility mapping (QSM).

METHODS

We used the data set of 62 consecutive non-demented prospective cohorts who initially diagnosed as subjective cognitive impairment (SCI, n=11) and mild cognitive impairment (MCI, n=51). Diagnosis of SCI and MCI was made on the basis of clinical and neuropsychological test. All patients underwent MRI study and cognitive assessment at baseline and follow-up up to2 years. CP volume was automatically segmented; the volume transfer constant (i.e., Ktrans) and fractional plasma volume (i.e., Vp) were determined using DCE MRI, and susceptibility was assessed using QSM based on previously described methods ^2-4. CP volume was expressed as the ratio to intracranial volume (ICV). Logistic regression analysis was performed to determine the predictors of dementia conversion after adjusting for age, education, and hippocampal atrophy.

RESULTS

Out of 62 patients, 7 (11.3%) patients progressed to dementia (age=73.5 IQR [73 - 76], all females) whereas 55 (88.7%) were non-converters (age = 72 [65 – 76], 32 females (58.2%)). CP volume was not statistically different between the two groups (p=0.064). Only education (Odd Ratio [OR] = 0.656, 95% CI [0.473-0.911], p=0.012) and hippocampal atrophy (OR= 0.076 [0.009-0.626], p=0.017) were the independent predictors of dementia conversion. In the subgroup analysis, female patients (n=32) showed larger CP volume (ratio of ICVx10³) in the converter group (1.433, IQR [1.227-1.534]) compared with the non-converter group (1.059, IQR [0.877-1.184], p=0.030), while showing no difference regarding permeability and susceptibility of CP according to the conversion status. Logistic regression analysis showed CP volume (OR =459.3 [1.954-108.0 x103], p=0.028) was an independent predictor for the dementia conversion , in addition to education level (OR = 0.571 [0.353-0.926], p = 0.023) and hippocampal volume (OR= 0.008 [0.000-0.409], p = 0.016).

DISCUSSION and CONCLUSION

Our results suggest the CP volume independently predicts the future dementia conversion in female non-demented patients with early cognitive impairments. Lack of relationship between permeability/susceptibility of CP and conversion to dementia is corroborated by the previous cross-sectional study finding ¹. Limitation of this study, however, are relatively small sample size and skewed sex distribution. In conclusion, CP volume measure could be utilized as a potential imaging marker for prediction of the future progression to the dementia in on-demented older subjects.

Acknowledgements

This work was supported by the Korea Health Technology R&D Project through the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number HI21C0222).