Down Presymptomatic View of Dementia Characteristics

Mohammad Amin Joshaghanian,Sassan Mohammadi,Zohreh Gholizadeh Ghozloujeh,Mehrdad Farahani,Kurosh Mojtabavi

doi:10.15171/icnj.2020.01

Abstract

Down syndrome (DS) is caused by complete or segmental chromosome 21 trisomy that results in neurodegeneration and progressive intellectual disability. Abnormal function in the prefrontal cortex, cerebellum, and hippocampus are the main reasons for cognitive deficits in DS that result in impaired cognitive function, delayed speech and language, learning and memory disability, and behavioral and emotional disorders. There is no specific treatment for DS, and our understanding of the mechanisms of the disorder is incomplete and causes to hamper the development of effective therapies regarding the development of neuropathology and memory loss in DS. Here, we review the literature on cognitive functioning, unique characteristics, environmental considerations, and recent findings on Alzheimer’s disease in DS.

Highlights

Down syndrome (DS) is one of the most common genetic disorders caused by the presence of 3 copies of chromosome 21 (Hsa21) instead of the usual two, which occurs during the meiotic cellular division phase.[1]
Data show that nearly 40% of people with DS known as the case of dementia after the 60s
Epilepsy is more common in those with DS who suffer from dementia

Summary

Introduction

Down syndrome (DS) is one of the most common genetic disorders caused by the presence of 3 copies of chromosome 21 (Hsa21) instead of the usual two, which occurs during the meiotic cellular division phase.[1] The worldwide prevalence of DS is 14 per 10 000 live birth This prevalence is different, based on socioeconomic factors.[2,3] Three different types of DS consist of trisomy 21 or non-disjunction (most common), Robertsonian translocation, and mosaicism.[4] DS impair normal brain development, cause a small cerebellum, frontal, and temporal cortex, as well as simplified appearances of sulci and a narrow superior temporal gyrus.[5] High-resolution MRI in subjects with DS demonstrates lower volume in different brain structures such as the cerebellum, cingulate gyrus, frontal cortex, superior temporal cortex, and hippocampus, compared to the normal population.[6] These changes could be the main reason for various range of intellectual abnormalities, including cognitive impairment and intellectual disabilities and Alzheimer’s disease. The different medical aspect of DS is well-known, properties of Alzheimer’s disease in subjects with DS has not been well discussed so far

Methods

Findings

Conclusion