Analysis of structure–function network decoupling in the brain systems of spastic diplegic cerebral palsy

한글 요약

뇌실주위 백질연화증을 동반한 경직성 양측마비 뇌성마비 환자에서 뇌의 구조적 연결망과 기능적 연결망이 서로 얼마나 잘 맞물려 있는지를 살핀 연구입니다. 확산텐서영상(DTI) 섬유추적으로 구조 연결망을, 휴지기 fMRI의 상관 및 부분상관 분석으로 기능 연결망을 구성하여 전뇌와 운동계 각각에서 구조-기능 결합 정도를 건강한 대조군과 비교했습니다. 환자의 전뇌 연결망에서는 구조 연결망의 효율이 크게 떨어졌음에도 기능 연결망은 비교적 보존되어 있었고, 반대로 운동계에서는 구조 연결망이 온전한데도 기능 연결망의 효율이 크게 낮아져 두 체계에서 서로 반대 방향의 구조-기능 탈동조화가 나타났습니다. 이러한 양상은 뇌성마비에서 인지 기능이 비교적 유지되는 반면 운동 기능이 손상되는 임상 특징을 설명해 주며, 특히 희소 기능적 연결성을 이용한 구조-기능 관계 분석이 뇌의 기능 재조직화를 이해하는 단서가 될 수 있음을 보여줍니다.

Manifestation of the functionalities from the structural brain network is becoming increasingly important to understand a brain disease. With the aim of investigating the differential structure-function couplings according to network systems, we investigated the structural and functional brain networks of patients with spastic diplegic cerebral palsy with periventricular leukomalacia compared to healthy controls. The structural and functional networks of the whole brain and motor system, constructed using deterministic and probabilistic tractography of diffusion tensor magnetic resonance images and Pearson and partial correlation analyses of resting-state functional magnetic resonance images, showed differential embedding of functional networks in the structural networks in patients. In the whole-brain network of patients, significantly reduced global network efficiency compared to healthy controls were found in the structural networks but not in the functional networks, resulting in reduced structural-functional coupling. On the contrary, the motor network of patients had a significantly lower functional network efficiency over the intact structural network and a lower structure-function coupling than the control group. This reduced coupling but reverse directionality in the whole-brain and motor networks of patients was prominent particularly between the probabilistic structural and partial correlation-based functional networks. Intact (or less deficient) functional network over impaired structural networks of the whole brain and highly impaired functional network topology over the intact structural motor network might subserve relatively preserved cognitions and impaired motor functions in cerebral palsy. This study suggests that the structure-function relationship, evaluated specifically using sparse functional connectivity, may reveal important clues to functional reorganization in cerebral palsy. Hum Brain Mapp 38:5292-5306, 2017. © 2017 Wiley Periodicals, Inc.