Personalized connectomic analysis for the patient-tailored rehabilitation of older adults with traumatic brain injury

Abstract

The rehabilitation of older victims with traumatic brain injury (TBI) presents substantial challenges due to the limited mobility and poor capacity for neurological recovery of older adults. In this study we present a novel approach for identifying TBI-affected white matter (WM) connections whose functional role likely involves them in modulating clinically-observed neurological deficits being targeted by rehabilitation routines for the elderly. This study was undertaken according to US federal law (45 CFR 46) and with IRB approval. Informed written consent was obtained from all volunteers. This study included 26 older victims of mild TBI (age: μ = 66.8 years, σ = 5.93 years) and 26 age- and sex-matched healthy control (HC) volunteers. MRI volumes were acquired using T 1 , T 2 , GRE/SWI and DWI sequences. Cerebral lesions were identified in each volunteer using a robust supervised classifier and deterministic tractography was implemented. Peri-lesional white matter (WM) streamlines were identified and changes in their functional anisotropy (FA) were assessed using a novel approach, which involved DTI streamline matching, streamline prototyping and along-tract analysis. WM streamlines found to experience substantial FA changes were integrated with a search engine which queries the scientific literature to identify aspects of brain function deficits modulated by TBI-affected connectivity. In all patients where CMBs had been identified, the WM connections identified as peri-lesional were found to be involved in specific circuits which modulates memory retrieval, processing speed, speech and executive control. The patient-specific insights gained can suggest how rehabilitation routines could be modified to benefit the individual needs of each patient. Because next-generation rehabilitation protocols for TBI victims will likely rely on the ability to understand which brain network alterations lead to neurological deficits in specific patients, personalized methods such as ours could one day be valuable to TBI rehabilitation professionals.