Correlations between clinical characteristics and neuroimaging in Chinese patients with subtypes of frontotemporal lobe degeneration

Neuroimaging in Frontotemporal Lobar Degeneration: Research and Clinical Utility

Frontotemporal lobar dementia (FTLD) is a clinically and pathologically complex disease. Advances in neuroimaging techniques have provided a specialized set of tools to investigate underlying pathophysiology and identify clinical biomarkers that aid in diagnosis, prognostication, monitoring, and identification of appropriate endpoints in clinical trials. In this chapter, we review data discussing the utility of neuroimaging biomarkers in sporadic FTLD, with an emphasis on current and future clinical applications. Among those modalities readily utilized in clinical settings, T1-weighted structural magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) are best supported in differential diagnosis and as targets for clinical trial endpoints. However, a number of nonclinical neuroimaging modalities, including diffusion tensor imaging and resting-state functional connectivity MRI, show promise as biomarkers to predict progression and as clinical trial endpoints. Other neuroimaging modalities, including amyloid PET, Tau PET, and arterial spin labeling MRI, are also discussed, though more work is required to establish their utility in FTLD in clinical settings.

The clinical characteristics and subtypes of patients with cognitive impairment in memory clinic

To explore the demographic characteristics and main types of memory impairment in the Memory Clinic of China and to provide references for future research. Demographic, cognitive, and etiological data of 2,742 cognitive impairment (CI) patients who were in the Memory Clinic at Tianjin Huanhu Hospital from January 2011 to October 2018 were analyzed. The main subtypes of CI were AD (38.33%), MCI (19.55%), VaD (8.57%), FTLD (7.37%) and DLB/PDD (5.91%). The mean age was 68.5 ± 9.97, with 82.13% older than 60 years. There were slightly more females (50.58%) than males (49.42%). There were a relatively equal number of patients who were educated less than (55.12%) and more than nine years (44.88%). Most patients (82.91%) were married and only 23.63% patients had a family history of CI. CI occurred primarily in the elderly, namely those who were between 60 and 79 years old. More than half of those with AD, DLB, PDD, and FTLD were categorized at mild or moderate levels. The bvFTD (n = 127, 62.9%) was the primary subtype of FTLD. Standardized diagnostic procedures, detailed neuropsychological assessments, molecular biology tests, and follow-ups are important for the early diagnosis and treatment of cognitive impairment diseases.

MR fingerprinting as a diagnostic tool in patients with frontotemporal lobe degeneration: A pilot study

Several very rare forms of dementia are associated with characteristic focal atrophy predominantly of the frontal and/or temporal lobes and currently lack imaging solutions to monitor disease. Magnetic resonance fingerprinting (MRF) is a recently developed technique providing quantitative relaxivity maps and images with various tissue contrasts out of a single sequence acquisition. This pilot study explores the utility of MRF-based T1 and T2 mapping to discover focal differences in relaxation times between patients with frontotemporal lobe degenerative dementia and healthy controls. 8 patients and 30 healthy controls underwent a 3 T MRI including an axial 2D spoiled gradient echo MRF sequence. T1 and T2 relaxation maps were generated based on an extended phase graphs algorithm-founded dictionary involving inner product pattern matching. A region of interest (ROI)-based analysis of T1 and T2 relaxation times was performed with FSL and ITK-SNAP. Depending on the brain region analyzed, T1 relaxation times were up to 10.28% longer in patients than in controls reaching significant differences in cortical gray matter (P = .047) and global white matter (P = .023) as well as in both hippocampi (P = .001 left; P = .027 right). T2 relaxation times were similarly longer in the hippocampus by up to 19.18% in patients compared with controls. The clinically most affected patient had the most control-deviant relaxation times. There was a strong correlation of T1 relaxation time in the amygdala with duration of the clinically manifest disease (Spearman Rho = .94; P = .001) and of T1 relaxation times in the left hippocampus with disease severity (Rho = .90, P = .002). In conclusion, MRF-based relaxometry is a promising and time-saving new MRI tool to study focal cerebral alterations and identify patients with frontotemporal lobe degeneration. To validate the results of this pilot study, MRF is worth further exploration as a diagnostic tool in neurodegenerative diseases.