Accurate automatic estimation of total intracranial volume: A nuisance variable with less nuisance

ObjectiveTo evaluate poly(GP), a dipeptide repeat protein, and neurofilament light chain (NfL) as biomarkers in presymptomatic C9orf72 repeat expansion carriers and patients with C9orf72‐associated frontotemporal dementia. Additionally, to investigate the relationship of poly(GP) with indicators of neurodegeneration as measured by NfL and grey matter volume.MethodsWe measured poly(GP) and NfL levels in cerebrospinal fluid (CSF) from 25 presymptomatic C9orf72 expansion carriers, 64 symptomatic expansion carriers with dementia, and 12 noncarriers. We explored associations with grey matter volumes using region of interest and voxel‐wise analyses.ResultsPoly(GP) was present in C9orf72 expansion carriers and absent in noncarriers (specificity 100%, sensitivity 97%). Presymptomatic carriers had lower poly(GP) levels than symptomatic carriers. NfL levels were higher in symptomatic carriers than in presymptomatic carriers and healthy noncarriers. NfL was highest in patients with concomitant motor neuron disease, and correlated with disease severity and survival. Associations between poly(GP) levels and small grey matter regions emerged but did not survive multiple comparison correction, while higher NfL levels were associated with atrophy in frontotemporoparietal cortices and the thalamus.InterpretationThis study of C9orf72 expansion carriers reveals that: (1) poly(GP) levels discriminate presymptomatic and symptomatic expansion carriers from noncarriers, but are not associated with indicators of neurodegeneration; and (2) NfL levels are associated with grey matter atrophy, disease severity, and shorter survival. Together, poly(GP) and NfL show promise as complementary biomarkers for clinical trials for C9orf72‐associated frontotemporal dementia, with poly(GP) as a potential marker for target engagement and NfL as a marker of disease activity and progression.

Section: Methodsmentioning

confidence: 99%

Poly(GP), neurofilament and grey matter deficits in C9orf72 expansion carriers

Meeter

Gendron

Sias

et al. 2018

“…Regions of interest (ROIs) included right and left hippocampus, entorhinal cortex, angular gyrus, parahippocampal gyrus, superior parietal lobule and the frontal and occipital cortex. Total intracranial volume (TIV) was calculated using the Statistical Parametric Mapping (SPM) 12 software, version 6470 (www.fil.ion.ucl.ac.uk/spm), running under Matlab R2014b (Math Works, Natick, MA, USA) 23…”

Section: Methodsmentioning

confidence: 99%

CSF neurogranin or tau distinguish typical and atypical Alzheimer disease

Wellington¹,

Paterson

Suárez‐González

et al. 2018

Self Cite

ObjectiveTo assess whether high levels of cerebrospinal fluid neurogranin are found in atypical as well as typical Alzheimer's disease.MethodsImmunoassays were used to measure cerebrospinal fluid neurogranin in 114 participants including healthy controls (n = 27), biomarker‐proven amnestic Alzheimer's disease (n = 68), and the atypical visual variant of Alzheimer's (n = 19) according to international criteria. CSF total‐tau, Aβ42, and neurofilament light concentrations were investigated using commercially available assays. All affected individuals had T1‐weighted volumetric MR images available for analysis of whole and regional brain volumes. Associations between neurogranin, brain volumes, total‐tau, Aβ42, and neurofilament light were assessed.ResultsMedian cerebrospinal fluid neurogranin concentrations were higher in typical and atypical Alzheimer's compared to controls (P < 0.001 and P = 0.005). Both neurogranin and total‐tau concentrations, but not neurofilament light and Aβ42, were higher in typical Alzheimer's compared to atypical patients (P = 0.004 and P = 0.03). There were significant differences in the left hippocampus and right and left superior parietal lobules in atypical patients, which were larger (P = 0.03) and smaller (P = 0.001 and P < 0.001), respectively, compared to typical patients. We found no evidence of associations between neurogranin and brain volumes but a strong association with total‐tau (P < 0.001) and a weaker association with neurofilament light (P = 0.005).InterpretationThese results show significant differences in neurogranin and total‐tau between typical and atypical patients, which may relate to factors other than disease topography. The differential relationships between neurogranin, total‐tau and neurofilament light in the Alzheimer's variants, provide evidence for mechanistically distinct and coupled markers of neurodegeneration.

“…This method analyzes the relation of tissue lesions with symptoms on a voxel‐by‐voxel basis 22. In order to detect joint areas of demyelination causing certain symptoms, images have to be brought into a standard space; this was achieved by spatially normalizing all demyelination load masks using the spatial deformation field generated by spatially normalizing high‐resolution T1 3D datasets to MNI space, applying segmentation functionality available within the statistical parametric mapping (SPM12) software (http://www.fil.ion.ucl.ac.uk/spm/software/spm12/) 23…”

Section: Methodsmentioning

confidence: 99%

Demyelination load as predictor for disease progression in juvenile metachromatic leukodystrophy

Strölin

Krägeloh‐Mann

Kehrer

et al. 2017

ObjectiveThe aim of this study was to investigate whether the extent and topography of cerebral demyelination correlates with and predicts disease progression in patients with juvenile metachromatic leukodystrophy (MLD).MethodsA total of 137 MRIs of 46 patients with juvenile MLD were analyzed. Demyelination load and brain volume were quantified using the previously developed Software “clusterize.” Clinical data were collected within the German Leukodystrophy Network and included full scale intelligence quotient (FSIQ) and gross motor function data. Voxel‐based lesion‐symptom mapping (VLSM) across the whole brain was performed to investigate the spatial relationship of cerebral demyelination with motor or cognitive function. The prognostic value of the demyelination load at disease onset was assessed to determine the severity of disease progression.ResultsThe demyelination load (corrected by the individual brain volume) correlated significantly with gross motor function (r = +0.55) and FSIQ (r = −0.55). Demyelination load at disease onset was associated with the severity of disease progression later on (P < 0.01). VLSM results associated frontal lobe demyelination with loss in FSIQ and more central region demyelination with decline of motor function. Especially progression of demyelination within the motor area was associated with severe disease progression.InterpretationWe were able to show for the first time in a large cohort of patients with juvenile MLD that the demyelination load correlates with motor and cognitive symptoms. Moreover, demyelination load at disease onset, especially the involvement of the central region, predicts severity of disease progression. Thus, demyelination load seems a functionally relevant MRI parameter.