Parkinson's disease with mild cognitive impairment: severe cortical thinning antedates dementia.

Mild cognitive impairment (MCI) in Parkinson's disease (PD) is a risk factor for dementia and thus, it is of interest to elucidate if specific patterns of atrophy in PD-MCI patients are associated with a higher risk of developing dementia. We aim to define pattern(s) of regional atrophy in PD-MCI patients who developed dementia during 31 months of follow-up using cortical thickness analysis Twenty-three PD-MCI patients and 18 controls underwent brain MRI and completed a neuropsychological examination at baseline, PD-MCI patients were followed after a 31 month follow-up in order to assess their progression to dementia. At follow up, 8 PD-MCI patients had converted to dementia (PD-MCI converters) whereas 15 remained as PD-MCI (PD-MCI non-converters).

Multimodal partial volume correction: Application to [C]PIB PET/MRI myelin imaging in multiple sclerosis.

The [C]PIB PET tracer, originally developed for amyloid imaging, has been recently repurposed to quantify demyelination and remyelination in multiple sclerosis (MS). Myelin PET imaging, however, is limited by its low resolution that deteriorates the quantification accuracy of white matter (WM) lesions. Here, we introduce a novel partial volume correction (PVC) method called Multiresolution-Multimodal Resolution-Recovery (MM-RR), which uses the wavelet transform and a synergistic statistical model to exploit MRI structural images to improve the resolution of [C]PIB PET myelin imaging.

Dysregulation of energy metabolism in multiple sclerosis measured in vivo with diffusion-weighted spectroscopy.

Objective: We employed diffusion-weighted magnetic resonance spectroscopy (DW-MRS), which allows to measure in vivo the diffusion properties of metabolites, to explore the functional neuro-axonal damage and the ongoing energetic dysregulation in multiple sclerosis (MS).

Methods: Twenty-five patients with MS and 18 healthy controls (HC) underwent conventional magnetic resonance imaging (MRI) and DW-MRS. The apparent diffusion coefficient (ADC) of total N-acetyl-aspartate (tNAA) and creatine-phosphocreatine (tCr) were measured in the parietal normal-appearing white matter (NAWM) and in the thalamic grey matter (TGM).

Validation of an automatic reference region extraction for the quantification of [F]DPA-714 in dynamic brain PET studies.

There is a great need for a non-invasive methodology enabling the quantification of translocator protein overexpression in PET clinical imaging. [F]DPA-714 has emerged as a promising translocator protein radiotracer as it is fluorinated, highly specific and returned reliable quantification using arterial input function. Cerebellum gray matter was proposed as reference region for simplified quantification; however, this method cannot be used when inflammation involves cerebellum.

Orthostatic tremor: a cerebellar pathology?

SEE MUTHURAMAN ET AL DOI101093/AWW164 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Primary orthostatic tremor is characterized by high frequency tremor affecting the legs and trunk during the standing position. Cerebellar defects were suggested in orthostatic tremor without direct evidence. We aimed to characterize the anatomo-functional defects of the cerebellar motor pathways in orthostatic tremor.