Marked brain asymmetry with intact cognitive functioning in idiopathic Parkinson's disease: a longitudinal analysis.
OBJECTIVE
A 71-year-old (MN) with an 11-year history of left onset tremor diagnosed as Parkinson's disease (PD) completed longitudinal brain magnetic resonance imaging (MRI) and neuropsychological testing. MRI scans showed an asymmetric caudate nucleus (right < left volume). We describe this asymmetry at baseline and the progression over time relative to other subcortical gray, frontal white matter, and cortical gray matter regions of interest. Isolated structural changes are compared to MN's cognitive profiles.


METHOD
MN completed yearly MRIs and neuropsychological assessments. For comparison, left onset PD (n = 15) and non-PD (n = 43) peers completed the same baseline protocol. All MRI scans were processed with FreeSurfer and the FMRIB Software Library to analyze gray matter structures and frontal fractional anisotropy (FA) metrics. Processing speed, working memory, language, verbal memory, abstract reasoning, visuospatial, and motor functions were examined using reliable change methods.


RESULTS
At baseline, MN had striatal volume and frontal lobe thickness asymmetry relative to peers with mild prefrontal white matter FA asymmetry. Over time only MN's right caudate nucleus showed accelerated atrophy. Cognitively, MN had slowed psychomotor speed and visuospatial-linked deficits with mild visuospatial working memory declines longitudinally.


CONCLUSIONS
This is a unique report using normative neuroimaging and neuropsychology to describe an individual diagnosed with PD who had striking striatal asymmetry followed secondarily by cortical thickness asymmetry and possible frontal white matter asymmetry. His decline and variability in visual working memory could be linked to ongoing atrophy of his right caudate nucleus.
['Tanner|Jared J|JJ|', 'Levy|Shellie-Anne|SA|', 'Schwab|Nadine A|NA|', 'Hizel|Loren P|LP|', 'Nguyen|Peter T|PT|', 'Okun|Michael S|MS|', 'Price|Catherine C|CC|']
D000368:Aged D000369:Aged, 80 and over D016880:Anisotropy D003071:Cognition D018450:Disease Progression D005260:Female D005625:Frontal Lobe D007839:Functional Laterality D066128:Gray Matter D006801:Humans D007807:Language Tests D008137:Longitudinal Studies D008279:Magnetic Resonance Imaging D008297:Male D008568:Memory D008570:Memory, Short-Term D008606:Mental Processes D008875:Middle Aged D017072:Neostriatum D010300:Parkinson Disease D011597:Psychomotor Performance D013028:Space Perception D066127:White Matter
white matter memory Neuroimaging executive function movement disorders