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A case report of a patient with mild cognitive impairment preceded by transient global amnesia with hypometabolism on FDG‐PET
Author(s) -
Yu Justine Megan F.,
Dominguez Jacqueline C
Publication year - 2020
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.045572
Subject(s) - transient global amnesia , amnesia , neuropsychology , psychology , neuropsychological assessment , abnormality , neuroimaging , cognitive impairment , medicine , cognition , anosognosia , audiology , neuroscience , psychiatry
Background This is the case of a 61‐year‐old Filipino female who presented with two episodes of transient global amnesia at the ages of 56 and 57. Method The patient underwent serial cranial MRI, cranial FDG‐PET/CT scan, and cognitive assessments over a period of five years. Result Cranial MRI at the time of the first episode in 2014 showed foci of restricted diffusion abnormality in the left hippocampus. Baseline cognitive assessment was negative for any impairment. On recurrence of TGA in 2015, brain FDG‐PET/CT scan was done which showed mild hypometabolism in the temporal and parietal cortices and hypometabolism in the posterior cingulate cortex. A second comprehensive cognitive assessment was negative for any impairment. Three years after the first episode (2017), she developed subtle changes in memory and thinking and had mild impairment in categorical fluency on neuropsychologic examination. Follow‐up cranial MRI (2017) showed slight decrease in hippocampal volumetry from the 43rd percentile to the 41st normative percentile. Follow‐up cranial FDG‐PET (2019) showed small mildly hypometabolic areas in the frontal, parietal and temporal lobes. The clinical assessment for the patient at this time is very mild cognitive impairment, non‐amnestic, probably secondary to a neurodegenerative process. Conclusion This case study shows that transient global amnesia can recur and it may be a risk for cognitive impairment. It also illustrates that existing brain pathology related to a neurodegenerative process can be evident on neuroimaging despite very subtle clinical and neuropsychological cognitive changes. These findings also support aggressive preventive measures of delaying cognitive impairment.