An 82‐year‐old male presented with progressively developed gait disturbances due to choreatic movements for 6 months. Brain MRI (see Fig. 1A) showed mild nonspecific white matter changes, general and mild striatal atrophy, but no other abnormalities (transversal and coronal slices) when compared to an age‐matched control (1B). FDG‐PET brain imaging showed a distinct bilateral striatal reduction in glucose metabolism, predominant in the putamen and caudate nucleus whereas a concomitant hypermetabolism was present in the left thalamus. Frontal association areas and the supplemental motor areas indicated a moderate hypometabolism (1C‐D). Diagnosis of Huntington's disease (HD) was confirmed genetically (42 ± 1 CAG‐repeats). In the established biomarker timeline of FDG‐PET in HD the thalamic upregulation is reported to turn into hypometabolism at symptom onset,1 implying that characteristics of functional imaging were delayed in comparison to the clinical presentation. The size of the CAG‐expansion is a primary determinant of age at clinical onset explaining the variance of disease manifestation.2
Figure 1.
Neuroimaging findings in an 83‐year‐old patient with late‐onset HD.
FDG‐PET imaging should be considered as diagnostic tool in aged patients with abnormal movements, as late‐onset HD could be a differential diagnosis even if structural MRI does not show striatal atrophy. Moreover, examination of aged patients may help to understand and identify protective factors that delay reductions of glucose metabolism in HD.
Author Roles
KF, MH, and AD: medical care of patient, diagnosing the clinical syndrome. KF and MB: manuscript preparation, review, critique, including medical writing for content. MB, PB, and AR: performing imaging of patient and evaluation of neuroimaging findings. KS: analyzing and interpretation and evaluation of neuroimaging findings, review of manuscript. MD: manuscript preparation including review of manuscript, critique, and medical writing for content. AD: review of manuscript including medical writing for content.
Disclosures
Ethical compliance statement: We confirm that we have read the journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines. Institutional Review Board (IRB) approval is not required based on the submission type.
Funding Sources and Conflict of Interest: The authors report no sources of funding or conflicts of interest.
Financial Disclosures for the previous 12 months: The authors report no sources of funding and no conflicts of interest.
Acknowledgments
We thank Katie Goettlinger for copyediting the manuscript.
Relevant disclosures and conflicts of interest are listed at the end of this article.
The first two authors contributed equally to this study.
References
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