Neuroimaging of Diabetic Striatopathy: More Questions than Answers.

Background: Diabetic striatopathy (DS), coined as a generic term, has been defined as a hyperglycemic condition associated with either one of the two following conditions: chorea/ballism or striatal hyperdensity on computed tomography or striatal hyperintensity on T1-weighted magnetic resonance imaging. This review highlights those "gray areas," which need further exploration to understand better hyperglycemia-induced striatal changes and diverse movement disorder phenotypes associated with these changes.

Results And Discussion: We searched in PubMed and Google Scholar the terms "diabetes mellitus," "movement disorders," "diabetic striatopathy," "chorea," "hemichorea," "ballism," "hemichorea-hemiballism," and "neuroradiology" in various combinations (time range from 1980 to March 2022). We selected the publications about our topic of discussion.

Summary: Hemichorea-hemiballismus is the most commonly associated movement disorder in DS, and the putamen is the most frequently affected anatomical region. The exact pathophysiological mechanisms remain elusive. Clinical-radiological discordance is not rare. Complete reversal of symptoms with the resolution of the imaging findings is the most prevalent outcome in patients with DS. Dramatic improvement of chorea can be achieved by either insulin monotherapy or combination therapy of insulin and D2-blocker or, in some cases, even spontaneously.

Conclusion: The term "diabetic striatopathy" is ambiguous and controversial. Pathological mechanisms behind clinical-radiological discordance in hyperglycemia-induced striatopathy need further exploration through well-designed studies. We propose a classification of DS that includes symptomatic DS (striatal neuroimaging lesions in association with a clinically evident movement disorder and hyperglycemia), clinically isolated DS (clinically evident movement disorders without striatal changes in neuroimaging), and radiologically isolated DS.