Dystypia following left lenticulostriate artery cerebral infarction: A case report with MR Tractography and SPECT analysis

Abstract

Objectives

To report a rare case of dystypia—a selective typing impairment—following a subcortical infarction, and to explore its neural correlates using clinical and imaging data.

Case Presentation

A 65-year-old right-handed man with proficient typing ability developed sudden difficulty typing during a web conference. He showed intact language comprehension, naming, and motor function, but exhibited romanization errors and touch-typing difficulties without agraphia, apraxia, or aphasia, while the Frontal Assessment Battery revealed impaired verbal fluency.

Imaging Findings

MRI revealed an acute infarct in the left putamen and corona radiata. Diffusion-weighted imaging with tractography showed partial involvement of the fronto-striatal tract connecting the putamen to the supplementary motor area. SPECT demonstrated hypoperfusion in the left frontal and parietal cortices.

Conclusion

This case suggests that disruption of the fronto-striatal tract may impair typing ability, even in the absence of classical language deficits. Subcortical lesions can cause highly selective cognitive-motor dysfunctions, and combined clinical and imaging approaches are key to understanding such atypical post-stroke presentations.