# Case report: Three characteristics of tyrosine kinase inhibitor-associated cerebrovascular stenosis. High threshold for infarction, atypical infarct area, and vascular recoverability under the use of ponatinib

## TL;DR

A 22-year-old leukemia patient developed brain vessel narrowing from ponatinib, showing unique stroke-like features that resolved after stopping the drug.

## Contribution

Identifies three novel characteristics of TKI-associated cerebrovascular stenosis distinct from typical stroke patterns.

## Key findings

- Brain imaging showed no infarction despite severe symptoms and prolonged hemiplegia.
- Ischemic changes occurred in atypical brain regions and resolved within 10 days after drug withdrawal.
- Arterial stenosis improved after discontinuing ponatinib, suggesting vascular recoverability.

## Abstract

While tyrosine kinase inhibitors (TKI)-associated cerebral vascular stenosis (CVS) exhibit distinct mechanisms compared to conventional stroke in basic research, the clinical strategy remains nearly the same other than TKI-switching. We present the case of a 22-year-old female with chronic myeloid leukemia without stroke risk factors, who developed ponatinib-associated CVS. Three potential characteristics of TKI-associated CVS were identified: a heightened threshold for infarction, an atypical infarct area, and vascular recoverability. Specifically, brain computed tomography remained normal despite 20 h of severe hemiplegia. The ischemic distribution was confined in gray matter and the anterior cerebral artery territory on magnetic resonance imaging, despite severe stenosis of the internal carotid artery. Ischemic changes resolved within 10 days and arterial stenosis improved after ponatinib withdrawal. These unique features, distinct from typical stroke, could lead to misdiagnosis as non-organic neurological disorders or other conditions in ponatinib-treated patients.