Diffusion Restriction in Bilateral Thalami

Background: Bilateral thalamic infarction, especially the medial thalamus, has been characteristically described in the artery of Percheron (AOP) affection. However, bilateral thalamic restriction has been described in many entities beyond the AOP infarction. Objective: Here we describe a case series (three cases) with infection as an etiology for bilateral thalamic lesions in the topographic distribution of the AOP from a tertiary care center in tropical India. Materials and Methods: Case series during a 1-year period collecting cases with bilateral thalamic diffusion restriction on MRI who did not have thalamic infarcts and their outcomes. Results: Bilateral thalamic lesion can occur in both bacterial and viral infections such as tuberculosis, dengue, and SARS-COV-2. Thus, we intend to add infections as one of the etiologies in the ever-expanding list of conditions that produce bilateral thalamic restriction. Conclusions: All the acute symmetric thalamic lesions are not always secondary to vascular insult. Accurate assessment and prompt diagnosis can prevent unnecessary delays in treatment. To our knowledge, this is the first case series in the literature that throws light on the bilateral thalamic lesions in the topographic distribution of the AOP secondary to infections in a tropical country like India.