gms | German Medical Science

Introduction: Hot cross bun sign refers to the cruciform-shaped hyperintensity on Fluid-attenuated-inversion-recovery- (FLAIR-) and T2 images due to the selective loss of myelinated transverse pontocerebellar fibers and neurons in the pontine raphe and sparing of the pontine tegmentum and corticospinal tracts [1]. Although it is found in a significant number of patients with neurodegenerative disorders, especially multisystem atrophy, it seems to be irrespective of the underlying pathogenetic process [2]. Here, we report a case of hot cross bun sign due to Wallerian degeneration following bilateral anterior inferior cerebellar artery (AICA) infarction.

Objectives: A 73-year-old female was admitted with a nausea, dysarthria, left sided central facial palsy and a left sided Hemiataxia.

Materials & Methods: MRI visualized an infarction in the territory of the left AICA. 24-hour ambulatory blood pressure monitoring (ABPM) revealed normal values. The patient was treated with Aspirin and Statin for a secondary prevention.

2 months later, dysarthria became worse. MRI now revealed an acute ischemic stroke in the distribution of the right AICA, so symmetrical infarct lesions in bilateral cerebellar peduncles could now be observed. The secondary prevention was switched on dual antiplatelet therapy.

Results: Follow-up MRI 4 years later demonstrated pontocerebellar atrophy and the hot cross bun sign. ABPM now revealed a nocturnal hypertension and a reverse dipping (inversion of the normal circadian variation), suggestive of an autonomic dysfunction.

Conclusion: Only a few prior descriptions of hot cross bun sign following bilateral AICA infarction are available from the literature [3], [4].

Our case demonstrated a patient with bilateral AICA infarction leading to severe pontocerebellar atrophy with the hot cross bun sign and causing an autonomic dysfunction.