Utility of thermographic measurements of laterality of body surface temperature to prevent misdiagnosis of acute Wallenberg's syndrome

INTRODUCTION: Acute Wallenberg's syndrome (WS) is sometimes misdiagnosed as a nonstroke disease including auditory vertigo, and careful neurological examination is required for a precise diagnosis. Lateral difference of body surface temperature (BST) had been reported as a symptom of WS, although further details of this symptom are currently lacking. Our aim was to investigate the laterality of BST of patients with acute WS using thermography and the usefulness of thermography to detect acute WS. METHODS: Nine consecutive patients with new‐onset acute WS and nine patients with acute pontine infarction, intended for a comparison, were enrolled. Using thermography, the BST of patients was measured and initially evaluated visually. Detailed BSTs were measured using dedicated software. We examined the relationship between BST and other clinical factors, including first diagnosis, clinical symptoms, and MRI findings. RESULTS: Four patients with WS (44.44%) were misdiagnosed with nonstroke disease and did not receive a thermography assessment at their first visit; in contrast, all acute pontine infarction patients were diagnosed with brain infarction. Eight patients with WS (89%) showed a laterality of BST at multiple sites, and three of eight patients showed a whole‐body laterality of BST; in contrast, only two pontine infarction patients showed laterality of BST at one or two sites. These lateral BST differences were easily observed visually using thermography within two minutes. The BST laterality gradually decreased over time in almost all patients with WS. The infarction size in the WS patients with whole‐body laterality of BST was craniocaudally larger than in the other patients, and the size was smallest in the patient showing no BST laterality. CONCLUSIONS: In contrast to acute pontine infarction patients, almost all patients with acute WS showed lateral BST differences, which was easily detected with thermography. Thermography may thus be a useful tool to prevent misdiagnosis of acute WS.