Lateral medullary infarction presenting with vertigo without other neurological signs

Usefulness of thermography for differentiating Wallenberg's syndrome from noncentral vertigo in the acute phase

OBJECTIVES

Wallenberg's syndrome (WS) is caused by a stroke in the lateral medulla and can present with various symptoms. One of the main symptoms is vertigo, which can be misdiagnosed as noncentral vertigo (NCV). Approximately 90% of the patients with acute WS have a lateral difference in body surface temperature (BST) due to autonomic pathway disturbances from infarction. Additionally, thermography can aid in WS diagnosis; however, whether BST differences occur in patients with acute NCV is unclear.

METHODS

This study used thermography to measure the BST of patients with NCV and acute WS to determine the effectiveness of BST to differentiate between the conditions. Forty-eight consecutive patients diagnosed with NCV whose BST was measured using thermography during a hospital visit or admission were enrolled. The left and right BST of four sites (face, trunk, and upper and lower limbs) were measured and compared with obtained BST of nine patients with WS.

RESULTS

Twenty-two patients had lateral differences in BST ≥ 0.5°C, three with ≥1.5°C, and none with ≥2.5°C. Only one patient with NCV had lateral differences in BST at two or more ipsilateral sites. When WS differentiated from NCV, a left-right difference ≥0.5°C in two or more ipsilateral sites had a sensitivity of 89% and specificity of 98%, and ≥1.0°C had a sensitivity of 78% and specificity of 98%.

DISCUSSION

Acute WS can be differentiated from NCV through BST and the number of sites with lateral differences via thermography, even in rooms where conditions are unregulated.

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.