Superior semicircular canal abnormalities are more common in patients presenting to the emergency room with...

Vertigo is associated with superior semicircular canal (SSC) abnormalities such as thinning (SST) and dehiscence (SSD). Recent work demonstrates that SST/SSD be reliably assessed using high-resolution non-contrast enhanced CT head (HR-NECTH). This study investigates and compares the prevalence of SST/SSD in emergency department (ED) patients without vertigo, with vertigo with identifiable causes of their symptoms (explained vertigo), and without (unexplained vertigo).

This retrospective study examined ED patients with and without vertigo who received HR-NECTH. Patients were enrolled and separated into three groups (patients without vertigo, explained vertigo, and unexplained vertigo) and their temporal bones (TB) were examined using HR-NECTH. Prevalence of SST/SSD on individual TB in patients without vertigo and of SSC abnormalities among the three cohorts were tabulated and analyzed with confidence intervals and Fisher's exact test.

Prevalence of SST/SSD was 2 % (95 %CI [0.63 %-5.4 %) and 1 % (95 %CI [0 %-2.4 %]), respectively, among 200 individual TB from ED patients without vertigo. There was statistically significant higher prevalence of SSC abnormalities in ED patients with explained vertigo (16 %, 95 %CI [8.8 %-23.2 %], P = 0.02) and unexplained vertigo (25 %, 95 %CI [16.5 %-33.5 %], P = 0.0001), compared to those without vertigo (5 %, 95 %CI [1.3 %-10.7 %]).

SST/SSD prevalence rate among ED patients without vertigo is similar to cadaveric gold-standard on HR-NECTH while those with vertigo had higher prevalence rates of SSC abnormalities. HR-NECTH can be used to assess for SSC abnormalities in ED vertigo patients to expedite diagnosis and forego additional TB imaging.