Medical Excellence - Issue 2

as benign positional vertigo). Due to the high proportion of missing information, we did not attempt statistical calculations on caloric testing. Menière’s disease and labyrinthitis were not diagnosed in this cohort. Brain imaging included cranial computed tomography (CT) in 66 (19.5%) and in 150 (44.2%) patients; CT or MRI showed definite new cerebral infarction in eight (2.4%) patients. Vessel imaging included duplex sonography in 327 (96.4%), CT angi- ography in ten (2.9%), MR angiography in 57 (16.8%) and digital subtraction angiography (DSA) in 14 (4.1%) patients. Vessel findings (Table 3) were assembled from all available information. Diagnosis and Follow-Up In the medical report from the initial contact, vertigo was con- sidered as ‘definitely cerebrovascular’ in 19 (5.6%) patients and ‘definitely or probably cerebrovascular’ in 48 (14.2%) patients. In 214 (63.1%) patients our files included at least one further presentation after the initial contact. The remaining 125 patients were contacted and 26 did not respond or refused to participate Table 2: Properties of vertigo. Total population ( n = 339) Type of vertigo a  Illusion of rotational movement, n (%) 120 (35.4)  Illusion of swaying movement, n (%) 132 (38.9)  Unclassifiable, n (%) 101 (29.8) Vertigo frequency  Median, range (n/week) 5/week, 1/week – 35/week  Below median, n (%) 40 (35.6 of noted)  Median or higher, n (%) 73 (64.4 of noted)  Not noted, n (%) 226 (66.7) Vertigo duration  Median, range (seconds) < 60s, 1 s – 10.800 s  Below median, n (%) 84 (56.4 of noted)  Median or higher, n (%) 65 (43.6 of noted)  Not noted, n (%) 190 (56.0) Vertigo trigger a  Spontaneous, n (%) 200 (59.0)  Turning the head, n (%) 61 (18.0)  Other change in body position, n (%) 123 (36.3)  Orthostatic stress, n (%) 37 (10.9)  Blood pressure-lowering situation, n (%) 40 (11.8) a Classification not exclusive as some patients reported multiple types in the survey. Ninety-nine patients gave their consent and pro- vided follow-up information (response rate 79.2%). Overall, we obtained follow-up information from 289 of 339 patients (85.3%, follow-up period 3 days to 7.7 years, 563 person years). The number of endpoint events and the resulting event rates are shown in Table 4. Determinants of the Clinical Diagnosis Age was positively associated with a higher risk for the diagnosis ‘definite or probable cerebrovascular vertigo’ (multivariate and univariate p = 0.024). Presentation because of vertigo was posi- tively related with the diagnosis ‘definite cerebrovascular vertigo’ (multivariate p = 0.013; univariate p = 0.014). Patients with fewer than five vertigo attacks per week were more likely to be diag- nosed with ‘definite or probable cerebrovascular vertigo’ (multi- variate and univariate p < 0.001). Patients with bilateral vertebral stenosis or basilar stenosis and patients with any stenosis were more likely to be diagnosed with ‘definite or probable cerebro- vascular vertigo’ (multivariate p = 0.047 and p = 0.048; univariate p < 0.001 each). Determinants of Future Cerebrovascular Events In patients who presented because of vertigo, the future risk for stroke or TIA was significantly higher than in patients who presented for other reasons (multivariate p = 0.028, univariate p = 0.005, adjusted HR 2.07 [1.11–3.84]; Fig. 1). When tested for the other endpoints (univariate), the reason for presentation was seen to be a significant determinator of stroke or TIA in the Fig. 1: Kaplan-Meier plot of the endpoint ‘any stroke or TIA’, stratified by presentation mode. Event rates (presentation because of vertigo (1) vs. other reasons (0)): 13.4 (95% CI 7.8-19.0) vs. 5.4 per 100 person years (95% CI 3.0-7.8). Presentation because of vertigo 1.0 0.8 0.6 0.4 0.2 0.0 0 1 0-censored 1-censored Survival function Event-free survival Days until stroke orTIA or end of follow-up 0 500 1000 2000 3000 1500 2500 Issue-2  |  15 MEDICAL EXCELLENCE