Medical Excellence - Issue 2

episodes of vertigo. On a population basis, the lifetime preva- lence of the latter is at least as high as that of the former [5]. The former patient is usually seen in a hospital emergency depart- ment, whereas the latter may consult a practitioner or an out- patient clinic. In symptomatic emergency patients we have the opportunity to notice subtle clinical (mainly neuro-ophthalmo- logical) findings that may give important clues, as reflected by the HINTS algorithm [14], and – if stroke is likely – acute magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) can often prove, but rarely exclude, this diagnosis [15– 21]. In outpatients with recurrent transient vertigo, neuro-oph- thalmological findings during the attack usually resolve unseen and other information may be lost or biased by recall. DWI may help only when residual microinfarctions persist; mostly MRI is negative in this situation [17]. The identification of patients with cerebrovascular cause of recurrent transient isolated vertigo remains an unsolved clini- cal problem. The purpose of the current study was to find de- terminants of cerebrovascular origin, find risk factors for future stroke, and – if possible - construct a predictive model to help guide the diagnosis in patients who presented with isolated tran- sient vertigo in a tertiary cerebrovascular outpatient unit. Methods We screened the patient files of our department’s neurovascular clinic (1 July 2007 to 30 June 2014) for adults who reported iso- lated vertigo without focal neurological symptoms (dysarthria, focal weakness, sensory symptoms, limb ataxia, diplopia and hemianopia; unsteady gait was allowed). We extracted history, clinical findings, and technical results. The diagnosis (made by a neurologist in training (third year or later) and a consultant with neurovascular specialization) in the initial report was categorized as ‘definite’, ‘probable’ or ‘improbable cerebrovascular vertigo’. Follow-up information on subsequent stroke or TIA was obtained from the files and a telephone interview. For each endpoint, the observation time was censored at the time of an endpoint event (whereas follow-up was continued for other end- points), or at the end of a patient’s follow-up. Associations between clinical and technical variables, di- agnosis and follow-up events were addressed with multivari- ate logistic and Cox regression models, and confirmed with the Kaplan-Meier log rank test and univariate logistic and Cox re- gression. To limit the number of statistical tests, a stepwise analy- sis strategy was defined a priori. Although originally planned, we did not attempt to construct a predictive model, as we found no consistent risk factors. All statistical calculations were made with SPSS® (IBM Inc., Armonk, NY, USA). Results From the electronic files of 4714 outpatient contacts, we identi- fied 1355 patient contacts with the relevant keywords and 339 eligible patients (Table 1); 183 (54%) patients had two or more modifiable risk factors and 215 (63%) had coronary, cerebral or peripheral atherosclerosis. On initial contact 187 (55.2%) patients came to see a neu- rologist because of vertigo, 152 for other reasons (mainly routine follow-up of known cerebrovascular disease), but reported tran- sient isolated vertigo when asked about new symptoms. Most vertigo episodes lasted less than a minute, details are summa- rized in Table 2. Neurological examination was unremarkable in 193 (56.9%) patients. Gait ataxia was present in 88 patients (26.0%, prevalent conditions excluded). In 112 patients, the Epley manoeuvre was performed on presentation and was suggestive of benign paroxysmal positional vertigo (BPPV) in 20 (17.9%) patients. Head impulse test was never documented, presumably because the vertigo had subsided by the time of presentation in all cases. Caloric vestibular testing was done in only 15 cases and showed under-excitability in three cases (all diagnosed as vestibular neuritis), and over-excitability in one case (diagnosed Table 1: Baseline characteristics of patients. Total population ( n = 339) Age, years (mean ± SD) 63.4 ± 12.7 Female gender, n (%) 143 (42.2) Male gender, n (%) 196 (57.8) Hypertension, n (%) 247 (72.9) Diabetes, n (%) 74 (21.8) Smoking, n (%) 77 (22.7) Hypercholesterolemia, n (%) 125 (36.9) Hypertriglyceridemia, n (%) 35 (10.3) Number of modifiable VRFs, #: n (%)  (Including hypertension, diabetes, smoking, hypercholesterolemia, and hypertriglyceridemia) 0: 49 (14.5) 1: 107 (31.6) 2: 123 (36.3) 3: 37 (10.9) 4: 21 (6.2) 5: 2 (0.6) Coronary heart disease (CHD), n (%) 65 (19.2) Peripheral arterial occlusive disease (AOD), n (%) 36 (10.6) Prevalent Stroke or TIA (CVD), n (%) 177 (52.2) Stroke or TIA in the last 6 months, n (%) 38 (11.2) At least one vessel disease (CHD, AOD or CVD), n (%) 215 (63.4) 14  |  Issue-2 MEDICAL EXCELLENCE