Assessing clinical reasoning skills following a virtual patient dizziness curriculum.

OBJECTIVES: Dizziness is a common medical symptom that is frequently misdiagnosed. While virtual patient (VP) education has been shown to improve diagnostic accuracy for dizziness as assessed by VPs, trainee performance has not been assessed on human subjects. The study aimed to assess whether internal medicine (IM) interns after training on a VP-based dizziness curriculum using a deliberate practice framework would demonstrate improved clinical reasoning when assessed in an objective structured clinical examination (OSCE). METHODS: All available interns volunteered and were randomized 2:1 to intervention (VP education) vs. control (standard clinical teaching) groups. This quasi-experimental study was conducted at one academic medical center from January to May 2021. Both groups completed pre-posttest VP case assessments (scored as correct diagnosis across six VP cases) and participated in an OSCE done 6 weeks later. The OSCEs were recorded and assessed using a rubric that was systematically developed and validated. RESULTS: Out of 21 available interns, 20 participated. Between intervention (n=13) and control (n=7), mean pretest VP diagnostic accuracy scores did not differ; the posttest VP scores improved for the intervention group (3.5 [SD 1.3] vs. 1.6 [SD 0.8], p=0.007). On the OSCE, the means scores were higher in the intervention (n=11) compared to control group (n=4) for physical exam (8.4 [SD 4.6] vs. 3.9 [SD 4.0], p=0.003) and total rubric score (43.4 [SD 12.2] vs. 32.6 [SD 11.3], p=0.04). CONCLUSIONS: The VP-based dizziness curriculum resulted in improved diagnostic accuracy among IM interns with enhanced physical exam skills retained at 6 weeks post-intervention.

Longitudinal Patient Outcomes in Chronic Dizziness: A Scoping Review.

BACKGROUND: Chronic dizziness can cause significant functional impairment. Outcome measures used in this patient population have not been examined systematically. Consequently, providers lack consensus on the ideal outcome measures to assess the impact of their interventions. OBJECTIVE AND METHODS: We conducted a scoping review to summarize existing literature on outcomes in chronic dizziness (with a minimum of 6 mo of patient follow-up). Among other details, we extracted and analyzed patient demographics, medical condition(s), and the specific outcome measures of each study. RESULTS: Of 19,426 articles meeting the original search terms, 416 met final exclusion after title/abstract and full-text review. Most studies focused on Ménière's disease (75%) and recurrent benign paroxysmal positional vertigo (21%). The most common outcome measures were hearing (62%) and number of attacks by American Academy of Otolaryngology-Head & Neck Surgery criteria (60%). A minority (35%) looked formally at quality-of-life metrics (Dizziness Handicap Index or other). CONCLUSIONS: Ménière's disease and benign paroxysmal positional vertigo are overrepresented in literature on outcome assessment in chronic dizziness. Objective clinical measures are used more frequently than quality-of-life metrics. Future work is needed to identify the optimal outcome measures that reflect new knowledge about the most common causes of chronic dizziness (including persistent postural-perceptual dizziness and vestibular migraine) and consider what is most important to patients.

Weak nystagmus in the dark persists for months after acute unilateral vestibular loss.

Background: Weak nystagmus with fixation removed can be seen both in normal individuals and in recovery from a unilateral vestibular insult, thus its clinical significance is unclear in patients with dizziness. We thus sought to compare features of nystagmus at various stages following unilateral vestibular loss (UVL). Methods: We enrolled thirty consecutive patients after acute UVL with impaired vestibulo-ocular reflex (VOR) gain. The patients were allocated into three groups according to time from onset of symptoms: acute (1-7 days), subacute (8-30 days), and chronic (>30 days). Patients underwent video-oculography (with and without fixation) and video head impulse testing (vHIT) to determine VOR gain. We examined the relationships amongst SPV, VOR gain, and time from symptom onset across groups. Results: There were 11, 10, and 9 patients in the acute, subacute, and chronic stages of UVL, respectively. With visual fixation, only 8 patients (26.7%) demonstrated nystagmus, all from the acute group. With fixation removed, 26 patients (86.7%) exhibited spontaneous nystagmus, including 90.9%, 90%, and 77.8% of the patients from the acute, subacute, and chronic groups, respectively. Horizontal nystagmus was paralytic (i.e., fast phase contralesional) in 25 (96.7%) cases. Horizontal SPV was negatively correlated with logarithm of time from onset to examination (r = -0.48, p = 0.007) and weakly negatively correlated with ipsilesional VOR gain (r = -0.325, p = 0.08). Conclusion: In the subacute or chronic stages of UVL, paralytic nystagmus with fixation removed persisted at a low intensity. Therefore, weak nystagmus in the dark may have diagnostic value in chronic dizziness.

Positive horizontal-canal head impulse test is not a benign sign for acute vestibular syndrome with hearing loss.

Background: Diagnosis of acute vestibular syndrome (AVS) with hearing loss is challenging because the leading vascular cause-AICA territory stroke-can appear benign on head impulse testing. We evaluated the diagnostic utility of various bedside oculomotor tests to discriminate imaging-positive and imaging-negative cases of AVS plus hearing loss. Method: We reviewed 13 consecutive inpatients with AVS and acute unilateral hearing loss. We compared neurologic findings, bedside and video head impulse testing (bHIT, vHIT), and other vestibular signs (including nystagmus, skew deviation, and positional testing) between MRI+ and MRI- cases. Results: Five of thirteen patients had a lateral pontine lesion (i.e., MRI+); eight did not (i.e., MRI-). Horizontal-canal head impulse test showed ipsilateral vestibular loss in all five MRI+ patients but only in three MRI- patients. The ipsilesional VOR gains of horizontal-canal vHIT were significantly lower in the MRI+ than the MRI- group (0.56 ± 0.11 vs. 0.87 ± 0.24, p = 0.03). All 5 MRI+ patients had horizontal spontaneous nystagmus beating away from the lesion (5/5). One patient (1/5) had direction-changing nystagmus with gaze. Two had skew deviation (2/5). Among the 8 MRI- patients, one (1/8) presented as unilateral vestibulopathy, four (4/8) had positional nystagmus and three (3/8) had isolated posterior canal hypofunction. Conclusion: The horizontal-canal head impulse test poorly discriminates central and peripheral lesions when hearing loss accompanies AVS. Paradoxically, a lateral pontine lesion usually mimics unilateral peripheral vestibulopathy. By contrast, patients with peripheral lesions usually present with positional nystagmus or isolated posterior canal impairment, risking misdiagnosis as central vestibulopathy.

Risk of stroke is low after transient ischemic attack presentation with isolated dizziness.

OBJECTIVE: Stroke presenting as dizziness is a diagnostic challenge in frontline settings, given the multitude of benign conditions that present similarly. The risk of stroke after episodic dizziness is unknown, leading to divergent guidance on optimal workup and management. Prior TIA risk scores have shown a history of dizziness is a negative predictor of subsequent stroke. Our objective was to assess the subsequent stroke risk within 90 days following emergency department assessment (ED) for isolated dizziness diagnosed as TIA during the index visit. METHODS: We conducted prospective, multicenter cohort studies at 13 Canadian EDs over 11 years. We enrolled patients diagnosed with TIA and compared patients with isolated dizziness to those with other neurological deficits. Our primary outcome was subsequent stroke within 90 days. Secondary outcomes were subsequent stroke within 2, 7, and 30 days, respectively, as well as subsequent TIA within 90 days. RESULTS: Only 4/483 (0.8%) patients with isolated dizziness had a stroke within 90 days compared to 320/11024 (2.9%) of those with any focal neurological sign or symptom (RR 0.29, 95% CI 0.11-0.76). Over the first 90 days, the two groups differ significantly in their probability of stroke (p = 0.007). Subsequent TIA was also significantly less common in the isolated dizziness group (1.7% vs. 5.6%, p = 0.001) with a relative risk of 0.30 (95% CI 0.15-0.60). CONCLUSION: The risk of subsequent stroke following ED presentation for TIA is low when the presenting symptoms are isolated dizziness.

RéSUMé: OBJECTIF: Les accidents vasculaires cérébraux (AVC) se présentant sous forme de vertiges constituent un défi diagnostique en première ligne, étant donné la multitude d'affections bénignes qui se présentent de la même manière. Le risque d'accident vasculaire cérébral (AVC) après des vertiges épisodiques est inconnu, ce qui donne lieu à des conseils divergents sur le bilan et la prise en charge optimaux. Des scores de risque d'AIT antérieurs ont montré que des antécédents de vertiges sont un facteur prédictif négatif d'accident vasculaire cérébral ultérieur. Notre objectif était d'évaluer le risque ultérieur d'accident vasculaire cérébral (AVC) dans les 90 jours suivant l'évaluation aux urgences d'un étourdissement isolé diagnostiqué comme un AIT lors de la visite de référence. MéTHODES: Nous avons mené des études de cohorte prospectives multicentriques dans 13 services d'urgence canadiens pendant 11 ans. Nous avons recruté des patients ayant reçu un diagnostic d'AIT et avons comparé les patients présentant des vertiges isolés à ceux présentant d'autres déficits neurologiques. Nous avons inscrit des patients ayant reçu un diagnostic d'AIT et comparé des patients ayant des étourdissements isolés à ceux présentant d'autres déficits neurologiques. Notre résultat primaire était l'AVC subséquent dans les 90 jours. Les résultats secondaires étaient l'AVC subséquent dans les 2, 7 et 30 jours, respectivement, ainsi que l'AIT subséquent dans les 90 jours. RéSULTATS: Seuls 4/483 (0,8 %) des patients présentant des vertiges isolés ont eu un AVC dans les 90 jours, contre 320/11 024 (2,9 %) de ceux présentant un signe ou symptôme neurologique focal (RR 0,29, IC 95 % 0,11-0,76). Au cours des 90 premiers jours, les deux groupes diffèrent significativement en termes de probabilité d'AVC (p = 0,007). L'AIT ultérieur était également significativement moins fréquent dans le groupe des vertiges isolés (1,7 % contre 5,6 %, p = 0,001) avec un risque relatif de 0,30 (IC 95 % 0,15-0,60). CONCLUSIONS: Le risque d'AVC ultérieur après une présentation aux urgences pour un AIT est faible lorsque les symptômes présentés sont des étourdissements isolés.

Vestibular paroxysmia: Long-term clinical outcome after treatment.

Objective: To study the long-term treatment outcome of vestibular paroxysmia (VP). Study design: Retrospective study. Setting: Tertiary referral hospital. Methods: We analyzed records of 29 consecutive patients who were diagnosed with VP and who were treated with VP-specific anticonvulsants for at least 3 months. Patients were followed for a minimum of 6 months. We recorded and assessed starting and target dosage of medications, time to achieve adequate therapeutic response, adverse effects, and the rates of short-term and long-term remission without medication. Results: All 29 patients were started on oxcarbazepine as first-line treatment, and 93.1% and 100% of patients reported good-to-excellent therapeutic response within 2 and 4 weeks, respectively. Three patients switched to other anticonvulsants at 3 months. At long-term follow-up (8-56 months), most (84.6%) oxcarbazepine-treated patients maintained good therapeutic response at doses between 300 and 600 mg/day. Eleven (37.9%) patients experienced complete remission without medication for more than 1 month, of which six (20.7%) had long-term remission off medication for more than 12 months. Nineteen (65.5%) patients had neurovascular compression (NVC) of vestibulocochlear nerve on MRI, but its presence or absence did not predict treatment response or remission. Conclusion: Low-dose oxcarbazepine monotherapy for VP is effective over the long term and is generally well-tolerated. About 20% of patients with VP in our study had long-term remission off medication.

The fixation suppression test can uncover vertical nystagmus of central origin in some patients with dizziness.

BACKGROUND: Identifying dangerous causes of dizziness is a challenging task for neurologists, as it requires interpretation of subtle bedside exam findings, which become even more subtle with time. Nystagmus can be instrumental in differentiating peripheral from central vestibular disorders. Conventional teaching is that peripheral vestibular nystagmus is accentuated by removal of visual fixation. We sought to systematically test the hypothesis that, in some cases, vertical nystagmus due to central vestibular disorders may also be easier to identify when fixation is removed. METHODS: To identify patients with vertical nystagmus, we retrospectively reviewed clinical, MRI, and VNG data of consecutive patients undergoing VNG in our vestibular clinic over a 9-month period. We analyzed clinical features, bedside neuro-otological examination, MRI results, and VNG findings in fixation as well as those with fixation removed. RESULTS: Two hundred and fourteen charts were reviewed. Twenty-six patients had vertical nystagmus with fixation removed on VNG. Only three (11.5%) of these patients had vertical nystagmus apparent with fixation (and only two had nystagmus observed clearly at the bedside with the unaided eye). Thirteen (50%) of the patients had posterior fossa lesions on MRI and eight of the rest (30.8%) were diagnosed with central vestibular disorders. Of the 13 patients with MRI-confirmed lesions, 3 patients (23.1%) had no neurological signs or conventional bedside oculomotor signs; in these cases, vertical nystagmus without fixation was the only sign of a central lesion. CONCLUSIONS: Our findings go against conventional teaching and show that removing fixation can uncover subtle vertical nystagmus due to central vestibular disease, particularly from focal or chronic lesions.

Stroke hospitalization after misdiagnosis of "benign dizziness" is lower in specialty care than general practice: a population-based cohort analysis of missed stroke using SPADE methods.

OBJECTIVES: Isolated dizziness is a challenging stroke presentation in the emergency department, but little is known about this problem in other clinical settings. We sought to compare stroke hospitalizations after treat-and-release clinic visits for purportedly "benign dizziness" between general and specialty care settings. METHODS: This was a population-based retrospective cohort study from a national database. We included clinic patients with a first incident treat-and-release visit diagnosis of non-specific dizziness/vertigo or a peripheral vestibular disorder (ICD-9-CM 780.4 or 386.x [not 386.2]). We compared general care (internal medicine, family medicine) vs. specialty care (neurology, otolaryngology) providers. We used propensity scores to control for baseline stroke risk differences unrelated to dizziness diagnosis. We measured excess (observed>expected) stroke hospitalizations in the first 30 d (i.e., missed strokes associated with an adverse event). RESULTS: We analyzed 144,355 patients discharged with "benign dizziness" (n=117,117 diagnosed in general care; n=27,238 in specialty care). After propensity score matching, patients in both groups were at higher risk of stroke in the first 30 d (rate difference per 10,000 treat-and-release visits for "benign dizziness" 24.9 [95% CI 18.6-31.2] in general care and 10.6 [95% CI 6.3-14.9] in specialty care). Short-term stroke risk was higher in general care than specialty care (relative risk, RR 2.2, 95% CI 1.5-3.2) while the long-term risk was not significantly different (RR 1.3, 95% CI 0.9-1.9), indicating higher misdiagnosis-related harms among dizzy patients who initially presented to generalists after adequate propensity matching. CONCLUSIONS: Missed stroke-related harms in general care were roughly twice that in specialty care. Solutions are needed to address this care gap.

Association between obstructive sleep apnea and persistent postural-perceptual dizziness.

BACKGROUND: Obstructive sleep apnea (OSA) has been linked to vestibular dysfunction, but no prior studies have investigated the relationship between Persistent Postural-Perceptual Dizziness (PPPD), a common cause of chronic dizziness, and OSA. OBJECTIVE AND METHODS: We determined the frequency of OSA in an uncontrolled group of PPPD patients from a tertiary dizziness clinic based on polysomnogram (PSG). We then assessed the sensitivity and specificity of common OSA questionnaires in this population. RESULTS: Twenty-five patients with PPPD underwent PSG (mean age 47, 60% female, mean BMI 29.5). A majority, or 56%, of patients were diagnosed with OSA, and in most, the OSA was severe. OSA patients were older (56 years versus 40 years, p = 0.0006) and had higher BMI (32 versus 26, p = 0.0078), but there was no clear gender bias (56% versus 64% female, p = 1.00). The mean sensitivity and specificity of the STOP BANG questionnaire for detecting OSA was 86% and 55%, respectively. Sensitivity and specificity of the Berlin Questionnaire was 79% and 45%, respectively. CONCLUSIONS: The prevalence of OSA was much higher in our small PPPD group than in the general population. Screening questionnaires appear to demonstrate good sensitivity to detect PPPD patients at risk of OSA in this small study. Future studies should confirm these findings and determine whether treatment of OSA improves symptoms in PPPD.

Real-world virtual patient simulation to improve diagnostic performance through deliberate practice: a prospective quasi-experimental study.

OBJECTIVES: Diagnostic errors are pervasive in medicine and most often caused by clinical reasoning failures. Clinical presentations characterized by nonspecific symptoms with broad differential diagnoses (e.g., dizziness) are especially prone to such errors. METHODS: We hypothesized that novice clinicians could achieve proficiency diagnosing dizziness by training with virtual patients (VPs). This was a prospective, quasi-experimental, pretest-posttest study (2019) at a single academic medical center. Internal medicine interns (intervention group) were compared to second/third year residents (control group). A case library of VPs with dizziness was developed from a clinical trial (AVERT-NCT02483429). The approach (VIPER - Virtual Interactive Practice to build Expertise using Real cases) consisted of brief lectures combined with 9 h of supervised deliberate practice. Residents were provided dizziness-related reading and teaching modules. Both groups completed pretests and posttests. RESULTS: For interns (n=22) vs. residents (n=18), pretest median diagnostic accuracy did not differ (33% [IQR 18-46] vs. 31% [IQR 13-50], p=0.61) between groups, while posttest accuracy did (50% [IQR 42-67] vs. 20% [IQR 17-33], p=0.001). Pretest median appropriate imaging did not differ (33% [IQR 17-38] vs. 31% [IQR 13-38], p=0.89) between groups, while posttest appropriateness did (65% [IQR 52-74] vs. 25% [IQR 17-36], p<0.001). CONCLUSIONS: Just 9 h of deliberate practice increased diagnostic skills (both accuracy and testing appropriateness) of medicine interns evaluating real-world dizziness 'in silico' more than ∼1.7 years of residency training. Applying condensed educational experiences such as VIPER across a broad range of common presentations could significantly enhance diagnostic education and translate to improved patient care.

Potential value of electronic health records in capturing data on geriatric frailty for population health.

OBJECTIVES: Despite the availability of many frailty measures to identify older adults at risk, frailty instruments are not routinely used for risk assessment in population health management. Here, we assessed the potential value of electronic health records (EHRs) and administrative claims in providing the necessary data for variables used across various frailty instruments. SETTING AND PARTICIPANTS: The review focused on studies conducted worldwide. Participants included older people aged 50 and older. DESIGN: We identified frailty instruments published between 2011 and 2018. Frailty variables used in each of the frailty instruments were extracted, grouped, and categorized across health determinants and various clinical factors. MEASURES: The availability of the extracted frailty variables across various data sources (e.g., EHRs, administrative claims, and surveys) was evaluated by experts. RESULTS: We identified 135 frailty instruments, which contained 593 unique variables. Clinical determinants of health were the best represented variables across frailty instruments (n = 516; 87 %), unlike social and health services factors (n = 33; ∼5% and n = 32; ∼5%). Most frailty instruments require at least one variable that is not routinely available in EHRs or claims (n = 113; ∼83 %). Only 22 frailty instruments have the potential to completely rely on EHR (structured or free-text data) and/or claims data, and possibly be operationalized on a population-level. CONCLUSIONS AND IMPLICATIONS: Frailty instruments continue to be highly survey-based. More research is therefore needed to develop EHR-based frailty instruments for population health management. This will permit organizations and societies to stratify risk and better allocate resources among different older adult populations.