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No 360: February 8, 2017

Zaleski A1, Bogle J, Starling A, Zapala DA, Davis L, Wester M, Cevette M. Vestibular evoked myogenic potentials in patients with vestibular migraine. Otol Neurotol. 2015 Feb;36(2):295-302. 

OBJECTIVE: Literature investigating otolith reflexes in patients with vestibular migraine (VM) is variable and primarily describes the descending saccular pathway. This research aimed to study ocular vestibular evoked myogenic potential (oVEMP) and cervical vestibular evoked myogenic potential (cVEMP) prevalence and response characteristics in patients with suspected VM and in control patients. The purpose is to assess vulnerabilities within the ascending utricular and descending saccular pathways in the VM population.

STUDY DESIGN: Retrospective study

SETTING: Tertiary academic referral center

PATIENTS: 39 adults with VM, 29 control patients

MAIN OUTCOME MEASURE(S): Air conducted oVEMPs and cVEMPs measured with 500 Hz tone burst stimuli

RESULTS: Age of headache onset was most often in childhood or adolescence, with dizziness onset occurring later. The rate of bilaterally absent oVEMPs was significantly higher (28%, p < 0.01) in the VM group compared with the control group (0%). oVEMP amplitude asymmetry ratios were significantly higher for the definite VM (p < 0.01) and probable VM (p = 0.023) groups than the control group. Eleven patients also had history of concussion; they were significantly more likely to demonstrate bilaterally absent oVEMPs (p < 0.01) in comparison to the control patients. When VM patients with a history of concussion were omitted from analysis, differences in oVEMP amplitude asymmetry (p < 0.01) and bilateral oVEMP absence remained significant (p = 0.015). There were no differences in the rate of bilateral cVEMP presence or response parameters between VM and control groups.

CONCLUSION: VEMP presentation differs for some patients diagnosed with VM. The higher rates of abnormal oVEMPs may suggest greater vulnerability within the ascending utricular-ocular pathway in patients with VM.

PMID:  25415464

No 359: February 1, 2017

Jung JH, Yoo MH, Song CI, Lee JR, Park HJ. Prognostic significance of vestibulospinal abnormalities in patients with vestibular migraine. Otol Neurotol. 2015 Feb;36(2):282-8.

OBJECTIVES: We evaluated vestibular function test results in vestibular migraine (VM) patients, including caloric, vestibular evoked myogenic potential (VEMP), and dynamic posturography measurements and assessed their relationship with treatment responses.

Retrospective case series review.

METHODS: We investigated a cohort of 80 VM patients who had suffered recurrent vertigo attacks for more than 6 months. A combination of lifestyle modifications and prophylactic medications were used to treat these subjects. The patients were asked to score the treatment success by ranking symptom score from 0% to 100% for the improvement in overall severity of headache and vertigo. Patients were then classified as complete remission, symptomatic improvement 50% or more, or less than 50% improvement after 6 months of treatment. The periods needed for symptomatic improvement in the 50% or more patient group were recorded, and the responsiveness to medications and the vestibular test result metrics were analyzed to identify clinical outcome predictors.

RESULTS: A symptomatic improvement of 50% or more in vertigo and headache was observed in 71% and 75% of the study subjects across mean periods of 2.3 and 2.2 months, respectively. Improvements in vertigo and headache did not coincide in all. Abnormal caloric, VEMP, and vestibular ratio measurements were found in 25%, 29%, and 58%, respectively. Abnormal vestibular ratios on posturography showed a significant correlation with a poor treatment response of vertigo, and a normal VEMP was significantly related to complete remission from headache, although abnormal caloric results showed no significant correlation with treatment responses. A poor response of vertigo symptoms was observed in 6% of patients with a normal vestibular ratio and 48% of patients with abnormal vestibular ratio. Complete remission from headache was observed in 61% of patients with a normal VEMP and 30% in patients with an abnormal VEMP.

CONCLUSION: More than 70% of the patients with VM experienced improvements in both headache and vertigo through a combination of lifestyle changes and prophylactic medications. Abnormal vestibular ratios on posturography and abnormal VEMP responses were frequent findings in VM patients with recurrent attacks for more than 6 months and were indicators of a poor prognosis. The pathophysiology of VM appears to be closely related to vestibular abnormalities, especially in vestibulospinal pathways. Further study with a large population is needed to establish the relationship exactly.

PMID:  25415464

No 358: January 25, 2017

Obrist D et al. Determinants for a Successful Sémont Maneuver: An In vitro Study with a Semicircular Canal Model. Front Neurol. 2016 Sep 16;7:150. eCollection 2016.

OBJECTIVE: To evaluate the effect of time between the movements/steps, angle of body movements as well as the angular velocity of the maneuvers in an in vitro model of a semicircular canal (SCC) to improve the efficacy of the Sémont maneuver (SM) in benign paroxysmal positional vertigo.

MATERIALS AND METHODS: Sémont maneuvers were performed on an in vitro SCC model. Otoconia trajectories were captured by a video camera. The effects of time between the movements, angles of motion (0°, 10°, 20°, and 30° below the horizontal line), different angular velocities (90, 135, 180°/s), and otoconia size (36 and 50 μm) on the final position of the otoconia in the SCC were tested.

RESULTS: Without extension of the movements beyond the horizontal, the in vitro experiments (with particles corresponding to 50 μm  diameter) did not yield successful canalith repositioning. If the movements were extended by 20° beyond the horizontal position, SM were successful with resting times of at least 16 s. For larger extension angles, the required time decreased. However, for smaller particles (36 μm), the required time doubled. The angular maneuver velocity (tested between 90 and 180°/s) did not have a major impact on the final position of the otoconia.

INTERPRETATION: The two primary determinants for success of the SM are the time between the movements and the extension of the movements beyond the horizontal. The time between the movements should be at least 45s. Angles of 20° or more below horizontal line (so-called Sémont+) should increase the success rate of SM.

PMID:  27695437

Link to free article:

No 357: January 18, 2017

Karatas et al.  Evaluation of Cervical Vestibular-Evoked Myogenic Potential Findings in Benign Paroxysmal Positional Vertigo. J Int Adv Otol. 2016 Dec;12(3):316-320. doi: 10.5152/iao.2016.2170. Epub 2016 Aug 1.

OBJECTIVE: Although there has been a wide consensus on the mechanism of nystagmus and clinical presentation of benign paroxysmal positional vertigo (BPPV), the neuroepithelial pathophysiology of BPPV still remains unclear. In this study, we aimed to clarify the pathophysiology of BPPV by evaluating the cervical vestibular-evoked myogenic potential (cVEMP) findings of patients.

MATERIALS AND METHODS: Thirty-six BPPV patients and 20 healthy volunteers were included. Bilateral cVEMP tests were performed on all participants. The participants were divided into the following three groups: those with a BPPV-affected ear, those with a BPPV-unaffected ear, and the healthy control group.

RESULTS: There were no significant differences regarding the latencies of the first positive (p1) and negative (n1) peaks among the three groups. The mean normalized amplitude asymmetry ratio also did not differ between the BPPV and control groups. However, the normalized amplitudes of the BPPV patients (with both affected and unaffected ears) were significantly lower than those of the healthy control group.

CONCLUSION: We detected that the cVEMP data of the affected and unaffected ears of the BPPV patients was similar and that their normalized amplitudes significantly differed from those of the healthy controls. Eventually, we concluded that even if the symptoms of BPPV were unilateral, the findings suggest that the bilateral involvement of the macular neuroepithelium is important in understanding the pathophysiology of BPPV. This finding supports the conclusion that the pathophysiological process starts with neuroepithelial membrane degeneration and continues with otoconia separation.

PMID: 28031157

No 356: January 11, 2017

Tirelli G et al. Repeated canalith repositioning procedure in BPPV: Effects on recurrence and dizziness prevention. Am J Otolaryngol. 2017 Jan - Feb;38(1):38-43.

PURPOSE: To evaluate whether a repeated canalith repositioning procedure (CRP) influences the residual symptoms and the rate of recurrence of benign paroxysmal positional vertigo (BPPV) in patients with post-CRP dizziness.

MATERIALS AND METHODS: In this retrospective study, we analyzed 292 patients at the referral center for ENT diseases with a first episode of BPPV treated with a single CRP following clinical practice guidelines. In 178 patients (67.9%) who presented dizziness after BPPV recovery at the follow-up visit, 94 patients underwent CRP (treated group) and 84 did not (non-treated group). A subjective evaluation of vertigo was made by way of a questionnaire. The rates of recurrence of BPPV and residual dizziness were statistically compared between the treated and the non-treated groups; survival analysis was carried out as well.

RESULTS: In an observational period ranging from 1 to 6years, BPPV recurred in 122 subjects (46.6%) of the investigated population. Among the patients with residual dizziness, the difference in rate of recurrence of BPPV between the treated group and the non-treated group was not statistically significant (p=0.84). The treated group presented a significantly higher rate of recovery from dizziness compared to the non-treated group (p<0.001).

CONCLUSIONS: A repeated CRP in patients with post-CRP dizziness increased the rate of recovery from dizziness but had no influence on BBPV recurrence.

PMID: 27806891

No 355: January 4, 2017

Balatsouras DG et al. Benign Paroxysmal Positional Vertigo Secondary to Mild Head Trauma. Ann Otol Rhinol Laryngol. 2017 Jan;126(1):54-60.

OBJECTIVES: We studied the clinical characteristics, nystagmographic findings, and treatment outcome of a group of patients with benign paroxysmal positional vertigo (BPPV) secondary to mild head trauma and compared them with a group of patients with idiopathic BPPV.

METHODS: The medical records of 33 patients with BPPV associated with mild head trauma were reviewed. Data of a complete otolaryngological, audiological, neurotologic, and imaging evaluation were available for all patients. Three hundred and twenty patients with idiopathic BPPV were used as a control group.

RESULTS: The patients with BPPV secondary to mild head trauma presented the following features, in which they differed from the patients with idiopathic BPPV: (1) lower mean age, with more intense symptoms; (2) increased rate of horizontal and anterior semicircular canal involvement and frequent multiple canal and bilateral involvement; (3) greater incidence of canal paresis and presence of spontaneous nystagmus; (4) poorer treatment results, attributed mainly to coexisting canal paresis in many patients, and higher rate of recurrence.

CONCLUSIONS: Benign paroxysmal positional vertigo associated with mild head trauma differs from idiopathic BPPV in terms of several epidemiological and clinical features; it responds less effectively to treatment and is prone to recurrence.

PMID: 27780909

No 354: December 28, 2016

Gallaway M, Scheiman M, Mitchell GL. Vision Therapy for Post-Concussion Vision Disorders. Optom Vis Sci. 2016 Aug 8.

PURPOSE: To determine the frequency and types of vision disorders associated with concussion, and to determine the success rate of vision therapy for these conditions in two private practice settings.

METHODS: All records over an 18-month period of patients referred for post-concussion vision problems were reviewed from two private practices. Diagnoses of vergence, accommodative, or eye movement disorders were based on pre-established, clinical criteria. Vision therapy was recommended based on clinical findings and symptoms.

RESULTS: Two hundred eighteen patient records were found with a diagnosis of concussion. Fifty-six percent of the concussions were related to sports, 20% to automobile accidents, and 24% to school, work, or home-related incidents. The mean age was 20.5 years and 58% were female. Eighty-two percent of the patients had a diagnosis of an oculomotor problem [binocular problems (62%), accommodative problems (54%), eye movement problems (21%)]. The most prevalent diagnoses were convergence insufficiency (CI, 47%) and accommodative insufficiency (AI, 42%). Vision therapy was recommended for 80% of the patients. Forty-six per cent (80/175) either did not pursue treatment or did not complete treatment. Of the 54% (95/175) who completed therapy, 85% of patients with CI were successful and 15% were improved, and with AI, 33% were successful and 67% improved. Clinically and statistically significant changes were measured in symptoms, near point of convergence, positive fusional vergence, and accommodative amplitude.

CONCLUSIONS: In this case series, post-concussion vision problems were prevalent and CI and AI were the most common diagnoses. Vision therapy had a successful or improved outcome in the vast majority of cases that completed treatment. Evaluation of patients with a history of concussion should include testing of vergence, accommodative, and eye movement function. Prospective clinical trials are necessary to assess the natural history of concussion-related vision disorders and treatment effectiveness.

PMID: 27505624

No 353: December 21, 2016

Ellis MJ, Cordingley DM, Vis S, Reimer KM, Leiter J, Russell K.  Clinical predictors of vestibulo-ocular dysfunction in pediatric sports-related concussion. J Neurosurg Pediatr. 2016 Sep 30:1-8

OBJECTIVE There were 2 objectives of this study. The first objective was to identify clinical variables associated with vestibulo-ocular dysfunction (VOD) detected at initial consultation among pediatric patients with acute sports-related concussion (SRC) and postconcussion syndrome (PCS). The second objective was to reexamine the prevalence of VOD in this clinical cohort and evaluate the effect of VOD on length of recovery and the development of PCS.

METHODS A retrospective review was conducted for all patients with acute SRC and PCS who were evaluated at a pediatric multidisciplinary concussion program from September 2013 to May 2015. Acute SRC was defined as presenting < 30 days postinjury, and PCS was defined according to the International Classification of Diseases, 10th Revision criteria and included being symptomatic 30 days or longer postinjury. The initial assessment included clinical history and physical examination performed by 1 neurosurgeon. Patients were assessed for VOD, defined as the presence of more than 1 subjective vestibular and oculomotor complaint (dizziness, diplopia, blurred vision, etc.) and more than 1 objective physical examination finding (abnormal near point of convergence, smooth pursuits, saccades, or vestibulo-ocular reflex testing). Poisson regression analysis was used to identify factors that increased the risk of VOD at initial presentation and the development of PCS.

RESULTS Three hundred ninety-nine children, including 306 patients with acute SRC and 93 with PCS, were included. Of these patients, 30.1% of those with acute SRC (65.0% male, mean age 13.9 years) and 43.0% of those with PCS (41.9% male, mean age 15.4 years) met the criteria for VOD at initial consultation. Independent predictors of VOD at initial consultation included female sex, preinjury history of depression, posttraumatic amnesia, and presence of dizziness, blurred vision, or difficulty focusing at the time of injury. Independent predictors of PCS among patients with acute SRC included the presence of VOD at initial consultation, preinjury history of depression, and posttraumatic amnesia at the time of injury.

CONCLUSIONS This study identified important potential risk factors for the development of VOD following pediatric SRC. These results provide confirmatory evidence that VOD at initial consultation is associated with prolonged recovery and is an independent predictor for the development of PCS. Future studies examining clinical prediction rules in pediatric concussion should include VOD. Additional research is needed to elucidate the natural history of VOD following SRC and establish evidence-based indications for targeted vestibular rehabilitation.

PMID:   27689244

No 351: December 14, 2016

Pearce KL et al. Near Point of Convergence After a Sport-Related Concussion: Measurement Reliability and Relationship to Neurocognitive Impairment and Symptoms. Am J Sports Med. 2015 Dec;43(12):3055-61. doi: 10.1177/0363546515606430.

BACKGROUND: Convergence insufficiency (CI) is a common binocular vision deficit after a sport-related concussion (SRC). CI may result in visual discomfort and vision-mediated functional difficulties such as slowed reading and compromised attention, leading to impaired academic, work, and sport performance.

PURPOSE: To test the reliability of repeated near point of convergence (NPC) measurements in a sample of athletes after an SRC; compare the symptoms and cognitive impairment of athletes with normal NPC to those with CI after an SRC; and explore the relationship among age, sex, learning disability, migraine history, and CI.

STUDY DESIGN: Cross-sectional study; Level of evidence, 3.

METHODS: A total of 78 athletes (mean age, 14.31 ± 2.77 years) who were seen a mean 5.79 ± 5.63 days after an SRC were administered 3 trials of an NPC assessment, along with neurocognitive (Immediate Post-Concussion Assessment and Cognitive Testing [ImPACT]) and symptom assessments. Patients were divided into normal NPC (NPC ≤ 5 cm; n = 45) and CI (NPC >5 cm; n = 33) groups. Intraclass correlation coefficients (ICCs) and repeated-measures analyses of variance (ANOVAs) assessed the consistency of NPC across the 3 trials. The ANOVAs were employed to examine differences on neurocognitive composites and symptoms between the normal NPC and CI groups. Stepwise regressions (controlling for age and symptom scores on the Post-Concussion Symptom Scale [PCSS]) were conducted to evaluate the predictive utility of the NPC distance for neurocognitive impairment.

RESULTS: Groups did not differ on demographic or injury characteristics. NPC differed between trial 1 and trials 2 (P = .02) and 3 (P = .01) for the CI group but not the normal NPC group. Internal consistency was high across NPC measurements (ICC range, 0.95-0.98). Patients with CI performed worse on verbal memory (P = .02), visual motor speed (P = .02), and reaction time (P = .001, η(2) = .13) and had greater total symptom scores (P = .02) after the injury. Results of hierarchical regression revealed that the NPC distance contributed significantly to the model for reaction time (P < .001).

CONCLUSION: CI was common (~42%) in athletes evaluated within 1 month after an SRC. Athletes with CI had worse neurocognitive impairment and higher symptom scores than did those with normal NPC. Clinicians should consider routinely screening for NPC as part of a comprehensive concussion evaluation to help inform treatment recommendations, academic accommodations, and referrals for vision therapy.

PMID:  26453625

No 350: December 7, 2016

Ellis MJ, Cordingley D, Vis S, Reimer K, Leiter J, Russell K. Vestibulo-ocular dysfunction in pediatric sports-related concussion. J Neurosurg Pediatr. 2015 Sep;16(3):248-55. doi: 10.3171/2015.1.PEDS14524.

OBJECT: The objective of this study was 2-fold: 1) to examine the prevalence of vestibulo-ocular dysfunction (VOD) among children and adolescents with acute sports-related concussion (SRC) and postconcussion syndrome (PCS) who were referred to a multidisciplinary pediatric concussion program; and 2) to determine if VOD is associated with the development of PCS in this cohort.

METHODS: The authors conducted a retrospective review of all patients with acute SRC (presenting 30 days or less postinjury) and PCS (3 or more symptoms for at least 1 month) referred to a multidisciplinary pediatric concussion program between September 2013 and July 2014. Initial assessment included clinical history, physical examination, and Post-Concussion Symptom Scale assessment. Patients were also assessed for VOD, which was defined as more than one subjective vestibular and oculomotor complaint (dizziness, blurred vision, and so on) and more than one objective physical examination finding (abnormal smooth pursuits, saccades, vestibulo-ocular reflex, and so on). This study was approved by the local institutional ethics review board.

RESULTS: A total of 101 patients (mean age 14.2 years, SD 2.3 years; 63 male and 38 female patients) participated, including 77 (76.2%) with acute SRC and 24 (23.8%) with PCS. Twenty-two of the 77 patients (28.6%) with acute SRC and 15 of the 24 (62.5%) with PCS met the clinical criteria for VOD. The median duration of symptoms was 40 days (interquartile range [IQR] 28.5-54 days) for patients with acute SRC who had VOD compared with 21 days (IQR 13-32 days) for those without VOD (p = 0.0001). There was a statistically significant increase in the adjusted odds of developing PCS among patients with acute SRC who had VOD compared with those without VOD (adjusted OR 4.10; 95% CI 1.04-16.16).

CONCLUSIONS: Evidence of VOD was detected in a significant proportion of children and adolescents with acute SRC and PCS who were referred to a multidisciplinary pediatric concussion program. This clinical feature was a significant risk factor for the subsequent development of PCS in this pediatric acute SRC cohort.

PMID:  26031619

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