Magdalena Krbot Skorić

Auditory evoked potentials and vestibular evoked myogenic potentials in evaluation of brainstem lesions in multiple sclerosis

OBJECTIVE The aim of this study was to determine the roles of magnetic resonance imaging (MRI), auditory evoked potentials (AEP) and vestibular evoked myogenic potentials (VEMP) in the evaluation of brainstem involvement in multiple sclerosis (MS). PATIENTS AND METHODS Altogether 32 patients with the diagnosis of MS participated in the study. The following data was collected from all patients: age, gender, Expanded Disability Status Scale (EDSS) score, brainstem functional system score (BSFS) (part of the EDSS evaluating brainstem symptomatology), and involvement of the brainstem on the brain MRI. AEP and ocular VEMP (oVEMP) and cervical VEMP (cVEMP) were studied in all patients. RESULTS BSFS, MRI, AEP, oVEMP and cVEMP involvement of the brainstem was evident in 9 (28.1%), 14 (43.8%), 7 (21.9%), 12 (37.5%) and 10 (31.0%) patients, respectively. None of the tests used showed statistically significant advantage in the detection of brainstem lesions. When combining oVEMP and cVEMP 18 (56.3%) patients showed brainstem involvement. This combination showed brainstem involvement in greater percentage than BSFS or AEP, with statistical significance (p=0.035 and p=0.007, respectively). CONCLUSION VEMP is a reliable method in detection of brainstem involvement in MS. It is comparable with MRI, but superior to clinical examination or AEP.

Autonomic dysfunction in clinically isolated syndrome suggestive of multiple sclerosis

OBJECTIVES The aim of this study was to determine the extent of autonomic dysfunction in patients with clinically isolated syndrome (CIS) by using a standardized battery of autonomic tests in the form of the Composite Autonomic Scoring Scale (CASS). METHODS This was a prospective, cross sectional study which included 24 consecutive patients who were diagnosed with CIS and 17 healthy controls. In all participants, heart rate and blood pressure responses to the Valsalva maneuver, heart rate response to deep breathing and blood pressure response to passive tilt were performed. In 16 patients, Quantitative Sudomotor Axon Reflex Test (QSART) and catecholamine measurement was performed. RESULTS The proportion of CIS patients with pathological adrenergic index was statistically significantly higher compared to healthy controls (12 vs 2, p=0.018), while there was no difference in cardiovagal index between groups. Five patients had a sudomotor index of 1 (in 4 there was hypohydrosis <50% and in 1 persistent foot hyperhidrosis). When combining adrenergic, cardiovagal and sudomotor index into CASS, 8 patients (50%) had evidence of autonomic dysfunction, 7 mild and one moderate. CONCLUSION Sympathetic nervous system is frequently affected in CIS patients. SIGNIFICANCE CASS is able to detect autonomic nervous system dysfunction in CIS patients.

Predictors of development of chronic vestibular insufficiency after vestibular neuritis

OBJECTIVES To evaluate the role of clinical parameters, MRI and ocular VEMP (oVEMP) and cervical VEMP (cVEMP) as predictors of development of chronic vestibular insufficiency after vestibular neuritis. METHODS Twenty-six patients with vestibular neuritis were included: 15 patients (58%) showed complete clinical recovery, and 11 patients (41%) were diagnosed with the syndrome of chronic vestibular insufficiency. Clinical parameters (vomiting, nystagmus, postural stability, and nausea) were assessed at diagnosis. MRI was performed within 3 months and VEMP within 6 days and at 1 year after the initial presentation. The amplitude asymmetry ratio (AR) was calculated using the following formula: AR=((healthy side-affected side)/(healthy side+affected side) × 100). RESULTS Of all studied parameters, only chronic white matter supratentorial lesions present on brain MRI negatively correlated with clinical recovery (Phi coefficient=-0.637, p=0.001). The logistic regression analysis showed that positive brain MRI and older age reduced odds for clinical recovery. There was no correlation between clinical recovery and oVEMP AR recovery between groups (p=0.781). Seven patients showed improvement, and 19 showed worsening on oVEMP AR after a 1-year follow-up. Statistical regression model for predicting the outcome of clinical recovery using asymmetry score recovery, as an independent variable, was not statistically significant. CONCLUSIONS Older age and chronic white matter lesions on brain MRI are positive predictors of development of chronic vestibular insufficiency after vestibular neuritis. VEMPs are not useful in predicting the development of chronic vestibular insufficiency.

The Role of Cervical and Ocular Vestibular- Evoked Myogenic Potentials in the Follow-Up of Vestibular Neuritis

This study evaluates the recovery of vestibular nerve function after vestibular neuritis (VN) by vestibular-evoked myogenic potentials (VEMPs). Twenty-six patients with the diagnosis of VN were included. All patients underwent ocular VEMP (oVEMP) and cervical VEMP (cVEMP) recordings, at 6 days and 6 months from the onset of the symptoms. Of the 26 patients, 14 showed improvement on oVEMP at month 6 (group 1), and 12 showed no change or worsening on oVEMP at 6 months (group 2). At the same time, there was no change in the amplitudes of the cVEMP on either healthy or affected sides in both groups. Inability to perform the Fukuda test, and chronic white matter supratentorial lesions present on brain magnetic resonance imaging (MRI) were more frequent in patients with worse outcome on oVEMP (P = 0.044 and 0.045, respectively). Although involvement of the inferior branch of the vestibular nerve was not associated with oVEMP outcome, oVEMP latencies (N10 and P13) were associated with improvement or worsening in oVEMP amplitudes, showing that prolonged latencies correlate with 6-month improvement in oVEMP amplitudes (Pearson correlation −0.472, P = 0.041 and −0.580, P = 0.009, respectively). This study identified clinical, MRI and neurophysiological predictors of recovery in patients with superior VN, and offers additional insight into, and better understanding of, the role of VEMP in diagnosis and prognosis of patients with VN. Further studies are needed to validate this diagnostic procedure and to assess its clinical usefulness in VN management.

Electroencephalographic Response to Different Odors in Healthy Individuals: A Promising Tool for Objective Assessment of Olfactory Disorders.

The aim of the present study was to examine human central nervous system response to three different odors. Electrophysiological activity was recorded in the baseline state and for 3 odors, lemon, peppermint, and vanilla, in 16 healthy participants. Electrodes were separated into groups according to the spatial position on the head. Fast Fourier transformation was performed on every set, and mean value of activity in theta was exported. As theta showed statistically significant results, further analysis was based only on the theta frequency band. On electrodes FP1, F3, Fz, F4, F8, T7, C3, Cz, C4, T8, TP9, CP5, CP1, CP2, CP6, P7, P3, Pz, P4, P8, PO9, and PO10 there was statistically significant difference in the electrical activity of the brain between four conditions. For peppermint and lemon, there was statistically significant difference in activity between different regions—F(1.576, 23.637) = 16.030, P = .000 and F(1.362, 20.425) = 4.54, P = .035, respectively—where the activity in the central area was significantly reduced compared with the activity in the other 4 areas and in the left and right anterior and left posterior area, respectively. There was no statistically significant difference for vanilla between specific areas, F(1.217, 18.257) = 1.155, P = .309. The results indicate that olfactory stimuli can affect the frequency characteristics of the electrical activity of the brain.

Evaluation of Brainstem Involvement in Multiple Sclerosis

BACKGROUND/AIMS the aim of the present study was to determine the optimum method to detect brainstem lesions in patients with Multiple Sclerosis (MS). METHODS 72 patients with the diagnosis of relapsing-remitting MS were prospectively included. brainstem functional system score (bSfS) (part of the expanded disability status scale (edSS) evaluating brainstem symptomatology) was calculated. Magnetic resonance imaging (Mri) was performed on 1.5t and t1, t2, pd and fluid-attenuated inversion recovery (flair) sequences were analyzed for presence of brainstem lesions. auditory evoked potentials (aep) and ocular and cervical vestibular evoked myogenic potentials (oVeMp and cVeMp) were performed according to the standardized protocol. RESULTS from 72 patients, 18 (25%) had clinical involvement of the brainstem. Mri showed brainstem involvement in 29 (40%) patients. of the neurophysiological tests, aep showed pathological result in 16 (22%) patients, oVeMp in 36 (50%) patients, cVeMp in 18 (25%) patients, and VeMp (combination of oVeMp and cVeMp) in 45 (63%) patients. VeMp detected brainstem lesions in higher percentage than clinical examination, Mri and aep, which was statistically significant (< 0.0001, 0.012 and < 0.0001, respectively). CONCLUSIONS results of the present study have shown that VeMps are the optimal method to detect brainstem lesions in multiple sclerosis and that they detect them significantly better than clinical examination, aep or Mri.

Postural Orthostatic Tachycardia Predicts Early Conversion to Multiple Sclerosis after Clinically Isolated Syndrome

Background/Aims: There have been suggestions that interactions exist between the autonomic nervous system (ANS) and the immune system functions in multiple sclerosis (MS). We aimed to evaluate the ANS dysfunction, more specifically postural orthostatic tachycardia syndrome (POTS), as a possible predictor of conversion to MS in patients with clinically isolated syndrome (CIS). Methods: In this observational, prospective, longitudinal study, 84 patients were enrolled (56 females, mean age 32.9 ± 8.9 years). Disease activity during a 6-month period was monitored (relapses and/or MRI disease activity indicated by new T2 or T1 enhancing lesions), and the following predictors analyzed: age, Expanded Disability Status Scale, MRI midbrain, pontine or medulla oblongata lesions, and POTS on the head up tilt test. Results: POTS was identified in 8 (9.5%) patients. Of 84 patients, 62 (73.8%) completed the 6-month follow-up, and 28 (45.2%) patients converted to MS. Results of the multivariate regression analysis revealed age (10-year increase) and POTS as significant predictors of early conversion to MS (OR 2.34, 95% CI 1.15-4.78, p = 0.019 and OR 12.40, 95% CI 1.13-136.62, p = 0.040). The logistic model was statistically significant, χ2 (6) = 13.885, p = 0.031. Conclusion: POTS may be an indicator of a more active disease course in CIS patients and possibly be used as a prognostic factor.

Tongue Somatosensory-Evoked Potentials Evaluation of the Afferent Trigeminal Pathway in Patients With Early Multiple Sclerosis

The aim of this study was to determine the efficacy of tongue somatosensory-evoked potentials (tSSEPs) in evaluation of afferent trigeminal pathway in patients with early multiple sclerosis (MS). The tSSEP was performed on 10 healthy volunteers and 10 patients with the first symptom of MS. Data were compared between the groups, and tSSEP findings of patients with MS were correlated with clinical and magnetic resonance imaging (MRI) data. Among 10 patients, 2 (20%) had clinically evident involvement of the brainstem, 5 (50%) had brainstem lesions on brain MRI, while 9 (90%) had prolonged latencies on tSSEP. Of the 8 patients with no clinical evidence of brainstem pathology, 7 (88%) had prolonged latencies/conduction block on tSSEP. Patients had statistically significant prolongation of N1, P1, and N2 latencies for stimulation of the right side and N2 latency for stimulation of the left side compared to healthy controls. The tSSEP is an efficient method for evaluating the afferent trigeminal pathway in patients with early MS. This study provides evidence that lesions of the afferent trigeminal pathway are more frequently found by tSSEP than by clinical examination or MRI.

Progressive multiple sclerosis patients have a higher burden of autonomic dysfunction compared to relapsing remitting phenotype

OBJECTIVE To determine autonomic dysfunction (AD) differences in patients with relapsing remitting multiple sclerosis (pwRRMS) and progressive MS (pwPMS). METHODS Composite autonomic scoring scale (CASS) and heart rate variability (HRV) were performed in 40 pwRRMS and 30 pwPMS. RESULTS pwPMS had a significantly higher sudomotor index and total CASS score compared to pwRRMS (p < 0.001 and p < 0.001, respectively). Disease duration positively correlated with sudomotor index and total CASS (rs = 0.409, p < 0.001 and rs = 0.472, p < 0.001, respectively), while the Expanded Disability Status Scale (EDSS) positively correlated with sudomotor index and total CASS (rs = 0.411, p < 0.001 and rs = 0.402, p = 0.001, respectively) in all patients. Type of multiple sclerosis (pwRRMS or pwPMS) corrected for age, sex and disease duration, was a statistically significant predictor of CASS value (B = 1.215, p = 0.019). Compared to pwRRMS, pwPMS had a significantly lower standard deviation of NN intervals (SDNN), low frequency (LF), and high frequency (HF), during both the supine and tilt-up phases (all p-values <0.006). pwPMS had a significantly lower LF/HF (p = 0.008) during tilt-up. CONCLUSION There is a significant difference in autonomic function in pwRRMS and pwPMS; with pwPMS having a higher burden of AD, which is particularly evident for sweating dysfunction. SIGNIFICANCE Further research is needed to establish whether parasympathetic and sudomotor dysfunction may serve as markers of progressive MS.

Vestibular evoked myogenic potentials and MRI in early multiple sclerosis: Validation of the VEMP score

BACKGROUND To validate the VEMP score as a measure of brainstem dysfunction in patients with the first symptom of multiple sclerosis (MS) (clinically isolated syndrome (CIS)) and to investigate the correlation between VEMP and brainstem MRI results. METHODS 121 consecutive CIS patients were enrolled and brainstem functional system score (BSFS) was determined. Ocular VEMP (oVEMP) and cervical VEMP (cVEMP) were analyzed for latencies, conduction block and amplitude asymmetry ratio and the VEMP score was calculated. MRI was analyzed for the presence of brainstem lesions as a whole and separately for the presence of pontine, midbrain and medulla oblongata lesions. RESULTS Patients with signs of brainstem involvement during the neurological examination (with BSFS ≥1) had a higher oVEMP score compared to patients with no signs of brainstem involvement. A binary logistic regression model showed that patients with brainstem lesion on the MRI are 6.780 times more likely to have BSFS ≥1 (p=0.001); and also, a higher VEMP score is associated with BSFS ≥1 (p=0.042). Furthermore, significant correlations were found between clinical brainstem involvement and brainstem and pontine MRI lesions, and prolonged latencies and/or absent VEMP responses. CONCLUSIONS The VEMP score is a valuable tool in evaluation of brainstem involvement in patients with early MS.