Sofía Santos-Pérez

Vibrotactile neurofeedback balance training in patients with Parkinson's disease: Reducing the number of falls

The aim of this study was to assess effectiveness of balance training with a vibrotactile neurofeedback system in improving overall stability in patients with Parkinsons disease (PD). Ten patients diagnosed with idiopathic PD were included. Individualization of the rehabilitation program started with a body sway analysis of stance and gait tasks (Standard Balance Deficit Test, SBDT) by using the diagnostic tool of the applied device (Vertiguard(®)-RT). Those tasks with the poorest outcome as related to age- and gender-related controls were included in the training program (not more than six tasks). Improvement of postural stability was assessed by performing SBDT, Sensory Organization Test (SOT) of Computerized Dynamic Posturography (CDP), Dizziness Handicap Inventory (DHI), activity-specific balance confidence scale and recording the number of falls over the past three months. Furthermore, scores of SOT and DHI of 10 PD patients previously trained in an earlier study (by using CDP) were compared with results of those in the present study. After neurofeedback training (NFT), there was a statistically significant improvement in body sway (calculated over all training tasks), number of falls, and scores of SOT, DHI and ABC. In comparison with CDP-training, a statistically significant higher increase of SOT score was observed for patients after NFT with the Vertiguard-RT device compared to CDP training. Our results showed that a free-field vibrotactile NFT with Vertiguard(®)-RT device can improve balance in PD patients in everyday life conditions very effectively, which might led in turn to a reduction of falls.

Vestibular rehabilitation with computerised dynamic posturography in patients with Parkinson's disease: Improving balance impairment

Purpose. In patients with Parkinsons disease (PD), balance impairment involves considerable morbi-mortality from the numerous falls that may result. In an earlier postural study, we detected that a deteriorated processing of vestibular input is implicated. The aim of the present study is to assess the effectiveness of vestibular rehabilitation in improving overall stability in patients with PD. Method. Out of an initial group of 45 patients with PD, we chose those presenting a high risk of falls, based on their score on the timed up and go test (TUG). Rehabilitation was performed on 10 patients using computerised dynamic posturography (CDP). Improvement was assessed using the dizziness handicap inventory (DHI), the TUG and the CDP. Results. We found statistically significant improvement in the sensorial organisation test (SOT) and the limits of stability and rhythmic weight shift tests measured by the CDP, the DHI and the TUG. These improvements continue to be statistically significant 1 year post-treatment. Conclusion. Vestibular rehabilitation in PD has shown to be effective in improving the activities of daily life, gait velocity and balance, as well as in reducing the risk of falls. Moreover, these benefits persist over time.

HLA-DRB1*1101 allele may be associated with bilateral Méniére's disease in southern European population.

Objective: To analyze the associations of HLA-DRB1* and DQB1* Class II alleles in patients with bilateral Méniéres disease (MD). Patients and Methods: Eighty patients from two ethnically defined groups with definite bilateral MD, according to the diagnostic scale of the American Academy of Otolaryngology-Head and Neck Surgery, were compared with normal controls from the same origin in a prospective multicenter study. We performed an allele-specific amplification for HLA-DRB1* and DQB1* genes of the major histocompatibility complex. Results: The allele HLA-DRB1*1101 was associated with bilateral MD in the Mediterranean population (odds ratio, 3.65 [95% confidence intervals, 1.5-9.1], corrected p = 0.029); however, this allele was not associated in the group from Galicia (northwest of Spain). No differences were found in the distribution of alleles for the gene HLA-DQB1* between patients and controls. Conclusion: The allele HLA-DRB1*1101 and the allelic group HLA-DRB1*11 may determine an increased susceptibility to develop bilateral MD in a southern European population.

What is the most effective vestibular rehabilitation technique in patients with unilateral peripheral vestibular disorders

Vestibular rehabilitation has been found to be effective and safe in patients with instability. There is insufficient evidence, however, for distinguishing between the efficacies of different rehabilitation techniques. The objective of this study is to verify whether there are differences between two instrumental vestibular rehabilitation techniques, computerised dynamic posturography (CDP) and optokinetic stimulation (OKN), in order to establish the optimal strategy for each patient. We conducted a prospective, comparative study of the two techniques (CDP and OKN) in patients with instability due to chronic unilateral peripheral vestibular disorder. We randomly included 12 patients in each group, performing the evaluation with the Dizziness Handicap Inventory and the CDP with the sensorial organisation test (SOT), rhythmic weight shift and limits of stability (LOS). We found a statistically significant improvement in both groups in average balance score according to the SOT. In the OKN group, however, improvement was greater in visual preference. The CDP group showed greater benefits in the visual and vestibular input and LOS. Patients with poor vestibular and visual input or with reduced LOS will benefit more from an exercise protocol with CDP. Patients with poor visual preference, however, are ideal candidates for rehabilitation with OKN.

A novel missense variant in PRKCB segregates low-frequency hearing loss in an autosomal dominant family with Meniere’s disease

Menieres Disease (MD) is a complex disorder associated with an accumulation of endolymph in the membranous labyrinth in the inner ear. It is characterized by recurrent attacks of spontaneous vertigo associated with sensorineural hearing loss (SNHL) and tinnitus. The SNHL usually starts at low and medium frequencies with a variable progression to high frequencies. We identified a novel missense variant in the PRKCB gene in a Spanish family with MD segregating low-to-middle frequency SNHL. Confocal imaging showed strong PKCB II protein labelling in non-sensory cells, the tectal cells and inner border cells of the rat organ of Corti with a tonotopic expression gradient. The PKCB II signal was more pronounced in the apical turn of the cochlea when compared with the middle and basal turns. It was also much higher in cochlear tissue than in vestibular tissue. Taken together, our findings identify PRKCB gene as a novel candidate gene for familial MD and its expression gradient in supporting cells of the organ of Corti deserves attention, given the role of supporting cells in K+ recycling within the endolymph, and its apical turn location may explain the onset of hearing loss at low frequencies in MD.

Clinical Subgroups in Bilateral Meniere Disease

Meniere disease (MD) is a heterogeneous clinical condition characterized by sensorineural hearing loss, episodic vestibular symptoms, and tinnitus associated with several comorbidities, such as migraine or autoimmune disorders (AD). The frequency of bilateral involvement may range from 5 to 50%, and it depends on the duration of the disease. We have performed a two-step cluster analysis in 398 patients with bilateral MD (BMD) to identify the best predictors to define clinical subgroups with a potential different etiology to improve the phenotyping of BMD and to develop new treatments. We have defined five clinical variants in BMD. Group 1 is the most frequently found, includes 46% of patients, and is defined by metachronic hearing loss without migraine and without AD. Group 2 is found in 17% of patients, and it is defined by synchronic hearing loss without migraine or AD. Group 3, with 13% of patients, is characterized by familial MD, while group 4, that includes 12% of patients, is associated by the presence of migraine in all cases. Group 5 is found in 11% of patients and is defined by AD. This approach can be helpful in selecting patients for genetic and clinical research. However, further studies will be required to improve the phenotyping in these clinical variants for a better understanding of the diverse etiological factors contributing to BMD.

Can we predict the risk of falls in elderly patients with instability

OBJECTIVE The aim of this study is to determine whether clinical and instrumental examination of balance can predict the risk of falls in elderly patients with instability. METHODS STUDY DESIGN It is a case control study, with cases defined by falls in the last year, developed in a third level university hospital. PATIENTS Seventy patients aged 65 years or more who met at least one of the following inclusion criteria: (a) at least one fall in the last year; (b) spend more than 15s during the timed up and go test (TUG); (c) a score of less than 68% average balance in the sensory organisation test (SOT) of the computerised dynamic posturography (CDP); or (d) at least one fall in the CDP-SOT. INTERVENTION TUG test, CDP-SOT, CDP centre of gravity balancing (CG) and limits of stability (LOS), Dizziness Handicap Inventory (DHI) test and short FES-I test. MAIN OUTCOME MEASURES Number of steps and time (TUG), average balance and use of sensorial information (CDP-SOT), speed and directional control (CDP-CG and LOS), DHI score and short FES-I score. RESULTS Comparing subjects without falls (non-fallers) vs subjects with at least one fall (fallers) in the last year, fallers obtain worse scores than non-fallers in condition 2 (p=0.043) and use of somatosensory information (p=0.039). Comparing subjects with five falls or less (non-multiple-fallers) vs subjects with more than five falls (multiple-fallers), multiple-fallers obtain worse scores than non-multiple-fallers in overall balance (p=0.023), condition 6 (p=0.036), directional control (swaying (p=0.006) and LOS (p=0.023)) and short FES-I score (p=0.007). CONCLUSION The three most useful parameters for identifying unstable elderly patients at particularly high risk of repeated falls are mean balance in the CDP SOT, directional control of CDP LOS and short FES-I score.

Intronic variants in the NFKB1 gene may influence hearing forecast in patients with unilateral sensorineural hearing loss in Meniere's disease.

Menieres disease is an episodic vestibular syndrome associated with sensorineural hearing loss (SNHL) and tinnitus. Patients with MD have an elevated prevalence of several autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus, ankylosing spondylitis and psoriasis), which suggests a shared autoimmune background. Functional variants of several genes involved in the NF-κB pathway, such as REL, TNFAIP3, NFKB1 and TNIP1, have been associated with two or more immune-mediated diseases and allelic variations in the TLR10 gene may influence bilateral affectation and clinical course in MD. We have genotyped 716 cases of MD and 1628 controls by using the ImmunoChip, a high-density genotyping array containing 186 autoimmune loci, to explore the association of immune system related-loci with sporadic MD. Although no single nucleotide polymorphism (SNP) reached a genome-wide significant association (p<10−8), we selected allelic variants in the NF-kB pathway for further analyses to evaluate the impact of these SNPs in the clinical outcome of MD in our cohort. None of the selected SNPs increased susceptibility for MD in patients with uni or bilateral SNHL. However, two potential regulatory variants in the NFKB1 gene (rs3774937 and rs4648011) were associated with a faster hearing loss progression in patients with unilateral SNHL. So, individuals with unilateral MD carrying the C allele in rs3774937 or G allele in rs4648011 had a shorter mean time to reach hearing stage 3 (>40 dB HL) (log-rank test, corrected p values were p = 0.009 for rs3774937 and p = 0.003 for rs4648011, respectively). No variants influenced hearing in bilateral MD. Our data support that the allelic variants rs3774937 and rs4648011 can modify hearing outcome in patients with MD and unilateral SNHL.

Can we predict the efficacy of the semont maneuver in the treatment of benign paroxysmal positional vertigo of the posterior semicircular canal

Objective: To establish success- or failure-predicting factors in Semont maneuver in the treatment of benign paroxysmal positional vertigo. Study Design: Prospective study. Setting: Referral center, institutional practice, ambulatory care (outpatient clinic). Patients: A consecutive sample of 135 patients diagnosed with unilateral benign paroxysmal positional vertigo of posterior semicircular canal for 3 years (September 2007 to August 2010). Intervention: Semont maneuver. Main Outcome Measures: Duration of the latency period and nystagmus status with the Dix-Hallpike test. Presence or absence of orthotropic nystagmus in the second position of the Semont maneuver. Effectiveness of the Semont maneuver (cure versus no cure). Results: The Semont maneuver is effective in 73% of the patients. Orthotropic nystagmus was present in 67% of the cases and absent in 33%; when we found orthotropic nystagmus, the maneuver was effective in 81% of the patients, but only in 57% if this nystagmus was not present (Fishers exact test, p = 0.004; odds ratio, 3.308; 95% confidence interval, 1.492-7.334). The maneuvers efficacy and the presence of orthotropic nystagmus were not affected by the duration of nystagmus status in the Dix-Hallpike test. The duration of the latency period had no effect on the maneuvers efficacy, but it did affect the appearance of orthotropic nystagmus (Mann-Whitney test, p = 0.016). Conclusion: The presence of orthotropic nystagmus in the second position of the Semont maneuver indicates a good prognosis, but its absence does not necessarily mean that the maneuver will fail. Orthotropic nystagmus is more common in patients with shorter latency periods, suggesting that its appearance is related to cupulolithiasis mechanisms.

Extended phenotype and clinical subgroups in unilateral Meniere disease: A cross-sectional study with cluster analysis

To define clinical subgroups by cluster analysis in patients with unilateral Meniere disease (MD) and to compare them with the clinical subgroups found in bilateral MD.