Functional positional eye and eyelid movements.

BACKGROUND: Positional manoeuvres are an important part of the neurological examination, particularly in patients with vertigo where the presence and characteristics of provoked nystagmus can help differentiate central from peripheral neurological disorders. METHODS: Case series of functional positional eye and eyelid movements. RESULTS: We report four patients with functional eye and eyelid movements provoked during positional manoeuvres. The range of abnormalities observed included positional convergence spasm, brief functional saccadic oscillations, and excessive positional blinking mimicking upbeat nystagmus. The functional movements described were present on a background of pre-existing peripheral or central nystagmus, or positional vertigo. CONCLUSION: Functional positional eye and eyelid movements may co-exist with organic nystagmus that renders an accurate interpretation of the manoeuvre more challenging. A thorough understanding of the clinical features that differentiate these two categories of eye/eyelid movements makes the analysis easier, thus preventing misdiagnosis and avoiding unnecessary investigations.

Practice Guidelines for the Diagnosis and Management of Benign Paroxysmal Positional Vertigo Otoneurology Committee of Spanish Otorhinolaryngology and Head and Neck Surgery Consensus Document. / Guía de Práctica Clínica Para el Diagnóstico y Tratamiento del Vértigo Posicional Paroxístico Benigno. Documento de Consenso de la Comisión de Otoneurología Sociedad Española de Otorrinolaringlogía y Cirugía de Cabeza y Cuello.

Benign Paroxysmal Positional Vertigo is the most frequent episodic vestibular disorder. The purpose of this guide, requested by the committee on otoneurology of the Spanish Society of Otolaryngology and Head and Neck Surgery, is to supply a consensus document providing practical guidance for the management of BPPV. It is based on the Barany Society criteria for the diagnosis of BPPV. This guideline provides recommendations on each variant of BPPV, with a description of the different diagnostic tests and the therapeutic manoeuvres. For this purpose, we have selected the tests and manoeuvres supported by evidence-based studies or extensive series. Finally, we have also included a chapter on differential diagnosis and a section relating to general aspects in the management of BPPV.

Spectrum analysis in postural strategy on static tests in a healthy population.

INTRODUCTION AND OBJECTIVES: The power spectral density can be used to find a hidden behaviour in a physical system. We studied postural behaviour in a healthy population, by means of power spectral density, and compared it with a situation of complete immobility. METHODS: A group of healthy volunteers carried out the modified Clinical Test for Sensory Interaction in Balance. A fibre optic gyroscope device was used to record the data. We compared the power spectral density in these tests and with another recording where the device was motionless. We looked for significant differences using the ANOVA test. RESULTS: A power peak appeared at 8.4 Hz in all static tests. The static group showed significant differences with all the other tests. We found no statistically significant differences when visual input discriminated between 2 tests. There were statistically significant differences for the proprioceptive input. CONCLUSIONS: Brief movements are needed to maintain the quiet stance. The distinctive feature of these movements is a fundamental frequency at 1.4 Hz and a harmonic frequency at 8.4 Hz. Proprioceptive input is essential for balance.

[Peripheral vertigo classification of the Otoneurology Committee of the Spanish Otorhinolaryngology Society: diagnostic agreement and update (version 2-2011)]. / Clasificación de los vértigos periféricos de la Comisión de Otoneurología de la Sociedad Española de Otorrinolaringología: concordancia diagnóstica y actualización (versión 2, año 2011).

INTRODUCTION: In 2008, the Otoneurology committee of the SEORL-PCF published a classification of peripheral vertigo, based on clinical criteria. The objective of this study was to validate this classification through analysing the diagnostic agreement among several medical assessors. METHODS: Seven medical assessors, all with clinical experience, from 6 different hospitals, participated in the study. One of them selected the clinical histories of 50 consecutive patients who had consulted as a result of balance disorders (24 men and 26 women) with an average age of 53.5 years. These clinical histories -without any information that would identify the patient, the diagnosis established and the treatment- were sent to another 6 assessors. Each of these investigators established their own diagnosis, trying to adjust it to the epigraphs of the classification. RESULTS: Of the 50 patients, there was substantial agreement as to the diagnosis (4 or more evaluators indicated the same one) in 31 cases (26 with a positive diagnosis and 5 with a negative one, which could not be included in any epigraph). The kappa index, which measures the level of accordance between 2 or more assessors, was 0.4198 (moderate level of agreement). Unanimity was achieved in only 7 cases (4 BPPV, 2 Ménière's disease and 1 vertigo associated with migraine). CONCLUSIONS: The current classification, with the criteria it includes, allows labelling with an acceptable consensus to only 62% of the patients. Therefore, a modification in the classification is proposed in relation with the probable BPPV epigraph, as well a revision of the entries for vertigo-migraine and vertigo associated with migraine.

Ocular counterrolling: an indicator of bilateral vestibulopathy.

The ocular counterrolling can be static or dynamic. The purpose of this work is to connect the clinical absence of dynamic ocular counterrolling with bilateral caloric paresis. A prospective study on 216 patients in whom the absence of dynamic ocular counterrolling was tested and standard caloric test was performed. The cut-off value for bilateral caloric paresis is an absolute reflectivity of 10 in nystagmic frequency and 8 in slow phase velocity. The adequate contingency tables were constructed and tests of Chi-squared calculated. Sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, and area under receiver operating characteristic (ROC) curve were also calculated. Using the reflectivity according to the nystagmic frequency, we obtained P = 0.000 for Chi-squared, area under ROC curve was 0.832 and positive likelihood ratio 11.47. For slow-phase velocity, the results were P = 0.000, area ROC of 0.735 and positive likelihood ratio 9.43. There is a statistically significant connection between the clinical absence of dynamic ocular counterrolling and bilateral caloric paresis, with a strong diagnostic power. The mechanisms by which this phenomenon can be attributed to canalicular damage instead of otolithic damage are discussed.

[Production of a virtual system to simulate nystagmus and ocular movements]. / Elaboración de un sistema virtual de simulación de nistagmos y movimientos oculares.

OBJECTIVE: To describe a realistic and interactive system to simulate nystagmus and other ocular movements for teaching and professional speaking. MATERIAL AND METHOD: We obtained the base images by means of digital video, then edited and integrated them into a commercial animation computer program. RESULTS: The "nistagmoteca virtual", available free at the web address indicated. CONCLUSIONS: The technique described is valid to simulate any ocular movement except torsional ones.