Spontaneous visual exploration during locomotion in patients with phobic postural vertigo

Background Earlier studies on stance and gait with posturographic and EMG-recordings and automatic gait analysis in patients with phobic postural vertigo (PPV) or visual height intolerance (vHI) revealed similar patterns of body stiffening with muscle co-contraction and a slow, cautious gait. Visual exploration in vHI patients was characterized by a freezing of gaze-in-space when standing and reduced horizontal eye and head movements during locomotion. Objective Based on the findings in vHI patients, the current study was performed with a focus on visual control of locomotion in patients with PPV while walking along a crowded hospital hallway. Methods Twelve patients with PPV and eleven controls were recruited. Participants wore a mobile infrared video eye-tracking system that continuously measured eye-in-head movements in the horizontal and vertical planes and head orientation and motion in the yaw, pitch, and roll planes. Visual exploration behavior of participants was recorded at the individually preferred speed for a total walking distance of 200 m. Gaze-in-space directions were determined by combining eye-in-head and head-in-space orientation. Walking speeds were calculated based on the trial duration and the total distance traversed. Participants were asked to rate their feelings of discomfort during the walk on a 4-point numeric rating scale. The examiners rated the crowdedness of the hospital hallway on a 4-point numeric rating scale. Results The major results of visual exploration behavior in patients with PPV in comparison to healthy controls were: eye and head positions were directed more downward in the vertical plane towards the ground ahead with increased frequency of large amplitude vertical orientation movements towards the destination, the end of the ground straight ahead. The self-adjusted speed of locomotion was significantly lower in PPV. Particularly those patients that reported high levels of discomfort exhibited a specific visual exploration of their horizontal surroundings. The durations of fixating targets in the visual surroundings were significantly shorter as compared to controls. Conclusion Gaze control of locomotion in patients with PPV is characterized by a preferred deviation of gaze more downward and by horizontal explorations for suitable auxiliary means for potential postural support in order to prevent impending falls. These eye movements have shorter durations of fixation as compared to healthy controls and patients with vHI. Finally, the pathological alterations in eye–head coordination during locomotion correlate with a higher level of discomfort and anxiety about falling.

O Benefício da Terapia Cognitivo- Comportamental na Tontura Persistente Postural-Paroxística

INTRODUÇÃO: A tontura persistente postural-paroxística é uma entidade recentemente reconhecida, que engloba cerca de 10% dos doentes com queixas de tontura. O seu tratamento passa pela terapêutica farmacológica com inibidores seletivos da recaptação da serotonina, associada ou não a um programa de reabilitação vestibular. Tendo em conta a difícil gestão destes doentes e resistência ao tratamento convencional, coloca-se a hipótese do uso da terapia cognitivo-comportamental no tratamento desta patologia. O objetivo deste trabalho é determinar se existe benefício da terapia cognitivo-comportamental no tratamento da tontura persistente postural-paroxística.METODOLOGIA: Foi realizada uma pesquisa usando as palavras-chave “persistent postural perceptual dizziness”, “cognitive behavioural therapy”, “phobic postural vertigo”, nas seguintes bases de dados: National Guideline Clearinghouse, Canadian Medical Association Practice Guidelines InfoBase, DARE - Database of abstracts of reviews of effectiveness, Evidence-Based Medicine e PubMed. Foram ainda incluídos artigos referenciados na bibliografia da pesquisa inicial.RESULTADOS: Foram selecionados três artigos nas bases de dados. Foram incluídos dois artigos adicionais referenciados na bibliografia inicial. No total foram incluídos cinco artigos: dois estudos caso-controlo e três revisões de literatura.DISCUSSÃO: É consistente o benefício da terapia cognitivo-comportamental como parte de uma abordagem multidisciplinar. Foram reportadas, nestes doentes, melhoria das queixas de tontura, ansiedade e depressão. Verificou-se ainda melhoria do controlo postural e diminuição da dose de medicação necessária. Os efeitos da terapia cognitivo-comportamental a longo prazo são ainda pouco consistentes.CONCLUSÃO: A terapia cognitivo-comportamental parece ser uma opção terapêutica válida, em associação com outras medidas. Destaca-se a escassez de evidência científica nesta área, e a necessidade de estudos adicionais.