Diego Piatti [Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179, Rome, Italy]
Laura Casagrande Conti [Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179, Rome, Italy]
Gianluca Paolocci [Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179, Rome, Italy; Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98125, Messina, Italy]
Elena Bergamini [Department of Management, Information and Production Engineering, University of Bergamo, 24044, Dalmine, BG, Italy]
Leonardo Manzari [MSA ENT Academy Center, 03043, Cassino, Italy]
Giuseppe Attanasio [Head and Neck Department, Policlinico Umberto I, 00161 Rome, Italy]
Iole Indovina [[Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179, Rome, Italy; Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98125, Messina, Italy]
Marco Tramontano [Department of Biomedical and Neuromotor Sciences (DIBINEM), Alma Mater University of Bologna, 40138, Bologna, Italy; Unit of Occupational Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138, Bologna, Italy]
Persistent postural-perceptual dizziness (PPPD) is a chronic functional disorder characterised by persistent dizziness, instability and non-rotational vertigo, often induced by visual stimuli (1,2). While peripheral vestibular conditions are common triggers of PPPD, other conditions including vestibular migraine, vestibular disorders and mild traumatic brain injuries can also precipitate PPPD (3). The development of changes of gait in patients with PPPD following precipitating illnesses is poorly understood. The first aim of this study is to compare parameters of gait in patients with PPPD or subacute unilateral vestibulopathies (sAUVP) to healthy controls (HC). The second aim is to verify the correlation between gait parameters and Patients-Reported Outcome Measure in patients with PPPD.
This cross-sectional study involved 9 patients with PPPD, 10 patients with sAUVP and 11 HC. All participants completed the 10 Meters Walk Test (10MWT) and the Fukuda Stepping Test (FST). During these motor tasks participants were equipped with five inertial measurement units (IMUs) (128 Hz, Opal, APDM, Portland, OR, USA): three IMUs were located on the occipital cranium bone, near the lambdoid suture of the head, at the centre of the sternum, and at L4/L5 level, just above the pelvis, and were used to quantify parameters of stability (normalized Root Mean Square), symmetry (improved Harmonic Ratio), and smoothness (Log dimensionless jerk) of gait, while the other two were located slightly above lateral malleoli and used to perform stride and step segmentation. Parameters of gait were compared among groups and correlated with Dizziness Handicap Inventory scores for PPPD group.
During the 10MWT the stability index at pelvis level along the medio-lateral (ML) axis was significantly higher for PPPD and sAUVP patients than HC. Simmetry of gait was lower for PPPD patients compared to HC group. Instead, during the FST, the simmetry index along the ML axis was significantly lower in sAUVP patients compared to PPPD patients and HC group. Smoothness of gait was significantly lower along the cranio-caudal axis in both patients groups with respect to HC group. Positive correlations were found between the self-assessed severity of dizziness symptoms and postural stability along the antero-posterior axis at head level in patients with PPPD.
Patients with PPPD exhibit objective alterations, assessed through a sensor-based evaluation, of postural stability compared with HC. Remarkably, in the absence of visual information PPPD performed better than sAUVP patients concerning the gait symmetry, implying an altered visual sensitivity. Positive correlations were found between the self-assessed severity of dizziness symptom and normalized Root Mean Square at head level for PPPD patients, suggesting the combined use of Patient-Reported Outcome Measure and instrumental assessments in clinical practice. The observed differences between sAUVP and PPPD patients in maintaining postural stability enable rehabilitative professionals to consider new treatment paradigms, based on the necessity of patients with PPPD to overcome visual sensitivity.
