The interrelationship between disease severity, dynamic stability, and falls in cerebellar ataxia

Abstract

Cerebellar ataxia (CA) results in discoordination of body movements (ataxia), a gait disorder, and falls. All three aspects appear to be obviously interrelated; however, experimental evidence is sparse. This study systematically correlated the clinical rating of the severity of ataxia with dynamic stability measures and the fall frequency in patients with CA. Clinical severity of CA in patients with sporadic (n = 34) and hereditary (n = 24) forms was assessed with the Scale for the Assessment and Rating of Ataxia (SARA). Gait performance was examined during slow, preferred, and maximally fast walking speeds. Spatiotemporal variability parameters in the fore-aft and medio-lateral directions were analyzed. The fall frequency was assessed using a standardized interview about fall events within the last 6 months. Fore-aft gait variability showed significant speed-dependent characteristics with highest magnitudes during slow and fast walking. The SARA score correlated positively with fore-aft gait variability, most prominently during fast walking. The fall frequency was significantly associated to fore-aft gait variability during slow walking. Severity of ataxia, dynamic stability, and the occurrence of falls were interrelated in a speed-dependent manner: (a) Severity of ataxia symptoms was closely related to instability during fast walking. (b) Fall frequency was associated with instability during slow walking. These findings suggest the presence of a speed-dependent, twofold cerebellar locomotor control. Assessment of gait performance during non-preferred, slow and fast walking speeds provides novel insights into the pathophysiology of cerebellar locomotor control and may become a useful approach in the clinical evaluation of patients with CA.

Wearable gait sensors to measure ataxia due to spinocerebellar degeneration

“…Summing up, both a greater step‐width variability (frontal view: wide‐based, lateral staggering gait) and a shorter step (lateral view), both of which could easily lead to falls, were relevant to SARA gait abnormalities in our cerebellar ataxia patients. This notion seems to be in accordance with a recent study showing that the occurrence of falls was associated with instability (fore–aft gait variability) during slow walking and the SARA score …”

“…This notion seems to be in accordance with a recent study showing that the occurrence of falls was associated with instability (fore-aft gait variability) during slow walking and the SARA score. 15 Limitations of this study include a small number of patients, nonuniform disease types, and a lack of controls. The decreased gait velocity, decreased symmetricity, changes in step/stride length, and increased variability of width with increased energy consumption are mostly nonspecific changes in patients with gait disorders in general that have been proved in different clinical disorders and indeed, in degenerative cerebellar ataxia.…”

Quantitative assessment of postural instability in spinocerebellar ataxia type 3 patients

“…7,8 Postural and balance instability are commonly regarded as contributing factors to ambulatory dysfunction and risk of falls. 9 Semiquantitative scales including the International Cooperative Ataxia Rating Scale (ICARS) and the Scale for the Assessment and Rating of Ataxia (SARA) are most commonly used to assess balance in a clinical setting. 10,11 However, research suggests that the SARA might underestimate disease severity in early phases 12 and the ICARS may not be sensitive to short-term changes in disease progression.…”

Exploring Risk of Falls and Dynamic Unbalance in Cerebellar Ataxia by Inertial Sensor Assessment

“…Patients suffering from cerebellar ataxia exhibit peculiar spatiotemporal and kinematic features that contribute to an unstable gait [1][2][3][4][5]. The gait impairment typically worsens over time, in parallel with the functional decline associated to the neurodegenerative process [6,7]. While stable gait is characterized by repeatable walking patterns [8], steadiness in the case of perturbations [9][10][11][12][13], and effectiveness in maintaining upright balance [14,15], ataxic gait is extremely variable over gait cycles [1] and exhibits inefficient coordination between upper and lower segments of body, even in the absence of external perturbations [16].…”

“…While stable gait is characterized by repeatable walking patterns [8], steadiness in the case of perturbations [9][10][11][12][13], and effectiveness in maintaining upright balance [14,15], ataxic gait is extremely variable over gait cycles [1] and exhibits inefficient coordination between upper and lower segments of body, even in the absence of external perturbations [16]. Taking into account such conditions, it is reasonable to hypothesize that when perturbation occurs in ataxic patients, the consequent fall risk increases, and the gait pattern can be defined as unstable [6,7].…”