1. Age-dependent gains after balance training in ataxic neuropathies B. MISSAOUI and P. THOUMIE Service de Rééducation Neuro-orthopédique, Hôpital Rothschild, APHP, 9 rue Santerre, 75012 PARIS and CIAMS Université Paris Sud 91405 ORSAY Background : Proprioception plays an essential role in maintaining static and dynamic balance in association with visual and labyrinthic afferents. In case of reduced proprioceptive afferents, a compensation may be provided by other sensory inputs, which is the basis for balance training in patients with ataxia. There is no evidence that the gain obtained in the treatment of ataxic neuropathy is preserved in the elderly when considering that motor sequence learning may be decreased in aged people even in the absence of cognitive impairment, Aims : The purpose of this study was to measure the effectiveness of a rehabilitation program in a population of patients with ataxic neuropathy and to determine the influence of age on the gains observed in static and dynamic conditions. Discussion and Conclusion : The main result of this study is to validate a rehabilitation program aimed at improving balance in patients with proprioceptive ataxia whichever the age of patients, i.e. to point out that age does not affect rehabilitation effects in ataxia rehabilitation. In our study, when young and older adults differed when considering age and balance performances, gains after training were similar in two groups suggesting that this protocol may be proposed without any consideration for age when no associated disease affecting balance was observed in these patients, Furthermore, the only difference between young and older adults concern the relative contribution of sensory and visual afferents: when younger adults tended to decrease the visual contribution to static balance (half of them was able to stay eyes closed after training) that means increase the sensory contribution, no change was observed in older adults. This negative aspect may be linked to a decrease aptitude to integrate new sensory inputs to regulate balance when dynamic balance can be improved without gains from sensory inputs as it was previously suggested. Matérial and Méthods : Patients Twenty patients with characterized bilateral sensory ataxia were included in this study. The main inclusion criterion was proprioceptive loss with a decrease in joint position sense at the big toe level or reduced turning torque perception at the foot level. All had clinical, electrophysiological and histological data corresponding to a well defined polyneuropathy, Proprioceptive loss was related to an ataxic neuropathy from various origin (Table 1).. A 256 Hz tuning fork was used to assess vibration perception and a pallesthetic score was determined as proposed by Merkies, Ten healthy subjects of similar age and sex constituted a control group to evaluate balance parameters. Method Three clinical tests were used to assess balance abilities: the Berg Balance Scale, the Timed Up-and-Go test and the Functional Reach Test, Romberg sign was tested as ability to maintain balance in an upright standing posture with closed eyes during 30 seconds. Results : Twenty two patients were included in this study. The median age was 69 years (range 43-83) Two subgroups were defined: young group (N=11, 7 females and 4 males, m=55, range: 43- 67) and old group (N=11, 6F and 5M, m= 76, range: 70-83). The initial values of instrumental tests are summarized in Table 2 Initial performances in clinical tests were significantly reduced in comparison with controls. Some differences were noticed between the two subgroups. Performances were lower during Balance tests in older when considering FRT and TUG when differences in BBS were not significant. Standing was impossible with the eyes closed (Romberg’s sign) respectively in 6/11 and 8/11 patients. Following the rehabilitation program (Table 3), significant improvement was noted in all balance tests. Two ways Anova (training x age) exhibited a significant group effect for training on BBS and FRT (p<0.001) without group effect for age. A similar group effect for training was observed on TUG (p<0.01) with a group interaction (training x age, p<0.05) corresponding to a higher effect in older patients. Romberg sign was observed in 2/11 and 8/11 patients after training with a significant difference between the two-subgroupes (Ki-2 = 6.6, p<0.01). References : Missaoui B, Thoumie P How do patients with sensory ataxia can benefit from so called « proprioceptive rehabilitation »? Neurophys. Clin. 2009 Oct-Nov;39(4-5):229-33 Missaoui B, Thoumie P, Balance training in ataxic neuropathies. Effects on balance and gait parameters Gait Posture. 2013 Jul;38(3):471-6 Rehabilitation program The rehabilitation program consisted of 15 sessions (three sessions per week for five weeks, each session lasting 2 hours and 30 minutes) comprised of different exercises aiming to improve sensory perception, and static and dynamic balance. The sensory function was stimulated using vibratory stimulation at 100 Hz above the perception threshold of the sole of both feet. Static and dynamic balance training was performed in different conditions with vision reduction using a mask with limited lower vision. Statistical analysis Patients were dived in two groups according their age, the threshold corresponding to the medial value observed in the total group. The data were analyzed for each group of subjects using a two-ways ANOVA with repeated measures and two subgroups (young-old) for quantitative data and a Khi-2 test (2x2) for qualitative data. The threshold of significance was established at p< 0.05.