Supplement 1: Clinical description and MRI of the subject.

a)Degree of ataxiaat E1 as determined by single items of the Scale for the Rating and Assessment of Ataxia (SARA)1. SARA gait 7 out of 8 points, stance 5 out of 6 points; sitting 2 out of 4 points; speech disturbance 4 out of 6 points; finger chase 2.5 out of 4 points; nose-finger 2 out of 4 points; fast alternating hand movements 3 out of 4 points; heel-shin slide 3 out of 4 points.

b)Non-ataxia symptoms, according to the Inventory of non-ataxia symptoms (INAS)2:areflexia upper and lower extremity, muscle atrophy distal lower limb, moderately impaired vibration sense (2-5/8) right and left foot; broken up smooth pursuit, horizontal and vertical oculomotor apraxia (i.e. inability to initiate saccades without concomittant head turn, increased latency of saccade initiation, and reduced saccade velocity); other: teleangiectasias eyes and skin.

c)MRI. Coronal T2 MRIat age 9 years shows marked cerebellar atrophy of both cerebellar hemispheres and vermis (red arrows).

Supplement 2: Video illustration of gait performance before and after the training intervention.Stance: in contrast to pre-training, the subject was able to stand without assistance after training. Gait: While the subject required two arms assistance for walking pre-training, he was able to walk with only one hand assistance after traning.

Supplement 3: Quantitative Movement analysis

The three-dimensional movement trajectories of the patients were recorded at a sampling rate of 120 Hz using a VICON MX motion capture system with 10 cameras and 41 reflecting markers. The marker trajectories were pre-processed using the commercial software provided by VICON. This software fits a clinically evaluated kinematic model to the marker trajectories and extracts velocities, joint angles, and the course of the centre of mass (CoM) see a more detailed description in 3.

In order to quantitatively analyse the balance capacity of the patient during sitting, we recorded 30 seconds trials of free sitting. The figure shows the recorded CoM-trajectories before the intervention (red: assessment E2) as well in different stages of the training program (blue: assessment E3, green: assessment E4)

Supplement 4: Goal attainment scaling by GAS score.

Five levels of goal attainment were defined before the interventionstarted. The aspired goals were chosen to represent individually important goals that facilitate the daily living and were determinedin collaboration with both the patient and his parents. The goal attainment was rated at examinations E1-4. The Score range was from -2 to +2 (-2=regression from current level, -1= current level of performance 0: expected level of performance, +1: greater than expected outcome, +2: much greater than expected outcome).

Sitting

Score / Description
-2 / Unable to sit without hand-support
-1 / Unable to sit and move the upper body without hand-support, cambered posture
0 / Uprightly posture with a little bit of support, movements of the upper body without support of the hands.
+1 / Uprightly posture while the upper-body is moving without support
+2 / Uprightly posture without support while the upper-body is moving, with big amplitudes,without support

Stance (25cm wide base)

Score / Description
-2 / Only with double hand support
-1 / Only with one hand support
0 / Free stance for <5 sec
+1 / Free stance for 5-10 sec
+2 / Free stance for >10 sec

Supplement 5: Whole-body controlled video-games for training in advanced ataxia

In thefollowing, wedescribe in briefthefivecommercial Nintendo Wiigames, used in thistrainingstudy. The gamesareincluded in Kinect Sports, Microsoft,ASIN:B003U9P0FI.

  1. Penguinslide: Players controltheright-lefttiltingdirectionof an icefloe on which a penguinissliding. The goalistoindirectlydirectthepenguinto catch asmanyfishaspossiblewithin a constrained time window, yetwithoutfalling off fromtheicefloe. The right-leftdirectionoftheicefloeiscontrolledbytheamountofright-left lateral weightshiftingoftheplayer’strunkwhilesitting on theWiibalanceboard. This gametrainstrunkbalanceand quick andprecisetrunkcoordinationunder time pressure.
  2. Table tilt: Players controltheright-leftandanterior-posteriortiltof a horizontal platform. Severalballs roll on theplatformsurfacewhichfollowthegravityandthetiltdirectionoftheplatform. The goalistodirectasmanyballsaspossibletowardsandthroughtheholes in theplatformwithin a constrained time window, yetwithoutallowingtheballsto fall off thesidesoftheplatform. The tiltdirectionoftheplatformiscontrolledbytheamountofright-leftandanterior-posteriorweightshiftingoftheplayer’strunkwhilesitting on theWiibalanceboard. This gametrainstrunkbalanceand quick andprecisetrunkcoordinationunder time pressure.
  3. Bubble balance: Players control a bubble in which a personalizedavatarislocated. The bubblemovesslowlydownwards a narrowandwindingriverfullofobstacles. The goalistodirectthebubbletowardstheendoftheriverwithin a constrained time window, yetwithoutallowingthebubbletohittherockshore on therightorleftoranyofthe potential damagingobstacles on theriver. The speedoftheavatariscontrolledbytheamountofanterior (fast forwardmovement) orposterior (slowforwardmovement) weightshiftingoftheplayer’strunkwhilesitting on theWiibalanceboard. The right-leftdirectionoftheavatariscontrolledbyright-leftweightshiftingoftheplayer’strunk. This gametrainstrunkbalanceand quick andprecisetrunkcoordinationunder time pressure.
  4. Ski slalom: Players control a personalizedavatarskiingdownhill. The goalistodirecttheskierdownhill on a slalomcourseas fast aspossible, yetwithoutmissinganyoftheslalompoles. The speedoftheavatariscontrolledbytheamountofanterior (fast forwardmovement) orposterior (slowforwardmovement) weightshiftingoftheplayer’strunksitting on theWiibalanceboard. The right-leftdirectionoftheavatariscontrolledbyright-leftweightshiftingoftheplayer’strunk. This gametrainstrunkbalanceand quick andprecisetrunkcoordinationunder time pressure.
  5. Tightropewalk: Players control a personalizedavatarwalkingover a thinropeabovetheabyssbetweentwotowerbuildings. The goalistocrosstheabyss on theropewithin a constrained time window, yetwithoutlosingbalanceandfalling off therope. The paceoftheavatariscontrolledbyrhythmicallyalternatingright-leftshiftingoftheplayer’scenterofmasswhilestandingon theWiibalanceboard. The avatar loses balanceifthealternatingshiftingis not rhythmic, too fast ortooslow. This gametrainsstaticbalancewhilestandingandprecisetrunkandstancecoordinationunder time pressure.

References:

1.Schmitz-Hubsch T, du Montcel ST, Baliko L, et al. Scale for the assessment and rating of ataxia: development of a new clinical scale. Neurology 2006;66(11):1717-1720.

2.Jacobi H, Rakowicz M, Rola R, et al. Inventory of Non-Ataxia Signs (INAS): validation of a new clinical assessment instrument. Cerebellum 2013;12(3):418-428.

3.Ilg W, Golla H, Thier P, Giese MA. Specific influences of cerebellar dysfunctions on gait. Brain 2007;130(3):786-798.

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