Physiological mobilization of very acute SCI patients effects on the cardiovascular system

Transcription

1 International Neurorehabilitation Symposium, University Irchel, Zuerich, Switzerland, Physiological mobilization of very acute SCI patients effects on the cardiovascular system R. Rupp, H. Plewa, C. Schuld, M. Schmidt, H.J. Gerner Orthopaedic University Hospital Heidelberg Department II / Focus Rehabilitation Medicine Director Prof. Dr. H.J. Gerner

2 Spinal cord injury (SCI) in Germany new spinal cord injuries per year in Germany ~ chronic SCI persons in Germany Para-/Tetraplegic 60/40 Main causes for spinal cord injuries: Traffic and work accidents (45%) Spinal cord diseases (30%) (Water-)Sports accidents (8%)

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4 Acute spine surgery Repositioning of vertebrae Recalibration of spinal canal Early decompression of the spinal cord Mechanical stabilization to allow early mobilization Performed in 99,9 % of the traumatic SCI patients within 24 hrs after trauma in Germany

5 Spinal Cord Injury Primary consequences Depending on the level of lesion loss / restrictions of respiration grasp function trunk stability walking function bladder / sexual function American Scientific

6 Effects of immobilisation Secondary complications of paralysis Reduced functional capacity of cardiovascular system 30% reduction of cardiac output in the first 3-4 weeks Muscle atrophy 40 % reduction of muscle strength during the first week Bone demineralisation Up to 1% per week Edema Increased risk of thrombosis Topp R. et al., AACN Clinical Issues 13(2), , 2002

7 The vicious circle of immobilization Bad Fitness Low blood pressure Secondary complications (thrombosis) Handicap in mobilisation Reduced blood volume Venous blood pooling No activity of skeletal muscles

8 Locomotion therapy on the treadmill Manually/robotic assisted treadmill walking with body weight support Improvement of bone density de Bruin et al., Arch Phys Med Rehabil, 80(2) , 1999 spasticity Skold, Arch Phys Med Rehabil, 81(2), , 2000 endurance/gait pattern Wernig et al., J Neurotrauma, 16(8), , 1999 Dietz et al., Phys Ther, 77(5), , 1997 Prerequisite: Stable cardiovascular system Ability to stand with BWS

9 Length of primary rehabilitation in traumatic SCI Tetraplegics Paraplegics Days

10 Time windows of primary rehabilitation? SCI 4 weeks 8 weeks 12 weeks 16 weeks Is it possible to apply an intensive locomotion therapy at an earlier time point?

11 History of devices for Continous Passive Motion Jakob Heine Der Motator

12 Kinematics and kinetics stance phase no extension of the hip maximum load on foot sole during swing phase swing phase Most prominent afferent inputs to spinal central pattern generator hip extension at the end of stance phase physiological loading of foot sole during stance phase Duysens et al, Gait & Posture, 16(8), , 1999 Dietz et al, Brain, 125(12), , 2002

13 Specifications for an earliest mobilization therapy in SCI Adaptation of patient position from horizontal to upright depending on the cardiovascular status Physiological kinematics and kinetics of the movements in regard to gait phase related loading/unloading of foot sole hip extension Step frequency increasable up to normal walking speed (1.2 Hz) Rupp R. et al., Biomed Tech 47, suppl. 1, , 2002

14 Passive tilt table

15 Adjustment of hip extension

16 Tilt table with passive foot plate

17 Active tilt table Dietz V., Colombo G., Rupp R.: Device and Method for Locomotion therapy, European patent number EP

18 Clinical application therapy

19 Clinical study Cardiovascular stabilization Does a stabilization of the cardiovascular system occur during the training with the active tilt-table? Inclusion criteria Complete (motor) spinal cord injury above T5 Acute SCI (date of injury <= 3 month) Patient during primary rehabilitation Patient can sit in the wheelchair for 30 to 60 minutes daily Exclusion criteria Pulmonary and/or cardiovascular diseases Metabolic or acute internal diseases Drugs with critical influences on autonomic, cardiovascular or pulmonary system Autonomic dysreflexia 5 patients (age 23-35, level of lesion C3-C6, ASIA A)

20 Clinical study Cardiovascular stabilization Therapy protocol resting position verticalization with movement verticalization without movement resting position Baseline -10 min. 0 min. 15 min. 30 min. Assessment of cardiovascular parameters (BP, CO) approx. 35 min.

21 Assessment of cardiovascular parameter Task force monitor Non-invasive integrated measurement of cardiovascular parameter ECG and Impedance- Cardiography Oscillometric and continuous blood pressure recording CNSystems, Graz, Austria Precision of measurements of cardiac output in the range of invasive thermodilution based devices Fortin J et al., Computers in Biology and Medicine 36, , 2006

22 Blood pressure during Erigo -therapy 30 Systolic BP Diastolic BP Changes in blood pressure (% to baseline) min min 30 min 35 min 60 no movement Therapy interval ** ** Colombo G., Schreier R., Mayr A., Plewa H., Rupp R., Proc. IEEE 9 th Int. Conf. on Rehabilitation Robotics, 2005

23 Cardiac output during Erigo -therapy Cardiac Output change in percent baseline orthostasis 5th min. orthostasis 25th min. orthostasis no movement rest Continuous increase in CO of approx. 15% during therapy = cardiac training

24 Open questions Is it possible to train the cardiovascular system of acute SCI with Erigo? Could the time to onset of wheelchair mobilization be shorten by earliest application of Erigo -therapy? Erigo in ICU What are the key afferent sources for the observed effects of increased CO and BP stabilization?

25 Training of the cardiovascular system 30 Change in BP in percent (% to baseline) ,88 8,77 8,59 4,37 0,78 0,67 <15 min >15-30 min >30 min Motor off map% onset study map% 3 weeks later -20,08 ** -12,13 ** Plewa H et al., Biomed Tech 50, Suppl 1, part 2, , 2005

26 Pilot study Parameter variation Which settings of the Erigo device have a significant influence on the cardiac output? Inclusion criteria Motor complete spinal cord injury above Th12 (ASIA A or B) Subacute to chronic SCI (12 weeks <= date of injury <= 2 years) patient can sit in the wheelchair for 30 to 60 minutes daily Exclusion criteria pulmonary and/or cardiovascular diseases metabolic or acute internal diseases drugs with critical influences on autonomic, cardiovascular or pulmonary system Autonomic dysreflexia 4 patients (level of lesion C4-T6, 3x ASIA A, 1x ASIA B)

27 Variation of Erigo settings Randomized variation of - Hip extension (0, 25 ) - Degree of verticalization (0, 70 ) - Degree of foot loading (< 5kg, 15kg, 30kg) - Number of step repetitions per minute (32, 60 steps/min.) Weekly measurements of cardiovascular parameter in 3 weeks Bilateral measurement of EMG of - M. quadriceps - Hamstrings - M. tibialis - M. gastrocnemius

28 Preliminary results on influence of stepping speed 4,6 4,4 4,2 4,0 Cardiac Index [l/min/m²] 3,8 3,6 3,4 3,2 3,0 2,8 2,6 2,4 2, Stepping speed [steps/min.] Mean Mean±SD Mean±1,96*SD

29 Preliminary results on influence of foot loading 4,6 4,4 4,2 4,0 Cardiac Index [l/min/m²] 3,8 3,6 3,4 3,2 3,0 2,8 2,6 2,4 2,2 low medium high Load Mean Mean±SD Mean±1,96*SD

30 Preliminary results on influence of hip extension 4,6 4,4 4,2 4,0 Cardiac Index [l/min/m²] 3,8 3,6 3,4 3,2 3,0 2,8 2,6 2,4 2, Hip Extension [ ] Mean Mean±SD Mean±1,96*SD

31 LTibAnt RTibAnt RGastroc LGastroc stance swing stance swing Step cycle [%] Step cycle [%] low vs. high load Stimulation of the CPG Variation of Degree of loading of foot sole Degree of hip extension Gait speed LTibAnt RTibAnt LGastroc RGastroc Ranking of influence factors 1. Gait speed 2. Loading of foot sole 3. Hip extension stance swing stance swing Low EMG amplitudes! Step cycle [%] Step cycle [%]

32 Summay and conclusions An early mobilization of SCI patients with the dynamic tilt table Erigo is feasible Physiological movement pattern in regard to loading of foot sole and hip extension stepping frequency Stabilization of the cardiovascular system of high lesioned SCI patients (> 500 therapy sessions without signs of presyncope or syncope) Positive effects not explainable only by activation of muscle pump in the lower extremities Hypothesis: Activation of vegetative efferents from somatosensory afferents via spinal crosslinks?

33 Novel drug interventions and locomotion therapy Ongoing phase I trial (Anti-NOGO, Novartis) of drug for spinal neuroregeneration/-plasticity since 06/06 Enhancement of neural plasticity by repetitive, physiological stimulation of afferent fibers of the lower extremities Erigo Lokomat

34 Time windows of clinical gait rehabilitation?? SCI 4 weeks 8 weeks 12 weeks 16 weeks Is it possible to mantain the intensity of the gait training after primary rehabilitation?

35 Safe, semi-lying patient positioning Pneumatic actuators ( artificial muscles ) with low stiffness Supported movement of ankle knee hip joints (positively driven) 01EZ602

36 Stimulative shoe 10 medio-lateral bars mounted on pneumatic oversquare cylinders Fixation of foot with anatomically adapted shoe tongue Simulation of physiological foot loading pattern

37 Acknowledgements Orthopedic University Hospital Heidelberg - H. Plewa - C. Schuld - W. Roth University of Zürich, Paracare Balgrist - Prof. Dr. V. Dietz - Dr. Gery Colombo Hocoma University of Ulm, Department of measurement and control - Prof. Dr. E.P. Hofer - Markus Knestel