Volition and imagery in neurorehabilitation

 You are on your own to figure out how to use this to recover. You'll have to create your own stroke protocols from this. Nobody is going to do it for you. So I'd suggest billing your doctor for that creation of protocols at $500 an hour for doing their job.

Volition and imagery in neurorehabilitation

2006, Cognitive and behavioral neurology
 Martin Lotze, MD* and Leonardo G. Cohen, MD
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Abstract:

 New interventional approaches have been proposed in the last few years to treat the motor deficits resulting from brain lesions. Training protocols represent the gold-standard of these approaches. However, the degree of motor recovery experienced by most patients remains incomplete. It would be important to improve our understanding of the mechanisms underlying functional recovery. This chapter examines the role of two possible mechanisms that could operate to improve motor function in this setting: volition and motor imagery. It is argued that both represent possible strategies to enhance training effects.
Key Words:
 motivation, attention, motor imagery, hemiparesis,rehabilitation, forced use, volition, stroke, motor system, motorcortex

 Motor training protocols(Where the fuck are they? I have never found one. Or are you mistaking guidelines for protocols and don't know the difference?) represent one of the fundamental bases of rehabilitative treatments after brain damage. Different strategies have been proposed to enhance training effects, including enhanced motivation,focused attention, motor imagery, progressive transfer of tasks towards the paretic limb, forced use, and integration of multimodal and emotional settings. The neural mechanisms underlying these strategies are poorly under-stood. In this review, we describe studies performed to better understand the influence of some of these factors on performance improvements and changes in intracortical excitatory and inhibitory mechanisms in humans undergoing training protocols. Focus is on the role of (a)volition in motor learning, (b) imagery in neurorehabilitation and motor control, and (c) neural substrates underlying performance of simple and complex movements after stroke.

 ROLE OF VOLITION IN MOTOR LEARNING

Motor training protocols in patients with brain lesions elicit well-described changes in brain organization and performance improvements.^1–6One limitation of training protocols is that patients with more profound weakness are unable to carry out the motor routines required. The finding that passively elicited motions lead to activation and cortical reorganization in brain regions common to those activated with performance of voluntary movements suggested that it could also elicit improvements in motor function.^7,8This proposal has important implications for the design of neurorehabilitative treatments after stroke, particularly in patients who are too weak to perform effective voluntary motor training.One recent study compared behavioral gains after short-term motor learning, changes in functional magnetic resonance imaging (fMRI) activation in the contralateral primary motor cortex (cM1) and in motor cortex excitability measured with transcranial magnetic stimulation (TMS) after a 30 minute training period consisting of either voluntarily or passively induced wrist movements in 2 different sessions in healthy volunteers.⁹During active training, subjects were instructed to perform voluntary wrist flexion-extension movements of a specified duration in an articulated splint. Therefore,voluntary movements falling within a specified time window displayed on the screen monitor were considered correct hits. Subjects received a feedback signal after each training movement and hits were rewarded. If the movement’s range was not complete, the program presented a negative feedback signal (‘‘no movement performed’’). Passive training consisted of wrist flexion-extension movements of the same amplitude and duration range as in the active task elicited by a torque motor.fMRI activation and TMS parameters of motor cortex excitability were measured before and after each training type. During the passive training session, each passive movement was followed by the presentation of a played-back feedback signal. Other training parameters were kept constant, including concentration, using a previously described electroencephalogram (EEG)-modulation task(modified from Ref. 10). Performance improvements were measured as the increase in the number of hits within the critical temporal window. Wrist flexion movements were only possible in the desired axis (flexion extension). Failure to execute a full motion resulted in a failed trial.The temporal features of each movement were monitored and feedback was provided. The main finding of the study was that active training resulted in clear performance  improvements in the motor task, whereas passive training did not. Resting motor thresholds (rMT), recruitment curves (RC), and intracortical inhibition and facilitation(ICF) were measured before and after each intervention from extensor carpi radialis muscle. Three separate analysis of variances for rMT, RC, and ICF with factors training (active/passive) and time (pre/post), revealed no changes in rMT but an increase of RC and ICF after active but not after passive training. fMRI revealed an increase of the activated cluster within the precentral and postcentral gyrus after active training. Therefore, active training resulted in more prominent performance improvements, accompanied by increased processing and motor cortical excitability within M1. Changes in ICF are consistent with the involvement of glutamatergic neurotransmission mechanisms.¹¹All together, these findingssupport the concept of a pivotal role of voluntary drive in motor learning.In another experiment, Kaelin-Lang et al¹²investigated the influence of voluntary and passively elicited thumb movements on encoding of an elementary motor memory in the primary motor cortex. In this experimental protocol, a group of healthy volunteers underwent a period of 30 minutes training consisting of performance of (a) voluntary thumb movements and (b) passively elicited movements, all performed at 1Hz in different sessions randomly ordered. The purpose was to determine to what extent each training strategy generated a directional bias in TMS evoked movements, a measure of encoding of an elementary motor memory in the primary motor cortex,^13,14that reflects the kinematic details of the practiced movements and may contribute to skill acquisition.¹³Thumb movements were recorded with a 2-dimensional accelerometer mounted on the proximal phalanx of the thumb and TMS was delivered to the optimal scalp position to elicit thumb movements in a consistent direction (60TMS stimuli at 0.1Hz before and after training). The baseline TMS evoked thumb movement direction was defined for each subject and session before training.^14,15In the active training session, subjects practiced voluntary, brisk thumb movements paced by anacoustic signal in a direction opposite to the baseline TMS evoked thumb movement direction for 30 minutes(1Hz¹³). After each voluntary movement, the thumb returned to the start position by relaxation, as confirmedby electromyogram (EMG) monitoring. Monitoring accuracy and consistency of training was carried out online using the acceleration signal. In the passive training session, the same experimenter moved the subject’s thumb passively and briskly in a direction opposite to the baseline TMS evoked movement direction for 30 minutes (1Hz). Each passive movement was paired with presentation of the same acoustic signal as in the active training session. To describe the training effects on TMS evoked movement directions, a training target zone as a window of ±20 degrees centered on the training direction was defined.^14,15The end point measure of this study was the increase in the proportion of TMS evoked movements that fell within the training target zone after training. The main result of this study was that active motor training led to encoding of a motor memory in the primary motor cortex, whereas passive training did not.Additionally, active training led to a differential modulation of corticomotor excitability, enhanced in muscles agonistic to the training motions and depressed in muscles antagonistic to the training motions, possibly reflecting the neurophysiologic correlates of ¹⁴or contributes to¹⁶the newly encoded motor memory.To what extent these findings in healthy volunteers impact on clinical neurorehabilitation remains to be determined. However, they suggest that the use of passive training strategies should not replace active motor training in able individuals. On the other hand, it is possible that passive training strategies may play a more prominent role in individuals unable to perform voluntary motions during rehabilitative treatments, an issue that deserves further investigation.Two recent studies used passive training protocols in moderately affected stroke patients. Hesse et al¹⁷used bilateral robot-assisted repetitive motor training for 15minutes a day over a period of 3 weeks in 12 chronic hemiparetic patients. They did not observe significant functional improvements of motor performance as assessed with the Rivermead Motor Scale but a significant decrease of spasticity of wrist and finger joints. In another study, Lindberg et al¹⁸combined passive and active training components in 10 chronic stroke patients who showed mild to severe functional impairment in the affected upper limb. Training lasted 4 weeks, was performed 4 times a week, and included active warm-up(5 to 10min) and stretching (for patients with increased muscle tone; 5min), repetitive passive movements guided by a physiotherapist in a functional movement pattern(reaching, grasping for 20min), and active training(5min, mimicking the passively guided movements). During passive training, subjects were instructed to‘‘observe and feel’’ the movement, probably activating additional neural networks involved in motor imagery and action observation. The authors reported an improvement in range of motion and Motor Assessment Scale.

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