References for this Rapid Review were identified through searches of PubMed for articles published from January, 1980, to September, 2010. I used the terms “human”, “stroke”, “infarct”, “motor”, “prognosis”, “predict”, “rehabilitation”, and “recovery”. I also identified articles through searches of my own files. Only papers published in English were reviewed, and the final reference list was selected on the basis of originality, recency, and topical relevance.
Rapid ReviewPrediction of recovery of motor function after stroke
Introduction
Stroke is the third most frequent cause of death and the most common cause of acquired adult disability in developed countries.1 Motor impairment is a frequent complication after stroke, and is an important contributory factor to a patient's ability to live independently.2 Decisions on the type, duration, and goals of rehabilitation are based on several factors, including estimates of the patient's potential for recovery of motor function, and have far-reaching consequences. Improvements in the accuracy of prognosis for the recovery of independence in daily activities would enable realistic goal-setting and efficient resource allocation by clinicians and patients.
The degree of motor impairment is the simplest indicator of prognosis, with greater initial impairment predicting worse functional recovery.3, 4 For example, voluntary shoulder and finger movements and leg motor power 7 days after stroke are strongly related to subsequent recovery of upper-limb function and gait, respectively.5, 6, 7 Notable inter-individual variability in the relation between initial impairment and subsequent recovery of function, however, means that accurate prognosis for each patient remains difficult (figure 1).8
Advances in neuroimaging with MRI and in non-invasive brain stimulation with transcranial magnetic stimulation (TMS) have provided new ways to visualise and understand the anatomical and functional changes in the motor system at given time points during the course of recovery.9, 10 Motor impairment at the subacute and chronic stages of recovery is clearly related to lesion location,11, 12, 13 the structural integrity of descending white matter pathways,14, 15 and cortical activation at rest16 and during voluntary movement.17 TMS can be used to focally stimulate the primary motor cortex (M1) and elicit motor evoked potentials (MEPs) in target muscles of the contralateral limb. The presence (and latency and amplitude) or absence of MEPs are measurements of the functional integrity and excitability of the corticomotor pathway, which are related to motor impairment at the time of testing.10 Studies of the upper limb show that ipsilesional corticomotor excitability is typically reduced after stroke, and recovery of motor function is associated with a return to balanced corticomotor excitability in the two hemispheres.18, 19 The few studies of lower-limb impairment have yielded mixed results.20, 21, 22
Use of MRI and TMS to assess the integrity of the corticomotor pathway can also assist with prediction of the patient's motor recovery.3, 23 When directly compared, the prognostic accuracy of TMS is similar to that of motor impairment assessment for the upper limb,24 and might be better when initial paresis is severe.25, 26 Assessment of the integrity of the corticomotor pathway, however, is not yet used routinely to make a prognosis, but there have been some interesting recent developments in this area.
Section snippets
Motor impairment scores
The sensitivity and specificity of voluntary finger extension and shoulder abduction as prognostic indicators have been assessed at multiple early time points by Nijland and colleagues.27 On the basis of findings in 156 patients, they reported that if both of these movements could be made within 72 h of stroke, there was a 98% probability of the patient recovering at least some manual dexterity within 6 months. If neither movement could be made within 72 h, the probability of recovering some
Neuroimaging
DeVetten and co-workers28 have recently reported the prognostic value of MRI when used at multiple early time points. In 20 patients, apparent diffusion coefficient maps were calculated from diffusion-weighted images acquired within 6 h and at 12 h, 24 h, and 7 days after stroke. Custom software was used to calculate signal intensity within regions of interest at three levels of the descending corticospinal tract, between the cervicomedullary junction and upper midbrain. These values were
Neurophysiological assessments
The prognostic accuracy of neurophysiological assessments has been extended by Di Lazzaro and colleagues,30 who used a repetitive TMS protocol to induce neural plasticity in M1 within 10 days of stroke in 17 patients. The protocol, known as intermittent theta-burst stimulation, can temporarily increase corticomotor excitability via mechanisms of synaptic plasticity.31 Intermittent theta-burst stimulation was delivered to ipsilesional M1, and a composite value of its immediate effects on the
Conclusions and future directions
The studies described above share some general limitations. First, the prognostic accuracy of the assessments was not confirmed with independent datasets. Second, the neuroimaging and neurophysiology studies did not compare the sensitivity or specificity of the new prognostic assessments with those of established clinical assessments. Finally, like most studies in this area, patients received so-called standard care, which is highly heterogeneous. Therapy type and dose are potential sources of
Search strategy and selection criteria
References (38)
- et al.
Prediction of walking function in stroke patients with initial lower extremity paralysis: the Copenhagen Stroke Study
Arch Phys Med Rehabil
(2000) - et al.
The relation between impairments and functional outcomes poststroke
Arch Phys Med Rehabil
(2000) - et al.
Arm function after stroke: neurophysiological correlates and recovery mechanisms assessed by transcranial magnetic stimulation
Clin Neurophysiol
(2006) - et al.
Brain lesion size and location: effects on motor recovery and functional outcome in stroke patients
Arch Phys Med Rehabil
(2000) - et al.
Clinical correlation between motor evoked potentials and gait recovery in poststroke patients
Arch Phys Med Rehabil
(2005) - et al.
Motor evoked potentials of the lower extremity in predicting motor recovery and ambulation after stroke: a cohort study
Arch Phys Med Rehabil
(2003) - et al.
Systematic review for the early prediction of motor and functional outcome after stroke by using motor-evoked potentials
Arch Phys Med Rehabil
(2002) - et al.
Direct current stimulation promotes BDNF-dependent synaptic plasticity: potential implications for motor learning
Neuron
(2010) - et al.
Non-invasive brain stimulation: a new strategy to improve neurorehabilitation after stroke?
Lancet Neurol
(2006) World Health Report 2003
(2003)
Predicting long-term independency in activities of daily living after middle cerebral artery stroke: does information from MRI have added predictive value compared with clinical information?
Stroke
A systematic review of voluntary arm recovery in hemiparetic stroke: critical predictors for meaningful outcomes using the international classification of functioning, disability, and health
J Neurol Phys Ther
Predicting improvement in the upper paretic limb after stroke: a longitudinal prospective study
Restor Neurol Neurosci
Active range of motion predicts upper extremity function 3 months after stroke
Stroke
Active finger extension: a simple movement predicting recovery of arm function in patients with acute stroke
Stroke
How imaging will guide rehabilitation
Curr Opin Neurol
Improved understanding of cortical injury by incorporating measures of functional anatomy
Brain
Effect of lesion location on upper limb motor recovery after stroke
Stroke
Structural integrity of corticospinal motor fibers predicts motor impairment in chronic stroke
Neurology
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