Quantification of learned non-use of the upper-limb after a stroke
Mrs Karima BAKHTIa, Prof Denis MOTTETb, Prof Nicolas SCHWEIGHOFERc, Dr Jerôme FROGERd, Prof Isabelle LAFFONTa
a CHU Montpellier Lapeyronie, b Université de Montpellier, c University of Southern California, d CHU Nimes Le Grau du Roi
Background. Following a cerebrovascular accident, CVA (or stroke), many patients experience learned non-use of the paretic arm (LNUUL). One part of LNU is explained by the fact that the patient moves his trunk forward instead of extending his arm to reach a given object, even though he is capable of extending his arm. This is because using the trunk for this task demands less energy and concentration than using the paretic arm. This phenomenon is known to be detrimental to neuroplasticity and recovery.
Objective. The aim of this study is to quantify this part of learned non-use of the paretic upper-limb during a hand-reaching task using 3D movement analysis.
Methods. Thirty-four post supratentorial stroke participants were asked to reach a cone placed in front of them at 80% of their arm length. The reaching movement was repeated 5 times with the paretic hand, and then 5 times with the less-impaired hand. This sequence was first performed with the trunk free, then with the trunk restrained. Learned non-use of the upper-limb (LNUUL) was obtained from the difference of the amount of trunk compensation between the free trunk condition and the restrained trunk condition.
Results. LNUUL was significantly higher for the paretic hand, with individual values ranging from 1% to 43%, and one half of the patients with a LNUUL higher than 15%.
Discussion/Conclusion. This quantification of LNUUL can be used to objectively pinpoint patients who have maladaptive trunk compensation and need specific trunk rehabilitation. It can be also used for monitoring the rehabilitation progress. This quantification of LNUUL may guide upper-limb rehabilitation towards more optimal motor recovery avoiding maladaptive trunk compensation and its consequences on neuroplasticity. Considering LNUU could advance both theoretical and practical knowledge about the recovery of arm use after a CVA.
Key Words: Learned Non-Use, Rehabilitation, Stroke, Upper Limb
Keywords : Learned Non-Use, Assessment, Stroke, Upper Limb