Effects of Temporary Functional Deafferentation on the Brain, Sensation, and Behavior of Stroke Patients

Abstract

Following stroke, many patients suffer from chronic motor impairment and reduced somatosensation in the stroke-affected body parts. Recent experimental studies suggest that temporary functional deafferentation (TFD) of parts of the stroke-affected upper limb or of the less-affected contralateral limb might improve the sensorimotor capacity of the stroke-affected hand. The present study sought evidence of cortical reorganization and related sensory and motor improvements following pharmacologically induced TFD of the stroke-affected forearm.Examination was performed during 2 d of Constraint-Induced Movement Therapy. Thirty-six human patients were deafferented on the stroke-affected forearm by an anesthetic cream (containing lidocaine and prilocaine) on one of the 2 d, and a placebo cream was applied on the other. The order of TFD and placebo treatment was counterbalanced across patients. Somatosensory and motor performance were assessed using a Grating orienting task and a Shape-sorter-drum task, and with somatosensory-evoked magnetic fields. Evoked magnetic fields showed significant pre-to postevaluation magnitude increases in response to tactile stimulation of the thumb of the stroke-affected hand during TFD but not following placebo treatment. We also observed a rapid extension of the distance between cortical representations of the stroke-affected thumb and little finger following TFD but not following placebo treatment. Moreover, somatosensory and motor performance of the stroke-affected hand was significantly enhanced during TFD but not during placebo treatment. Thus, pharmacologically induced TFD of a stroke-affected forearm might improve the somatosensory and motor functions of the stroke-affected upper limb, accompanied by cortical plasticity.

Expansion of sensorimotor cortical activation for unilateral hand motion during contralateral hand deafferentation

“…The concept of motor modulation through sensory deprivation has been applied in clinical settings [1][2][3][20][21][22][23]. For example, reduction of afferent input from the distal forearm of unaffected (contralateral) hand [1,2] or from the proximal forearm of affected (ipsilateral) hand [20] led to enhancement of paretic hand ability in patients.…”

“…For example, reduction of afferent input from the distal forearm of unaffected (contralateral) hand [1,2] or from the proximal forearm of affected (ipsilateral) hand [20] led to enhancement of paretic hand ability in patients. In addition, when combined with constraint-induced movement therapy [24], temporary functional deafferentation led to additional practiceinduced improvement in hand function [21][22][23]. Further studies are warranted that investigate whether, and if so how, the deafferentation-induced expansion of ipsilateral SM1 is linked to motor functional recovery in these patients.…”

Effects of Sensory Deficit on Phalanx Force Deviation During Power Grip Post Stroke

“…The results of this study support the importance of treating sensory impairment for stroke survivors in addition to motor impairment. Methods exist to improve hand sensation, such as transcutaneous electrical stimulation (Conforto et al, 2007), temporary functional de-afferentation (Sens et al, 2012), subsensory vibrotactile stimulation (Collins et al, 1996, Enders et al, 2013, Kurita et al, 2013, Lakshminarayanan et al, 2015), and tactile coactivation (Dinse et al, 2006, Dinse and Tegenthoff, 2015). The timing of such sensory rehabilitation may optimally be at the acute phase to preserve the sensory cortical representations of the upper limb (Weiss et al, 2004).…”

Verhaltensmedizin in der Neurologie: State of the Art

“…Eine derartige temporäre funktionelle Deafferentierung (TFD) führt in Kombination mit einer intensiven Shaping-Prozedur in den contralateralen somatosensorischen Feldern offenbar zu einer erhöhten Exitabilität. Weiterhin erfolgt eine Reorganisation der rezeptiven kortikalen Areale, was zu einer verminderten interhemisphärischen Inhibition und damit letztlich zu einer verbesserten motorischen Funktion führt [Sens et al, 2012].…”