Effects of temporary functional deafferentation on the brain, sensation, and behavior of stroke patients.
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.
Biological and Clinical Psychology, Friedrich Schiller University, Jena D-07743, Germany.
Elisabeth
E
Sens
Ulrike
U
Teschner
Winfried
W
Meissner
Christoph
C
Preul
Ralph
R
Huonker
Otto W
OW
Witte
Wolfgang H R
WH
Miltner
Thomas
T
Weiss
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology*; D002648:Child; D005260:Female; D005542:Forearm / Q000294:innervation*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008012:Lidocaine / Q000494:pharmacology; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D015915:Motion Therapy, Continuous Passive / Q000379:methods*; D009068:Movement / Q000502:physiology; D011318:Prilocaine / Q000494:pharmacology; D011597:Psychomotor Performance / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology*; D020521:Stroke / Q000473:pathology / Q000503:physiopathology; D000071939:Stroke Rehabilitation; D013997:Time Factors
D000779:Anesthetics, Local; D011318:Prilocaine; D008012:Lidocaine