Sensorimotor Retraining in Chronic Stroke

Somatosensory deficits are a common symptom after stroke, affecting a high percentage of survivors (50-80%). These impairments have a long-term influence on somatosensory capacity, motor ability and functional performance. Although several authors have studied the effect of sensorimotor retraining on recovery of the paretic upper limb, a few have investigated its effect on the paretic lower limb. Furthermore, most of them have done so in the acute and subacute phases after stroke. Thus, in this field there is a lack of studies of high methodological quality that provide effective physiotherapeutic interventions, especially in chronic stroke.

On the other hand, the importance of motor recovery of the paretic lower limb in order to achieve a better balance, gait and independence in the activities of daily living is well established. In this regard, sensory loss in the feet may difficult effective motor function recovery due to its impacts upon ambulatory activity. After stroke, sensory dysfunction in the lower limb has been related to reductions in static and dynamic balance as well as in gait speed and symmetry. Therefore, successful recovery of sensory function after stroke may allow for the appropriate integration of sensory inputs in order to maintain balance and adapt to changing environmental demands during gait.

Since the current evidence indicates that there may be recovery of sensory loss during the chronic phase of stroke, the present study aims to evaluate the effect of a sensorimotor retraining program on sensory and functional recovery of the paretic lower limb in chronic stroke. The investigators hypothesized that stroke survivors receiving the somatosensory training program would demonstrate significantly greater improvement in sensation, static and dynamic balance and gait pattern in comparison with the control intervention.

To cope with the objective of the study, a prospective randomized double-blind clinical trial will be conducted. By means of advertisements in supporting groups, rehabilitation facilities and the external consultations of various hospitals, subjects who meet the inclusion criteria will be recruited. After screening and giving signed consent, participants will be randomly allocated to the intervention group or the control group. In addition to the usual physical activity, participants will complete fifteen 40-minute sessions of sensorimotor retraining (intervention group) or of Jacobson relaxation (control group) over a 5-week period. Participants will be assessed prior to treatment and on completion of treatment.

Inclusion criteria

• Chronic hemiplegia or hemiparesis from a first ever stroke (onset > 6 months prior to study enrolment)
• No severe cognitive deficit (Mini-Mental State Examination score ≥ 22)
• Subjective reports of sensory loss
• Triceps surae muscles scoring ≤ 2 on the Modified Ashworth Scale
• Able to walk for at least 10 meters indoor over ground without assistance

Exclusion criteria

• Ataxia
• Co-existing sensory deficits from peripheral neuropathies (i.e. diabetes mellitus)
• Lower extremity claudication
• Pain > 3/10 on a visual analogue scale
• Prior lower extremity surgical history
• Blindness, visual impairments and other pathologic condition that influence posture and balance.