Long-Term Enhancement of Botulinum Toxin Injections for Post-Stroke Spasticity by Use of Stretching Exercises-A Randomized Controlled Trial

Abstract

Botulinum toxin A (BONT/A) injections play a central role in the treatment of upper limb spasticity in stroke patients. We proposed structured stretching exercises to enhance the effect of post-stroke spasticity relief of the upper limbs following BONT/A injections. A total of 43 patients who had a stroke with grade 2 spasticity or higher on the Modified Ashworth Scale (MAS) in their upper-limb muscles were randomly assigned to the intervention (n = 21) or control group (n = 22). The former received structured stretching exercises after their BONT/A injections for 20 min, 5 days per week, for 6 months at a hospital, while the others conducted self-stretching exercises at home. The outcome measures were assessed before the intervention (T0) and after three (T1) and six months (T2). Significantly greater improvements in the MAS scores of the elbows, wrists, and fingers were found in the intervention group's patients at T1 and T2. The behavioral outcome measures, including shoulder pain, activities of daily living, and quality of life, and our electrophysiological studies also showed a significantly higher enhancement in this patient group. In conclusion, the structured stretching exercises plus BONT/A injections for six months showed a superior effect in relieving post-stroke upper-limb spasticity compared to self-stretching exercises.

Keywords: dystonia; pain; physical therapy; rehabilitation; spasticity; stretching; stroke.

Figure 1

CONSORT flow diagram of recruitment to, allocation within, and participation in this study.

Figure 2

Comparison of the Modified Ashworth Scale (MAS) scores between the intervention group and the control group over time. Significant time and group interaction effects are found in the modified MAS scores of the elbows, wrists, and fingers. In the between-group comparison, the spasticity relief effect of BONT/A continues until the 6-month time point (T2) in the intervention group of patients. In contrast, the anti-spastic effect of BONT/A is almost lost at 6 months in the control patients. (A) Elbow; (B) wrist; and (C) fingers. * p < 0.05.

Figure 3

Comparison of the secondary outcome indicators between the intervention and control groups over time. Significant time and group interaction effects are found in the VAS scores of pain in the affected shoulder, K-MBI, and EQ-5D over time. The patients in the intervention group show greater improvements in their VAS, K-MBI, and EQ-5D scores at T1 and T2. However, no time and group interaction effect are found in FMA_UE. (A) VAS of shoulder pain; (B) K-MBI; (C) EQ-5D; and (D) FMA_UE. * p < 0.05. VAS, Visual Analogue Scale; K-MBI, Korean version of the Modified Barthel Index; EQ-5D, EuroQol-5 Dimension (EQ-5D); and FMA_UE, Fugl-Meyer Assessment of Upper Extremities.

Figure 4

Comparison of the root mean square (RMS) using electromyography between the groups. A significant time and group interaction effect is found for RMS flexion and extension over time. The patients in the intervention group show greater enhancement in RMS flexion and extension than those in the control group. A higher RMS means that spasticity relief has been achieved. (A) RMS flexion; and (B) RMS extension. * p < 0.05.

Figure 5

Structured stretching exercises after botulinum toxin A (BONT/A) injection. (Blue circle: Target joints. Pink arrow: Directions for stretching.) The patient is assisted in performing stretching exercises immediately after their BONT/A injections while lying down. Starting with the finger joints, each joint is slowly stretched at a low intensity in the opposite direction of the bend. When the patient reaches the maximum angle at which the pain is tolerable, the position is held for 2 s, and then the muscle is relaxed. Each upper-limb muscle is stretched individually to avoid pain. The physiatrist holds the patient’s scapular in place. Then, by slowly rotating the shoulder, the shoulder girdle muscles are stretched clockwise or counterclockwise to an angle that the patient can tolerate. (A) Metacarpophalangeal joint; (B) proximal interphalangeal joint; (C) distal interphalangeal joint; (D) wrist joint; (E) elbow joint; and (F) shoulder joint.