Interval training-induced alleviation of rigidity and hypertonia in patients with Parkinson's disease is accompanied by increased basal serum brain-derived neurotrophic factor.

OBJECTIVE: To examine the effects of cycloergometric interval training on parkinsonian rigidity, relaxed biceps brachii muscle tone in affected upper extremities, and serum level of brain-derived neurotrophic factor.
DESIGN: Case series, repeated-measures design, pilot study. SUBJECTS/PATIENTS: Eleven patients with mild-to-moderate Parkinson's disease (Hoehn & Yahr scale 2.3 ± 0.72), recruited from a neurological clinic, underwent cycle training and were tested along with non-trained, healthy control subjects (n = 11) in a motor control laboratory.
METHODS: Patients underwent 8 weeks of interval training (3 × 1-h sessions weekly, consisting of a 10-min warm-up, 40 min of interval exercise, and 10-min cool-down) on a stationary cycloergometer. Parkinsonian rigidity (Unified Parkinson's Disease-Rating-Scale) in the upper extremity, resting biceps brachii muscle tone (myometric stiffness and frequency), and brain-derived neurotrophic factor level were measured 1-3 days before interval training cycle started and 6-10 days after the last training session.
RESULTS: Training resulted in a decrease in rigidity (p = 0.048) and biceps brachii myometric muscle stiffness (p = 0.030) and frequency (p = 0.006), and an increase in the level of brain-derived neurotrophic factor (p = 0.035) relative to pre-training values. The increase in brain-derived neurotrophic factor level correlated with improvements in parkinsonian rigidity (p = 0.025), biceps brachii myometric stiffness (p = 0.001) and frequency (p = 0.002).
CONCLUSION: Training-induced alleviation of parkinsonian rigidity and muscle tone decrease may be associated with neuroplastic changes caused by a training-induced increase in the level of brain-derived neurotrophic factor.