BOTULINUM TOXIN - INFLUENCE ON RESPIRATORY HEART-RATE VARIATION

Remote adverse effects of local intramuscular botulinum toxin were inv estigated in a prospective follow-up study. Twenty-six patients with s pasmodic torticollis were examined (18 women, eight men, 45 +/- 13 yea rs). Respiratory heart rate variation (HRV) was investigated by a comp uterized method. Different parameters were recorded (beats per minute, coefficient of variation, root mean square successive difference (RMS SD), spectral analysis, difference and quotient between maximum and mi nimum RR intervals, mean circular resultant). After one intramuscular injection of 12.5 ng botulinum toxin (Porton Products Ltd., England), no significant influence on HRV was seen. After the second injection, a significant attenuation was seen of four parameters (coefficient of variation, Rmax - Rmin, Rmax divided by Rmin, mean circular resultant) that lasted up to several months. No clinically manifest remote side effects and no cardiac arrhythmia were seen for several months of botu linum toxin treatment. Our investigation proves an effect of local int ramuscular botulinum toxin on autonomic cardiac innervation.