Generalised muscular weakness after botulinum toxin injections for dystonia: a report of three cases

Three patients are reported on who developed transient generalised weakness after receiving therapeutic doses of botulinum toxin for cervical dystonia (one case) and symptomatic hemidystonia (two cases) respectively. Clinical and electrophysiological findings were in keeping with mild botulism. All patients had received previous botulinum toxin injections without side effe cts and one patient continued injections without recurrence of generalised weakness. The cause is most Likely presynaptic inhibition due to systemic s pread of the toxin. Patients with symptomatic dystonia may be more likely t o have this side effect and botulinum toxin injections in these patients sh ould be carried out cautiously.