While the majority of
chemodenervation clinics worldwide typically use
botulinum toxins for the treatment of common conditions such as blepharopsams,
cervical dystonia,
limb dystonia, and spasticity, the unusually high concentration of
X-linked dystonia-parkinsonism (XDP) has allowed us to collect and describe our experience in the use of
botulinum toxin type A (
BoNT-A) on rarer dystonic patterns.
BoNT-A (Dysport®) was injected in a total 109 dystonias of XDP. Our cohort included: 50 cases in the oromandibular area (jaw opening: 32 cases, jaw closing: 12 cases, and jaw deviation: 6 cases); 35 cases in the lingual area (tongue protrusion: 27 cases and tongue curling: 8 cases); and, 24 cases in the truncal-axial area (flexor: 12 cases, extensor: 7 cases, and lateral-extensor: 5 cases). Interestingly,
pain, often a nonprominent symptom of dystonias, was frequently reported in 40/50 XDP cases with oromandibular
dystonia and 18/24 XDP cases with truncal-axial
dystonia. All
BoNT-A procedures were performed under electromyography guidance. A "high potency, low dilution"
BoNT-A protocol was applied for oromandibular, lingual, cranial, cervical, and distal limb dystonias; whereas for dystonias of the abdominal, paraspinal, and proximal limb muscles, a "low potency, high dilution"
BoNT-A injection protocol was applied. Outcomes measures included: the global
dystonia rating scale (DRS) and
pain visual analog scale (VAS) reduction at week 4; duration of
BoNT-A effects; and, side effect profile. The median DRS score after 4 weeks was 3 ("substantial improvement") for oromandibular and lingual dystonias and 2 ("moderate improvement") for truncal-axial dystonias.
Pain reduction was significantly reduced (75%-80% in oromandibular; 30%-80% in truncal-axial dystonias). The median duration of
BoNT-A effect was 16 weeks for oromandibular, 12 weeks for lingual, and 11 weeks for truncal-axial dystonias. Compared to a generally safe and well-tolerated
BoNT-A injections for truncal-axial dystonias, the oromandibular-lingual dystonias had the following frequency of adverse events: oromandibular--19% in jaw opening and 17% in jaw closing dystonias; lingual--19% in tongue protrusion and 13% in tongue curling dystonias. The most frequent adverse events were
mouth dryness and
dysphagia. Thus,
BoNT-A injection working protocols may be adopted in XDP
dystonia that adheres to cost minimization (e.g., lower dose end per selected muscle), while achieving some benefit, and potentially reduce the adverse event profile.