Fourteen patients with "dystonic clenched fist" (three with Corticobasal Ganglionic Degeneration, seven with Parkinson's disease, and four with Dystonic-Complex Regional Pain Syndrome) were treated with botulinum toxin A (BTXA, Dysport). The muscles involved were identified by the hand posture and EMG activity recorded at rest and during active and passive flexion/extension movements of the finger and wrist. EMG was useful in distinguishing between muscle contraction and underlying contractures and to determine the dosage of BTX. All patients had some degree of flexion at the proximal metacarpophalangeal joints and required injections into the lumbricals. The response in patients depended on the severity of the deformity and the degree of contracture. All patients had significant benefit to pain, with accompanying muscle relaxation, and palmar infection, when present, was eradicated. Four patients with Parkinson's disease and one patient with Dystonia-Complex Regional Pain Syndrome obtained functional benefit.

We studied 20 patients with cervical dystonia who had started to respond poorly to botulinum toxin A (BTXA) injections after an initial good response. All patients had extensor digitorum brevis (EDB) tests performed in addition to BTXA immunoprecipition assay (IPA) and mouse bioassay (MBA) antibody testing. The patients were reexamined and then treated with carefully placed electromyogram (EMG)-guided BTXA. Nine patients had a good clinical response to EMG-guided injections and all of these patients showed an obvious decrement on the EDB test. All were BTXA blocking antibodies (Abs)-negative via IPA and MBA (apart from one patient who had low BTXA antibodies titers using IPA but no antibodies by MBA). In the other 11 patients, there was a poor clinical response to EMG-guided BTXA injections. Seven of these 11 had small EDB decrement and BTXA antibodies using IPA, suggesting resistance to BTXA. Of the remaining four patients, two had obvious EDB decrement and low antibody titers via IPA (one of them had no antibodies via MBA), while the other two patients showed obvious decrement on the EDB test and no antibodies via IPA. This study shows that the EDB test correlates better with the clinical response than the antibody assays and that EDB decrement does not always correlate quantitatively with the BTXA antibody titers. In patients with secondary nonresponsiveness, it is recommended that an EDB test is the initial investigation of choice. In those patients where the EDB test does not demonstrate resistance to BTXA, a reexamination of the patients and carefully placed injections under EMG guidance may improve results.

The purpose of this study was to investigate the impact of botulinum toxin (BoNT) treatment on the quality of life (QoL) for patients with prominent lingual dystonia (LD) using a disease-specific questionnaire, the oromandibular dystonia questionnaire-25 (OMDQ-25). This is a prospective, observational study of a cohort of 30 patients treated with BoNT injections for LD, with or without concurrent jaw dystonia. Primary efficacy outcome was the absolute difference between total OMDQ-25 baseline score and total OMDQ-25 scores 4 and 8 weeks after the treatment. Safety outcome was the occurrence of adverse effects. The mean total OMDQ-25 baseline score was 46.8 ± 17.8. After BoNT treatment, there was a significant reduction in the mean total OMDQ-25 score at 4 weeks (38.2 ± 17.6; p = 0.004), as well as at 8 weeks (39.6 ± 18.1; p = 0.008). At the multiple regression analysis, a jaw deviation pattern (JDD) and high questionnaire baseline total score were detected as predictors of a better outcome, whilst associated jaw tremor was a predictor of poor outcome. In patients with JDD, jaw-opening muscles were more frequently injected and genioglossus less frequently than in patients without JDD. No major adverse events were detected. A consistent and measurable improvement in QoL, with good safety and tolerability, can be achieved in patients with prominent LD by injecting BoNT into genioglossus and/or other muscles of the oromandibular region.

The efficacy of botulinum toxin (BTX) without systemic effects has led to the rapid development of applications in neuromuscular disorders, hyperactivity of sudomotor cholinergic-mediated glandular function, and pain syndromes. The successful use of BTX in conditions with muscle overactivity, such as dystonia and spasticity, has been established and new areas in the field of movement disorders such as tics, tremor, myoclonic jerks, and stuttering has been explored with satisfactory results. Strategies to temporarily inactivate muscle function after orthopaedic or neurosurgery have also been developed. BTX treatment of hyperhidrosis was followed by its application in other hypersecretory conditions (hyperlacrimation and nasal hypersecretion) and in excessive drooling. Studies are in progress, aimed at optimising the technique and protocol of administration. Other applications for BTX have been proposed in gastroenterological and urogenital practice; it appears to be effective in replacing standard surgical procedures. Trials of BTX in painful conditions are ongoing mainly on refractory tension headache, migraine, and backache as well as dystonia-complex regional pain syndrome and myofascial pain with promising results. Recently, the fastest growing use for BTX toxin has been in the cosmetic applications. Clearly, the indications for the use of BTX are expanding, but further clinical trials will be needed in many different areas.

This appears to be a paradoxic reaction to LTG in the setting of BECTS.