Electromyography in cervical dystonia: changes after botulinum and trihexyphenidyl.

BACKGROUND: The value of physical examination in detecting involved neck muscles in cervical dystonia (CD) is uncertain and little is known about changes in electromyographic (EMG) features after botulinum toxin type A (BTA) treatment. METHODS: In a double-blind, randomized study we recorded the EMG activities of 420 neck muscles in 42 patients with CD before and after treatment with BTA or trihexyphenidyl. We regarded any needle EMG activity higher than 100 microV as the gold standard for involuntary involvement of a muscle in the dystonic posture and compared this with the results of physical examination. We calculated EMG total scores by adding the scores of the individual muscles. RESULTS: Physical examination had a low predictive value in the detection of involved muscles. There was a significant correlation between changes in EMG total scores and changes in clinical measurements. We observed increased EMG activity in 20% of noninjected muscles after BTA treatment and in 27% of noninjected muscles after trihexyphenidyl treatment. A switch from one most active muscle to another was seen equally in both groups and had no influence on clinical response. CONCLUSION: Physical examination alone is not sufficient to detect involved muscles, and repeated, simultaneous EMG-guided application of BTA may be helpful. In addition to clinical measurements, changes in EMG activity due to treatment can be used as a physiologic measure in evaluating treatment response. Increased activity of noninjected muscles and a switch from one most active muscle to another are not related to BTA treatment, but are probably pathophysiologic phenomena of CD itself.

Treatment of cervical dystonia: a comparison of measures for outcome assessment.

UNLABELLED: There is little agreement on which outcome measures to use to express the efficacy of treatments for cervical dystonia. We analyzed change scores on various scales of 64 new patients with cervical dystonia before and after repeated injections with botulinum toxin. METHOD: The association between change in impairment (Tsui), and change in pain (TWSTRS-Pain) and functional health (TWSTRS-D, MOS-20) was expressed in percentages of variance explained. Effect sizes of the outcome measures from patients who continued botulinum treatment and dropouts were compared. Performance of outcome measures to distinguish patients who continued treatment and dropouts was analyzed with ROC curves and areas under the curve (AUC). RESULTS: Impairments explained < or =7% of the score variance in functional health. There were no differences between the effect sizes of impairment and pain of patients who continued treatment and dropouts (p > 0.60). This suggests a poor reflection of the treatment efficacy by these outcome measures. Conversely, there were significant differences between the effect sizes of the functional status scales of the patients who continued treatment and the dropouts (p < or = 0.01). ROC curve analysis showed that the disability, handicap, and global disease burden scale accurately distinguished between the two groups (AUCs > 0.80). Impairments showed no discriminative accuracy (AUC = 0.46). CONCLUSION: Neurologic impairments have a small impact on the functional health of cervical dystonia patients. Disability, handicap, and a global measure of disease burden were the most suitable outcome parameters to express the clinical efficacy of botulinum therapy.

Long-term effect of botulinum toxin on impairment and functional health in cervical dystonia.

We investigated the long-term effect of botulinum toxin type A (BTA) on impairment as well as functional health in terms of disability, handicap, and quality of life in 64 patients with cervical dystonia. These patients, who first participated in a double-blind trial, were followed for another 12 months. Fifty-four patients continued treatment after 12 months of follow-up and showed improvement on all scales. Furthermore, this effectiveness appeared to increase during follow-up, which suggests a cumulative clinical effect of BTA.

Treatment outcomes in cervical dystonia: a clinimetric study.

We reviewed 21 studies (8 blinded and 13 open) on the treatment of botulinum toxin type A for cervical dystonia, directed to the health aspects used to evaluate the patients' response to treatment (Medline search 1985-1993, English language literature). The prerequisite for comparing the treatment results was that studies had to evaluate similar aspects of disease. The ICIDH model, outlined by the World Health Organization in 1980, orders the different health outcomes into distinct classes of disease consequences. Our aim was to order the health outcomes according to the model and, thus, to study the comparability of treatment outcomes. Three differences could be identified between the objective and the subjective instruments. (a) The aspects measured by the subjective instruments varied substantially; of the 22 different subjective instruments identified in 18 studies, 8 measured impairments, 5 disability, and 9 could not be classified according to the ICIDH model. The objective instruments measured impairments. (b) All objective instruments were multiitem, whereas only 2 of 22 subjective instruments could be identified as multiitem. (c) The subjective instruments were generally poorly documented with regard to the number of items, score range, or grading. We conclude that the treatment outcomes can only be compared on the objective level of assessment and with regard to the patients with painful dystonia. The subjective instruments, particularly those focusing on disease-specific disability, deserve further research. The ICIDH model offers a useful framework for selection, improvement, and development of outcome instruments. Because the model clearly demarcates the different consequences of disease, adoption will enhance the comparability of outcomes in cervical dystonia intervention trials.

[Cornea protection in ptosis induced by botulinum injection]. / Corneabescherming door ptosis opgewekt door botuline-injectie.

Two patients, men aged 82 and 53 years, with weakness of the facial muscles after surgery in the posterior fossa had keratitis caused by the inability to blink and to close the eye. Botulinum toxin type A was injected into the levator palpebrae superioris muscle under electromyographic control. A selective, reversible paralysis of this muscle was induced without weakness of the anatomically related rectus superior muscle. This botulinum toxin-induced protective ptosis appeared to be effective and safe in the treatment and prevention of keratitis in patients with a temporary weakness of the facial muscles.

Botulinum toxin versus trihexyphenidyl in cervical dystonia: a prospective, randomized, double-blind controlled trial.

BACKGROUND: Botulinum toxin type A (BTA) is replacing trihexyphenidyl as the treatment of choice for idiopathic cervical dystonia (ICD), but there has never been a direct comparative study. METHODS: This trial compares the effectiveness of BTA with that of trihexyphenidyl in a prospective, randomized, double-blind design. Sixty-six consecutive patients with ICD were randomized to treatment with trihexyphenidyl tablets plus placebo injection or placebo tablets plus BTA injections. Tablets were administered daily according to a fixed schedule. Dysport or saline was injected under EMG guidance at study entry and again after 8 weeks. Patients were assessed for efficacy at baseline and after 12 weeks by different clinical rating scales. RESULTS: Sixty-four patients completed the study, 32 in each group. Mean dose of BTA was 292 mouse units (first session) and 262 mouse units (second session). Mean dose of trihexyphenidyl was 16.25 mg. The changes on the Disability section of the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS-Disability) (primary outcome), Tsui Scale, and the General Health Perception Subscale were significantly in favor of BTA. More patients treated with BTA had an improvement of at least three points on the TWSTRS-Disability (14 versus 6) and on the Tsui Scale (23 versus 12). Adverse effects were significantly less frequent in the BTA group. CONCLUSION: BTA is significantly more effective in the treatment of ICD, with less adverse effects.

Pretarsal application of botulinum toxin for treatment of blepharospasm.

The response to botulinum toxin type A was compared after two injection techniques in 45 patients with blepharospasm. Initially, patients were treated according to a triple injection technique; two injections into the upper eyelid and one injection into the lower eyelid. Subsequently, without altering the dose, the same patient group received two further injections into the pretarsal portion of the orbicularis oculi muscle of the upper lid. Triple injections were given in 227 treatments, of which 81% were successful. Mean duration of benefit was 8.5 weeks. Additional pretarsal injections were given in 183 treatment sessions. The number of successful treatments significantly increased, to 95% (P < 0.001), and the mean duration of benefit increased to 12.5 weeks (P < 0.001). Ptosis occurred significantly less often after pretarsal injections (P < 0.01). Patients with combined blepharospasm and involuntary levator palpebrae inhibition responded better to the pretarsal injection technique.

Botulinum toxin in cervical dystonia: low dosage with electromyographic guidance.

Sixty patients with idiopathic cervical dystonia were treated a total of 240 times with botulinum toxin type A (BTA). Selected muscles were injected with BTA under electromyographic (EMG) guidance. The clinical effect was measured on the Tsui scale and a 10-point anchored visual analogue scale. A dosage of 150-300 mouse units was used in 77% of the treatments (mean 204 mouse units). Based on the Tsui scale, 45% of 240 treatments were still effective at the moment of reinjection (median improvement 2 points). Based on the 10-point anchored visual analogue scale, 73% of treatments were successful (median improvement 3 points). Forty-eight patients (80%) responded favourably to the treatment. Side-effects were mild and transient. Dysphagia occurred in 9% of treatments. Antibody production was investigated in 41 patients and was negative in all. A striking difference from previous reports is the lower dosage used in this study. The clinical response, however, was similar to that of other studies. We conclude that a dosage of 200-400 mouse units BTA (Dysport) may also be effective in the treatment of cervical dystonia, but with fewer side effects. EMG guidance and application of BTA into deep cervical muscles may further improve the clinical effect.

[Blepharospasm; results of treatment with botulin]. / Blefarospasme; resultaten van behandeling met botuline.

OBJECTIVE: Discussion of clinical symptoms and differential diagnosis of blepharospasm and treatment with botulinum A toxin. Blepharospasm is an involuntary spasmodic contraction of the eyelids. Within a few years 35%-70% of the patients becomes severely disabled. DESIGN: Prospective, open study. SETTING: Academical Medical Centre, Amsterdam. METHOD: In the period 1985-1992 we have seen 85 patients with blepharospasm. Of these 69 were treated with botulinum toxin, a total of 436 treatments, with a mean dose of 25 IU for each eye. RESULTS: The cause of blepharospasm was unknown in 71 patients. Secondary blepharospasm occurred in: peripheral facial palsy (one patient), herpes zoster infection of the trigeminal nerve (2), brain infarct (1), use of neuroleptics (2), progressive supranuclear palsy (2), Shy-Drager syndrome (1), kernicterus (1), and morbus Sjögren (4). There were 18 patients with autoimmune diseases. 77 (91%) patients had a (very) severe form of blepharospasm. Electromyographic registration revealed a dysfunction of M. levator palpebrae in 7 patients. More than 70% of the patients were free of symptoms for a mean period of two months after each treatment. Local side effects were seen in 61 (14%) of the 436 treatments: ptosis, haematoma, dry eyes, and diplopia. CONCLUSION: Blepharospasm is a disabling disease and occurs sometimes in association with other neurological and ophthalmological diseases. Botulinum A toxin is a safe and effective therapy. Electrophysiological investigation is important in the differential diagnosis; it is unnecessary to do CT or MRI routinely.