Cynthia L. Comella

Randomized, double-blind trial of glial cell line-derived neurotrophic factor (GDNF) in PD

Objective: To assess the safety, tolerability, and biological activity of glial cell line-derived neurotrophic factor (GDNF) administered by an implanted intracerebroventricular (ICV) catheter and access port in advanced PD. Background: GDNF is a peptide that promotes survival of dopamine neurons. It improved 6-OHDA- or MPTP-induced behavioral deficits in rodents and monkeys. Methods: A multicenter, randomized, double-blind, placebo-controlled, sequential cohort study compared the effects of monthly ICV administration of placebo and 25, 75, 150, 300, and 500 to 4,000 μg of GDNF in 50 subjects with PD for 8 months. An open-label study extended exposure up to an additional 20 months and maximum single doses of up to 4,000 μg in 16 subjects. Laboratory testing, adverse events (AE), and Unified Parkinson’s Disease Rating Scale (UPDRS) scoring were obtained at 1- to 4-week intervals throughout the studies. Results: Twelve subjects received placebo and seven or eight subjects were assigned to each of the other GDNF dose groups. “On” and “off” total and motor UPDRS scores were not improved by GDNF at any dose. Nausea, anorexia, and vomiting were common hours to several days after injections of GDNF. Weight loss occurred in the majority of subjects receiving 75 μg or larger doses of GDNF. Paresthesias, often described as electric shocks (Lhermitte sign), were common in GDNF-treated subjects, were not dose related, and resolved on discontinuation of GDNF. Asymptomatic hyponatremia occurred in over half of subjects receiving 75 μg or larger doses of GDNF; it was symptomatic in several subjects. The open-label extension study had similar AE and lack of therapeutic efficacy. Conclusions: GDNF administered by ICV injection is biologically active as evidenced by the spectrum of AE encountered in this study. GDNF did not improve parkinsonism, possibly because GDNF did not reach the target tissues—putamen and substantia nigra.

Safety and efficacy of NeuroBloc (botulinum toxin type B) in type A–responsive cervical dystonia

OBJECTIVE To determine the safety and efficacy of botulinum toxin type B (BoNT/B) in patients with cervical dystonia (CD). BACKGROUND BoNT/B is a form of chemodenervation therapy for the treatment of patients with CD. METHODS The authors performed a 16-week, randomized, multicenter, double-blind, placebo-controlled trial of BoNT/B in patients with CD who continue to respond to botulinum toxin type A. Placebo, or 5,000 U or 10,000 U of BoNT/B was administered in two to four muscles involved clinically in CD. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Total score at week 4 was the primary efficacy measure. Clinical assessments and adverse events were recorded for treatment day 1 and at weeks 2, 4, 8, 12, and 16. RESULTS A total of 109 patients were enrolled randomly across all three treatment groups. The mean improvement in the TWSTRS-Total scores in each group at week 4 was 4.3 (placebo), 9.3 (5,000 U), and 11.7 (10,000 U). For the prospectively defined primary contrast (10,000 U versus placebo), highly significant differences were noted for the primary (TWSTRS-Total, baseline to week 4, p = 0.0004) and supportive secondary (Patient Global Assessment, baseline to week 4, p = 0.0001) outcome measures. Improvement in pain, disability, and severity of CD occurred for patients who were treated with BoNT/B when compared with placebo-treated patients. Overall, improvements associated with BoNT/B treatment were greatest for patients who received the 10,000-U dose. The duration of treatment effect for BoNT/B was 12 to 16 weeks for both doses. CONCLUSION Botulinum toxin type B (NeuroBloc) is safe and efficacious at 5,000 U and 10,000 U for the management of patients with cervical dystonia.

Sleep-related violence, injury, and REM sleep behavior disorder in Parkinson's disease

Objective: To determine the occurrence of REM sleep behavior disorder (RBD) and sleep-related injury (SRI) in an outpatient PD practice. Background: RBD is a frequent cause of SRI in older individuals. Although RBD is seen in PD, the association of SRI and RBD in PD has not been previously assessed. Design/Methods: Consecutive patients with PD and their caregivers were interviewed using a structured questionnaire assessing the presence of RBD and SRI. Patients fulfilling the International Classification of Sleep Disorders (ICSD) criteria for RBD were compared with non-RBD patients. In a separate analysis, patients with a prior SRI were compared to those without. Results: Of the 61 patient/caregiver pairs, 15% (7 men and 2 women) met the clinical criteria for RBD. There were more episodes of SRI in the RBD group, with 33% causing injury to themselves or to their caregivers compared with 6% of the non-RBD group (χ2 = 13, p = 0.005). In the second analysis, 15% (all men) patient/caregiver pairs reported SRI. Of these, 66% of the patients had behaviors resembling those seen in RBD, and 33% had recalled dream content. There is a significant association between SRI and RBD for dream-enacting sleep behaviors (Fishers exact test, p = 0.0001). Conclusion: PD patients with SRI frequently have behavioral features of RBD. If RBD underlies most SRI, treatment with appropriate pharmacologic agents, such as clonazepam, may prevent future occurrences of SRI.

High-resolution diffusion tensor imaging in the substantia nigra of de novo Parkinson disease

Background: In the midbrain of patients with Parkinson disease (PD), there is a selective loss of dopaminergic neurons in the ventrolateral and caudal substantia nigra (SN). In a mouse model of PD, investigators have administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and found that measures derived using diffusion tensor imaging (DTI) were correlated with the number of dopamine neurons lost following intoxication. Methods: Twenty-eight subjects (14 with early stage, untreated PD and 14 age- and gender-matched controls) were studied with a high-resolution DTI protocol at 3 Tesla using an eight-channel phase array coil and parallel imaging to study specific segments of degeneration in the SN. Regions of interest were drawn in the rostral, middle, and caudal SN by two blinded and independent raters. Results: Fractional anisotropy (FA) was reduced in the SN of subjects with PD compared with controls (p < 0.001). Post hoc analysis identified that reduced FA for patients with PD was greater in the caudal compared with the rostral region of interest (p < 0.00001). A receiver operator characteristic analysis in the caudal SN revealed that sensitivity and specificity were 100% for distinguishing patients with PD from healthy subjects. Findings were consistent across both raters. Conclusions: These findings provide evidence that high resolution diffusion tensor imaging in the substantia nigra distinguishes early stage, de novo patients with Parkinson disease (PD) from healthy individuals on a patient by patient basis and has the potential to serve as a noninvasive early biomarker for PD.

Fatigue in Parkinson's disease: A review

Fatigue is a common problem in Parkinsons disease (PD), often the most troubling of all symptoms. It is poorly understood, generally under‐recognized, and has no known treatment. This article reviews what is known about the symptom, putting it into the context of fatigue in other disorders, and outlines a program for developing better understanding and therapy.

Longitudinal outcome of Parkinson’s disease patients with psychosis

Objectives: To examine the long-term outcome of PD patients with psychosis requiring antipsychotic therapy; to explore predictors of mortality, nursing home placement, dementia, and persistent psychosis; and to compare outcomes of those with persistent psychosis vs those whose psychosis resolved. Methods: Baseline data available from 59 patients enrolled in the PSYCLOPS (PSychosis and CLOzapine in PD Study) trial included age, age at onset of PD, duration of PD and psychosis, character of psychosis, medications, living setting, and scores for Mini-Mental State Examination (MMSE), Unified Parkinson’s Disease Rating Scale, Hoehn and Yahr Scale, and Clinical Global Impression Scale. Longitudinal data were collected 26 months later regarding four outcomes: death, nursing home placement, diagnosis of dementia, and persistence of psychosis. Logistic regression was used to explore whether any baseline characteristics were associated with an increased likelihood of one of these outcomes. Results: At baseline, 56% of patients had an MMSE score of <25, 12% were in a nursing home, 95% had hallucinations, and 60% had paranoia. On follow-up, 25% were dead, nursing home placement occurred in 42%, psychosis was persistent in 69%, and dementia was diagnosed in 68%. Select baseline characteristics predicted individual outcomes: Nursing home placement was associated with the presence of paranoia and older age; persistent psychosis was associated with younger age at onset of PD and longer disease duration; dementia was associated with older age at PD onset and lower initial MMSE score; no characteristics predicted death. Whether psychosis persisted or not had no significant effect on the development of the other three outcomes. The prevalence of hallucinations at follow-up was not different between groups currently receiving antipsychotics vs those on no treatment. Conclusions: Psychosis in PD requiring antipsychotic therapy is frequently associated with death, nursing home placement, development and progression of dementia, and persistence of psychosis. Still, it appears the prognosis has improved with atypical antipsychotic therapy based on the finding that 28% of NH patients died within 2 years compared with 100% in a previous study done prior to availability of this treatment.

Rating scales for dystonia: A multicenter assessment

The evaluation of dystonia requires a reliable rating scale. The widely used Fahn‐Marsden Scale (F‐M) has not been sufficiently tested across multiple centers and investigators. The Dystonia Study Group developed the Unified Dystonia Rating Scale (UDRS) and a Global Dystonia Rating Scale (GDS) to serve as instruments to assess dystonia severity. In this study, 25 dystonia experts evaluated the UDRS, F‐M, and GDS for internal consistency and reliability. One hundred dystonia patients were videotaped using a standardized videotape protocol. Each examiner rated 20 patients using the UDRS, F‐M, and GDS in random order. The examiner then assessed each scale for ease of use. Statistical analysis used Cronbachs α, intraclass correlation coefficients (ICC), generalized weighted κ statistic, and Kendalls coefficient of concordance. The UDRS, F‐M, and GDS showed excellent internal consistency (Cronbachs α 0.89–0.93) and good to excellent correlation among the raters (ICC range from 0.71–0.78). Inter‐rater agreement was fair to excellent (Kendalls 0.54–0.87; κ 0.37–0.91) being lowest for eyes, jaw, face, and larynx. The modifying ratings (Duration in the UDRS and Provoking Factor in the F‐M) showed less agreement than the motor severity ratings. Among scales, the total scores correlated (Pearsons r, 0.977–0.983). Overall, 74% of raters found the GDS the easiest to apply. The GDS with its simplicity and ease of application may be the most useful dystonia rating scale.

Efficacy and safety of botulinum type A toxin (Dysport) in cervical dystonia: Results of the first US randomized, double-blind, placebo-controlled study

Botulinum toxin type A (Dysport) has been shown in European studies to be a safe and effective treatment for cervical dystonia. This multicenter, double‐blind, randomized, controlled trial assessed the safety and efficacy of Dysport in cervical dystonia patients in the United States. Eighty patients were randomly assigned to receive one treatment with Dysport (500 units) or placebo. Participants were followed up for 4 to 20 weeks, until they needed further treatment. They were assessed at baseline and weeks 2, 4, 8, 12, 16, and 20 after treatment. Dysport was significantly more efficacious than placebo at weeks 4, 8, and 12 as assessed by the Toronto Western Spasmodic Torticollis Rating Scale (10‐point vs. 3.8‐point reduction in total score, respectively, at week 4; P ≤ 0.013). Of participants in the Dysport group, 38% showed positive treatment response, compared to 16% in the placebo group (95% confidence interval, 0.02–0.41). The median duration of response to Dysport was 18.5 weeks. Side effects were generally similar in the two treatment groups; only blurred vision and weakness occurred significantly more often with Dysport. No participants in the Dysport group converted from negative to positive antibodies after treatment. These results confirm previous reports that Dysport (500 units) is safe, effective, and well‐tolerated in patients with cervical dystonia.

Comparison of botulinum toxin serotypes A and B for the treatment of cervical dystonia

Objective: To directly compare two serotypes of botulinum toxin (BoNTA and BoNTB) in cervical dystonia (CD) using a randomized, double-blind, parallel-arm study design. Methods: Subjects with CD who had a previous response from BoNTA were randomly assigned to BoNTA or BoNTB and evaluated in a blinded fashion at baseline, 4 weeks, 8 weeks, and 2-week intervals thereafter until loss of 80% of clinical effect or completion of 20 weeks of observation. CD severity was measured with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), and adverse events were assessed by structured interview. Statistical analysis included Wilcoxon rank sum test, log rank tests, and Kaplan–Meier survival curves for duration of effect. Results: A total of 139 subjects (BoNTA, n = 74; BoNTB, n = 65) were randomized at 19 study sites. Improvement in TWSTRS score was found at 4 weeks after injection and did not differ between serotypes. Dysphagia and dry mouth were more frequent with BoNTB (dysphagia: BoNTA 19% vs BoNTB 48%, p = 0.0005; dry mouth (BoNTA 41% vs BoNTB 80%, p < 0.0001). In clinical responders, BoNT A had a modestly longer duration of benefit (BoNTA 14 weeks, BoNTB 12.1 weeks, p = 0.033). Conclusion: Both serotypes of botulinum toxin (BoNTA and BoNTB) had equivalent benefit in subjects with cervical dystonia at 4 weeks. BoNTA had fewer adverse events and a marginally longer duration of effect in subjects showing a clinical response.

Botulinum toxin injection for spasmodic torticollis Increased magnitude of benefit with electromyographic assistance

To determine the usefulness of EMG-assisted botulinum toxin (BOTOX) injections for the treatment of spasmodic torticollis (ST), we randomized 52 ST patients into two groups and studied them prospectively. In one group [(E+C)RX, N = 28], the muscles were selected for BOTOX injection using both clinical and EMG examination and then injected with EMG assistance. In the second group [(C)RX, N = 24] the muscles were selected for BOTOX injection based solely on clinical examination and injected without EMG assistance. The percentage of patients showing any improvement after BOTOX was similar in both the (E+C)RX and (C)RX groups. A significantly greater magnitude of improvement was present in the (E+C)RX group, as well as a significantly greater number of patients with marked improvement. In particular, patients with retrocollis, head tilt, and shoulder elevation demonstrated additional benefit with EMG-assisted BOTOX injection. EMG assistance may be effective because the technique increases the ability to effectively identify and treat the deep cervical muscles.