Neuronal nicotinic receptor agonists improve gait and balance in olivocerebellar ataxia.

Clinical studies have reported that the nicotinic receptor agonist varenicline improves balance and coordination in patients with several types of ataxia, but confirmation in an animal model has not been demonstrated. This study investigated whether varenicline and nicotine could attenuate the ataxia induced in rats following destruction of the olivocerebellar pathway by the neurotoxin 3-acetylpyridine (3-AP). The administration of 3-AP (70 mg/kg followed by 300 mg niacinamide/kg; i.p.) led to an 85% loss of inferior olivary neurons within one week without evidence of recovery, and was accompanied by a 72% decrease in rotorod activity, a 3-fold increase in the time to traverse a stationary beam, a 19% decrease in velocity and 31% decrease in distance moved in the open field, and alterations in gait parameters, with a 19% increase in hindpaw stride width. The daily administration of nicotine (0.33 mg free base/kg) for one week improved rotorod performance by 50% and normalized the increased hindpaw stride width, effects that were prevented by the daily preadministration of the nicotinic antagonist mecamylamine (0.8 mg free base/kg). Varenicline (1 and 3 mg free base/kg daily) also improved rotorod performance by approximately 50% following one week of administration, and although it did not alter the time to traverse the beam, it did improve the ability to maintain balance on the beam. Neither varenicline nor nicotine, at doses that improved balance, affected impaired locomotor activity in the open field. Results provide evidence that nicotinic agonists are of benefit for alleviating some of the behavioral deficits in olivocerebellar ataxia and warrant further studies to elucidate the specific mechanism(s) involved.

Placebo-controlled trial of lubiprostone for constipation associated with Parkinson disease.

OBJECTIVE: To evaluate the efficacy and tolerability of lubiprostone (Amitiza) for constipation in Parkinson disease (PD) in a double-blind, randomized, controlled study. METHODS: Patients with PD and clinically meaningful constipation (constipation rating scale score > 10 [range: 0-28]) were recruited from 2 academic movement disorder centers to participate in the study. After enrollment, patients were initially followed for 2 weeks and then were randomly assigned 1:1 to lubiprostone, and the dose was titrated up to 48 µg/day. They returned 4 weeks later for a final assessment. Data included stool diaries and global impressions (co-primary endpoints), demographics, Unified Parkinson's Disease Rating Scale scores, constipation scale scores, visual analog scale (VAS) scores, a stool diary, and adverse events. RESULTS: Fifty-four subjects (39 male, mean age 67.0 ± 10.1 years, and mean duration of PD 8.3 ± 5.4 years) were randomly assigned to lubiprostone or placebo. One patient in the drug group discontinued the study because of logistics, and one patient in the placebo group discontinued the study because of lack of efficacy. A marked or very marked clinical global improvement was reported by 16 of 25 (64.0%) subjects receiving drug vs 5 of 27 (18.5%) subjects receiving placebo (p = 0.001). The constipation rating scale (p < 0.05), VAS (p = 0.001), and stools per day in the diary (p < 0.001) all improved with drug compared with placebo. Adverse events with drug were mild, most commonly intermittent loose stools. CONCLUSION: In this randomized controlled trial, lubiprostone seemed to be well tolerated and effective for the short-term treatment of constipation in PD.

A randomized trial of varenicline (Chantix) for the treatment of spinocerebellar ataxia type 3.

OBJECTIVE: The objective of this double-blind, placebo-controlled, randomized study was to evaluate the efficacy of varenicline (Chantix), a partial agonist at α4ß2 neuronal nicotinic acetylcholine receptors used for smoking cessation, in patients with spinocerebellar ataxia (SCA) 3. METHODS: Patients with genetically confirmed SCA3 were randomly assigned to receive either varenicline (4 weeks for titration and 4 weeks at a dose of 1 mg twice daily) or placebo. Outcome measures included changes in the Scale for the Rating and Assessment of Ataxia (SARA) scores at endpoint (8 weeks) compared with baseline, a timed 25-foot walk and 9-hole peg test, measurements of mood and anxiety, and adverse events. RESULTS: Twenty patients with SCA3 (mean age = 51 ± 10.98 years; mean disease duration = 14 ± 9.82 years; mean SARA score = 16.13 ± 4.67) were enrolled in the study, and data on 18 patients were analyzed in period I. The most common side effect associated with varenicline was nausea. Improvements were noted in the SARA subsections for gait (p = 0.04), stance (p = 0.03), rapid alternating movements (p = 0.003), and timed 25-foot walk (p = 0.05) and Beck Depression Inventory scores (p = 0.03) in patients taking varenicline compared with those taking placebo at endpoint, with a trend toward improvement in the SARA total score (p = 0.06) in the varenicline group. CONCLUSIONS: In this controlled study, varenicline significantly improved axial symptoms and rapid alternating movements in patients with SCA3 as measured by SARA subscores and was fairly well tolerated. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that varenicline improved the axial functions of gait, stance, and timed 25-foot walk but did not improve appendicular function, except for rapid alternating movements, in adult patients with genetically confirmed SCA3.

Evidence-based guideline update: treatment of essential tremor: report of the Quality Standards subcommittee of the American Academy of Neurology.

BACKGROUND: This evidence-based guideline is an update of the 2005 American Academy of Neurology practice parameter on the treatment of essential tremor (ET). METHODS: A literature review using MEDLINE, EMBASE, Science Citation Index, and CINAHL was performed to identify clinical trials in patients with ET published between 2004 and April 2010. RESULTS AND RECOMMENDATIONS: Conclusions and recommendations for the use of propranolol, primidone (Level A, established as effective); alprazolam, atenolol, gabapentin (monotherapy), sotalol, topiramate (Level B, probably effective); nadolol, nimodipine, clonazepam, botulinum toxin A, deep brain stimulation, thalamotomy (Level C, possibly effective); and gamma knife thalamotomy (Level U, insufficient evidence) are unchanged from the previous guideline. Changes to conclusions and recommendations from the previous guideline include the following: 1) levetiracetam and 3,4-diaminopyridine probably do not reduce limb tremor in ET and should not be considered (Level B); 2) flunarizine possibly has no effect in treating limb tremor in ET and may not be considered (Level C); and 3) there is insufficient evidence to support or refute the use of pregabalin, zonisamide, or clozapine as treatment for ET (Level U).

Clinical vignettes in Parkinson's disease: a collection of unusual medication-induced hallucinations, delusions, and compulsive behaviours.

Hallucinations, delusions, and compulsive behaviors are frequent iatrogenic complications of the treatment of motor dysfunction in Parkinson's disease (PD). Although these have been studied, and the phenomenology described, there are few detailed descriptions of the various psychiatric problems our treated PD patients live with that allow physicians who do not have a great deal of experience with PD patients to appreciate the extent of their altered lives. This report is a compilation of vignettes describing these behavioral problems that the treating neurologist or psychiatrist attributed to the medications used for treating PD.

Practice Parameter: treatment of nonmotor symptoms of Parkinson disease: report of the Quality Standards Subcommittee of the American Academy of Neurology.

OBJECTIVE: Nonmotor symptoms (sleep dysfunction, sensory symptoms, autonomic dysfunction, mood disorders, and cognitive abnormalities) in Parkinson disease (PD) are a major cause of morbidity, yet are often underrecognized. This evidence-based practice parameter evaluates treatment options for the nonmotor symptoms of PD. Articles pertaining to cognitive and mood dysfunction in PD, as well as treatment of sialorrhea with botulinum toxin, were previously reviewed as part of American Academy of Neurology practice parameters and were not included here. METHODS: A literature search of MEDLINE, EMBASE, and Science Citation Index was performed to identify clinical trials in patients with nonmotor symptoms of PD published between 1966 and August 2008. Articles were classified according to a 4-tiered level of evidence scheme and recommendations were based on the level of evidence. RESULTS AND RECOMMENDATIONS: Sildenafil citrate (50 mg) may be considered to treat erectile dysfunction in patients with Parkinson disease (PD) (Level C). Macrogol (polyethylene glycol) may be considered to treat constipation in patients with PD (Level C). The use of levodopa/carbidopa probably decreases the frequency of spontaneous nighttime leg movements, and should be considered to treat periodic limb movements of sleep in patients with PD (Level B). There is insufficient evidence to support or refute specific treatments for urinary incontinence, orthostatic hypotension, and anxiety (Level U). Future research should include concerted and interdisciplinary efforts toward finding treatments for nonmotor symptoms of PD.

Treatment of imbalance with varenicline Chantix(R): report of a patient with fragile X tremor/ataxia syndrome.

We describe the case of a man with Fragile X tremor/ataxia syndrome, whose ataxia and imbalance improved with the use of varenicline (Chantix) and reverted to baseline 10 days after varenicline was discontinued. Varenicline was started as part of a smoking cessation program.

Social Security Disability Insurance (SSDI) in Parkinson's disease.

OBJECTIVE: Parkinson's disease (PD) causes significant economic burden for patients and caregivers. Social Security Disability Insurance (SSDI) provides insurance to workers in the United States who have been gainfully employed, but who are no longer able to work due to a medical condition. We performed a descriptive pilot study that examined PD patients' experience with SSDI. METHODS: PD patients who were diagnosed with PD prior to age 60 and were followed at an academic movement disorders center were consecutively invited to participate in a survey concerning their employment history and experience with SSDI. RESULTS: All 68 invited patients participated in the study (mean age 58 years, mean disease duration 9.5 years). Eighty-two percent of patients felt that they were too disabled to work full time at a mean of 3.4 years after PD diagnosis. Patients applied for SSDI at a mean of 5 years after diagnosis, and two-thirds of PD patients who applied for SSDI obtained it on their first attempt. The primary debilitating symptom that subjectively contributed to work disability was fatigue (49% of patients). Patients who successfully acquired SSDI had extensive documentation of physician visits, and the aid of a disability lawyer. CONCLUSIONS: Patients felt they were too disabled to work full time at a mean of 3.4 years after diagnosis. Those who applied for SSDI did so at a mean of 5 years after diagnosis. Patients who obtained SSDI awards had extensive documentation of medical records or the help of a disability lawyer.

Practice Parameter: diagnosis and prognosis of new onset Parkinson disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology.

OBJECTIVE: To define key issues in the diagnosis of Parkinson disease (PD), to define features influencing progression, and to make evidence-based recommendations. Two clinical questions were identified: 1) Which clinical features and diagnostic modalities distinguish PD from other parkinsonian syndromes? 2) Which clinical features predict rate of disease progression? METHODS: Systematic review of the literature was completed. Articles were classified according to a four-tiered level of evidence scheme. Recommendations were based on the evidence. RESULTS AND CONCLUSIONS: 1. Early falls, poor response to levodopa, symmetry of motor manifestations, lack of tremor, and early autonomic dysfunction are probably useful in distinguishing other parkinsonian syndromes from Parkinson disease (PD). 2. Levodopa or apomorphine challenge and olfactory testing are probably useful in distinguishing PD from other parkinsonian syndromes. 3. Predictive factors for more rapid motor progression, nursing home placement, and shorter survival time include older age at onset of PD, associated comorbidities, presentation with rigidity and bradykinesia, and decreased dopamine responsiveness. Future research into methods for earlier and more accurate diagnosis of the disease and identification and clarification of predictive factors of rapid disease progression is warranted.

Practice Parameter: neuroprotective strategies and alternative therapies for Parkinson disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology.

OBJECTIVE: To define key issues in the management of Parkinson disease (PD) relating to neuroprotective strategies and alternative treatments, and to make evidence-based treatment recommendations. METHODS: Two clinical questions were identified. 1) In a patient diagnosed with PD, are there any therapies that can slow disease progression? 2) Are there any nonstandard pharmacologic or nonpharmacologic therapies that have been shown to improve motor function in PD? Articles were classified according to a four-tiered level of evidence scheme. Recommendations were based on the evidence. RESULTS AND CONCLUSIONS: 1. Levodopa does not appear to accelerate disease progression. 2. No treatment has been shown to be neuroprotective. 3. There is no evidence that vitamin or food additives can improve motor function in PD. 4. Exercise may be helpful in improving motor function. 5. Speech therapy may be helpful in improving speech volume. 6. No manual therapy has been shown to be helpful in the treatment of motor symptoms, although studies in this area are limited. Further studies using a rigorous scientific method are needed to determine efficacy of alternative therapies.

Practice parameter: therapies for essential tremor: report of the Quality Standards Subcommittee of the American Academy of Neurology.

BACKGROUND: Essential tremor (ET) is one of the most common tremor disorders in adults and is characterized by kinetic and postural tremor. To develop this practice parameter, the authors reviewed available evidence regarding initiation of pharmacologic and surgical therapies, duration of their effect, their relative benefits and risks, and the strength of evidence supporting their use. METHODS: A literature review using MEDLINE, EMBASE, Science Citation Index, and CINAHL was performed to identify clinical trials in patients with ET published between 1966 and August 2004. Articles were classified according to a four-tiered level of evidence scheme and recommendations were based on the level of evidence. RESULTS AND CONCLUSIONS: Propranolol and primidone reduce limb tremor (Level A). Alprazolam, atenolol, gabapentin (monotherapy), sotalol, and topiramate are probably effective in reducing limb tremor (Level B). Limited studies suggest that propranolol reduces head tremor (Level B). Clonazepam, clozapine, nadolol, and nimodipine possibly reduce limb tremor (Level C). Botulinum toxin A may reduce hand tremor but is associated with dose-dependent hand weakness (Level C). Botulinum toxin A may reduce head tremor (Level C) and voice tremor (Level C), but breathiness, hoarseness, and swallowing difficulties may occur in the treatment of voice tremor. Chronic deep brain stimulation (DBS) (Level C) and thalamotomy (Level C) are highly efficacious in reducing tremor. Each procedure carries a small risk of major complications. Some adverse events from DBS may resolve with time or with adjustment of stimulator settings. There is insufficient evidence regarding the surgical treatment of head and voice tremor and the use of gamma knife thalamotomy (Level U). Additional prospective, double-blind, placebo-controlled trials are needed to better determine the efficacy and side effects of pharmacologic and surgical treatments of ET.

Heart failure in Parkinson's disease: analysis of the United States medicare current beneficiary survey.

OBJECTIVE: We sought to examine the prevalence of heart failure in elderly PD versus non-PD patients using a national sample of Medicare beneficiaries in the United States. SCOPE: The prevalence of heart failure in elderly PD patients was 2.27 times that of non-PD patients (19.4% versus 8.7%, 95% CI = 1.43-3.60, p 0.0005), and remained twice as high after excluding patients with stroke and possible vascular parkinsonism. CONCLUSIONS: In this cross-sectional study of a national Medicare database, heart failure occurred twice as frequently in elderly PD patients as in non-PD patients. Prospective studies are warranted to verify these findings.

Driving safety in Parkinson's disease.

In this study, 39 patients with PD and 25 control subjects without neurologic disease completed testing in a driving simulator. PD patients had more total collisions on the driving simulator than control subjects (t = -3.7, p < 0.01). In PD patients, collisions were associated with Hoehn and Yahr stage (chi(2) = 12.4, p = 0.006) and correlated with Unified Parkinson's Disease Rating Scale score (r = 0.5, p < 0.01).

Phenomenology and treatment of tremor disorders.

Tremor is classified according to anatomic distribution among body parts, and by frequency and amplitude during rest, postural maintenance, movement, intention, and the performance of specific tasks. Key historical features include age at onset, progression over time, family history, exacerbating and remitting factors and behaviors, response to alcohol and medications, and additional neurological signs and symptoms. Accurate diagnosis is a critical factor in predicting the natural history and response to treatment.

Neurosurgery for Parkinson's disease.

Medical therapy for Parkinson's disease (PD) often becomes inadequate over several years. Disability increases despite maximal medical management and many patients develop motor fluctuations and dyskinesia. In addition, medications provide good control of tremor in only 50% of cases. In appropriately selected cases, surgical therapies for PD provide benefit for medically refractory symptoms. Recent advances have provided a greater array of surgical options. Unilateral thalamotomy and thalamic stimulation are considered safe and effective procedures to treat contralateral tremor. Pallidotomy and pallidal stimulation primarily reduce contralateral dyskinesia, with lesser effects on bradykinesia and rigidity. Studies indicate that subthalamic nucleus (STN) stimulation improves "off" period function, decreases "off" time, and lessens dyskinesia. Fetal cell transplantation remains experimental, and studies are underway to evaluate the safety and efficacy of porcine fetal cell and human retinal pigment epithelial cell transplantation. This chapter reviews the history of surgical procedures for PD, describes current procedures, and offers a look into the future of neurosurgical options for PD.

Pramipexole-induced somnolence and episodes of daytime sleep.

Pramipexole is a non-ergot dopamine agonist used to treat Parkinson's disease (PD). Because of concern regarding driving safety, we evaluated the incidence and nature of somnolence experienced by patients receiving pramipexole in clinical trials at our center. A retrospective chart review was performed and structured interviews were conducted with patients who had reported moderate or severe somnolence. In addition, two patients underwent polysomnography (PSG) and multiple sleep latency tests (MSLT) while on and 2 weeks after discontinuation of pramipexole. Forty patients with PD participating in pramipexole clinical trials were identified. In the double-blind phases of the studies, 22 patients were randomized to pramipexole and 18 were randomized to placebo. Six patients assigned to pramipexole reported somnolence as an adverse event (1 moderate, 5 mild) compared with two patients assigned to placebo (1 severe, 1 moderate; p = 0.19, one-tailed Fisher's exact test). Thirty-seven patients participated in open-label extension studies. Twenty-one (57%) reported somnolence as an adverse event. Eleven (30%) patients reported moderate somnolence and three (8%) patients reported severe somnolence. For patients with moderate or severe somnolence, the onset of worst-reported somnolence occurred at a mean (+/- standard error) pramipexole dose of 4.0 +/- 0.4 mg (range, 0.75-4.5 mg) per day. Patients had been taking pramipexole for a total of 10.0 +/- 1.5 months (range, .03-22 mos) and at their maximal dose for 6.7 +/- 1.5 months (range, .03-20 mos). During structured interviews with 12 of the 14 patients reporting moderate or severe somnolence, seven reported falling asleep while driving and two reported minor motor vehicle accidents caused by falling asleep. Most patients reported relatively continuous drowsiness that led to falling asleep without acute warning during periods of inactivity. Three patients reported discreet waves of irresistible sleepiness heralded by prodromal symptoms occurring against a background of normal wakefulness. MSLT in two of these patients revealed decreased latency to sleep without early onset of rapid eye movements. Sleep latency normalized after withdrawal of pramipexole. Intensive patient education is necessary to prevent motor vehicle accidents in patients taking pramipexole. We recommend that patients who are experiencing generalized drowsiness and falling asleep during periods of inactivity be instructed not to drive because these patients do fall asleep without acute warning. Somnolence usually resolves with pramipexole dose reduction or discontinuation. Patients should also be alerted to pull over and stop driving immediately if they feel a wave of sleepiness coming on. Patient education and compliance are critical to maximize safety.

A home diary to assess functional status in patients with Parkinson's disease with motor fluctuations and dyskinesia.

In clinical trials for patients with Parkinson's disease (PD) with motor fluctuations, efficacy is generally ascribed to an intervention if motor function is significantly improved or if "off" time is significantly reduced. However, we have argued that patients might not be improved if off time is reduced only to the extent that unwanted dyskinesia is increased. Therefore, a home diary should include an assessment of dyskinesia to provide an accurate reflection of clinical status over a period of time. We undertook two studies to develop a home diary to assess functional status in patients with PD with motor fluctuations and dyskinesia. In both studies, patients concurrently completed a test and a reference diary. In Study I, we evaluated the impact of different severities of dyskinesia on patient-defined functional status. There were 1,149 evaluable half-hour time periods from 24 patients; 94.3% of off time was considered "bad" time and 90.2% of "on" time without dyskinesia, 72.6% of on time with mild dyskinesia, 43.0% of on time with moderate dyskinesia, and 15.2% of on time with severe dyskinesia was considered "good" time. In Study II, we evaluated a new home diary designed to separate dyskinesia that had a negative impact on patient-defined functional status from dyskinesia that did not. There were 816 evaluable time periods from 17 patients; 84.9% of off time and 89.9% of on time with troublesome dyskinesia was considered bad time while 85.5% of on time without dyskinesia and 93.8% of on time with nontroublesome dyskinesia was considered good time. With this diary (Diary II), the effect of an intervention can be expressed as the change in off time and the change in on time with troublesome dyskinesia (bad time). The sum can be used as an outcome variable and compared to baseline or across groups. In evaluating the efficacy of an intervention, assessment of change in off time and change in on time with troublesome dyskinesia provides a more accurate reflection of clinical response than change in off time alone.

Sildenafil citrate (Viagra) for the treatment of erectile dysfunction in men with Parkinson's disease.

Sildenafil citrate (Viagra) is a phosphodiesterase type V inhibitor used to treat erectile dysfunction. Ten men with idiopathic Parkinson's disease (PD) and erectile dysfunction were prescribed 50-100 mg sildenafil citrate to use in eight sexual encounters over a 2-month period. Patients underwent Unified Parkinson's Disease Rating Scale (UPDRS) evaluations and completed a Beck's Depression Inventory (BDI) and a Sexual Health Inventory-M version (SHI-M) at baseline and after 8 weeks. There was statistically significant improvement in total SHI-M scores (23.8 +/- 2.0 vs 16.6 +/- 2.8; p = 0.01), overall sexual satisfaction (p = 0.03), satisfaction with sexual desire (p = 0.04), ability to achieve erection (p = 0.02), ability to maintain erection (p = 0.03), and ability to reach orgasm (p = 0.04) with use of sildenafil citrate. UPDRS and BDI scores were not significantly changed. Side effects included headache in one patient during three sexual encounters. In this open-label study, sildenafil citrate significantly improved sexual function in men with PD and erectile dysfunction.

Current issues in depression in Parkinson's disease.

Depression affects 40%-50% of Parkinson's disease (PD) patients. The authors, by use of a Mednet and manual search of pertinent literature, summarize current issues in the treatment of depression in PD. Open-label studies suggest that antidepressants may be effective for treating depression in PD. Although case reports indicate that selective serotonin reuptake inhibitors (SSRIs) can potentially worsen the motor symptoms of PD, this effect has not been confirmed in the small number of open-label studies that have been performed to date. The occurrence of the serotonin syndrome resulting from a combination of selegiline and an SSRI appears to be rare. Double-blind prospective studies are needed to evaluate the safety and efficacy of antidepressants in PD and their effect on motor function.