The Controversy Concerning Plasma Homocysteine in Parkinson Disease Patients Treated with Levodopa Alone or with Entacapone

Levodopa treatment of Parkinson disease results in hyperhomocysteinemia (HHcy) as a consequence of levodopa methylation by catechol-O-methyltransferase (COMT). Although inhibition of COMT should theoretically prevent or reduce levodopa-induced HHcy, results from several prospective studies are conflicting. Our review of these studies suggests that the ability of COMT inhibition to reduce or prevent levodopa-induced HHcy in Parkinson disease patients may be attributed to differences in the vitamin status of the study participants. In patients with low or low-normal folate levels, levodopa administration is associated with a greater increase in homocysteine and concomitant entacapone administration is associated with a greater reduction in homocysteine.

Open-label pilot study of levetiracetam (Keppra) for the treatment of chorea in Huntington's disease

The objective of this study is to evaluate the tolerability and preliminary efficacy of levetiracetam (LEV) in reducing chorea in Huntington's disease (HD) patients in a prospective open-label pilot study. Nine HD patients with chorea were treated with LEV in doses up to 3,000 mg/day for up to 48 days. The primary endpoint measure was the Unified Huntington's Disease Rating Scale (UHDRS) chorea subscore. The mean dose (+/-SD) of LEV at endpoint was 2,583.3 +/- 1,020.6 mg/day. Mean UHDRS chorea score decreased from 12.6 +/- 3.0 at baseline to 6.7 +/- 4.3 at endpoint (P = 0.01). There was no significant change in UHDRS total motor scores (38.8 +/- 11.4 at baseline and 33.6 +/- 26.7 at endpoint; P = 0.24). Somnolence contributed to a 33% drop-out rate, and 3 patients developed Parkinsonism. Results of this open label study suggest that LEV may be efficacious in reducing chorea in HD patients.

Use of nutritional supplements in Parkinson's disease patients

The use of nutritional supplements has almost doubled in the elderly population in the United States (US) in the past decade. We evaluated the use of nutritional supplements in Parkinson's disease (PD) patients to determine the prevalence of their use and whether patients were aware of possible side effects and drug interactions in the supplements they were taking. Consecutively selected PD patients from an academic movement disorders center completed a 33-item questionnaire regarding their use of nutritional supplements. A total of 120 PD patients completed the questionnaire and were included in the data analysis (mean age +/- SD = 68.2 +/- 11.65 years, 67 [55.8%] men and 53 women). Seventy-six patients (63%) took nutritional supplements at the time of data collection. Vitamins were the most common nutritional supplements used, and vitamin E was the most commonly used vitamin. Thirty-six patients (47%) who took nutritional supplements consulted with their doctor before taking them, and only 4% of patients who took nutritional supplements were aware of possible side effects from their use. Twenty patients (16.7%) reported that they were currently taking nutritional supplements because of symptoms related to their Parkinson's disease. The vast majority of PD patients surveyed were not aware that nutritional supplements could cause adverse side effects. Less than half of the patients who took nutritional supplements consulted their physician before starting them. Greater awareness of nutritional supplement use in PD patients is warranted to avoid potentially harmful effects and drug interactions.

Open-label pilot study of levetiracetam (Keppra) for the treatment of levodopa-induced dyskinesias in Parkinson's disease

We evaluated the tolerability and preliminary efficacy of levetiracetam (LEV; Keppra) in reducing levodopa-induced dyskinesias in Parkinson's disease (PD) in an open-label pilot study. Nine PD patients who were experiencing peak-dose dyskinesias for at least 25% of the awake day and were at least moderately disabling were treated with LEV in doses up to 3,000 mg for up to 60 days. The primary outcome measure was the percent of the awake day that patients spent on without dyskinesia or with nontroublesome dyskinesia (good on time). The mean dose of LEV at endpoint was 625+/-277 mg/day. LEV significantly improved percent of the awake day on without dyskinesia or with nontroublesome dyskinesia at endpoint compared to baseline (43% +/- 12% vs. 61% +/- 17%; P=0.02). Percent on time with troublesome dyskinesia decreased from 23% +/- 10% at baseline to 11% +/- 6% at endpoint, although not significantly. There was no significant increase in off time from baseline to endpoint. There was a 56% dropout rate, mostly due to somnolence. In PD patients who experienced peak-dose dyskinesia for at least 25% of the awake day, LEV significantly improved on time without dyskinesia or with nontroublesome dyskinesia.

Levetiracetam for the treatment of generalized dystonia

We report the case of a woman with generalized dystonia whose symptoms improved with the use of levetiracetam. Improvements were noted in blepharospasm, cervical, and truncal dystonia. The patient has been on LEV for a total of 20 weeks, and has experienced sustained improvement of symptoms.

Ropinirole in the treatment of Parkinson's disease

In this review, the pharmacokinetics, safety and tolerability, and clinical efficacy of ropinirole (Requip), a non-ergoline dopamine agonist approved for use in the treatment of Parkinson's disease (PD) are examined. A summary of preclinical and clinical studies is presented. Ropinirole is safe and efficacious as monotherapy in the treatment of early PD and as an adjunct to levodopa in more advanced cases.

Levetiracetam-Induced Parkinsonism in a Huntington Disease Patient

The authors present a man with Huntington disease who was treated with levetiracetam (Keppra) in an effort to reduce chorea. Chorea was markedly reduced, but the patient developed parkinsonism and lethargy after 6 weeks of treatment. Symptoms consisted of resting tremor, rigidity, increased dystonia, and gait difficulty. Side effects from levetiracetam resolved completely within 7 days of levetiracetam discontinuation, and chorea returned to baseline.

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.

Chorea in a patient with cerebral palsy: Treatment with levetiracetam

We report on the case of an adult cerebral palsy patient who developed severe chorea coincident with a febrile illness from a nonstreptococcal infection. The chorea improved markedly with the use of levetiracetam (LEV, Keppra).

Substantial improvement in a Meige's syndrome patient with levetiracetam treatment

We report on a woman with idiopathic Meige's syndrome whose dystonia improved with the use of levetiracetam (LEV, Keppra, UCB Pharma, Smyrna, GA). This report and data from an animal model of paroxysmal dystonia suggest that LEV might be helpful in the treatment of dystonia.

Botulinum toxin A for the treatment of cervical dystonia

Idiopathic cervical dystonia (ICD) is the most common adult-onset focal dystonia. It is characterised by relatively sustained, involuntary contractions of neck muscles. Injections of botulinum toxin (BTX)-A are safe and effective for the treatment of ICD, and have substantially improved its treatment. BTX-A is manufactured by Allergan Pharmaceuticals in the US and Ireland, and is distributed as Botox. In Europe, BTX-A is manufactured and distributed by Ipsen Pharmaceuticals as Dysport. Success rates for BTX-A injections for ICD ranges 64-90%, with 76-93% of injected patients experiencing pain reduction. Side effects are generally mild and include dysphagia and neck weakness.

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.

Essential Tremor

BACKGROUND

Essential tremor (ET) is the most common adult tremor disorder and is characterized by postural and kinetic tremor. Symptoms are typically progressive and potentially disabling, often forcing patients to change jobs or seek early retirement. Proper treatment is contingent on a correct diagnosis, and other possible causes of tremor must be excluded.

REVIEW SUMMARY

Although primidone and propranolol have been regarded as the mainstays of pharmacologic therapy for ET, additional agents may be useful in reducing tremor. Surgical procedures are available that effectively ameliorate tremor that is refractory to medical management. This article reviews the epidemiology, pathophysiology, and treatment options for ET.

CONCLUSIONS

Despite a range of treatment options currently available, further research is necessary to manage this syndrome most effectively. Double-blind, controlled trials are needed to determine whether primidone, propranolol, or a combination of these medications is superior in the initial management of ET. Other pharmacologic agents have shown potential to reduce tremor and should be investigated further. Additional studies are also needed to determine the best treatment of head and voice tremor with pharmacologic and surgical interventions. With proper treatment, tremor is sufficiently reduced in the majority of patients.

Sleep attacks and dopamine agonists for Parkinson's disease: what is currently known?

The aetiology of sleep disturbances in patients with Parkinson's disease is multifactorial. Medications, the disease process and underlying sleep disorders may contribute to sleepiness in patients with the disease. Somnolence, excessive daytime sleepiness and sleep attacks appear to be more common in patients with Parkinson's disease who are treated with dopamine receptor agonists than in those who are treated with other antiparkinsonian agents, although virtually all dopaminergic antiparkinsonian medications may contribute to sleepiness. Somnolence caused by dopamine agonists may be dose related and occurs most frequently during the dose-escalation phase. Somnolence may also emerge or worsen after a period of time on a stable dose. Patients with Parkinson's disease and caregivers should be informed about the risk of sleepiness and sleep attacks associated with dopaminergic medications and the potential implications for driving safety.

Autonomic Nervous System Dysfunction in Parkinson's Disease

Autonomic nervous system (ANS) dysfunction is common in Parkinson's disease (PD), affects 70% to 80% of patients, and causes significant morbidity and discomfort. Autonomic nervous system dysfunction symptoms in PD include sexual dysfunction, swallowing and gastrointestinal disorders, bowel and bladder abnormalities, sleep disturbances, and derangements of cardiovascular regulation, particularly, orthostatic hypotension. Autonomic nervous system dysfunction in PD may be caused by an underlying degenerative process that affects the autonomic ganglia, brainstem nuclei, and hypothalamic nuclei. Anti-parkinsonian medications can cause or worsen symptoms of ANS dysfunction. The care of a PD patient with ANS dysfunction relies on its recognition and directed treatment, including coordinated care between the neurologist and appropriate subspecialist. Pharmacotherapy may be useful to treat orthostasis, gastrointestinal, urinary, and sexual dysfunction.

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).

Clozapine withdrawal symptoms in a Parkinson's disease patient

Abrupt clozapine withdrawal can cause rebound psychosis and severe somatic symptoms in psychiatric patients. We report on the case of an advanced Parkinson's disease patient who developed myoclonus, tremor, rigidity, hyperreflexia, and stupor after abrupt clozapine withdrawal. The patient's symptoms resolved with treatment with cyproheptadine. This clinical picture suggests serotonergic rebound as an explanation for the patient's symptoms, although other pharmacological mechanisms are possible. Clozapine should be gradually withdrawn over a period of 1 to 2 weeks when possible, and abruptly discontinued only when necessary.

Management of essential tremor

Essential tremor (ET) is the most prevalent tremor syndrome. It commonly affects the hands, head, voice, and other body parts. Appropriate management begins with correct diagnosis. Primidone and propranolol are the first-line medications for the treatment for ET, but several other medications may also provide benefit. In patients with medically refractory tremor, alternative therapies, including surgery or injections of botulinum toxin, may be considered.

Depression in Parkinson's disease

Depression is common in Parkinson's disease (PD), and its identification and treatment are critically important in disease management. Despite depression's high prevalence and major impact on patient quality of life, questions remain regarding its epidemiology and preferred treatment. The authors of this paper summarize available information on the epidemiology of depression in PD, review treatment options, and discuss possible interactions between antidepressants and other agents. This information may help guide clinical treatment and define the need for further studies.

Diffuse Lewy Body Disease

Diffuse Lewy body disease (DLB) is a neurodegenerative disorder characterized by dementia, fluctuations in mental status, hallucinations, and parkinsonism. Diffuse Lewy body disease is the second most common cause of dementia, following Alzheimer's disease. The treatment of DLB includes cholinergic therapy for cognitive impairment, atypical neuroleptics to alleviate hallucinations, and levodopa/carbidopa to improve parkinsonism. The recognition and diagnosis of DLB has critical treatment implications. Centrally acting cholinesterase inhibitors, such as rivastigmine, donepezil, and galantamine partially reverse decreased cortical cholinergic activity and may improve cognition and neuropsychiatric symptoms in DLB. Rivastigmine has been demonstrated to improve cognition and neuropsychiatric symptoms in patients with DLB without worsening parkinsonian features. Due to the potential adverse events associated with neuroleptics in this population, treatment with cholinesterase inhibitors is currently considered first-line therapy in the treatment of hallucinations and mental status fluctuations in DLB. Exquisite sensitivity to neuroleptic medications is a hallmark of DLB and life-threatening complications have been reported. Caution should be exercised when implementing antipsychotic therapy for the treatment of behavioral disturbances of DLB. When required, atypical neuroleptics with the least extrapyramdial side effects, such as quetiapine, should be used. The parkinsonian features of DLB may respond to dopaminergic therapy with levodopa. If parkinsonian symptoms result in clinical disability, a trial of levodopa is warranted. Unfortunately, dopaminergic medications may worsen hallucinations. Because dopamine agonists have a greater tendency to induce hallucinations and somnolence, levodopa is the treatment of choice for parkinsonism in DLB. Rapid eye movement (REM) sleep behavior disorder (RBD) is now recognized as a feature of DLB. Awareness of the presence of this symptom in patients with DLB is important and treatment with low dose clonazepam may help. Cholinergic aumentation may also improve these symptoms in patients with DLB.

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.