Parkinson Disease Medication
- Author: Robert A Hauser, MD, MBA; Chief Editor: Selim R Benbadis, MD more...
Medication Summary
The cornerstone of symptomatic treatment for Parkinson disease (PD) is dopamine replacement therapy. The criterion standard of symptomatic therapy is levodopa (L-dopa), the metabolic precursor of dopamine, in combination with carbidopa, a peripheral decarboxylase inhibitor (PDI). This combination provides the greatest symptomatic benefit with the fewest short-term adverse effects.
Dopamine agonists such as pramipexole and ropinirole can be used as monotherapy to improve symptoms in early disease or as adjuncts to levodopa in patients whose response to levodopa is deteriorating and in those who are experiencing fluctuations in their response to levodopa.
Monoamine oxidase (MAO)-B inhibitors inhibitors such as rasagiline and selegiline provide symptomatic benefit as monotherapy in early disease and as adjuncts to levodopa in patients experiencing motor fluctuations.
Catechol-O -methyl transferase (COMT) inhibitors inhibitors such as entacapone and tolcapone may be used to increase the peripheral half-life of levodopa, thereby delivering more levodopa to the brain over a longer time.
Anticholinergic medications can be used for the treatment of resting tremor. However, they are not particularly effective for bradykinesia, rigidity, gait disturbance, or other features of advanced Parkinson disease; and cognitive side effects are common. Therefore, anticholinergics are usually reserved for the treatment of tremor that is not adequately controlled with dopaminergic medications.
Dopamine Agonists
Class Summary
Dopamine agonists are effective as monotherapy in early PD and as adjuncts to levodopa/PDI (peripheral decarboxylase inhibitor) in moderate to advanced disease. Dopamine agonists directly stimulate postsynaptic dopamine receptors to provide antiparkinsonian benefit. All available dopamine agonists stimulate D2 receptors, an action that is thought to be clinically beneficial. The role of other dopamine receptors is currently unclear.
Dopamine agonists are effective to treat motor features of early PD, and they cause less development of motor fluctuations and dyskinesia than levodopa. For patients with motor fluctuations on levodopa/PDI, the addition of a dopamine agonist reduces off time, improves motor function, and allows lower levodopa doses.
Carbidopa/levodopa (Sinemet, Sinemet CR, Parcopa)
Carbidopa/levodopa is approved for the treatment of symptoms of idiopathic PD, postencephalitic parkinsonism, and symptomatic parkinsonism that may follow injury to the nervous system by carbon monoxide and/or manganese intoxication. Levodopa, combined with a peripheral decarboxylase inhibitor (PDI) such as carbidopa, is the criterion standard of symptomatic treatment for PD; it provides the greatest antiparkinsonian efficacy in moderate to advanced disease with the fewest acute adverse effects. When administered alone, levodopa causes a high incidence of nausea and vomiting due to the formation of dopamine in the peripheral circulation. Carbidopa inhibits the decarboxylation of levodopa to dopamine in the peripheral circulation thereby reducing nausea and allowing for greater levodopa distribution into the CNS. Carbidopa does not cross the blood-brain barrier.
Apomorphine (Apokyn)
Apomorphine is a nonergoline dopamine agonist indicated for the acute, intermittent treatment of hypomobility "off" episodes ("end-of-dose wearing off" and unpredictable "on/off" episodes) associated with advanced PD. It is administered by a subcutaneous injection. Although the exact mechanism by which apomorphine exerts its therapeutic effects in PD is unknown, it is thought to occur via activation of postsynaptic D2 receptors in the striatum.
Pramipexole (Mirapex, Mirapex ER)
Pramipexole is approved as monotherapy in early disease and as adjunctive therapy to levodopa/PDI in more advanced stages. The mechanism of action of pramipexole as a treatment for Parkinson disease is unknown, although it is believed to be related to its ability to stimulate D2 dopamine receptors in the striatum. It is available as an immediate-release and an extended-release tablet.
Ropinirole (Requip and Requip XL)
Ropinirole is approved as monotherapy in early disease and as adjunctive therapy to levodopa/PDI in more advanced disease. Ropinirole is a nonergot dopamine agonist that has high relative in vitro specificity and full intrinsic activity at the D2 subfamily of dopamine receptors; it binds with higher affinity to D3 than to D2 or D4 receptor subtypes. The mechanism of action of ropinirole is stimulation of dopamine D2 receptors in striatum. It is available as an immediate-release and an extended-release tablet.
Amantadine
Amantadine is approved for the treatment of idiopathic PD, postencephalitic parkinsonism, and symptomatic parkinsonism, which may follow injury to the nervous system by carbon monoxide intoxication. It is also indicated in those elderly patients believed to develop parkinsonism in association with cerebral arteriosclerosis. The usual dosage is 100 mg given twice a day when used alone.
Rotigotine (Neupro)
Dopamine agonist stimulating D3, D2, and D1 receptors. Improvement in Parkinson-related symptoms thought to be its ability to stimulate D2 receptors within the caudate putamen in the brain. Indicated for the treatment of the signs and symptoms of idiopathic Parkinson disease (PD). Dosage ranges differ for early-stage PD and advanced-stage PD. Available as transdermal patch that provides continuous delivery for 24 h
Anticholinergic
Class Summary
Anticholinergics are commonly used as symptomatic treatment of PD, both as monotherapy and as part of combination therapy. Anticholinergic agents provide benefit for tremor in approximately 50% of patients but do not substantially improve bradykinesia or rigidity. If one anticholinergic does not work, try another.
Trihexyphenidyl
Trihexyphenidyl is indicated as an adjunct in the treatment of all forms of parkinsonism (postencephalitic, arteriosclerotic, and idiopathic). It is often useful as adjuvant therapy when treating these forms of parkinsonism with levodopa.
It is a synthetic tertiary amine anticholinergic agent. It has a direct antispasmodic action on smooth muscle and has weak mydriatic, antisecretory, and positive chronotropic activities. In addition to suppressing central cholinergic activity, trihexyphenidyl may also inhibit reuptake and storage of dopamine at central dopamine receptors, thereby prolonging the action of dopamine. It is commonly used in combination with other antiparkinsonian agents. Generally, anticholinergic agents can help control tremor but are less effective for treating bradykinesia or rigidity.
Benztropine mesylate (Cogentin)
Benztropine mesylate is approved for use as an adjunct in the therapy of all forms of PD. It partially blocks striatal cholinergic receptors, and by blocking muscarinic cholinergic receptors in the CNS, benztropine reduces the excessive cholinergic activity present in parkinsonism and related states. It can also block dopamine reuptake and storage in CNS cells. In general, anticholinergic agents can help control tremor but are less effective for treating bradykinesia or rigidity.
MAO-B inhibitors
Class Summary
MAO-B inhibitors inhibit the activity of MAO-B oxidases that are responsible for inactivating dopamine.
Selegiline (Eldepryl)
Selegiline is approved as adjunctive therapy to levodopa/carbidopa in patients who exhibit deterioration in response to that therapy. For patients who are experiencing motor fluctuations on levodopa/carbidopa, the addition of selegiline reduces off time, improves motor function, and allows levodopa dose reductions. If a patient experiences an increase in troublesome dyskinesia, reduce the levodopa dose. Selegiline blocks the breakdown of dopamine and extends the duration of action of each dose of levodopa.
Rasagiline (Azilect)
Rasagiline is indicated for the treatment of the signs and symptoms of idiopathic PD as initial monotherapy and as adjunctive therapy to levodopa. Rasagiline is an irreversible MAO-B inhibitor that blocks dopamine degradation. Rasagiline at a dosage of 1 mg once daily is given as monotherapy. When it is given as adjunctive therapy, an initial dose of 0.5 mg once daily is administered. Dosage adjustments are required if clinical response is not seen.
Acetylcholinesterase Inhibitors, Central
Class Summary
Pathologic changes in dementia associated with PD involve cholinergic neuronal pathways that project from the basal forebrain to the cerebral cortex and hippocampus. These pathways may be involved in memory, attention, learning, and other cognitive processes. Acetylcholinesterase inhibitors may exert their therapeutic effect by enhancing cholinergic function through inhibition of acetylcholinesterase.
Donepezil (Aricept)
Donepezil is a reversible inhibitor of ACh and exerts its beneficial effects by enhancing cholinergic function. It is indicated for the treatment for dementia of the Alzheimer type.
Rivastigmine (Exelon)
Rivastigmine is indicated for the treatment of mild to moderate dementia associated with PD. In addition, it is also approved for the treatment of mild to moderate dementia of the Alzheimer type.
Rivastigmine is a selective, competitive, and reversible acetylcholinesterase (ACh) inhibitor. It may reversibly inhibit cholinesterase, which may, in turn, increase concentrations of ACh available for synaptic transmission in CNS and thereby enhance cholinergic function. The effect may lessen as the disease process advances and fewer cholinergic neurons remain functionally intact.
Galantamine (Razadyne, Razadyne ER)
Galantamine is a competitive and reversible inhibitor of ACh. It is approved for the treatment of mild to moderate dementia of the Alzheimer type.
NMDA Antagonists
Class Summary
Persistent activation of CNS N-methyl-D-aspartate (NMDA) receptors by the excitatory amino acid glutamate has been hypothesized to contribute to the symptomatology of dementia. Agents such as memantine, which is an NMDA receptor antagonist, can prevent activation of the NMDA receptors.
Memantine (Namenda, Namenda XR)
Memantine is approved for the treatment of moderate to severe dementia in Alzheimer disease. Initial dosage is 5 mg once daily for immediate-release tablets and 7 mg once daily for extended-release tablets. Dosage titration may be required based on clinical response.
Memantine is postulated to exert its therapeutic effect through its action as a low- to moderate-affinity, uncompetitive NMDA receptor antagonist. Blockade of NMDA receptors by memantine slows the intracellular calcium accumulation and helps prevent further nerve damage.
COMT Inhibitors
Class Summary
Catechol-O -methyl transferase (COMT) inhibitors inhibit the peripheral metabolism of levodopa, making more levodopa available for transport across the blood-brain barrier over a longer time. For patients with motor fluctuations on levodopa/carbidopa, the addition of a COMT inhibitor decreases off time, improves motor function, and allows lower levodopa doses.
Tolcapone (Tasmar)
Tolcapone is an adjunct to levodopa/carbidopa therapy in PD in patients who are experiencing motor fluctuations. Because of the risk of hepatotoxicity, tolcapone is reserved for patients who have not responded adequately to, or are not appropriate candidates for, other adjunctive medications. If improvement is not apparent within 3 weeks, this medication should be withdrawn.
Tolcapone is a selective and reversible inhibitor of COMT. In the presence of a decarboxylase inhibitor such as carbidopa, COMT is the major degradation pathway for levodopa. By inhibiting COMT, there are more sustained plasma levels of levodopa, as well as enhanced central dopaminergic activity.
Entacapone (Comtan)
Entacapone is approved as an adjunct to levodopa/carbidopa for patients who are experiencing signs and symptoms of end-of-dose "wearing-off." The mechanism of action of entacapone is related to its ability to inhibit COMT and alter plasma pharmacokinetics of levodopa. When given in conjunction with levodopa and an aromatic amino acid decarboxylase inhibitor (eg, carbidopa), plasma levels of levodopa are more sustained than after administration of levodopa and an aromatic amino acid decarboxylase inhibitor alone. These sustained plasma levels of levodopa may result in more constant dopaminergic stimulation in the brain. This may lead to greater effects on signs and symptoms of PD, as well as increased levodopa adverse effects (which sometimes require a levodopa dose decrease).
Carbidopa, levodopa, and entacapone (Stalevo)
Carbidopa/levodopa/entacapone is indicated for the treatment of PD to substitute (with equivalent strengths of each of the 3 components) for immediate-release carbidopa/levodopa and entacapone previously administered as individual products. It is also used to replace immediate-release carbidopa/levodopa therapy (without entacapone) when patients experience the signs and symptoms of end-of-dose "wearing-off" (only for patients taking a total daily dose of levodopa of 600 mg or less and not experiencing dyskinesias).
Carbidopa inhibits dopa decarboxylation, thereby allowing more complete levodopa distribution to the CNS. Levodopa is a dopamine precursor capable of crossing the blood-brain barrier, thereby increasing CNS dopamine following conversion. Entacapone inhibits COMT, another enzyme that metabolizes levodopa. COMT inhibition increases and sustains levodopa plasma levels, enabling more blood-brain barrier penetration.
Hauser RA, Grosset DG. [(123) I]FP-CIT (DaTscan) SPECT Brain Imaging in Patients with Suspected Parkinsonian Syndromes. J Neuroimaging. Mar 16 2011;[Medline].
Wirdefeldt K, Adami HO, Cole P, Trichopoulos D, Mandel J. Epidemiology and etiology of Parkinson's disease: a review of the evidence. Eur J Epidemiol. Jun 2011;26 Suppl 1:S1-58. [Medline].
Ballard PA, Tetrud JW, Langston JW. Permanent human parkinsonism due to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP): seven cases. Neurology. Jul 1985;35(7):949-56. [Medline].
Tanner CM, Ottman R, Goldman SM, Ellenberg J, Chan P, Mayeux R, et al. Parkinson disease in twins: an etiologic study. JAMA. Jan 27 1999;281(4):341-6. [Medline].
Polymeropoulos MH, Lavedan C, Leroy E, Ide SE, Dehejia A, Dutra A, et al. Mutation in the alpha-synuclein gene identified in families with Parkinson's disease. Science. Jun 27 1997;276(5321):2045-7. [Medline].
Krüger R, Kuhn W, Müller T, Woitalla D, Graeber M, Kösel S, et al. Ala30Pro mutation in the gene encoding alpha-synuclein in Parkinson's disease. Nat Genet. Feb 1998;18(2):106-8. [Medline].
Bekris LM, Mata IF, Zabetian CP. The genetics of Parkinson disease. J Geriatr Psychiatry Neurol. Dec 2010;23(4):228-42. [Medline]. [Full Text].
Alcalay RN, Caccappolo E, Mejia-Santana H, Tang MX, Rosado L, Ross BM, et al. Frequency of known mutations in early-onset Parkinson disease: implication for genetic counseling: the consortium on risk for early onset Parkinson disease study. Arch Neurol. Sep 2010;67(9):1116-22. [Medline].
Samanta J, Hauser RA. Duodenal levodopa infusion for the treatment of Parkinson's disease. Expert Opin Pharmacother. Apr 2007;8(5):657-64. [Medline].
Vekrellis K, Xilouri M, Emmanouilidou E, Rideout HJ, Stefanis L. Pathological roles of a-synuclein in neurological disorders. Lancet Neurol. Nov 2011;10(11):1015-25. [Medline].
Kordower JH, Chu Y, Hauser RA, Freeman TB, Olanow CW. Lewy body-like pathology in long-term embryonic nigral transplants in Parkinson's disease. Nat Med. May 2008;14(5):504-6. [Medline].
Muangpaisan W, Mathews A, Hori H, Seidel D. A systematic review of the worldwide prevalence and incidence of Parkinson's disease. J Med Assoc Thai. Jun 2011;94(6):749-55. [Medline].
Grimes DA, Lang AE. Treatment of early Parkinsons disease. Can J Neurol Sci. Aug 1999;26 Suppl 2:S39-44. [Medline].
Thobois S, Delamarre-Damier F, Derkinderen P. Treatment of motor dysfunction in Parkinsons disease: an overview. Clin Neurol Neurosurg. Jun 2005;107(4):269-81. [Medline].
Suchowersky O, Reich S, Perlmutter J, Zesiewicz T, Gronseth G, Weiner WJ. 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. Neurology. Apr 11 2006;66(7):968-75. [Medline].
National Collaborating Centre for Chronic Conditions. Parkinson's disease: National clinical guideline for diagnosis and management in primary and secondary care. London, UK: Royal College of Physicians; 2006.
Simuni T, Sethi K. Nonmotor manifestations of Parkinson's disease. Ann Neurol. Dec 2008;64 Suppl 2:S65-80. [Medline].
Sato Y, Iwamoto J, Honda Y. Vitamin D Deficiency-Induced Vertebral Fractures May Cause Stooped Posture in Parkinson Disease. Am J Phys Med Rehabil. Jan 5 2011;[Medline].
Brin MF, Velickovic M, Remig LO. Dysphonia due to Parkinson's disease; pharmacological, surgical, and behavioral management perspectives. In: Vocal Rehabilitation in Medical Speech-Language Pathology. Austin: Pro-Ed; 2004:209-69.
Perez KS, Ramig LO, Smith ME, Dromey C. The Parkinson larynx: tremor and videostroboscopic findings. J Voice. Dec 1996;10(4):354-61. [Medline].
[Best Evidence] Hoops S, Nazem S, Siderowf AD, Duda JE, Xie SX, Stern MB. Validity of the MoCA and MMSE in the detection of MCI and dementia in Parkinson disease. Neurology. Nov 24 2009;73(21):1738-45. [Medline].
Weintraub D, Comella CL, Horn S. Parkinson's disease--Part 3: Neuropsychiatric symptoms. Am J Manag Care. Mar 2008;14(2 Suppl):S59-69. [Medline].
Reid WG, Hely MA, Morris JG, Loy C, Halliday GM. Dementia in Parkinson's disease: a 20-year neuropsychological study (Sydney Multicentre Study). J Neurol Neurosurg Psychiatry. Sep 2011;82(9):1033-7. [Medline].
Tolosa E, Gaig C, Santamaría J, Compta Y. Diagnosis and the premotor phase of Parkinson disease. Neurology. Feb 17 2009;72(7 Suppl):S12-20. [Medline].
Braak H, Ghebremedhin E, Rüb U, Bratzke H, Del Tredici K. Stages in the development of Parkinson's disease-related pathology. Cell Tissue Res. Oct 2004;318(1):121-34. [Medline].
Grosset D, Taurah L, Burn DJ, MacMahon D, Forbes A, Turner K, et al. A multicentre longitudinal observational study of changes in self reported health status in people with Parkinson's disease left untreated at diagnosis. J Neurol Neurosurg Psychiatry. May 2007;78(5):465-9. [Medline]. [Full Text].
Caslake R, Macleod A, Ives N, Stowe R, Counsell C. Monoamine oxidase B inhibitors versus other dopaminergic agents in early Parkinson's disease. Cochrane Database Syst Rev. 2009;(4):CD006661. [Medline].
Antonini A, Cilia R. Behavioural adverse effects of dopaminergic treatments in Parkinson's disease: incidence, neurobiological basis, management and prevention. Drug Saf. 2009;32(6):475-88. [Medline].
Bayulkem K, Lopez G. Clinical approach to nonmotor sensory fluctuations in Parkinson's disease. J Neurol Sci. Nov 15 2011;310(1-2):82-5. [Medline].
Miyasaki JM, Shannon K, Voon V, Ravina B, Kleiner-Fisman G, Anderson K, et al. Practice Parameter: evaluation and treatment of depression, psychosis, and dementia in Parkinson disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. Apr 11 2006;66(7):996-1002. [Medline].
[Guideline] Zesiewicz TA, Sullivan KL, Arnulf I, et al. Practice Parameter: treatment of nonmotor symptoms of Parkinson disease: report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. Mar 16 2010;74(11):924-31. [Medline].
Stocchi F, Rascol O, Kieburtz K, et al. Initiating levodopa/carbidopa therapy with and without entacapone in early Parkinson disease: the STRIDE-PD study. Ann Neurol. Jul 2010;68(1):18-27. [Medline].
Hauser RA, McDermott MP, Messing S. Factors associated with the development of motor fluctuations and dyskinesias in Parkinson disease. Arch Neurol. Dec 2006;63(12):1756-60. [Medline].
Rascol O, Brooks DJ, Korczyn AD, De Deyn PP, Clarke CE, Lang AE. A five-year study of the incidence of dyskinesia in patients with early Parkinson's disease who were treated with ropinirole or levodopa. 056 Study Group. N Engl J Med. May 18 2000;342(20):1484-91. [Medline].
Constantinescu R, Romer M, McDermott MP, Kamp C, Kieburtz K. Impact of pramipexole on the onset of levodopa-related dyskinesias. Mov Disord. Jul 15 2007;22(9):1317-9. [Medline].
Thomas A, Bonanni L, Gambi F, Di Iorio A, Onofrj M. Pathological gambling in Parkinson disease is reduced by amantadine. Ann Neurol. Sep 2010;68(3):400-4.
Weintraub D, Sohr M, Potenza MN, Siderowf AD, Stacy M, Voon V, et al. Amantadine use associated with impulse control disorders in Parkinson disease in cross-sectional study. Ann Neurol. Dec 2010;68(6):963-8. [Medline].
Schapira AH, Barone P, Hauser RA, Mizuno Y, Rascol O, Busse M, et al. Extended-release pramipexole in advanced Parkinson disease: a randomized controlled trial. Neurology. Aug 23 2011;77(8):767-74. [Medline].
Effects of tocopherol and deprenyl on the progression of disability in early Parkinson's disease. The Parkinson Study Group. N Engl J Med. Jan 21 1993;328(3):176-83. [Medline].
Shults CW. Effect of selegiline (deprenyl) on the progression of disability in early Parkinson's disease. Parkinson Study Group. Acta Neurol Scand Suppl. 1993;146:36-42. [Medline].
Palhagen S, Heinonen E, Hagglund J, Kaugesaar T, Maki-Ikola O, Palm R. Selegiline slows the progression of the symptoms of Parkinson disease. Neurology. Apr 25 2006;66(8):1200-6. [Medline].
Tatton WG, Greenwood CE. Rescue of dying neurons: a new action for deprenyl in MPTP parkinsonism. J Neurosci Res. Dec 1991;30(4):666-72. [Medline].
Olanow C, Rascol O. Early Rasagaline treatment slows UPDRS decline in the ADAGIO delayed start study. Poster work in progress (WIP-11). 12th Congress of European Federation of Neurological Societies. Sept 23, 2008.
Olanow CW, Rascol O, Hauser R, Feigin PD, Jankovic J, Lang A. A double-blind, delayed-start trial of rasagiline in Parkinson's disease. N Engl J Med. Sep 24 2009;361(13):1268-78. [Medline].
A controlled trial of rasagiline in early Parkinson disease: the TEMPO Study. Arch Neurol. Dec 2002;59(12):1937-43. [Medline].
Hauser RA, Lew MF, Hurtig HI, Ondo WG, Wojcieszek J, Fitzer-Attas CJ. Long-term outcome of early versus delayed rasagiline treatment in early Parkinson's disease. Mov Disord. Mar 15 2009;24(4):564-73. [Medline].
A controlled, randomized, delayed-start study of rasagiline in early Parkinson disease. Arch Neurol. Apr 2004;61(4):561-6. [Medline].
Fahn S, Oakes D, Shoulson I, Kieburtz K, Rudolph A, Lang A, et al. Levodopa and the progression of Parkinson's disease. N Engl J Med. Dec 9 2004;351(24):2498-508. [Medline].
Parkkinen L, O'Sullivan SS, Kuoppamäki M, Collins C, Kallis C, Holton JL, et al. Does levodopa accelerate the pathologic process in Parkinson disease brain?. Neurology. Oct 11 2011;77(15):1420-6. [Medline].
Dopamine transporter brain imaging to assess the effects of pramipexole vs levodopa on Parkinson disease progression. JAMA. Apr 3 2002;287(13):1653-61. [Medline].
Schapira AH, Olanow CW. Neuroprotection in Parkinson disease: mysteries, myths, and misconceptions. JAMA. Jan 21 2004;291(3):358-64. [Medline].
Suchowersky O, Gronseth G, Perlmutter J, Reich S, Zesiewicz T, Weiner WJ. 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. Neurology. Apr 11 2006;66(7):976-82. [Medline].
Shemisa K, Hass CJ, Foote KD, Okun MS, Wu SS, Jacobson CE 4th, et al. Unilateral deep brain stimulation surgery in Parkinson's disease improves ipsilateral symptoms regardless of laterality. Parkinsonism Relat Disord. Dec 2011;17(10):745-8. [Medline].
Weaver FM, Follett K, Stern M, Hur K, Harris C, Marks WJ Jr. Bilateral deep brain stimulation vs best medical therapy for patients with advanced Parkinson disease: a randomized controlled trial. JAMA. Jan 7 2009;301(1):63-73. [Medline].
Follett KA, Weaver FM, Stern M, Hur K, Harris CL, Luo P, et al. Pallidal versus subthalamic deep-brain stimulation for Parkinson's disease. N Engl J Med. Jun 3 2010;362(22):2077-91. [Medline].
Foltynie T, Zrinzo L, Martinez-Torres I, Tripoliti E, Petersen E, Holl E, et al. MRI-guided STN DBS in Parkinson's disease without microelectrode recording: efficacy and safety. J Neurol Neurosurg Psychiatry. Apr 2011;82(4):358-63. [Medline].
Castrioto A, Lozano AM, Poon YY, Lang AE, Fallis M, Moro E. Ten-year outcome of subthalamic stimulation in Parkinson disease: a blinded evaluation. Arch Neurol. Dec 2011;68(12):1550-6. [Medline].
Oshima H, Katayama Y, Morishita T, Sumi K, Otaka T, Kobayashi K, et al. Subthalamic nucleus stimulation for attenuation of pain related to Parkinson disease. J Neurosurg. Jan 2012;116(1):99-106. [Medline].
Kim HJ, Jeon BS, Paek SH. Effect of deep brain stimulation on pain in Parkinson disease. J Neurol Sci. Nov 15 2011;310(1-2):251-5. [Medline].
Kim HJ, Jeon BS, Lee JY, Paek SH, Kim DG. The benefit of subthalamic deep brain stimulation for pain in Parkinson disease: a 2-year follow-up study. Neurosurgery. Jan 2012;70(1):18-23; discussion 23-4. [Medline].
Broen M, Duits A, Visser-Vandewalle V, Temel Y, Winogrodzka A. Impulse control and related disorders in Parkinson's disease patients treated with bilateral subthalamic nucleus stimulation: a review. Parkinsonism Relat Disord. Jul 2011;17(6):413-7. [Medline].
Svennilson E, Torvik A, Lowe R, Leksell L. Treatment of parkinsonism by stereotatic thermolesions in the pallidal region. A clinical evaluation of 81 cases. Acta Psychiatr Scand. 1960;35:358-77. [Medline].
Laitinen LV, Bergenheim AT, Hariz MI. Leksell's posteroventral pallidotomy in the treatment of Parkinson's disease. J Neurosurg. Jan 1992;76(1):53-61. [Medline].
Lang AE, Widner H. Deep brain stimulation for Parkinson's disease: patient selection and evaluation. Mov Disord. 2002;17 Suppl 3:S94-101. [Medline].
Okun MS, Fernandez HH, Pedraza O, Misra M, Lyons KE, Pahwa R. Development and initial validation of a screening tool for Parkinson disease surgical candidates. Neurology. Jul 13 2004;63(1):161-3. [Medline].
Olanow CW, Kordower JH, Lang AE, Obeso JA. Dopaminergic transplantation for Parkinson's disease: current status and future prospects. Ann Neurol. Nov 2009;66(5):591-6. [Medline].
Silberstein P, Bittar RG, Boyle R, Cook R, Coyne T, O'Sullivan D. Deep brain stimulation for Parkinson's disease: Australian referral guidelines. J Clin Neurosci. Aug 2009;16(8):1001-8. [Medline].
Stover NP, Watts RL. Spheramine for treatment of Parkinson's disease. Neurotherapeutics. Apr 2008;5(2):252-9. [Medline].
Farag ES, Vinters HV, Bronstein J. Pathologic findings in retinal pigment epithelial cell implantation for Parkinson disease. Neurology. Oct 6 2009;73(14):1095-102. [Medline].
Witt J, Marks WJ Jr. An update on gene therapy in Parkinson's disease. Curr Neurol Neurosci Rep. Aug 2011;11(4):362-70. [Medline].
Lewitt PA, Rezai AR, Leehey MA, Ojemann SG, Flaherty AW, Eskandar EN, et al. AAV2-GAD gene therapy for advanced Parkinson's disease: a double-blind, sham-surgery controlled, randomised trial. Lancet Neurol. Apr 2011;10(4):309-19. [Medline].
Miyasaki JM, Shannon K, Voon V, Ravina B, Kleiner-Fisman G, Anderson K, et al. Practice Parameter: evaluation and treatment of depression, psychosis, and dementia in Parkinson disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. Apr 11 2006;66(7):996-1002. [Medline].
Frisina PG, Borod JC, Foldi NS, Tenenbaum HR. Depression in Parkinson's disease: Health risks, etiology, and treatment options. Neuropsychiatr Dis Treat. Feb 2008;4(1):81-91. [Medline].
Barbas NR. Cognitive, affective, and psychiatric features of Parkinson's disease. Clin Geriatr Med. Nov 2006;22(4):773-96, v-vi. [Medline].
Truong DD, Bhidayasiri R, Wolters E. Management of non-motor symptoms in advanced Parkinson disease. J Neurol Sci. Mar 15 2008;266(1-2):216-28. [Medline].
Ziemssen T, Reichmann H. Non-motor dysfunction in Parkinson's disease. Parkinsonism Relat Disord. Aug 2007;13(6):323-32. [Medline].
Hassan A, Bower JH, Kumar N, Matsumoto JY, Fealey RD, Josephs KA, et al. Dopamine agonist-triggered pathological behaviors: Surveillance in the PD clinic reveals high frequencies. Parkinsonism Relat Disord. May 2011;17(4):260-4. [Medline].
Barone P, Poewe W, Albrecht S, Debieuvre C, Massey D, Rascol O, et al. Pramipexole for the treatment of depressive symptoms in patients with Parkinson's disease: a randomised, double-blind, placebo-controlled trial. Lancet Neurol. Jun 2010;9(6):573-80. [Medline].
Allain H, Pollak P, Neukirch HC. Symptomatic effect of selegiline in de novo Parkinsonian patients. The French Selegiline Multicenter Trial. Mov Disord. 1993;8 Suppl 1:S36-40. [Medline].
Treatment of Parkinson's disease. Psychological disorders: striking a balance in order to optimise antiparkinsonian treatment. Prescrire Int. Oct 2011;20(120):242-5. [Medline].
Ferreri F, Agbokou C, Gauthier S. Recognition and management of neuropsychiatric complications in Parkinson's disease. CMAJ. Dec 5 2006;175(12):1545-52. [Medline].
Friedman JH, Millman RP. Sleep disturbances and Parkinson's disease. CNS Spectr. Mar 2008;13(3 Suppl 4):12-7. [Medline].
Tomlinson CL, Patel S, Meek C, Clarke CE, Stowe R, Shah L, et al. Physiotherapy versus placebo or no intervention in Parkinson's disease. Cochrane Database of Systematic Reviews. Feb 2012.
Ahlskog JE. Does vigorous exercise have a neuroprotective effect in Parkinson disease?. Neurology. Jul 19 2011;77(3):288-94. [Medline]. [Full Text].
Herd CP, Tomlinson CL, Deane KHO, Brady MC, Smith CH, Sackley C, et al. Speech and language therapy versus placebo or no intervention for speech problems in Parkinson's disease. Cochrane Database Syst Rev. Apr 11 2011;CD002812.
Fahn S. A pilot trial of high-dose alpha-tocopherol and ascorbate in early Parkinson's disease. Ann Neurol. 1992;32 Suppl:S128-32. [Medline].
Berke GS, Gerratt B, Kreiman J, Jackson K. Treatment of Parkinson hypophonia with percutaneous collagen augmentation. Laryngoscope. Aug 1999;109(8):1295-9. [Medline].
Kim HJ, Jeon BS, Paek SH. Effect of deep brain stimulation on pain in Parkinson disease. J Neurol Sci. Nov 15 2011;310(1-2):251-5. [Medline].
Hauser RA. Future treatments for Parkinson's disease: surfing the PD pipeline. Int J Neurosci. 2011;121 Suppl 2:53-62. [Medline].
Koller WC. Levodopa in the treatment of Parkinson's disease. Neurology. 2000;55(11 Suppl 4):S2-7; discussion S8-12. [Medline].
Marks WJ Jr, Bartus RT, Siffert J, et al. Gene delivery of AAV2-neurturin for Parkinson's disease: a double-blind, randomised, controlled trial. Lancet Neurol. Dec 2010;9(12):1164-72. [Medline].
Scottish Intercollegiate Guidelines Network (SIGN). Diagnosis and pharmacological management of Parkinson's disease. A national clinical guideline. Edinburgh (Scotland): Scottish Intercollegiate Guidelines Network (SIGN); Jan 2010:61 p. (SIGN publication; no. 113). [Full Text].
Shults CW, Oakes D, Kieburtz K, Beal MF, Haas R, Plumb S. Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline. Arch Neurol. Oct 2002;59(10):1541-50. [Medline].
Whone AL, Watts RL, Stoessl AJ, Davis M, Reske S, Nahmias C, et al. Slower progression of Parkinson's disease with ropinirole versus levodopa: The REAL-PET study. Ann Neurol. Jul 2003;54(1):93-101. [Medline].
Liu R, Guo X, Park Y, Huang X, Sinha R, Freedman ND, et al. Caffeine Intake, Smoking, and Risk of Parkinson Disease in Men and Women. Am J Epidemiol. Apr 13 2012;[Medline].
Richard IH, McDermott MP, Kurlan R, Lyness JM, Como PG, Pearson N, et al. A randomized, double-blind, placebo-controlled trial of antidepressants in Parkinson disease. Neurology. Apr 17 2012;78(16):1229-1236. [Medline].

