Deep Brain Stimulation (DBS) [For the list of services and procedures that need preauthorization, please refer to www.mcs.com.pr go to Comunicados a Proveedores, and click Cartas Circulares.] Medical Policy: MP-DME-07-10 Original Effective Date: November 18, 2010 Reviewed: November 01, 2012 Revised: November 21, 2013 This policy applies to products subscribed by the following corporations, MCS Life Insurance Company (Commercial), and MCS Advantage, Inc. (Classicare) and, provider s contract; unless specific contract limitations, exclusions or exceptions apply. Please refer to the member s benefit certification language for benefit availability. Managed care guidelines related to referral authorization, and precertification of inpatient hospitalization, home health, home infusion and hospice services apply subject to the aforementioned exceptions. DESCRIPTION Central Nervous System Stimulators are divided in: I. Dorsal Column (Spinal Cord) Neurostimulation - The surgical implantation of neurostimulator electrodes within the Dura mater (endodural) or the percutaneous insertion of electrodes in the epidural space. The goal of spinal cord stimulation is to suppress pain in specific areas for individuals with a variety of chronic pain disorders, including, refractory, neuropathic pain. II. Depth Brain Neurostimulation - The stereotactic implantation of electrodes in the deep brain (e.g., thalamus and periaqueductal gray matter). Deep brain stimulation (DBS) is a medical procedure that involves the delivery of continuous, high frequency electrical impulses to specific areas in the brain responsible for movement. This medical procedure is reversible and causes no permanent damage to the brain. Prior to implantation, a stereotactic rigid frame, or frame based system, is secured to the patient's skull, and the initial targeted area is selected by the surgeon using an imaging technique acquired by (e.g., magnetic resonance imaging [MRI], computed tomography [CT] or ventriculography). One of the alternative that the surgeon have to the frame-based system is the frameless stereotactic system which may use external fiducially markers and/or internal anatomic landmarks. A Deep Brain electrode is introduced and located into the specific brain area and test simulations are performed to evaluate and adjust tremor amplitude, diffusion of stimulation, and determination of the threshold for paresthesias and speech disturbances. Those electrodes are connected to a computerized pulse generator which is typically implanted underneath the skin near the collarbone. 1
The Deep Brain Stimulation system in some medical scenarios may be implanted either unilaterally or bilaterally, depending on the distribution of the patient s symptoms. When the intended targets include both sides of the brain, two separate systems are implanted in each side of the Brain lobule. The Deep brain stimulation system also includes a handheld therapy controller and a control magnetic. There are currently three targets for DBS: Thalamic Ventralis Intermedius Nucleus (VIM), Subthalamic Nucleus (STN) and Globus Pallidus interna (GPI). The Deep Brain stimulation system is designed to treat patients that are treated with Beta-adrenergic blockers and anticonvulsant medications and do not adequately responds or cannot tolerate these medications (e.g., Essential tremor (ET)). Essential tremor (ET) is a progressive, disabling tremor most often affecting the hands. ET may also affect the head, voice and legs. The precise pathogenesis of ET is unknown. While it may start at any age, ET usually peaks within the second and sixth decades. Beta-adrenergic blockers and anticonvulsant medications are usually the first line treatments for reducing the severity of tremor. Many patients, however, do not adequately respond or cannot tolerate these medications. In these medically refractory ET patients, thalamic VIM DBS may be helpful for symptomatic relief of tremor. (CMS, 2004) In other medical scenarios when patients who become unresponsive to medical treatments and/or have intolerable side effects from medications like in the Parkinson Disease (PD), DBS for symptom relief may be considered. Parkinson s disease (PD) is an age-related progressive neurodegenerative disorder involving the loss of dopaminergic cells in the substantia nigra of the midbrain. The disease is characterized by tremor, rigidity, bradykinesia and progressive postural instability. Dopaminergic medication is typically used as a first line treatment for reducing the primary symptoms of PD. However, after prolonged use, medication can become less effective and can produce significant adverse events such as dyskinesias and other motor function complications. (CMS, 2004) COVERAGE Coverage for electrical stimulation devices is subject to the terms, conditions and limitations of the applicable benefit plan s Durable Medical Equipment (DME) benefit and schedule of copayments. Please refer to the applicable benefit plan document to determine benefit availability and the terms, conditions and limitations of coverage. 2
INDICATIONS, (MCS) considers medically necessary unilateral or bilateral thalamic Ventralis Intermedius Nucleus (VIM) DBS for the treatment of Essential Tremor (ET) and/or Parkinsonian tremor and unilateral or bilateral Subthalamic Nucleus (STN) or Globus pallidus interna (GPi) DBS for the treatment of Parkinson s disease (PD) ONLY under the following conditions: I. For thalamic VIM DBS for treatment of Essential Tremor and/or Parkinsonian tremors to be considered medically necessary, Members must meet ALL of the following criteria: a. Diagnosis of essential tremor (ET) based on postural or kinetic tremors of hand(s) without other neurologic signs, or diagnosis of idiopathic PD (presence of at least two (2) cardinal PD features (tremor, rigidity or bradykinesia)) which is of a tremor- dominant form. b. Marked disabling tremor of at least level 3 or 4 on the Fahn -Tolosa-Marin Clinical Tremor Rating Scale (or equivalent scale) in the extremity intended for treatment, causing significant limitation in daily activities despite optimal medical therapy. c. Willingness and ability to cooperate during conscious operative procedure, as well as during post-surgical evaluations, adjustments of medications and stimulator settings. Note 1 : Members must also meet criteria in indication number III of this policy. II. For STN or GPi DBS for treatment of Parkinson s Disease to be considered medically necessary, the Member must meet ALL of the following criteria: a. Diagnosis of PD based on the presence of at least two (2) cardinals PD features (tremor, rigidity or bradykinesia). b. Advanced idiopathic PD as determined by the use of Hoehn and Yahr stage or Unified Parkinson s Disease Rating Scale (UPDRS) part III motor subscale. c. L-dopa responsive with clearly defined on i periods. d. Persistent disabling Parkinson s symptoms or drug side effects (e.g., dyskinesias ii, motor fluctuationsiii, or disabling off iv periods) despite optimal medical therapy. e. Willingness and ability to cooperate during conscious operative procedure, as well as during post-surgical evaluations, adjustments of medications and stimulator settings. 3
Note 2 : Members must also meet criteria in indication number III of this policy. III. MCS will not consider coverage for the implantation of Deep Brain Stimulation or services and supplies related to such implantation UNLESS ALL of the following conditions have been met: a. Other treatment modalities (pharmacological, surgical, physical or psychological therapies) have been tried and did not prove satisfactory or are judged unsuitable or contraindicated for the given patient. b. Patients have undergone careful screening, evaluation and diagnosis by a multidisciplinary team prior to implantation (such screening must include psychological as well as physical evaluation). c. All facilities, equipment and personnel required for the proper diagnosis, treatment, training and follow-up of the patient must be available. LIMITATIONS I., (MCS) does not consider DBS medically necessary and does not cover for ET or PD patients with ANY of the following: 1. Non-idiopathic Parkinson s disease or Parkinson s Plus syndromes. 2. Cognitive impairment, dementia or depression, which would be worsened by or would interfere with the patient s ability to benefit from DBS. 3. Current psychosis, alcohol abuse or other drug abuse. 4. Structural lesions such as basal ganglionic stroke, tumor or vascular malformation as etiology of the movement disorder. 5. Previous movement disorder surgery within the affected basal ganglion. 6. Significant medical, surgical, neurologic or orthopedic co-morbidities contraindicating DBS surgery or stimulation. II. MCS considers Experimental and Investigational deep brain stimulation (DBS) for tremor from other causes such as trauma, multiple sclerosis (MS), degenerative disorders, metabolic disorders, infectious diseases, and drug-induced movement disorders because DBS has not been shown to be effective for treating tremors due to these other causes. In addition to the aforementioned conditions, the following indications are also consider experimental and investigational, Alzheimer's disease, Parkinson s disease-related dysarthria/speech deficits, head or voice tremor, blepharospasm, obesity, depression, epilepsy, chronic cluster headache, obsessive-compulsive 4
disorder; and tourette syndrome because there is insufficient evidence to support its effectiveness for these indications. CONTRAINDICATIONS 1. Contraindications to surgery for insertion of deep brain stimulation (DBS) device could include a medication regimen with anticoagulants. 2. Diathermy v is contraindicated for all patients with DBS implants. Serious brain injury may be caused by exposure of any part of the implantable pulse generator (IPG) device to diathermy. 3. DBS should be performed with extreme caution in patients with cardiac pacemakers or other electronically controlled implants which may adversely affect or be affected by the DBS system. 4. Any type of MRI is contraindicated for patients with DBS implants, which may adversely affect the DBS system or adversely affect the brain around the implanted electrodes. CODING INFORMATION CPT Codes (List may not be all inclusive) CPT Codes DESCRIPTION 61862 Twist drill, burr hole, craniectomy for stereotactic implantation of one neurostimulator array in subcortical site (e.g., thalamus, globus pallidus, subthalamic nucleus, periventricular, periaqueductal gray) 61863 Twist drill, burr hole, craniotomy, or craniectomy with stereotactic implantation of neurostimulator electrode array in subcortical site (e.g., thalamus, globus pallidus, subthalamic nucleus, periventricular, periaqueductal gray), without use of intraoperative microelectrode recording; first array 61864 Twist drill, burr hole, craniotomy, or craniectomy with stereotactic implantation of neurostimulator electrode array in subcortical site (e.g., thalamus, globus pallidus, subthalamic nucleus, periventricular, periaqueductal gray), without use of intraoperative microelectrode recording; each additional array (list separately in addition to primary procedure) 61867 Twist drill, burr hole, craniotomy, or craniectomy with stereotactic implantation of Neurostimulator electrode array in subcortical site (e.g., thalamus, globus pallidus, subthalamic nucleus, periventricular, periaqueductal gray), with use of intraoperative microelectrode recording: first array 61868+ Each additional array (List separately in addition to primary procedure) 61880 Revision or removal of intracranial neurostimulator electrodes 61885 Incision and subcutaneous placement of cranial neurostimulator pulse generator or receiver, direct or inductive coupling; with connection to a single electrode array 61886 Incision and subcutaneous placement of cranial neurostimulator pulse generator or 5
receiver, direct or inductive coupling; with connection to two or more electrode arrays 61888 Revision or removal of cranial neurostimulator pulse generator or receiver 95961 Functional cortical and subcortical mapping by stimulation and/or recording of electrodes on brain surface, or of depth electrodes, to provoke seizures or identify vital brain structures; initial hour of physician attendance 95962 Functional cortical and subcortical mapping by stimulation and/or recording of electrodes on brain surface, or of depth electrodes, to provoke seizures or identify vital brain structures; each additional hour of physician attendance (List separately in addition to code for primary procedure) (Use 95962 in conjunction with code 95961) 95970* Electronic analysis of implanted neurostimulator pulse generator system (e.g., rate, pulse amplitude and duration, configuration of wave form, battery status, electrode selectability, output modulation, cycling, impedance and patient compliance measurements); simple or complex brain, spinal cord, or peripheral (i.e., cranial nerve, peripheral nerve, autonomic nerve, neuromuscular) neurostimulator pulse generator/transmitter, without reprogramming 95971 Electronic analysis of implanted neurostimulator pulse generator system (e.g., rate, pulse amplitude and duration, configuration of wave form, battery status, electrode selectability, output modulation, cycling, impedance and patient compliance measurements); simple brain, spinal cord, or peripheral (i.e., peripheral nerve, autonomic nerve, neuromuscular) neurostimulator pulse generator/transmitter, with intraoperative or subsequent programming 95972 Electronic analysis of implanted neurostimulator pulse generator system (e.g., rate, pulse amplitude and duration, configuration of wave form, battery status, electrode selectability, output modulation, cycling, impedance and patient compliance measurements); complex brain, spinal cord, or peripheral (except cranial nerve) neurostimulator pulse generator/transmitter, with intraoperative or subsequent programming, first hour 95973 Electronic analysis of implanted neurostimulator pulse generator system (e.g., rate, pulse amplitude and duration, configuration of wave form, battery status, electrode selectability, output modulation, cycling, impedance and patient compliance measurements); complex brain, spinal cord, or peripheral (except cranial nerve); complex brain, spinal cord, or peripheral (except cranial nerve) neurostimulator pulse generator/transmitter, with intraoperative or subsequent programming, additional 30 minutes after hour (List separately in addition to code for primary procedure) (Use 95973 in conjunction with code 95972) 95978 Electronic analysis of implanted neurostimulator pulse generator system (e.g., rate, pulse amplitude and duration, battery status, electrode selectability and polarity, impedance and patient compliance measurements), complex deep brain 6
neurostimulator pulse generator/transmitter, with initial or subsequent programming; first hour 95979+ Each additional 30 minutes after first hour (List separately in addition to code for primary procedure) Current Procedural Terminology (CPT ) 2013 American Medical Association: Chicago, IL. *Note 3: MCS would not expect to see a frequency greater than once every 30 days for CPT code 95970, unless documentation is provided establishing medical necessity. ICD-9 CM Diagnosis Codes (List may not be all inclusive) ICD-9 CM DESCRIPTION CODES 332.0 Parkinson s disease, with paralysis agitans 333.1 Essential and other specified forms of tremor 333.6 Genetic Torsion dystonia 333.79 Other acquired torsion dystonia 333.83 Spasmodic torticollis 723.5 Torticollis, unspecified 2014 ICD-9-CM For Physicians, VOLUMES I & II, Professional Edition (American Medical Association). ICD-9 Diagnosis Codes NOT COVERED/UNPROVEN (List may not be all inclusive) ICD-9 CM DESCRIPTION CODES 294.1 Dementia in conditions classified elsewhere with behavioral disturbance 300.3 Obsessive compulsive disorders (OCD) 301.4 Obsessive-compulsive personality disorder 307.23 Tourette s disorder 311 Depressive disorder, not elsewhere classified 312.30 Impulse control disorder, unspecified 332.1 Secondary Parkinsonism 340 Multiple Sclerosis (MS) 345.00 Generalized nonconvulsive epilepsy; without mention of intractable epilepsy 345.01 Generalized nonconvulsive epilepsy; with intractable epilepsy (Pharmacoresistant (Pharmacological resistant), poorly controlled, refractory (medically) or treatment resistant 345.10 Generalized convulsive epilepsy; without mention of intractable epilepsy 345.11 Generalized convulsive epilepsy; with intractable epilepsy (Pharmacoresistant (Pharmacological resistant), poorly controlled, refractory (medically) or treatment resistant 345.2 Petit mal status 7
345.3 Grand Mal Status 345.40 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures; without mention of intractable epilepsy 345.41 Localization-related (focal) (partial) epilepsy and epileptic syndromes with complex partial seizures; with intractable epilepsy (Pharmacoresistant (Pharmacological resistant), poorly controlled, refractory (medically) or treatment resistant 345.50 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures; without mention of intractable epilepsy 345.51 Localization-related (focal) (partial) epilepsy and epileptic syndromes with simple partial seizures; with intractable epilepsy (Pharmacoresistant (Pharmacological resistant), poorly controlled, refractory (medically) or treatment resistant 345.60 Infantile spasms; without mention of intractable epilepsy 345.61 Infantile spasms; with intractable epilepsy (Pharmacoresistant (Pharmacological resistant), poorly controlled, refractory (medically) or treatment resistant 345.70 Epilepsia partialis continua; without mention of intractable epilepsy 345.71 Epilepsia partialis continua; with intractable epilepsy (Pharmacoresistant (Pharmacological resistant), poorly controlled, refractory (medically) or treatment resistant 345.80 Other forms of epilepsy and recurrent seizures; without mention of intractable epilepsy 345.81 Other forms of epilepsy and recurrent seizures; with intractable epilepsy (Pharmacoresistant (Pharmacological resistant), poorly controlled, refractory (medically) or treatment resistant 345.9 Epilepsy, unspecified 346.20 Variants of migraine, not elsewhere classified; without mention of intractable migraine without mention of status migrainosus 346.21 Variants of migraine, not elsewhere classified; with intractable migraine, so stated, without mention of status migrainosus 350.1 Trigeminal neuralgia 353.6 Phantom limb (syndrome) 2014 ICD-9-CM For Physicians, VOLUMES I & II, Professional Edition (American Medical Association). HCPCS CODES (List may not be all inclusive) HCPCS CODES C1767 C1778 C1787 C1816 C1820 DESCRIPTION Generator; neurostimulator (implantable), nonrechargeable Lead, neurostimulator (implantable) Patient programmer; neurostimulator Receiver and/or transmitter; neurostimulator (implantable) Generator, neurostimulator (implantable), with rechargeable battery and charging 8
C1883 C1897 L8680 L8681 L8682 L8683 L8685 L8686 L8687 L8688 L8689 Adaptor/Extension, pacing lead or neurostimulator lead (implantable) Lead, Neurostimulator test kit (implantable) Implantable neurostimulator electrode, each Patient programmer (external) for use with implantable programmable neurostimulator pulse generator, replacement only Implantable neurostimulator radiofrequency receiver Radiofrequency transmitter (external) for use with implantable neurostimulator radiofrequency receiver Implantable neurostimulator pulse generator, single array, rechargeable, includes extension Implantable neurostimulator pulse generator, single array, non-rechargeable, includes extension Implantable neurostimulator pulse generator, dual array, rechargeable, includes extension Implantable neurostimulator pulse generator, dual array, non-rechargeable, includes extension External recharging system for battery (internal) for use with implantable neurostimulator, replacement only 2013 HCPCS LEVEL II Professional Edition (American Medical Association). REFERENCES 1. American Society of Stereotactic and Functional Neurosurgery. Deep brain stimulation: indications, techniques, and practice parameters. 2011. Accessed November 19, 2013. Available at URL address: http://www.assfn.org/clinical.html 2. Centers for Medicare & Medicaid Services (CMS). National Coverage Determination (NCD) for Deep Brain Stimulation for Essential Tremors and Parkinson s disease (160.24). Effective date April 1, 2003. Accessed November 19, 2013. Available at URL address: http://www.cms.gov/medicare-coverage-database/details/ncddetails.aspx?ncdid=279&ncdver=1&bc=agaagaaaaaaa& 3. Centers for Medicare & Medicaid Services (CMS). CMS Manual System. Medicare Claims Processing. Pub.100-4. Transmittal 128. March 26, 2004. Searched November 19, 2013. Document unavailable at the website. Document is available at MCS electronic folder. 4. Department of Health & Human Services Centers for Medicare & Medicaid Services (CMS) Program Memorandum Intermediaries/Carriers. Deep brain Stimulation for Essential Tremor and Parkinson s disease. Transmittal AB-03-023. February 14, 2003. Accessed November 19, 2013. Available at URL address: http://www.cms.gov/transmittals/downloads/ab03023.pdf 9
5. Ecri Institute. Deep Brain Stimulation for Parkinson s disease and Essential Tremors. July 10, 2009. Searched November 19, 2013. Available at URL address: Document not available at webserver. Document available at MCS electronic folder. 6. Ecri Institute. Deep Brain Stimulation for Treating Non-Parkinsonian Neurologic and Psychiatric Disorders. November 2012. Accessed Nov 21, 2013. Available at URL address: https://members2.ecri.org/components/hotline/documents/issuefiles/7819.pdf 7. Medtronic. Important Safety Information (Indications, Contraindications, and Others). Last Updated April 23, 2013. Accessed November 21, 2013. Available at URL address: http://www.medtronic.com/patients/parkinsons-disease/important-safetyinformation/index.htm 8. Medtronic. What is DBS Therapy? Last Updated: Jan 03, 2012. Accessed November 21, 2013. Available at URL address: http://www.medtronic.com/patients/parkinsonsdisease/therapy/what-is-it/index.htm 9. National Guideline Clearinghouse. Care of the movement disorder patient with deep brain stimulation. 2009. Accessed November 20, 2013. Available at URL address: http://www.guideline.gov/content.aspx?id=15087&search=tremors 10. National Institute for Health and Clinical Excellence (NICE). CG 35 Parkinson s disease: full guidance. Jun 28, 2006. Accessed November 20, 2013. Available at URL address: http://www.nice.org.uk/nicemedia/live/10984/30087/30087.pdf 11. Technology Evaluation Center, Blue Cross & Blue Shield Association. Joan B. Vatz, M.D., Contact Assessor. Bilateral Deep Brain Stimulation (DBS) of the Subthalamic Nucleus (STN) or the Globus Pallidus Interna (GPi) for treatment of Advance Parkinson s disease. January 2002. Accessed November 20, 2013. Available at URL address: http://www.cms.gov/determinationprocess/downloads/id15ta.pdf 12. MDSTF on Rating Scales for Parkinson s disease. The Unified Parkinson s Disease Rating Scale (UPDRS): Status and Recommendations. Movement Disorders. Vol 18. No. 7, 2003, pp.738-750. 153-63. Accessed November 20, 2013. Available at URL address: http://www.movementdisorders.org/userfiles/unified.pdf 13. Fahn S. (2000). The spectrum of levodopa-induced dyskinesias. Ann Neurol, 47:S2-9. Accessed November 20, 2013. Available at URL address: http://www.ncbi.nlm.nih.gov/pubmed/10762127 14. U.S. Food and Drug Administration. FDA Patient Safety News: Show #5, June 2002. New Device for Bilateral Control of Parkinson Symptoms. Accessed November 20, 2013. Available at URL address: http://www.accessdata.fda.gov/psn/printer-full.cfm?id=14 15. U.S. Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH). Medtronic Activa Dystonia Therapy - H020007. New Humanitarian Use Device Approval. CDRH Consumer Information. Rockville, MD: FDA; April 15, 2003. Accessed November 20, 2013. Available at URL address: 10
http://www.fda.gov/medicaldevices/productsandmedicalprocedures/deviceapprovalsandclear ances/recently-approveddevices/ucm082535.htm 16. U.S. Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH). Medtronic Activa Dystonia Therapy. Implantable multi-programmable quadripolar deep brain stimulation system. FDA Summary of Safety and Probable Benefit. Humanitarian Device Exemption (HDE) No. H020007. Rockville, MD: FDA; Date of Approval to the Applicant: April 15, 2003. Accessed November 20, 2013. Available at URL address: http://www.accessdata.fda.gov/cdrh_docs/pdf2/h020007b.pdf 17. U.S. Food and Drug Administration (FDA). FDA approves humanitarian device exemption for deep brain stimulator for severe obsessive-compulsive disorder. FDA News. Rockville, MD: FDA; February 19, 2009. Accessed November 20, 2013. Available at URL address: http://www.fda.gov/newsevents/newsroom/pressannouncements/2009/ucm149529.htm POLICY HISTORY DATE ACTION COMMENT November 18, 2010 November 1, 2011 Origination of Policy Yearly review November 1, 2012 Yearly review References updated. November 21, 2013 Yearly review 1. References updated. 2. New contraindication #4 was added to the Medical Policy. 3. New HCPCS codes (C1767, C1778, C1787, C1816, C1820, C1883, and C1897) were added to the Medical Policy. 4. New reference #6 was added to the Medical Policy. This document is for informational purposes only. It is not an authorization, certification, explanation of benefits, or contract. Receipt of benefits is subject to satisfaction of all terms and conditions of coverage. Eligibility and benefit coverage are determined in accordance with the terms of the member s plan in effect as of the date services are rendered., (MCS) medical policies are developed with the assistance of medical professionals and are based upon a review of published and unpublished information including, but not limited to, current medical literature, guidelines published by public health and health research agencies, and community medical practices in the treatment and diagnosis of disease. Because medical practice, information, and technology are constantly changing, Medical Card System, Inc., (MCS) reserves the right to review and update its medical policies at its discretion., (MCS) medical policies are intended to serve as a resource to the plan. They are not intended to limit the plan s ability to interpret plan language as deemed appropriate. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment they choose to provide. i On - The period of maximum mobility and smooth motor function occurring in response to a dose of levodopa and/or other antiparkinsonian medication ii Dyskinesia- Abnormal involuntary movements, usually choreiform or dance-like, but may also have the appearance of dystonia, myoclonus, and tics. Levodopa-induced dyskinesia tends to affect the head, neck, torso, limbs, respiratory muscles, are reversible, and rapidly disappears with reduction of withdrawal of levodopa; Anticholinergic induced dyskinesia involves the oro-facial-lingual muscles, as with tardive dyskinesia Peak dose dyskinesia (improvement-dyskinesia-improvement or I-D-I): the earliest and most common form of dyskinesia, occurring at the time of maximum or peak-dose levodopa response D-I-D dyskinesia: a diphasic pattern of adventitious 11
dyskinetic movements which appear before therapeutic response to levodopa has begun, disappear during the on period, then re-emerge as the beneficial effect of levodopa wears off. (dyskinesia improvement dyskinesia) iii Motor Fluctuations - Alternations between on periods, during which the patient experiences a good response to antiparkinsonian medication (that is, experiences good mobility and dexterity) and off periods, during which parkinsonian symptoms become worse. Patients are said to experience motor fluctuations once the benefit of a dose of levodopa lasts less than 4 hours. Most patients treated with levodopa experience predictable off periods as the effect of the most recent dose wears off (see end-of-dose or wearing off above). Some patients experience unpredictable off periods that occur suddenly without warning, over a period of seconds or minutes, last minutes to hours, and appear to have no relationship to the time of levodopa administration or the plasma levodopa concentration. iv offs - Has been used to refer to a variety of conditions, ranging from brief periods when patients experience certain parkinsonian symptoms, such as immobility and loss of dexterity, due to a temporary loss of medication effect to the condition that occurs after a prolonged withdrawal of anti-parkinsonian medication v Diathermy - is a type of ultrasound therapy that helps to reduce pain. This therapy involves applying a heat coil to the skin or body, which heats brain electrodes and can cause serious brain injury or death. Diathermy is used by dentists, pain specialists, sports medicine physicians, and physical therapists. 12