Martin A. Samuels, M.D. MOVEMENT DISORDERS

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1 Martin A. Samuels, M.D. MOVEMENT DISORDERS I. Nomenclature of Movement Disorders A. Too Little Movement 1. Paralysis (paresis) 2. Rigidity a. spasticity (pyramidal) b. "lead pipe" (extra pyramidal) c. paratonia (frontal lobe) 3. Akinesia (bradykinesia or Parkinsonism) B. Too Much Movement 1. Tremor a. tremor in repose (1) relieved by action (Parkinsonism) (2) exacerbated by action (Rubral or Cerebellar Outflow) b. action tremors (1) goal directed movement (cerebellar) (2) postural (a) physiologic (b) essential (senile, familial) 2. Fibrillation 3. Fasciculation 4. Myoclonus and Asterixis 5. Chorea and ballism 6. Dystonia a. focal (e.g. writer's cramp; musician's dystonias) b. segmental (torticollis; blepharospasm; Meige syndrome) c. generalized (dystonia musculorum deformans; genetic) d. dopamine responsive (genetic) e. with Parkinsonism 7. Athetosis 8. Akathisia and restless legs (The Ekbom Syndrome) 9. Tics N.B. Tardive dyskinesia refers to the delayed onset of a movement disorder after initiation of a neuroleptic drug. Tardive dyskinesias may be chorea (particularly oral-buccal-lingual), dystonia, athetosis, akithesia or bradykinesia/akinea (i.e. Parkinsonism).

2 2 II. Review of Neuroanatomy Relevant to Movement Disorders A. Corticospinal ("Pyramidal") Motor System B. "Parapyramidal" Motor Systems 1. reticulospinal 2. vestibulospinal 3. rubrospinal C. "Extrapyramidal" Motor Systems (basal ganglia) DIRECT PATHWAY INDIRECT PATHWAYS D 1 Striatu D 2- Striatu Striatu SP/Dyn GPi Enk GPe Sth GPi + Glu GPe GPi Thalamu Thalamu Thalamu NET RELEASE NET INHIBITION

3 3 D. Cerebellar Motor Control System 1. Cerebellopetal 2. Cerebellum 3. Cerebellofugal III. Specific Common Syndromes A. Parkinsonism (akinesia, rigidity, tremor) 1. Parkinson Disease (paralysis agitans) 2. Post-encephalitic Parkinsonism 3. Drug induced Parkinsonism 4. Parkinsonism associated with degenerative disease of the nervous system: a. progressive supranuclear palsy (Steele, Richardson, Olszewski) b. multisystem atrophy (Shy-Drager) c. Parkinsonism-dementia complex (Guam type, sporadic type) d. strionigral degeneration e. olivopontocerebellar atrophy f. dementia with Lewy bodies g. cortical-basal degeneration 5. Parkinsonism associated with deposition of minerals in the basal ganglia. a. Wilson Disease (copper) b. Fahr Disease (calcium and others) sometimes associated with hypoparathyroidism. c. Hallervorden Spatz Disease (Iron) d. Miner's Parkinsonism (Manganese) 6. Toxic Parkinsonism (e.g.mptp induced Parkinsonism) 7. Metabolic Parkinsonism (e.g. Leighs subacute necrotizing encephalomyelopathy and other mitochondrial diseases) B. Huntington disease C. Drug Induced Movement Disorders 1. Parkinsonism (reversible) 2. Acute dystonia (reversible and treatable with anticholinergic drugs) 3. Tardive dyskinesias (often irreversible; sometimes treatable with reserpine or tetrabenazine) a. tardive chorea (usually predominantly oro-bucco-lingual) b. tardive dystonia and athetosis c. akathisia (Ekbom syndrome)

4 4 D. Tremors 1. enhanced physiologic tremor (peripheral) a. drugs (e.g. amphetamines, lithium, caffeine, antidepressant, adrenergic agents, cocaine) b. drug withdrawal (e.g. sedatives, alcohol) c. hyperthyroidism d. anxiety 2. Essential tremors (central) 3. Cerebellar tremors 4. Parkinsonian tremor IV. Treatment A. Tremors 1. Parkinsonian tremor a. L-dopa b. ethopropazine (Parsidol) 2. Cerebellar a. limb weights b. isoniazid 3. Exaggerated physiologic tremor a. avoid precipitating factors b. anxiolytics c. beta blockers (need not cross the blood brain barrier) 4. Essential tremors a. primidone (Mysoline) b. beta blockers which cross the blood-brain barrier (e.g. propranolol) c. methazolamide d. octonol e. avoid alcohol as a treatment B. Parkinsonism 1. Treat underlying disease or remove offending drug or toxin, if possible. 2. Pharmacologic therapy a. central dopamine replacement with L-dopa and carbidopa (Sinemet) b. improve central dopamine release with amantadine (Symmetrel) which is also an N-methyl D-aspartate (NMDA) glutamate receptor antagonist

5 c. central anticholinergic drugs such as: trihexyphenidyl (Artane), benztropine (Cogentin) d. central dopamine receptor agonist such as bromocriptine (Parlodel), pergolide (Permax) pramipexole (Mirapex), or ropinirol (Requip) e. reduce production of putative endogenous toxin with monoamine oxidase inhibitor - deprenyl (Eldepryl) f. reduce metabolism of dopamine with a catachol-o-methyl transferase inhibitor such as tolcapone (Tasmar) or entacapone (Comtan) g. cellular protection with Co-enzyme Q shows some promise 3. Surgical therapy with striatal implants of dopamine producing cells (fetal or adrenal medulla), pallidotomy, pallidal stimulation, thalamic stimulation, subthalmic nucleus deep brain stimulation. 4. Clozapine (Clozaril) is the best anti-psychotic in patients with Parkinsonism, but monitor blood counts. Other atypical drugs (e.g. olanzapine (Zyprexa) resperidone (Risperdal)or quitiapine (Seraquel) may also be helpful but good evidence is lacking. C. Chorea 1. Anti-dopamine therapy with central dopamine receptor antagonists such as haloperidol (Haldol). 2. Cholinergic therapy with precursors of centrally acting acetylcholine such as choline and lecithin. 3. Cholinergic agonist therapy with deanol (Deaner) 4. Anticholinesterase therapy with physostigmine 4. Benzodiazepines 5. Dopamine depleting drugs (e.g. reserpine and tetrabenazine) 6. Amantadine (Symmetrel) 7. Coenzyne Q D. Myoclonus 1. Improve central serotonergic function with 5-hydroxy-tryptophan and carbidopa. 2. Benzodiazepines 3. Anti-epileptic drugs 4. Central serotonin reuptake inhibitors (e.g. Fluoxitine) 5 E. Dystonia 1. no good therapy known except in small subgroup of dopamine responsive dystonia 2. trihexyphenidyl (Artane), benzodiazepines, carbamazepine (Tegretol), baclofen (lioresal) and tetrabenazine may be helpful in individual patients.

6 V. READING 3. Pallidotomy or deep brain stimulationof the subthalamic nucleus may help in drug resistant cases. 4. surgery sometimes required 5. Botulinum toxin injection for focal and segmental dystonias (e.g. blepharospasm and tortecollis) F. Drug Induced Movement Disorders 1. Tardive dyskinesia a. discontinue offending drug even if this transiently increases the movement disorder b. no proved effective drug treatment but there may be some benefit with: (1) reserpine up to 4mg/day (2) lecithin up to several gms/day (3) deanol up to 1gm/day (4) valproate 10-20mg/kg/day (5) baclofen up to 100mg/day (6) tetrabenazine (not yet available in the U.S.) 2. Parkinsonism a. discontinue offending drug b. anticholinergic therapy 3. Akathisia a. discontinue offending drug b. no known drug therapy 4. Acute dystonia a. anticholinergic therapy with benztropine (Cogentin) 1mg I.M. or I.V. b. antihistaminic therapy with diphenhydramine (Benadryl) 50mg I.V G. Tics 1. developmental tics will disappear spontaneously 2. Haloperidol up to - 16mg qd 3. Clonidine up to 20mg/day 6. Tricyclic and tetracyclic anti-depressants 1. Sudarsky, LR: Movement Disorders. In: MANUAL OF NEUROLOGY, 7th Edition, M.A. Samuels, ed., Boston: Little, Brown (2004) pps