movement disorder Flashcards
classification of tremor
- 14-18Hz primary orthostatic tremor
- 7-12Hz physiological tremor
- 4-12Hz essential tremor, dystonic tremor syndromes
- 2-12Hz neuropathic tremor, drug induced tremor, multiple sclerosis
- s disease
essential tremor?
- rhythmic
- symmetrical
- postural
- family history
- alcohol response 50%
- increase cerebellar outflow
treatment of essential tremor (level A effective)
- propranolol and primidone
- may combined
- may used for dystonic tremor
treatment of essential tremor (level B probably effective)
- alprazolam
- atenolol
- gabapentin
- sotalol
- topiramate
treatment of essential tremor (level C possibly effective)
- nadolol
- nimodipine
- clonazepam
- botulinum toxin A
- deep brain stimulation
- thalamotomy
treatment of essential tremor (not effective)
- levetiracetam
- 3,4- diaminopyridine
- flunarizine
- pregabalin
- zonisamide
- clozapine
parkinson’s disease diagnostic criteria
- progressive neurodegenerative disease
- age >60
- mutations in LRRK, PRKN, PINK1, DJ1, SNCA genes
- loss of dopaminergic nigrostriate neurones in substantia nigra
- synucleinopathy (alpha-synuclein aggregates)
- neurotoxicity/necrosis
- apoptosis
- bradykinesia and rigidity/ rest tremor/ postural instability (not cause by proprioception problem)
staging of alpha-synuclein pathology
stages 1 & 2: presymptomatic (inclusion bodies medulla and pons, olfactory
stages 3 & 4: classic (SN, midbrain, forebrain)
stages 5 & 6: dementia (neocortex)
types of dopamine pathway
- nigrostriate (origin: SN)
- mesocortical (origin: ventral tegmental area)
- mesolimbic (origin: VTA to nucleus accumbens)
- tuberoinfundibular (origin: hypothalamus)
stimulatory G protein
dopamine D1 and D5 receptors
inhibitory G protein
dopamine D2, D3, D4 receptors
levodopa?
- precursor dopamine and first line treatment
- always given with DOPA decarboxylase inhibitor
- either benserazide or carbidopa
- start at low dose and increase slowly
levodopa effects
- benefits:
- treats Bradykinesia
- treats Rigidity
- tremor responds to ANTIMUSCARINIC - disadvantages:
- short half life (2 hours)
- dyskinesia
- fluctuation
levodopa short term problems
- short half life
- need to control release
- need to give as intraduodenal infusion
- need to watch dietary protein and timing - side effects:
- nausea, vomiting
- dizzy
- flushing, rash
- sweating
- hypotension
- delusions, hallucination
- arrhythmias
- liver function
levodopa long term problems
- levodopa therapy:
- cumulative dose
- duration of therapy-3hours - dyskinesia:
- peak dose dyskinesia
- diphasic dyskinesia
- off period dystonia - on-off:
- wearing off
- freezing
- fluctuations ‘on-off’ effect
dopamine agonists drugs
- ropinirole D2
- pramipexole D3
- apomorphine
- rotigotine patch
characteristics of dopamine agonists drugs
- non ergot drugs
- do not need enzymatic conversion
- no toxic metabolites
- less dyskinesia
- help restless legs
- may be antioxidant
- can be use monotherapy or adjunctive therapy
- older drugs (bromocriptine, pergolide) cause cardiac valve fibrosis!
side effects of dopamine agonist drugs
- somnolence (sleepiness)
- impulsive control disorder (ICD)
- hallucinations (psychiatric effects)
- D2 side effects
apomorphine?
- dopamine agonist
- subcutaneous (penject)
- continuous infusion
- very emetogenic
- pretreat with domperidone
- 3 doses/day
rotigotine patch?
- dopamine agonist
- non ergoline agonist
- 24 hour duration
- ensures compliance
selegiline (MAO B inhibitor)?
- orally
- irreversible inhibitor
- AMPHETAMINE byproducts of catabolism
- protect dopamine from degradation
- delay need for levodopa
- reduce daily dose levodopa
1. side effects: - nausea, weight loss
- headache
- agitation (disturbance)
- interactions
rasagilinie (MAO B inhibitor)?
- irreversible inhibitor
- NO AMPHETAMINE as byproducts
- available as a patch
COMT inhibitors characteristic and drugs
- prolong duration of action of levodopa
- increase bioavailability
- no intrinsic benefit alone
- efficacy high
- increase dopaminergic adverse events
- ENTACAPONE- vascular risk
- TOLCAPONE- affects brain COMT and liver failure. cause orange discolouration of urine
amantadine- releasing dopamine
- avoid in heart failure and ulcer disease
- action:
- anticholinergic
- NMDA
- moderately effective
- may be helpful in dyskinesia - side effects:
- tolerance
- hallucinations, confusion
- dry mouth
- livedo
- oedema
- hypotension
- leukopenia
- GI upset
antimuscarinic?
- for tremor
- for drug induced parkinsonism
- for acute dystonic reactions
- exacerbate dementia
- poorly tolerate in olderly
- ORPHINADRINE, PROCYCLIDINE, TRIHEXYPHENIDYL
1. side effects: - blurred vision
- constipation
- retention
- mentation
non-motor findings
- level A: modafinil for excessive daytime sleepiness
- level B: levodopa/ carbidopa for periodic limb movement disorder (PLMS)
- level C:
- sildenafil for erectile dysfunction
- polyethylene glycol for constipation
- methylphenidate for fatigue
parkinsonism?
- parkinson plus DO NOT respond to levodopa
- parkinsonism DO NOT respond to levodopa
- drug induced parkinsonism (DIP) may RESPOND to antimuscarinic
what are the clues for DIP?
- subacute bilateral onset
- early presence of postural tremor
- concurrent oral dyskinesia
risk factors for DIP
- high dose, high potency
- elderly
- female
- hereditary parkinson disease
- AIDS
causes of chorea (st. vitus’s dance)
- sydenhams
- vascular
- increase RBC (poplycythemia)
- toxins: CO, Mg, Hg
- uremia
- SLE
- senile chorea
- drugs - AED
- APLA syndromes
- neurodegenerative
- conception: preggy, OCP
- endocrine: hyperthyroidism, hypo/hyperglycemia
treatment of chorea
- tetrabenazine (most important)
- amantadine
- riluzole
actions of botulinum toxin
- inhibits release of ACh into junction
- causes focal chemodenervation and transient weakness
- last about 3 months
- dose depends on site and severity
side effects of botulinum toxin
- soreness at site
- dysphagia
- dry mouth