Introduction to movement disorders Flashcards
What is the internal capsule?
Myelinated fibres running from Cortex to brainstem
3 components of basal ganglia
Head of caudate, lentiform and thalamus
Cardinal signs of Parkinson’s
Rigidity, tremor, bradykinesia, postural instability
Brain changes in Parkinson’s
Loss of dopamine in substantia nigra
Cardinal signs of Parkinsons on DAT scan
Asymmetry and loss of comma shaped substantia nigra
Dx Parkinson’s
Levodopa trial, DAT scan
How does L-dopa work?
L-dopa can cross BBB (dopamine cant) where decarboxylase converts to dopamine. Dopamine is packaged into vesicles and enters synapse
How does carbidopa work?
Normally, a reduced amount of l-dopa can cross BBB because it is broken down by DDC in periphery
Carbidopa inhibits DDC to stop breaking down l-dopa
Carbidopa can’t pass BBB so in brain, L-dopa is broken down into dopamine in brain to increase levels
Drug treatment for Parkinson’s
Levodopa, carbodopa, dopamine agonists, COMT inhibitors, MOAB inhibitors
How do dopamine agonists work?
They mimic dopamine so bind to receptors and reduce side effects of low dopamine levels
Only <65
How do COMT inhibitors work?
COMT is an enzyme that normally breaks down dopamine
COMT inhibitors stop this so more dopamine can get to brain
How do MOAB inhibitors work?
Mono amino oxidase B breaks down dopamine so MOAB inhibitors stop this
Surgical treatment for Parkinson’s
Make lesions using ultrasound and MRI, DBS, reconstruct lost circulation
DBS
Electrodes inserted into sub thalamic nucleus, must be careful because optic nerve runs below
How do we reconstruct lost circulation in Parkinson’s patients?
Relevant brain area is dissected from developing foetus which is made into suspension and injected into brain, acts as stem cells
Side effects of dopamine agonists
Hyper sexuality, personality changes like gambling
What is Parkinsonism?
A set of characteristic symptoms that can be caused by Parkinson’s disease but also drugs/alcohol etc
What is Parkinson’s-plus syndrome
Parkinson’s but additional sx too - PSP, MSA, Wilson’s disease, CBD
Symptoms os PSP
Parkinsonism, can’t look up or down without moving head, Pseudobulbar palsy (mood swings), rigid neck and trunk, dysarthria, dementia
MSA
Multiple system atrophy -
MSA sx
parkinsonism, autonomic failure, cerebellar degeneration (poor balance), pyramidal signs (spastic paraparesis and weakness), deep sighs and sleep apnoea
Dx MSA
Characteristic hot cross bun sign in midbrain on MRI
Tx MSA
L-dopa, anticholinergics, fludrocortisone
Dx dyskinesia
PD (rest) or intention tremor (primary), drugs responsible or hyperthyroidism (secondary), get pt to draw spiral to see hand tremor, MRI won’t be of use because tremor won’t be visible
