CVA, Parkinson’s and MG Flashcards
bulbar
involvement of speech
opthalmoplegia
eyes not moving together
muscle problem
bilateral asymmetrical fatiguable ptosis
ptosis- drooping of upper eyelid
myasthenia gravis
autoimmune, antibody mediated disorder of the neuromuscular junction
classically starts w ocular symptoms then progresses over the years to proximal weakness
worsens with exertion
can lead to life threatening respiratory decompensation
symptoms of MG and presentation
fluctuating fatigability and weakness affecting ocular, bulbar, and proximal limb skeletal muscle groups
Cogan’s lid twitch and ice pack test positive
ptosis
opthalmoplegia
pathophysiology of MG
acetylcholine receptor gets blocked/destroyed by antibody
acetylcholine cannot bind
acetylcholinesterase breaks down Ach for inhibition of signal (so can inhibit these to reduce symptoms)
fewer receptors=fewer nerve signals
muscle weakness
investigations for MG
antibodies in blood eg. Anti-AchR (acetylcholinesterase), anti-MUSK,
electrophysiology - repetitive nerve stimulation
edrophonium test- a reversible acetylcholinesterase inhibitor
check for other autoimmune conditions
CT chest- AchR Ab +ve
thymoma and MG
presence of thymoma causes MG
thymus produces AntiAchR antibodies
thymoma
when thymus gland is overgrown/
tumour grown
can remove surgically
triggers for MG
physical exertion
infections
surgery
pregnancy
hypokalaemia
drugs: Abx (antibiotics)
CCBs
beta blockers
diazepam
treatment for MG
AchR inhibitor first (acetylcholinesterase inhibs)
then
presnisolone
steroid sparing agents
acute deterioration (IVIG or plasma exchange)
monoclonal antibody treatments
thymectomy for thymoma
Parkinson’s
Parkinson’s disease (PD) is a degenerative, progressive disorder that affects nerve cells in deep parts of the brain called the basal ganglia and the substantia nigra
sporadic
onset in late middle age
Parkinson’s presenting symptoms
Facial hypomimia.
Right sided rest tremor, bradykinesia and rigidity.
Flexed posture, shuffling gait and decreased arm swing on the right.
Common in elderly, but can present in young
- Presenting symptoms
– Tremor
– difficulty with fine movements
– stiffness of a limb (e.g. Frozen shoulder)
– falls
Parkinsons pathology main features
Loss of pigmented (dopamine-containing) neurons in substantia nigra
Alpha Synuclein (microtubule protein) misfolding is the main intracellular trigger of cell death - becomes sticky and clumps together to form lewy bodies
Presence of Lewy bodies - [pink] intracytoplasmic inclusions in the neurons that contain brown neuromelanin - toxic to cells and kills dopaminergic neurons
PD pathophysiology
dopamine role
Neurotransmitters carry messages between neurons by crossing the synapse between them
* To fine-tune coordination of movement, the amount of dopamine in the synapse is regulated. Too much or too little dopamine makes smooth continuous movement difficult
PD cardinal features
Akinesia/Bradykinesia
- Slowness of movement
+ decrement in amplitude of repetitive movement - Difficulty initiating movement
- Mask-like facies (facial hypomimia)
- Reduced spontaneous blinking
- Lack of arm swing
- Finger taps, playing piano, heel taps
repetitive test
movement gets smaller and slower
PD cardinal features
Tremor
- 4-7 Hz
- Rest
- Pill-rolling
- Reduces on action
- Unilateral initially
- Arms, legs, head
- Hands in lap, outstretched, in front of face, finger-to-nose
PD cardinal features
Rigidity
- Stiffness through a range of movement
- Like a lead pipe combined with tremor ‘cogwheel’ rigidity
- Examine at wrist, elbow and other joints, co-activation
PD cardinal features
Postural instability
Gait – stooped, festinant (shuffling steps)
* Falls
* Ability to stand with arms crossed, gait, pull test
Positive pull test (>2 corrective steps back or patient is about to fall)
PD non motor features
Neuropsychiatric
– Depression, apathy
– Anxiety
Cognitive
– Dementia (fluctuating alertness and cognition,visual hallucinations)
Sleep-related problems
– Excessive daytime sleepiness
– Vivid dreams
– REM sleep behaviour disorder
Autonomic dysfunction
– Postural hypotension
– Urinary incontinence
– Constipation
– Erectile dysfunction
PD diagnosis
- History & examination usually confirm diagnosis
Queen square Brain bank diagnostic criteria - DAT scan (helps differentiate between essential tremor or Parkinson’s Disease) measures dopaminergic activity
secondary parkinsonism
when symptoms similar to Parkinson disease are caused by certain medicines, a different nervous system disorder, or another illness
can be caused by
Brain injury.
Diffuse Lewy body disease (a type of dementia)
Encephalitis.
HIV/AIDS.
Meningitis.
Multiple system atrophy.
Progressive supranuclear palsy.
Stroke.
treatment of pd
Levodopa/L-Dopa
* Increases circulating dopamine in the brain, therefore improving the symptoms of PD
* Effects eventually wear off with time
* Side effects - nausea & vomiting, confusion & hallucinations, end-of -dose dyskinesias, on-off syndrome
Dopamine agonists
* Less effective than L-dopa, but fewer late unwanted dyskinesia
* Side effects – impulse control disorders (e.g. compulsive gambling, shopping, hypersexuality, punding)
MAOB inhibitors
* Inhibits breakdown of dopamine
COMT inhibitors
* Inhibits breakdown of dopamine
Apomorphine
– Directly acting dopamine agonist
– Given sub-cutaneously as daily
infusion or bolus injections
– Best method of smoothing out
fluctuations/managing
troublesome
dyskinesias in advanced PD
– Side effects - nausea, confusion, low BP
Duodopa
– L-dopa administered continuously
and directly into small intestine via
PEJ tube for rapid uptake into
bloodstream
