Parkinson's Disease Flashcards
What is the aetiology of PD?
Unknown
Outline the pathophysiology of PD
Chronic, progressive movement disorder
Triad of bradykinesia, tremor and rigidity
Degeneration of substantia nigra = deficiency of dopamine
What are the symptoms and signs of PD?
Tremor = resting
Bradykinesia - shuffling gait, falls
Hypertonia = rigidity (cog-wheel)
Abnormal gait = shuffling, flexed posture, reduced arm swing, turning en-bloc
Hypophonia
Reduced facial expression
Postural instability = falls
Micrographia (small cramped handwriting)
Non-motor =
- Dementia (can see lewy-body before PD), psychosis
- Depression
- Salivation
- Sweating
- Sphincter problems
- Sleep disorders
- Pain
How should PD be investigated?
Hx - timeline, lifestyle, previous head injury, DH (antiepileptics, antipsychotics)
Neurological exam - tone, power, gait, handwriting
Bloods = Hb, TFT (hypo), U+Es, LFTs, B12/folate
MSU = rule out infection
Imaging = CT, MRI, PET
DAT scan = used to diff PD from central tremor
Carbidopa-levodopa test - do symptoms improve
How is PD managed?
Lifestyle = aerobic exercise
Carbidopa-levodopa
- SE = nausea, orthostatic hypotension (don’t give B-blockers)
- quick half life = needs to be taken every few hours
- don’t suddenly stop taking = neuroleptic malignant syndrome (fever, marked rigidity, altered consciousness, leucocytosis, high CK)
- will end up stop working (converted in dopaminergic neurons, eventual loss of pre-synaptic - give dopamine agonist ropinirole (SE impulsivity))
Dopamine agonists (ropinirole)
- AD: less dyskinesia or motor fluctuation, longer duration of action, not neurotoxic
- DIS: less efficacy than L-DOPA, more psychiatric SEs, expensive
- SE = postural hypotension, nausea, psychosis, hallucinations, impulse control disorders (gambling, hypersexual, shopping)
MAO B inhibitors (selegiline) = help prevent breakdown of dopamine by inhibiting monoamine oxidase B, prolong action of L-DOPA
COMT inhibitors (entacapone, tolcapone) = reduce peripheral breakdown of L-DOPA, have to use with levodopa
DBS = electrodes in STN, generator in the chest (needs to be responding to levodopa but having severe SE)
Sleep problems = melatonin
What are the possible complications of PD?
Dementia
Depression
Swallowing difficulties
How is PD clinically diagnosed?
Clinical diagnosis
Bradykinesia + at least ONE of the following
- Muscular rigidity = typically lead pipe (can be cog wheel - when tremor present)
- 4 – 6 Hz rest tremor = pill rolling
- Postural instability not caused by primary visual, vestibular, cerebellar, or proprioceptive ◦ dysfunction
What are the features of supportive criteria for a PD Dx?
Unilateral
Rest tremor present
Progressive
Persistent asymmetry
Excellent response (70 – 100%) to LD
Severe LD-induced chorea
LD response for ≥5 years
Clinical course of ≥10 years
What are the non-motor symptoms of PD?
Neuropsychiatric dysfunction ◦ Mood Disorders ◦ Apathy + anhedonia ◦ Frontal executive dysfunction ◦ Dementia + Psychosis
Sleep Disorders ◦ Sleep fragmentation + insomnia ◦ RBD ◦ PLMS / RLS ◦ Excessive daytime somnolence
Autonomic dysfunction
◦ Orthostatic hypotension
◦ Urogenital dysfunction
◦ Constipation
Sensory symptoms + pain
◦ Olfactory dysfunction
◦ Abnormal sensations
◦ Pain
What is a DAT scan?
Focus on the activity of the dopamine transporter
Loflupane I123 injection
Used with single-photon emission computed tomography (SPECT)
Detecting dopamine transporters (DaT) in suspected parkinsonian syndromes
What is deep brain stimulation?
Deep brain stimulation involves the implantation of a wire, with 4 electrodes at its tip, into one of 3 target sites in the brain:
- the thalamus (this procedure is known as thalamic stimulation)
- the globus pallidus (this procedure is pallidal stimulation)
- the subthalamic nucleus (this procedure is subthalamic stimulation)
Outline Hoehn and Yahr scale
- STAGE 1 = Unilateral disease
- STAGE 2 = Bilateral disease, without impairment of balance
- STAGE 3 = Mild to moderate bilateral disease; some postural instability; physically independent
- STAGE 4 = Severe disability; still able to walk or stand unassisted
- STAGE 5 = Wheelchair bound or bedridden unless aided
Outline UPDRS
Unified Parkinsons Disease Rating Scale
42 question assessment • 1 = mentation, behaviour, mood • 2 = ADL • 3 = motor sections • 4 = modified Hoehn and Yahr scale • 5 = Schwab and england ADL scale
What is an essential tremor?
Progressive tremor of the upper extremities and head, present in posture and action, without other neurological signs or symptoms
Mainly symmetrical, rhythmic, involuntary oscillation movement disorder of the hands and forearms (69% of patients) that is usually absent at rest and present during posture and intentional movements