Parkinson's disease Flashcards
what is the definition of PD?
Idiopathic Parkinson’s disease (PD) is a neurodegenerative disorder. The cardinal features include resting tremor, rigidity, bradykinesia, and postural instability. Patients may demonstrate a combination of these motor symptoms, as well as other non-motor symptoms.
what is the epidemiology of PD?
Mean onset age 65
Greater incidence in men
More common in white people
what is the aetiology of PD?
The aetiology of PD is unknown, although several factors have been implicated. There is probably a genetic predisposition, with subsequent environmental factors/exposures contributing to the evolution of clinical disease. Within this multifactorial model, age is the only undisputed risk factor.
what are the risk factors for PD?
Increased age
Family history of young onset disease
Mutation in gene encoding glucocerebrosidase
MPTP exposure
what is the pathophysiology of PD?
The underlying pathophysiology of PD is unknown. Selective loss of nigrostriatal dopaminergic neurons in the substantia nigra pars compacta (SNc) occurs with findings of intracytoplasmic eosinophilic inclusions (Lewy bodies) and neurites, both of which are composed of the protein synuclein. One theory suggests that misfolded alpha-synuclein can recruit endogenous alpha-synuclein to seed further protein aggregation in new neurons in a prion-like fashion. Loss of striatal dopaminergic output within the circuitry of the basal ganglia accounts for the constellation of motor symptoms. It is believed that decreased activity of the direct pathway and increased activity of the indirect pathway cause increased inhibitory activity from the globus pallidus internus (GPi)/substantia nigra zona reticulata to the thalamus, and therefore reduced output to the cortex.
what are the key presentations of PD?
Risk factors Bradykinesia Resting tremor Redigidity Postural instability
what are the first line and gold standard investigations for PD?
The diagnosis of PD is made clinically, and in cases without atypical features no additional diagnostic testing is indicated.
Dopaminergic agent trial - levodopa may improve symptoms
Atypical features = MRI., functional neuroimaging, olfactory testing, genetic testing, neuropsychometric testing , serum ceruloplasmin, urine copper
what are the differential diagnoses for PD?
Essential tremor
PSP
MSA
Lewy body dementia
how is PD managed?
Mild:
MAO-B inhibitor - rasagiline: 1 mg orally once daily or dopaminergic agent - pramipexole: 0.125 mg orally (immediate-release) three times daily initially or amantadine 100 mg orally once daily initially for 1 week or trihexyphenidyl 1 mg orally (immediate release) once daily initially and physical therapy, carbidopa or domperidone can be added
Moderate:
As above, deep brain stimulation, COMT inhibitor
how is PD monitored?
Monitoring by a movement disorder specialist is recommended every 4 months.
what are the complications of PD?
Levodopa induced dyskinesias
Motor fluctuations
Dementia
Constipation
what is the prognosis of PD?
Treatment of PD is symptomatic as no curative or disease-modifying agents are available. Therefore, the course is progressive. Unilateral symptoms ultimately become bilateral. Rates of progression vary between patients.
