Parkinson Disease Concept Map: An Overview
What is Parkinson Disease (PD)?
The map starts with the disease’s definition, epidemiology, etiology, and signs and symptoms.Parkinson disease is an idiopathic, slowly progressive, degenerative disorder that is characterized by resting tremor, stiffness (rigidity), slow and decreased movement (bradykinesia), and gait and/or postural instability. The etiology of Idiopathic Parkinson Disease (IPD) is unknown, but most likely IPD is a result of interactions between aging, genetic predisposition, and environmental factors.
Common motor signs of Parkinson disease include tremor, rigidity, bradykinesia, and postural instability. Each of these signs is stated in the map with corresponding features in the form of a table. For example, features of bradykinesia include:
- Smaller handwriting (micrographia)
- Infrequent blink
- Excessive drooling (sialorrhea) may contribute to disability
- Soft voice trails off
- Speech becomes hypophonic, … etc.
Parkinson Disease Differential Diagnosis
Parkinson disease must be differentiated from other conditions presenting tremors, especially “Atypical Parkinsonism”. As shown in the map, atypical parkinsonism refers to a set of symptoms typically seen in PD, but caused by other disorders. It is caused not only by cell loss in the substantia nigra pars compacta (SNc), but also by additional degeneration of cells in the parts of the nervous system that normally contain DA receptors (striatum). Also mentioned in the map:
- Common features of atypical parkinsonism that differentiate it from PD.
- Forms of atypical parkinsonism and associated conditions.
On this part of the map, you’ll find an inter-link (dotted line) between the disease’s pathophysiology and treatment. Starting from the disease’s pathophysiology; the main pathological feature of PD is the death of dopaminergic neurons in the substantia nigra pars compacta (SNc), causing the motor manifestations of PD. This point helps in understanding the role of dopamine and dopamine metabolism in disease’s pathophysiology and treatment.
This part of the map links between dopamine metabolism in presynaptic neurons and antiparkinson drugs mechanisms of action. Pharmacological treatment of PD aims to restore dopaminergic function in the brain using one or more of the following:
- COMT Inhibitors
- MAO-B Inhibitors
- DA Agonists
- Anticholinergic Medications
For each drug or drug class, its mechanism of action, efficacy against PD symptoms, adverse effects, precautions, or drug interactions if present are explained. It is important to state that treatment of PD doesn’t prevent the progression of the disease and drug choice is based on symptoms. For example, Levodopa is most effective at relieving bradykinesia and rigidity, although it often substantially reduces tremors. On the other hand, anticholinergic medications are effective against IPD tremor in about 50% of patients; not bradykinesia or rigidity.
Antiparkinson Drugs Table Comparisons
Besides using the way of concept mapping to build information upon each other (information about drugs mechanisms of action and indications are built upon dopamine metabolism), there are also table comparisons for antiparkinson drugs. There are three tables that compare:
- Catechol-O-methyl transferase inhibitors (COMT inhibitors): Tolcapone and Entacapone.
- Monoamine oxidase B inhibitors (MAO-B inhibitors): Selegiline and Rasagiline
- Nonergot dopamine agonists: Apomorphine, Pramipexole, Ropinirole, and Rotigotine transdermal.
L-dopa motor complications
Despite its efficacy as a symptomatic treatment of Parkinson disease, long-term L-dopa therapy is associated with disabling motor complications. These complications include:
- End-of-dose wearing off (motor fluctuation)
- “Delayed-on” and “no-on” response
- “Off-period” dystonia
These complications are represented in the map through a table that contains clinical features, mechanisms, and management approaches for each of l-dopa motor complications.
Surgical Management of Parkinson Disease
Surgery should be considered as an adjunct to pharmacotherapy in case of PD symptoms are not adequately controlled with optimized medical therapy. The map briefly states surgical procedures for the treatment of PD, including the most common procedure which is Deep brain stimulation (Thalamic Stimulation) and its patient selection criteria.
Management of Special Situations
Parkinson disease is associated with nonmotor symptoms that may be caused by either the disease itself or the antiparkinson drugs. These nonmotor symptoms can be hallucinations/psychosis, cognitive disorders, sleep disorders, depression, agitation, anxiety, constipation, orthostatic hypotension, seborrhea, and blepharitis. The goal in the management of Parkinson disease is to improve motor and nonmotor symptoms in order to improve the quality of life. This part of the map gives an overview of medications that can be used in the management of nonmotor complications and those that should be avoided in order not to worsen Parkinson symptoms.
Order the map
You can order the Parkinson Disease concept map in any of the following forms according to your preference. Our maps are comprehensive in a way that can benefit both students and clinicians.
This map is available in two forms;
1. Printable version.
2. Whole map version.
Check them out below to know the difference, so that you can choose what is suitable for you. And please feel free to leave your feedback, comments, or questions in the comments section below.