Parkinson resident survival guide

Parkinson Resident Survival Guide Microchapters
Overview
Causes
Diagnosis
Treatment
Do's
Don'ts

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Fahimeh Shojaei, M.D., Moises Romo, M.D.

Synonyms and keywords:Parkinson's disease management, Parkinson's disease workup, Parkinson's disease approach, approach to Parkinson's disease, Parkinson's disease treatment

Overview

Parkinson's disease is a degenerative movement disorder of the central nervous system. It is characterized by motor symptoms such as bradykinesia, rigidity, and tremor, but also cognitive and comunicative symptoms such as facial masking and dysarthria. These primary symptoms are the results of decreased stimulation of the motor cortex by the basal ganglia, normally caused by the insufficient formation and action of dopamine. Diagnosis is mainly clinical, it may be supported by MRI findings and dopamine transporter single-photon emission computed tomography (DaT SPECT), but definitive diagnosis is made by autopsy. The mainstay of therapy for motor symptoms of Parkinson disease are: Levodopa, dopamine agonists, monoamine oxidase (MAO) B inhibitors, anticholinergic agents, amantadine, catechol-O-methyl transferase (COMT) inhibitors, estrogen and other drugs such as Exenatide, uric acid, isradipine, nilotinib and GDNF infusion. Other therapies will depend on comorbidities.

Causes

Life Threatening Causes

Life-threatening causes include conditions that may result in death or permanent disability within 24 hours if left untreated.

• Parkinson's disease is not a life-threatening condition that may result in death or permanent disability within 24 hours if left untreated.

Common Causes

• The cause of Parkinson's disease is a dopamine depletion due to a necrosis of dopaminergic neurons in the substantia nigra.
• Factors that may contribute to the development of Parkinson's disease are:
  • Low norepinephrine levels
  • The presence of Lewy bodies
  • Autoimmune factors

Diagnosis

Shown below is an algorithm summarizing the diagnosis of Parkinson's disease according to the American Academy of Neurology guidelines:

Prodromal period

Possible early symptoms of Parkinson disease • Rapid eye movement sleep behavior disorder • Autonomic symptoms (eg, constipation, orthostatic hypotension) • Hyposmia

Family history • First-degree relative with Parkinson disease • Known Parkinson disease gene mutation in family

Physical examination Findings must include • Bradykinesia • Rigidity and/or tremor Findings may include • Hypophonia • Micrographia • Decreased arm swing • Short step length

Patient medical history Symptoms may include • Slowness • Tremor • Gait changes • Soft voice • Decreased facial expression • Depression and/or anxiety

Other factors • Dopamine transporter single-proton emission computed tomography imaging findings • Genetic data

Evaluation consistent with Parkinson disease

Assessment of features potentially indicative of atypical parkinsonism • Rapid progression • Early and recurrent falls • Severe early dysphonia or dysarthria • Severe early autonomic failure • Cerebellar findings (eg, dysmetria)

All features present?

Yes

No

Evaluate for patient response to levodopa

Response?

Yes

No

Consider diagnosis of atypical parkinsonism

Confirmation of Parkinson disease diagnosis

(DO NOT MODIFY)

Treatment

Shown below is an algorithm summarizing the treatment of Parkinson's disease according to the American Academy of Neurology guidelines:

(DO NOT MODIFY)

Do's

• Use levodopa preparations, dopamine agonists, and monoamine oxidase-B (MAO-B) inhibitors initially for motor symptoms.
• Be aware of cognitive impairment and other side effects when using anticholinergic agents in young people.
• Use rivastigmine for Parkinson disease dementia. There is no evidence of memantine usefulness for mild cognitive impairment.
• Use selective serotonin reuptake inhibitors, selective serotonin norepinephrine reuptake inhibitors, and tricyclic antidepressants for depression in Parkinson disease.
• Use anticholinergics, amantadine, dopamine agonists, MAO-B inhibitors for psychosis in Parkinson disease.
• Use fludrocortisone, midodrine, and droxidopa are all possibly useful for orthostatic hypotension in Parkinson disease.
• Prescribe an appropriate exercise regimen at the time of diagnosis and throughout the disease.
• Use deep brain stimulation and other surgical approaches when individuals with Parkinson disease experience either the “wearing off” phenomenon or dyskinesias that do not respond to medication.

Don'ts

• Do not use neuroimaging or genetic screening for Parkinson's disease diagnosis.
• Do not confuse Parkinson's disease with a parkinsonian syndrome. Distinguish them by performing a dopaminergic challenge with either levodopa or apomorphine.