What is the initial workup and treatment for Parkinson's disease?

From the Guidelines

The initial workup for Parkinson's disease involves a comprehensive neurological examination focusing on cardinal motor symptoms, along with a detailed medical history, and brain imaging like MRI may be performed to rule out other conditions. The diagnosis of Parkinson's disease is primarily clinical, as no definitive diagnostic tests exist 1. A thorough medical history and physical examination are essential to identify the cardinal motor symptoms of Parkinson's disease, including resting tremor, bradykinesia, rigidity, and postural instability.

Some key points to consider in the initial workup include:

• A comprehensive neurological examination to assess motor symptoms and cognitive function
• A detailed medical history to identify potential causes of secondary parkinsonism
• Brain imaging, such as MRI, to rule out other conditions that may be causing the symptoms
• Assessment of autonomic function, as autonomic dysfunction is a common feature of Parkinson's disease

Treatment typically begins with levodopa/carbidopa (Sinemet), starting at 25/100 mg three times daily and titrating based on symptom response. For younger patients (<65 years) with milder symptoms, dopamine agonists like pramipexole (0.125-0.5 mg three times daily) or ropinirole (0.25-1 mg three times daily) may be initiated first to delay levodopa-related motor complications 1. MAO-B inhibitors such as rasagiline (1 mg daily) or selegiline (5 mg twice daily) can be used as initial monotherapy in early disease or as adjuncts.

Additionally, non-pharmacological approaches such as physical therapy, exercise programs, and occupational therapy are essential and should begin early in the treatment process. These approaches can help improve mobility, balance, and overall quality of life for patients with Parkinson's disease. Regular monitoring of body weight and vitamin status is also recommended, as weight changes and vitamin deficiencies are common in patients with Parkinson's disease 1.

From the FDA Drug Label

The effectiveness of pramipexole dihydrochloride tablets in the treatment of Parkinson's disease was evaluated in a multinational drug development program consisting of seven randomized, controlled trials The Unified Parkinson's Disease Rating Scale (UPDRS), or one or more of its subparts, served as the primary outcome assessment measure Studies in Patients with Early Parkinson's Disease had a mean disease duration of 2 years, limited or no prior exposure to levodopa Patients treated with pramipexole dihydrochloride tablets had a starting daily dose of 0.375 mg and were titrated to a maximally tolerated dose, but no higher than 4.5 mg/day in three divided doses.

The initial workup for Parkinson's disease typically involves evaluating the patient's medical history, performing a physical examination, and assessing their symptoms using the Unified Parkinson's Disease Rating Scale (UPDRS).

• The UPDRS is a four-part multi-item rating scale intended to evaluate mentation, Activities of Daily Living (ADL), motor performance, and complications of therapy.
• The initial treatment for Parkinson's disease may involve medications such as pramipexole dihydrochloride tablets or rasagiline tablets, which have been shown to be effective in reducing symptoms in patients with early or advanced Parkinson's disease 2 3.
• The dosage of pramipexole dihydrochloride tablets is typically started at 0.375 mg/day and titrated to a maximally tolerated dose, but no higher than 4.5 mg/day in three divided doses.
• The dosage of rasagiline tablets is typically 1 mg/day or 2 mg/day, with or without concomitant levodopa or dopamine agonist therapy.

From the Research

Initial Workup for Parkinson's Disease

• The diagnosis of Parkinson's disease is based on history and examination, including prodromal features, characteristic movement difficulty, and psychological or cognitive problems 4.
• Examination typically demonstrates bradykinesia with tremor, rigidity, or both 4.
• Dopamine transporter single-photon emission computed tomography can improve the accuracy of diagnosis when the presence of parkinsonism is uncertain 4.

Treatment for Parkinson's Disease

• Treatment is symptomatic, focused on improvement in motor and nonmotor signs and symptoms 4.
• Dopamine-based therapies typically help initial motor symptoms 4.
• Nonmotor symptoms require nondopaminergic approaches, such as selective serotonin reuptake inhibitors for psychiatric symptoms and cholinesterase inhibitors for cognition 4.
• Rehabilitative therapy and exercise complement pharmacologic treatments 4.
• Advanced treatments, such as therapy with levodopa-carbidopa enteral suspension or deep brain stimulation, can help individuals with medication-resistant tremor, worsening symptoms when the medication wears off, and dyskinesias 4.

Thyroid Function in Parkinson's Disease

• Thyroid disease is the endocrine dysfunction most frequently reported in association with idiopathic Parkinson's disease (PD) 5.
• The prevalence of thyroid autoimmunity in PD patients appeared similar to that in the general population, though thyroid dysfunction was observed in over 10% of PD patients 5.
• Treatment with l-dopa and/or dopaminergic drugs and the stage of Parkinson's disease did not affect thyroid function 5.
• Hypothyroidism is associated with obesity, hypercholesterolemia, anemia, and altered cerebral blood flow, which are associated with PD pathology 6.
• Thyroid disturbances, including hypothyroidism, Hashimoto's thyroiditis, hyperthyroidism, and Graves' disease, not only increase the risk of PD but also share some clinical signs with PD 6.