Diagnostic Criteria and Assessment of Parkinson's Disease

Essential Clinical Assessment

The diagnosis of Parkinson's disease requires bradykinesia plus at least one of the following: resting tremor or rigidity, according to the American Academy of Neurology 1
Resting tremor is characterized by a 4-6 Hz "pill-rolling" tremor present when the limb is completely supported and relaxed, as noted by the International Parkinson and Movement Disorder Society 2
Rigidity is defined as constant resistance throughout passive range of motion or ratchet-like resistance when combined with tremor, as described by the American Academy of Neurology 1
Postural instability typically appears later in disease progression, according to the American Academy of Neurology 1

MRI brain without contrast is the optimal initial imaging modality to rule out structural causes and identify diffuse white matter lesions or strategic subcortical infarcts, as recommended by the American College of Radiology 1
I-123 ioflupane SPECT/CT (DaTscan) should be obtained when the clinical presentation is atypical or uncertain to differentiate Parkinson's disease from essential tremor or drug-induced tremor, according to the Society of Nuclear Medicine and Molecular Imaging 1

The Unified Parkinson's Disease Rating Scale (UPDRS) or Movement Disorder Society-UPDRS (MDS-UPDRS) should be used for standardized assessment of activities of daily living, motor examination, and other factors, as recommended by the International Parkinson and Movement Disorder Society 1
Nutritional risk assessment is important, as 15% of community-dwelling Parkinson's disease patients are malnourished, according to the Academy of Nutrition and Dietetics 1

Patients with a history of anti-BCMA CAR T-cell therapy should be considered for Movement and Neurocognitive Treatment-Emergent Adverse Events (MNTs), which can manifest similarly to Parkinson's disease but are levodopa unresponsive, as noted by the National Comprehensive Cancer Network 3