What is the workup for a patient presenting with mask-like facies, shuffling gait, and bradykinesia?

Workup of Parkinsonism: Mask-like Facies, Shuffling Gait, and Bradykinesia

The diagnosis of Parkinson's disease is primarily clinical based on the presence of bradykinesia plus either resting tremor or rigidity, with MRI brain imaging and I-123 ioflupane SPECT/CT serving as supportive diagnostic tools when the clinical presentation is unclear. 1

Essential Clinical Assessment

Cardinal Motor Signs to Confirm

The diagnosis requires bradykinesia (the essential feature) plus at least one of the following: 1, 2

• Resting tremor: 4-6 Hz "pill-rolling" tremor present when the limb is completely supported and relaxed 3
• Rigidity: Constant resistance throughout passive range of motion (lead-pipe rigidity) or ratchet-like resistance when combined with tremor (cogwheel rigidity) 1
• Postural instability: Though this typically appears later in disease progression 1

Rigidity Assessment Technique

To properly assess rigidity in your patient: 1

• Instruct the patient to relax completely while you passively move their limbs
• Test both upper and lower extremities, comparing sides for asymmetry
• Move joints through full range of motion at varying speeds
• Use activation maneuvers (have patient open/close the opposite hand) to enhance detection of subtle rigidity
• Note any cogwheel phenomenon

Red Flags Suggesting Alternative Diagnoses

Carefully evaluate for features that would suggest parkinsonian syndromes other than idiopathic Parkinson's disease: 1

• Vertical gaze palsy (especially downward): suggests Progressive Supranuclear Palsy
• Asymmetric rigidity with alien hand phenomenon: suggests Corticobasal Syndrome
• Ataxia: suggests alternative diagnosis
• Pyramidal signs, wider-based gait with variable stride length, early subcortical dementia: suggests vascular parkinsonism 4
• Poor or non-sustained response to levodopa: suggests vascular parkinsonism or atypical parkinsonian syndromes 4

Diagnostic Imaging Algorithm

First-Line Imaging

MRI brain without contrast is the optimal initial imaging modality: 1

• Rules out structural causes (tumors, hydrocephalus, vascular lesions)
• Often normal in early Parkinson's disease
• Can identify diffuse white matter lesions or strategic subcortical infarcts suggesting vascular parkinsonism 4

Second-Line Imaging (When Diagnosis Unclear)

I-123 ioflupane SPECT/CT (DaTscan) should be obtained when: 1

• Clinical presentation is atypical or uncertain
• Need to differentiate Parkinson's disease from essential tremor or drug-induced tremor
• Shows decreased radiotracer uptake in the striatum (beginning in putamen, progressing to caudate) in Parkinson's disease
• A normal DaTscan essentially excludes parkinsonian syndromes 1

Additional Workup Considerations

Medication History

Review all medications to exclude drug-induced parkinsonism: 1

• Antipsychotics (typical and atypical)
• Antiemetics (metoclopramide, prochlorperazine)
• Calcium channel blockers
• Valproic acid

Functional and Nutritional Assessment

Monitor throughout disease course: 1

• Body weight changes
• Vitamin status
• Dysphagia screening
• Nutritional risk assessment (15% of community-dwelling PD patients are malnourished) 1

Disease Severity Assessment

Use the Unified Parkinson's Disease Rating Scale (UPDRS) or Movement Disorder Society-UPDRS (MDS-UPDRS) for standardized assessment of: 1

• Mentation
• Activities of daily living
• Motor examination
• Complications of therapy

Common Pitfalls to Avoid

• Don't confuse spasticity with rigidity: Spasticity is velocity-dependent (increases with faster stretching), while rigidity shows constant resistance throughout movement 1
• Don't miss subtle rigidity: Failure to use activation maneuvers may cause you to miss early or mild rigidity 1
• Don't overlook asymmetry: Asymmetric onset with unilateral symptoms is characteristic of Parkinson's disease, while symmetric presentation may suggest alternative diagnoses 3
• Don't rely solely on tremor: Only 70% of Parkinson's disease patients have tremor at presentation; bradykinesia is the essential diagnostic feature 1, 5

Special Consideration: CAR T-Cell Therapy History

If the patient has received anti-BCMA CAR T-cell therapy (ciltacabtagene autoleucel or idecabtagene vicleucel), consider Movement and Neurocognitive Treatment-Emergent Adverse Events (MNTs): 6

• Typical onset 11-108 days post-therapy (later than ICANS)
• Manifestation similar to Parkinson's disease with bradykinesia, tremor, postural instability
• These cases are levodopa unresponsive 6
• Risk factors include high baseline tumor burden, grade ≥2 CRS, prior ICANS, high CAR T cell expansion 6