Movement Disorder Diagnosis

Primary Classification Framework

Movement disorders are fundamentally divided into two categories: hypokinetic (reduced movement) and hyperkinetic (excessive movement), with the dominant phenomenology guiding the entire diagnostic approach 1

Cardinal features of hypokinetic disorders include bradykinesia (essential for diagnosis) plus at least one of: resting tremor, rigidity, or postural instability 2
The American College of Radiology recommends MRI brain without contrast as the initial imaging study for hypokinetic disorders, though it may be normal early in the disease 2
I-123 ioflupane SPECT/CT (DaTscan) differentiates Parkinson's disease from essential tremor or drug-induced tremor; a normal scan excludes parkinsonian syndromes 2

The Journal of the American College of Radiology states that Huntington's disease is the most common cause of chorea in adults, with an autosomal dominant inheritance pattern and CAG repeat expansion (>38 repeats diagnostic) on chromosome 4 5
Chorea associated with antiphospholipid antibodies/APS is a characteristic feature of Systemic Lupus Erythematosus (SLE), and treatment with dopamine antagonists, glucocorticoids, and immunosuppressives may be necessary 6

The American College of Radiology recommends MRI with DWI and T2-FLAIR sequences as the optimal imaging for Creutzfeldt-Jakob disease, which is a rapidly progressive dementia with movement disorders 1, 5
Wilson's disease should be considered in all patients under 40 with movement disorders, chronic hepatitis, or cirrhosis, and diagnosis is established by Kayser-Fleischer rings plus low ceruloplasmin (<0.1 g/L) and 24-hour urinary copper >1.6 μmol/24h 8
The Journal of Hepatology recommends lifelong chelation therapy for Wilson's disease 8

Sandifer syndrome is a condition characterized by head tilt after eating due to gastroesophageal reflux, and benign paroxysmal torticollis is a recurrent painless head posture that may evolve to migraine 7
Transient dystonia of infancy is a self-limiting condition that resolves by 3-5 years without sequelae, and hyperekplexia is a condition characterized by excessive startle response to sudden stimuli, present from birth 7

The Journal of the American College of Radiology recommends establishing phenomenology (hypokinetic vs. hyperkinetic) and obtaining MRI brain without contrast to exclude structural, vascular, inflammatory causes 1, 2
For parkinsonian syndromes, referral to a neurologist for clinical diagnosis confirmation and consideration of I-123 ioflupane SPECT/CT if diagnosis is unclear is recommended 2
For chorea in adults, genetic testing for Huntington's disease, checking for SLE/antiphospholipid antibodies, and excluding drugs and metabolic causes is necessary 5, 6