Clinical meaning
Parkinson disease results from progressive loss of dopaminergic neurons in substantia nigra pars compacta with alpha-synuclein Lewy body accumulation. Loss of >60-80% of neurons produces motor features. Levodopa crosses BBB via large neutral amino acid transporter, converted to dopamine. Carbidopa blocks peripheral conversion. Motor complications develop in 40-50% after 5 years.
Diagnosis & workup
Diagnostics & workup: - CT angiography of head and neck (vessel occlusion, aneurysm, dissection) - Visual field testing and fundoscopic exam for papilledema - Neuropsychological testing for cognitive domain assessment - EMG/NCS for peripheral neuropathy, radiculopathy, myopathy evaluation - Lumbar puncture with CSF analysis (cell count, protein, glucose, cultures, oligoclonal bands) - Glasgow Coma Scale (GCS) for consciousness level assessment - EEG for seizure characterization and localization
Risk factors: - Family history of neurological disease (first-degree relative) - Chronic migraine with aura (increased stroke risk in women on OCPs) - Obesity and metabolic syndrome with neuroinflammation - Diabetes with peripheral and autonomic neuropathy - Prior head trauma or TBI history - Atrial fibrillation with cardioembolic stroke risk - Chronic alcohol use with neurotoxicity