Parkinson disease (PD) is a progressive neurologic disorder that is characterized by resting tremor, slowed movement, rigidity, and postural instability. PD is also associated with a variety of nonmotor symptoms, including diminished sense of smell, abnormalities of the autonomic nervous system, impaired cognition, and depression. The symptoms of PD develop as a result of degeneration of neurons that originate in a portion of the midbrain known as the substantia nigra. These cells project to another region of the brain (the striatum) where they release the neurotransmitter dopamine. Although not curable, PD is treatable using a variety of medications that increase dopamine synthesis and release within the brain. PD may also be treated using surgery and other nonpharmacologic approaches. Because of the significant degree of overlap between the symptoms of PD and those of other motor disorders, it can be challenging to identify patients with PD, especially those with early disease. Routine neuroimaging approaches such as magnetic resonance imaging and computed tomography often fail to identify the subtle neurologic changes associated with PD. The US Food and Drug Administration recently approved the single-photon emission computed tomography ligand 123I-ioflupane for the assessment of dopamine function in patients with suspected PD. Several other radioligands are used in research settings and may also be helpful in identifying patients with PD. This article provides an overview of PD evaluation and treatment, including the typical clinical presentation, pathophysiology, pharmacologic and nonpharmacologic treatment approaches, assessment of brain dopamine activity using single-photon emission computed tomography, and other imaging methods that may also be useful in PD research, diagnosis, and treatment.
After reading this article, the participant should be able to:
- List common diagnostic features of PD.
- Summarize the underlying pathophysiologic changes that occur in patients with PD.
- Identify common PD treatments and describe their mechanisms of action.
- Identify and describe imaging methods that may be used in the assessment of patients with PD.
Categories: Nuclear Medicine