Complete and readily reversible blocking of striatal DaTscan binding by methylphenidate

Area of Science:

• Neurology
• Radiology
• Pharmacology

Background:

• DaTscan (ioflupane I 123-)], a dopamine transporter imaging agent, is crucial for diagnosing Parkinson disease.
• Parkinson disease diagnosis relies on visualizing dopamine transporter levels in the striatum via DaTscan.
• Methylphenidate is a central nervous system stimulant sometimes used in elderly patients.

Observation:

• An 80-year-old male Parkinson disease patient exhibited no DaTscan uptake in the basal ganglia.
• The patient was concurrently taking methylphenidate, a medication known to affect neurotransmitter systems.
• A follow-up DaTscan after a 48-hour methylphenidate cessation showed normal striatal uptake.

Findings:

• Methylphenidate administration can completely inhibit physiologic DaTscan uptake in the striatum.
• This inhibitory effect is reversible upon short-term discontinuation of methylphenidate.
• Accurate DaTscan interpretation requires awareness of potential medication interferences.

Implications:

• Clinicians should inquire about methylphenidate use in patients undergoing DaTscan.
• Methylphenidate cessation protocols may be necessary to ensure diagnostic accuracy.
• Understanding drug-induced DaTscan alterations is vital for correct Parkinsonian syndrome diagnosis.