On 2016 Jul 14, David Keller commented:

The placebo effect is mediated via the very same neural pathways damaged in Parkinson's disease

Neural imaging studies have demonstrated that the placebo effect in healthy subjects is mediated by the same neural pathway damaged in Parkinson disease (PD), namely the transport and release of dopamine from the substantia nigra to the striatum.[1] This is why placebos of all types can cause surprisingly robust and durable clinical improvements in PD. The authors of this anecdotal case note that meditation has been shown to release dopamine in the striatum. The questions include: does meditation release more dopamine than placebo? What is an effective placebo control for meditation, and how can it be distinguished or truly differ from real meditation? How can subjects be instructed to meditate or placebo-meditate in a double-blinded fashion? and so on. The hypothesis that meditation might cure, remit, or benefit PD patients in any way more so than placebo seems difficult if not impossible to test. For people with Parkinson's who doze off when they try to meditate, it may at least be helpful in inducing drowsiness, which in turn can increase their sleep benefit.

Incidentally, there was no indication for a DaT scan in this patient, whose clinical diagnosis of Parkinson's disease was indisputable at the time the scan was done. I point this out because the DaT scan selectively delivers 21 times as much ionizing radiation to the striatum than does a standard CT scan of the whole brain.[2]

References

1: de la Fuente-Fernández R, Lidstone S, Stoessl AJ. Placebo effect and dopamine release. J Neural Transm Suppl. 2006;(70):415-8. Review. PubMed PMID: 17017561.

21: Keller DL. Proposal for a clinical trial to test the safety of a widely-used radionuclide scan. Comment on PMID: 26236969. In: PubMed Commons [Internet]. 2015 Sept 15 [cited 2015 Nov 20]. Available from http://www.ncbi.nlm.nih.gov/pubmed/26236969#cm26236969_11818

On 2016 Jul 14, David Keller commented:

The placebo effect is mediated via the very same neural pathways damaged in Parkinson's disease

Neural imaging studies have demonstrated that the placebo effect in healthy subjects is mediated by the same neural pathway damaged in Parkinson disease (PD), namely the transport and release of dopamine from the substantia nigra to the striatum.[1] This is why placebos of all types can cause surprisingly robust and durable clinical improvements in PD. The authors of this anecdotal case note that meditation has been shown to release dopamine in the striatum. The questions include: does meditation release more dopamine than placebo? What is an effective placebo control for meditation, and how can it be distinguished or truly differ from real meditation? How can subjects be instructed to meditate or placebo-meditate in a double-blinded fashion? and so on. The hypothesis that meditation might cure, remit, or benefit PD patients in any way more so than placebo seems difficult if not impossible to test. For people with Parkinson's who doze off when they try to meditate, it may at least be helpful in inducing drowsiness, which in turn can increase their sleep benefit.

Incidentally, there was no indication for a DaT scan in this patient, whose clinical diagnosis of Parkinson's disease was indisputable at the time the scan was done. I point this out because the DaT scan selectively delivers 21 times as much ionizing radiation to the striatum than does a standard CT scan of the whole brain.[2]

References

1: de la Fuente-Fernández R, Lidstone S, Stoessl AJ. Placebo effect and dopamine release. J Neural Transm Suppl. 2006;(70):415-8. Review. PubMed PMID: 17017561.

21: Keller DL. Proposal for a clinical trial to test the safety of a widely-used radionuclide scan. Comment on PMID: 26236969. In: PubMed Commons [Internet]. 2015 Sept 15 [cited 2015 Nov 20]. Available from http://www.ncbi.nlm.nih.gov/pubmed/26236969#cm26236969_11818