#70: Dr Tarun Singhal, MD

Microglial activation as a common root of neuroinflammatoy conditions but also brain fog, fatigue and mood changes


Listen to this episode: Spotify | Apple Podcasts


Description

Microglial cells are responsible for sensing and driving the immune response in the central nervous system. Their activity, be it supportive or destructive, can be at the root of many different neuroinflammatory conditions including diseases like MS, ALS, Alzheimer’s, Parkinson’s, and TBI (Traumatic Brain Injury), but may also play a large role in the vague hallmark symptoms of complex and chronic disease like brain fog, fatigue, pain, alertness and mood changes including OCD, ADD, and depression.

Dr Singhal systematically walks us through an easily understood description of the types of cells in the brain (neurons, macroglia (astrocytes & oligodendrocytes), microglia) and their functions. The microglia are a fascinating type of neuroimmune cell that sense and act protectively in good times and then can change shape and release various cytokines, chemokine and neurotransmitters in response to the development of disease, which then impacts microglia function further. We used to only be able to see this on autopsy- there are no blood tests available to measure microglial activation (although neurofilament light chains (NfL) from neurons and glial fibrillary acid protein (GFAP) from astrocytes can reflect central nervous system cellular injury).

But PET imaging can visualize microglial activation! Dr Singhal explains in elucidating detail the nature, function, and power of Positron Emission Tomography (PET) imaging, like starting with the Big Bang, anti-matter particles, medical cyclotrons and gamma rays. “PET brings physics, chemistry and biology together in real time to provide novel insights at a cellular and molecular level”, including microglial activation. “If you know yourself and know your enemy, you’ll win 1000 battles” is the way he describes what PET can do for neuroinflammatory conditions.

We end the show with a discussion of treatment theories and options targeting microglial activation. It’s a combination of re-evaluating known therapies (even the old antibiotic minocycline!) for their impact on microglia as well as mention of some novel therapies, including a nasal spray ‘vaccine’ for MS. Of course, we bring up non-pharmacologic therapy potentials including exercise, the Ayurvedic perspective including panchakarma detoxification, the power of breathing to impact cerebrospinal fluid flow, ketogenic diet, and consideration of various adaptogenic herbs with the goal of supporting the immune system’s intelligence.


Podcast Reference Links

More Places to Listen: Google Podcasts | Stitcher | Radio Public | PCA Pocket Casts | Overcast | Anchor


Bio

Dr. Tarun Singhal is Director of PET Imaging Program in Neurologic Diseases at the Ann Romney Center for Neurologic Diseases at Brigham and Women’s Hospital in Boston, MA and an Assistant Professor of Neurology at Harvard Medical School. Tarun completed his medical school at All India Institute of Medical Sciences and completed a nuclear medicine residency in India prior to coming to USA in 2006. He completed a post doctoral fellowship at Yale PET Center and Kettering PET center followed by neurology and nuclear medicine residency and fellowship at Harvard. He is board certified in neurology and nuclear medicine and on the Harvard faculty since 2014. Tarun has led several molecular imaging projects in the neuroscience field, including work on [C-11]Methionine PET in brain tumors, Norepinehrine Transporter imaging of the central nervous system, and now more recently neuroinflammation PET imaging in multiple sclerosis and related disorders. Tarun maintains an active clinical practice of seeing MS patients in addition to leading the recently founded PET Imaging program in Neurologic Diseases at ARCND.