#brainstem

Pinky And The Brain Original Production Cel on Original Background: Brain

One of the most “primitive” parts of the brain, the little brainstem at the base of the brain, controls many of the involuntary aspects of our physiology – you know, little things like breathing, sleeping, alertness, eating, and pain sensitivity.  When we exercise, it’s our brainstem that senses the amount of carbon dioxide present and has us breathe faster to remove it – and speeds up the flow of oxygen to our muscles.

The fact that it affects such core processes makes it of real interest in ME/CFS. Recent studies suggest that brainstem dysfunction in the parabrachial nucleus (PBN) may be present in fibromyalgia as well. One review called the PBN “a ‘hub’ for pain and aversion” that responds to any potentially dangerous situation.

With regard to long COVID, the coronavirus apparently has a predilection for nestling in the brainstem, and one researcher has proposed that long COVID is caused by a “persistent, low-grade brainstem dysfunction” driven by a viral invasion of the brainstem.

Through a series of studies, an Australian team has found problems with “communication” inside and outside the brainstem, microstructural changes, and white matter changes that appeared to affect symptoms as well as autonomic nervous system functioning in ME/CFS.

Their latest study employed the most powerful MRI in the world – a Tesla 7 – to assess the volume of the brainstem and its different regions in a small number of ME/CFS and long-COVID patients and healthy controls.

The study found increased volume of the brainstem as a whole and in several regions of it in both ME/CFS and long-COVID patients but not in the healthy controls. It was only, however, able to link only one symptom – pain – to increased brainstem volume. (Shortness of breath was associated with reduced volumes of the midbrain.)

Larger is not better with the brainstem. A larger brainstem suggests that inflammation and/or viral invasion has occurred. Interestingly, studies indicate that inflammation outside the brainstem can end up producing inflammation inside it – suggesting that taming inflammation, say, in the gut, might be able to reduce inflammation in the brainstem itself.

This study does three things. One, it links ME/CFS and long COVID ever more closely together. We can add increased brainstem volume to the long list of similar findings (EBV reactivation, invasive CPET abnormalities, low heart rate variability, small fiber neuropathy, gut flora alteration, blood vessel issues, hypercoagulation, dysautonomia) in these diseases.

Two, this study and past studies have been too small to definitively tell us if the brainstem is playing a major role in ME/CFS. Now we need larger studies that can tell definitively us if this intriguing part of the body really does play a major role in these diseases.