Sjogren’s Disease: Autoimmune dry eye Part 4

When we consider the regulation of tearing and salivation (mouth moisture, AKA spit production), these functions are under the direction of the so-called autonomic nervous system. This is the collection of nerves connecting our brain with the visceral organs (basic breathing, heart beating, digestion, etc.) as opposed to the nerves connecting the brain with our skin and muscles (the somatic nervous system). Autonomic is equivalent to “automatic” and allows our body to function without conscious thought.

Sjogren’s disease can damage and “reprogram” this autonomic nerve control and according to a neurologist, Dr. Goodman, specializing in this branch of the nervous system, it can account for or cause nearly any neurological syndrome. He postulated an interesting concept – wondering if the autonomic nervous system might be able to “prime” the immune system (where conventional thought would be the reverse (that the immune system might damage or reprogram the nervous system). This would allow for what he terms “maladaptive remodeling,” where the nervous system “learns” to behave badly.

Additional thought from the GI doctors, is that the gut “microbiome” (the germs that populate our intestines and are important to our digestion, nutrition, and general well-being) may contribute to the autoimmune response. This makes sense, as the body’s reaction to germs is an innate immune response and will begin interacting at the first contact with germs – including – and perhaps especially – to those in our gut. The defenses we mount include small chemicals (cytokines) that can be released into the circulation and find their way throughout the body – including the eyes, mouth and nervous system. At the level of the gut, we find Sjogren’s causing a dry mouth, GERD – an improper movement along the GI tract resulting in reflux from the stomach and up the esophagus. The stomach can become inflamed (gastritis), and often gets “run over” by a common germ, H. Pylori, which has been associated with stomach inflammation as well as Rosacea and a variety of other ailments. Further inflammation can target the gallbladder, pancreas, liver, small and large intestines – causing havoc along the entire digestive system.

Dr. Robert Fox, a rheumatologist specializing in Sjogren’s, points out that headache is a common manifestation of this disease. Interestingly, the Trigeminal nerve – the main sensory nerve of the face, which also supplies pain feelings from the eyes – under stress from Sjogren’s, releases small protein complexes called Calcitonin Related Group Peptides (or CGRPs) that enter the brain (at the thalamus) and can dilate blood vessels which can trigger migraines and can start a cascade of pain signals including pain in the eyes and photophobia (eye pain from light). At the same time as these amplified pain signals come along, there is a second small protein (Pituitary Adenylate Cyclase-Associated Peptides, or PACAPs) that lowers the threshold to feel pain related to light, sound and muscle activity. It can also be associated with so-called “brain fog” common to those suffering from Post-Traumatic Brain Syndrome, or Post-Traumatic Stress Disorder (PTSD). This compound is also found in the tear and saliva gland regions of the Trigeminal Nerve and may release into the same (thalamus) portion of the brain responsible for sensing pain – and decrease pain thresholds (so a little pain can go a long way towards hurting).

Unfortunately, there appear to be many routes to fatigue and brain fog – including autoantibodies and depression – so there does not appear to be a “silver bullet” for fixing these problems. Dr. Kate Hackett is a PhD Occupational Therapist involved in dealing with Pain, Fatigue and Sleep. She points out that sleep apnea is more common in the Sjogren’s group – which is of interest to eye doctors, as you recall my post about the “Floppy Lids” that are commonly also related to sleep apnea – so we are more apt to refer patients for sleep studies from a common eye exam. Interestingly, the common recommendation eye doctors make to dry eye patients – about using a humidifier – appears to help patients with Sjogren’s get better sleep. She points out how important it is for patients dealing with chronic pain to get adequate rest and adequate sleep – so finding helpful tools like a humidifier can really help. Also helpful is gentle exercise and taking frequent breaks (what she calls “activity management”). Others also point to the benefits of meditation, yoga, and exercise as possible means to help “reprogram” the runaway autonomic nervous system. There is a subset of Long Haul Covid that can result in an unusual and unwanted sudden increase in heart beating (so called tachycardia) when transitioning between lying down to sitting up (called POTS – a good link here: https://www.hopkinsmedicine.org/health/conditions-and-diseases/postural-orthostatic-tachycardia-syndrome-pots ). This has also been found in some Sjogren’s patients and fortunately the same reprograming from meditation, yoga, and exercise appears beneficial for this syndrome – so all these interventions appear likely to be a mainstay of therapy for so called “autonomic dysregulation,” whether from Sjogren’s (or other diseases like long haul Covid).

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Next week, we will explore: “what does the future look like for Sjogren’s patients?” Fortunately there are new consortiums of research activities that appear to bode well for a good answer.