Hypermobility Spectrum, Ehlers-Danlos and Neurodivergence

What is Hypermobility? (it’s not flexibility!)

Recent research has found that hypermobility spectrum disorder and hypermobile Ehler’s Danlos Syndrome are 10 times more common than previously thought and could affect 1 in 500 people.

Having hypermobility means that your joints have a larger than normal range of movement, which is directly related to a laxity in the ligaments. This happens when the ligaments and structures of the joint capsule lack integrity and this allows for more movement of the joint in the capsule leading to instability. Some people colloquially referred to this as “double-jointed”.

One big misconception is that hypermobility equals flexibility, but they are not related! Flexibility on the other hand is the ability to change your range of motion, elongate muscles or change joint position and this is a combination of joints, muscles and nerves - under control of the nervous system. Which is why flexibility can be trained. It is entirely possible to have hypermobile joints and not be flexible.

You can be hypermobile in just one joint or multiple joints around the body. Usually this is bilateral (both sides) but not in every case. It can also occur after trauma or injury (for example with a dislocated shoulder where structures are torn) or secondary to a connective tissue disorder or autoimmune conditions such as Lupus. Although for many of my patients there is a genetic predisposition.

What is Ehlers Danlos Syndrome?

EDS is a group of inherited connective tissue disorders, of which there are 13 subcategories. Most of these types are characterised by joint hypermobility to varying degrees. The most common is hypermobile EDS or hEDS. hEDS is currently the only subtype where they are still trying to identify the genetic biomarker, so it still needs to be diagnosed by clinical assessment.

Collagen:

There are many types of collagen in our bodies, at least 28 have been identified which play a huge

role throughout the body, not just our muscles and ligaments. For those who have a genetic basis for hypermobility, there is an issue with our collagen production.

Collagen is widely represented throughout the body making up about 30% of our total protein content. It allows for the transmission of force and adds ‘stiffness’ and structure to our tissues.

This stiffness gives ‘integrity’ to structures such as our gut (in order for us to have normal motility and bowel transition) and our arteries (in order for us to pump blood throughout the cardiovascular system). Our eyes, skin, heart valves and uterine lining are all composed of collagen too. So when we have a collagen disorder, we can get a huge array of symptoms.

Overlapping and associated conditions

Neurodivergence. Studies have found people with EDS are 7 times more likely to be autistic and 6 times more likely to have ADHD.

Anxiety, depression and fear. There is a very strong link to mental health conditions. Brain imaging studies have found people with joint hypermobility have larger fear processing centres in the brain.

Cardiovascular issues. Such as tachycardia (rapid heart rate) or a mitral valve prolapse (usually picked up on imaging for the heart). If arteries or heart valves are lacking stiffness to move blood around the body, then on increased physical demand people can run into problems in getting enough blood to the areas that need them. POTS / orthostatic issues are also a common problem.

Dysautonomia which is the inability of your autonomic nervous system to regulate itself and maintain balance (homeostasis), which include your ‘vitals’ such as blood pressure, body temperature, blood sugar levels. So you can have great difficulties adapting if the room temperature changes, or adjusting from sitting to standing positions. Moreover joint hypermobility was found to be the link between dysautonomia and pain in neurodivergent people, where the greater number of hypermobile joints correlating to higher degrees of pain and nervous system dysfunction.

Headaches, migraines and jaw pain, particularly if unresponsive to medical treatments or medications. In rare cases, a Chiari malformation (a condition where part of the brain, the cerebellum herniates through the base of the skull) may be the basis of unusual neurological symptoms such as migraines or headaches along with, nausea, numbness and tingling, neck pain, dizziness, muscle weakness and problems with balance or coordination).

Chronic fatigue syndrome: some studies suggest figures as high as 81% of CFS and Fibromyalgia clients meet the criteria of hypermobility syndromes and 18% specifically for EDS

Pain: especially chronic pain syndromes such as Fibromyalgia. People who are hypermobile often have reduced proprioception and spatial awareness. It becomes harder to activate muscles because joints prefer to take the load. Joints are more likely to sublux and because there is a delay in “feedback” to the brain, the person is more injury prone as pain signals (which are usually warning signals) are delayed or absent until it is too late. In addition, people with hEDS may have a constant low baseline of perceived pain and central nervous system has difficulties discriminating between danger or safety when changes happen in the body.

Functional gastrointestinal disorders: IBS, acid reflux, SIBO, abdominal hernias and chronic constipation. Our entire gut is a muscular tube is made up of proteins such as collagen and ‘programmed’ or synchronised by the autonomic nervous system. We require rigidity and muscularity to move food through our intestinal tract so we can digest and absorb – known as gut motility, but also to perform “housekeeping duties” such as sweeping debris, bacteria and unabsorbed food fibres into our large intestine when we are in a fasting state – similar to “self-cleaning” and this is known as the Migrating Motor complex which is controlled by the vagus nerve. People who are hypermobile may also have intestinal hyper-permeability, known as “leaky gut” and this can increase incidences of food intolerances and trigger autoimmune processes.

Reproductive health /fertility issues: a survey by the EDS foundation in 1352 women found that 43.3% reported fertility issues. Amongst those who were able to conceive at 54.5% experienced at least 1 miscarriage and 29.6% delivered prematurely. 74.2% of women experienced pain on intercourse and 50.6% reported heavy periods.

Additionally:

Mast-cell activation syndrome or histamine intolerance disorders

Respiratory issues, recurrent respiratory infections and obstructive sleep apnoea

Degenerative joint diseases

Autoimmunity

I find my clients are usually experience a number of these associated conditions at the same time.

How do I know if I have it?

You can assess joint hypermobility using the Beighton’s scale which uses a 9 point scoring system. Initial assessment is usually by a healthcare practitioner such as a physio, osteopath or GP who can refer you for a formal diagnosis with a geneticist, rheumatologist or joint specialist.

Due to the lack of molecular biomarker hypermobile EDS is a diagnosis of exclusion, it can often be missed where symptoms overlap with another medical diagnosis (such as Generalised anxiety disorder) or due to a lack of awareness and education.

The path to a formal diagnosis can take years. See the Ehlers Danlos Society for diagnostic routes and further support.

Clinicial experience note: I have seen people who do not fit the typical Beighton’s profile for hypermobile joints, but have the wider characteristics of EDS and it can be a frustrating journey to get formally assessed, diagnosed and supported. EDS is largely an invisible disability and people can go unsupported (leading to more health complications) or have inappropriate support for their condition for a number of years.