Ross Hauser, MD
One of the more frightening symptoms reported by people with Ehlers-Danlos syndrome (EDS) is an unexplained seizure or seizure-like episode. Many patients describe years of testing, emergency room visits, neurological evaluations, and medications before anyone asks whether the problem could be related to the connective tissue disorder itself.
Some people with EDS do develop true epilepsy. Others experience events that look very much like seizures but are actually caused by fainting (convulsive syncope), disturbances in blood flow to the brain, autonomic nervous system dysfunction, or structural problems affecting the upper cervical spine and craniocervical junction.
Are seizures more common in Ehlers-Danlos syndrome?
Several studies have reported that neurological complications, including epilepsy and seizure-like events, occur more frequently in patients with EDS than in the general population. While epilepsy remains relatively uncommon, autonomic dysfunction, syncope, migraines, Chiari malformation, tethered cord syndrome, and craniocervical instability are all more prevalent in EDS and can contribute to episodes that resemble seizures.
In 1999, Dr. Daniel E. Jacome published findings (1) on seven patients who ranged in age from 28 to 70. Each had a different combination of seizure types and brain or nerve findings:
- Patient 1: Partial seizures; scar tissue in the front of the brain. He could stop seizures by bending his head far backward.
- Patient 2: Partial seizures; a brain structure difference called Dandy Walker malformation; also had non-epileptic seizure-like episodes.
- Patient 3: Complex partial seizures; reduced pain response; an underdeveloped artery at the base of the brain.
- Patient 4: Seizures with speech difficulty; smaller left side of the brain; wasting of the right arm and left leg.
- Patient 5: Focal seizures; a blood vessel cluster in the brain; exaggerated startle response; nighttime head movements; nerve damage from a blood condition; Tourette syndrome.
- Patient 6: Complex partial seizures; mood disorder; chronic fatigue; after a brain bleed, saw himself from outside his body during seizures.
- Patient 7: Grand mal seizures; prior stroke; nerve disease in the limbs.
The key finding was: “EDS may be accompanied by congenital or acquired central nervous system disorders and epilepsy. Additional neurologic conditions that are unrelated to EDS may be present.”
As we see, some people can control seizures by altering head and neck position. As we have shown, patients’ seizures appeared to change with neck position.
When a “seizure” is not epilepsy
One of the most common reasons an EDS patient experiences seizure-like activity is autonomic dysfunction. Many patients with hypermobile EDS also have postural orthostatic tachycardia syndrome (POTS) or other forms of dysautonomia. These conditions impair the body’s ability to regulate blood pressure and heart rate during standing or physical activity. When blood pressure suddenly falls, or cerebral blood flow decreases, oxygen levels drop, the patient loses consciousness, and the body may stiffen or jerk, creating what is known as convulsive syncope. The episode may appear identical to an epileptic seizure.
Cervical instability as a contributing factor to epilepsy-like seizures
Multiple studies have demonstrated an association between hypermobile Ehlers-Danlos syndrome (hEDS) and autonomic dysfunction, particularly postural orthostatic tachycardia syndrome (POTS) and orthostatic intolerance.
In a landmark 2014 study (2), doctors at Ghent University Hospital in Belgium found 74% of patients with hEDS had symptoms of orthostatic intolerance, significantly more than healthy controls, confirming that dysautonomia is a common feature of hEDS. A 2021 study (x) led by doctors at the University of Arizona also found autonomic symptoms as common systemic manifestations in people with hEDS and hypermobility spectrum disorders and a key component of the underlying biology of hypermobile Ehlers-Danlos syndrome.
A December 2025 (3) study of 84 women with hypermobile Ehlers-Danlos syndrome (hEDS) or hypermobility spectrum disorders (HSD) found that 58.3% had physician-diagnosed POTS, highlighting the strong association between these connective tissue disorders and autonomic dysfunction. Doctors from Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, reported that nearly all participants (98.8%) reported chronic pain, while migraine (54.8%), mast cell activation syndrome (32.1%), and myalgic encephalomyelitis/chronic fatigue syndrome (26.2%) were also common. One in four patients had the clinical triad of hEDS/HSD, POTS, and mast cell activation syndrome. Participants demonstrated severe autonomic dysfunction and markedly reduced quality of life, leading the researchers to conclude that dysautonomia is a common and clinically significant feature of hEDS and HSD.
A December 2025 (4) study from Brigham and Women’s Hospital demonstrated that patients with hEDS frequently exhibit autonomic dysfunction, reduced cerebral blood flow during standing, and evidence of small fiber neuropathy, providing objective evidence of autonomic impairment.
Although epilepsy is not considered a common condition of hEDS, autonomic dysfunction can cause transient cerebral hypoperfusion leading to convulsive syncope, which can closely mimic an epileptic seizure. Therefore, in patients with hEDS with unexplained seizure-like episodes, autonomic dysfunction should be considered as part of the diagnostic evaluation.
While true epilepsy is not a common feature of hypermobile Ehlers-Danlos syndrome (hEDS), seizure-like episodes are an important clinical concern because they may result from dysautonomia, convulsive syncope, or structural neurological abnormalities in certain EDS subtypes rather than primary epilepsy.
A 22-year-old woman with Ehlers-Danlos Syndrome
We saw a 22-year-old woman with Ehlers Danlos Syndrome confirmed by geneticists. Her mom also has the condition. The patient has a long history of multiple joints popping out and needing regular manipulation and physiotherapy. She states the previous neck treatments did not help her seizure-like activity, facial tremors, severe fatigue, and brain fog. She is so disabled that she is no longer able to work. Her mom confirms that there are times when the patient gets a blank look with eyes half closed and is nonresponsive for up to a minute when she starts having facial and hand twitches. The patient says she is aware of her surroundings during this time, but cannot do anything. At its worst, this happens five-six times/day. After the episodes, she has tremendous brain fog. She notes a dull, continual headache. Other symptoms include extremely loose TMJs, which often go out. She has painful, difficult swallowing, neck stiffness, a nauseated feeling, lightheadedness, and muscle spasms throughout her face and neck. Previous workups of CT scans of the head and MRI of the neck were negative. Digital motion x-ray confirmed multiple levels of instability in the cervical spine, especially C1-C3.
In this case, neck ligament injury was treated with Prolotherapy (which will be explained below). After the first Prolotherapy treatment, she had only one episode of “zoning out” and twitching. When she arrived, her C1 was rotated to the left so the left side of her neck was treated along with the left TMJ for the first time. After this visit, her fatigue and brain fog were significantly less. She had no episodes of shakes or seizures. She was able to go out by herself without fear of getting lost. Her painful, difficult swallowing was still present. Her left TMJ was not popping out as much. Repeat DMX showing significant improvement (40%) in the upper cervical instability. She was prescribed some neck and chest weights to wear to help correct her increased C1 angle and lower cervical kyphosis. After six visits to her neck and four to her left TMJ, the patient resolved over 75% of her symptoms. She was able to live a “normal existence,” as in go out with friends, and was looking for part-time work. Her neck and TMJ are much more stable. She has no more shaking and seizure-like activity. She states it is as if “the cloud over my mind has been lifted.” Her painful, difficult swallowing has resolved.
In this case, cervical ligament weakness played a role in the patient’s symptoms. This is not typical of all patients with seizure disorders.
Read our research
Are Ehlers-Danlos Syndrome Headaches and Migraines Caused by Cervical Spine and Neck Instability?
References
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