Ehlers- Danlos syndrome is a connective tissue disorder, characterized by joint hypermobility. It has 13 subtypes. Many are associated with distinct gene mutations. The most common syndrome, the hypermobile type, is autosomal dominant but the gene is yet unknown.
Here we are discussing only the joint hypermobility variant of EHD, and we are not considering the other variants.
Hypermobility is scored using the Beighten score. Cutoffs vary by age.
5 elements, and 1 point for each side (so could have 9 points max);
Image is from https://www.physio-pedia.com/Beighton_score
Cutoffs vary with age, namely
This is because people get stiffer with age.
EHD is occasionally associated with several types of dizziness
- Chiari malformation
- Basilar impression (or invagination)
- CSF leak
- POTS (postural orthostatic tachycardia syndrome)
- Cervical spine disorders -- accelerated disk disease
- Carotid dissections, vertebral artery dissections (more of a cause of stroke than dizziness).
- TMJ disorders (not a big cause of dizziness, but still a correlation)
Practically, the association between EHD, POTS and migraine seems to be the most prevalent.
One would expect that there would be more PLF (perilymph fistula) as well, but so far we have not encountered a patient with PLF and EHD.
According to Bendik et al (2011), migraine is found in 75% of persons with the joint hypermobility variant of EHD. Migraine is much more common than EHD, and this is more relevant to diagnosis of dizziness in EHD than diagnosing migraine.
Chung et al (2017) reported a single case of bilateral SCD. Being just a single case report, this association may not be valid.
Many of these disorders are related to the fragility of collagen (Henderson et al, 2017).
EHD is a diverse genetic disorder and one would expect that there would be genetic variants that include hearing loss. The FKBP14 autosomal recessive variant does indeed have some hearing loss, in association with myopathy, scoliosis, skin hypermobility. The hearing impairment is sensorineural (Bauman et al, 2012; Bursztejn et al, 2017; Giunta et al, 2018 and others). These patients seem to be just a small portion of the overall EHD genetic spectrum.
We have encountered several patients to date with dizziness, eventually traced to EHD. Two of these patients underwent a cervico-occiptal fusion for an unstable upper cervical spine. This is a heroic procedure where bolts are put into the skull and upper cervical vertebrae to keep the head stable on the upper spine.
We have also had several patients with POTS and EHD together.
There is no medical treatment for EHD, and all treatments are based on managing the complications. When spine stabilization is being contemplated, Dr. Fraser Henderson is a EHD specialist neurosurgeon in Maryland.