For many in the hEDS-MCAS-POTS Trifecta, there is a symptom that feels more "structural" than the rest.
It’s the feeling that your head is a "bowling ball on a toothpick." The sensation that your neck cannot support your skull. The sudden drop in vision, the "internal tremors," and the fainting spells that happen when you turn your head too quickly.
In standard neurology, these symptoms are often dismissed as "tension headaches." But when you have Ehlers-Danlos Syndrome, the issue isn't tension—it’s Instability.
Today, we look at the clinical reality of Craniocervical Instability (CCI).
1. The Anatomy: The Most Dangerous Junction
The Craniocervical Junction is where your skull (the Occiput) meets the first two vertebrae of your spine (C1 and C2). This is the most mobile part of the human body, and it houses the most critical real estate: The Brainstem.
In a typical body, a complex web of ligaments (the Alar and Transverse ligaments) acts as "high-tensile cables" to keep the skull perfectly aligned.
The EDS Failure:
If you have hypermobile EDS, your collagen (the glue) is faulty. These cables become over-stretched and "lax." Instead of a stable pivot, your skull begins to "slide" on your spine.
2. The Pathophysiology: The "Brainstem Squeeze"
CCI is a mechanical problem with systemic consequences. When the ligaments fail to hold the skull in place, two things happen:
Mechanical Compression: The C1 or C2 vertebrae can physically "poke" or compress the brainstem or the cerebellum. This interferes with the signals traveling from your brain to the rest of your body.
Vascular & CSF Obstruction: The instability can kink the Vertebral Arteries (restricting blood to the brain) or obstruct the flow of Cerebrospinal Fluid (CSF). This creates "internal pressure" that drives debilitating migraines and "brain-on-fire" fog.
3. The Systemic Alarm: Why CCI Triggers POTS & MCAS
CCI is the ultimate "Bucket Filler." The brainstem is the command center for your Autonomic Nervous System.
The POTS Connection: When the brainstem is irritated by mechanical sliding, it sends "False Alarms" to the heart and blood vessels. This is why your POTS may feel "refractory" (unresponsive to salt or meds)—the trigger is a physical pinch in your neck.
The MCAS Connection: The Vagus nerve exits near this junction. Mechanical irritation of the Vagus nerve keeps your body in Sympathetic Overdrive. This chronic "Threat State" tells your Mast Cells to stay in a permanent state of high alarm.
I can help connect the dots with this, here is my calendar to book a 1-1 appt.
4. The Diagnostic Gap: Why Standard MRIs are "Normal"
The biggest tragedy of CCI is that it is invisible on a standard MRI.
If you are lying flat (supine) during a scan, gravity is not acting on your neck. Your skull slides back into a "normal" position, and the scan looks perfect.
To find CCI, you require Dynamic Imaging:
Upright MRI with Flexion/Extension: You must be scanned while sitting up, moving your head forward and backward, to show the "slide" in real-time.
Digital Motion X-Ray (DMX): A live-action X-ray that records the movement of your vertebrae as you move your head.
Measurement Analysis: We look for specific clinical markers like the CXA (Clivo-Axial Angle) or the Grabb-Oakes Measurement.
I have some final last slots left for 1-1 consults, book here if interested. The purpose of the first consult is to be in depth and help connect. the dots and come up with a clear roadmap.
Stay well
Dr Ahmed
Disclaimer: Mend provides educational data and clinical insights only. This content is not a substitute for professional medical advice or diagnosis. CCI is a serious structural condition requiring specialized dynamic imaging (Upright MRI/DMX). Always consult your physician before starting any stabilization protocol. In an emergency, call 999 or 911.
