Paradoxical Orthostatic Intracranial Hypertension with Joint Hypermobility

Introduction: Headaches are a common phenomenon among women with joint hypermobility or Ehlers-Danlos hypermobile type. One hypothesis of headache etiology in joint hypermobility is that cervical spine instability leads to... [ view full abstract ]

Introduction:
Headaches are a common phenomenon among women with joint hypermobility or Ehlers-Danlos hypermobile type. One hypothesis of headache etiology in joint hypermobility is that cervical spine instability leads to functional obstruction of cerebral spinal fluid flow and paradoxical increase in intracranial pressure in the upright position. Ultrasonography of the optic nerve sheath diameter is a low cost and widely available indicator of intracranial hypertension. We present a patient with joint hypermobility and evidence of headache and paradoxical orthostatic increased intracranial pressure as measured by optic nerve sheath ultrasound in the upright and supine positions.

Case Report:
A 25 year old woman presented for follow-up after recent hospitalization for syncope. Her past medical history is significant for migraine headaches and depression with anxiety. She had an intense migraine beginning 2 days prior to the onset of syncope and it occurred in the frontal area, improving while lying down and was accompanied by some visual blurring and tinnitus in the right ear only. On the day of hospitalization she had two separate episodes where she looked down at the ground while standing or sitting up-right and passed out. She was admitted to the hospital and MRI of the brain, echocardiogram, cardiac event monitor and electroencephalogram (EEG) were all normal. The patient was discharged, with no additional events during the 4 day hospital stay. Patient controlled forward flexion of the head induced a sensation of “dizziness”. Radiography of the cervical spine was unremarkable. The optic nerve sheath diameter measurement 3mm caudal to the retina was performed in both the upright and supine positions. The patient was started on propranolol for headache prophylaxis in the setting of suspected hyperadrenergic dysautonomia associated with joint hypermobility. At clinic follow-up 4 days later her headache had resolved and she stated that she felt “better than since age 14.” Optic nerve ultrasound was repeated at this time.

Discussion:
The clinical overlap between Ehlers-Danlos syndrome Hypermobile Type and Benign Joint Hypermobility Syndrome leaves the two entities clinically indivisible. In both syndromes there is a significant incidence of headache that may not respond as expected to typical headache therapy. While the patient is upright, the weight of the head, in conjunction with cervical ligamentous laxity, could hypothetically cause a functional obstruction to CSF flow or venous egress via the vertebral plexus. When the patient lies down and finds a position that is comfortable, the obstruction is relieved and CSF flow is re-established. Evaluation of positional intracranial pressure has been historically limited by available technology. Traditional methods of ICP measurement such as lumbar puncture are invasive and carry some small degree of risk and discomfort. In the setting of possible obstruction, lumbar puncture may not accurately reflect intracranial pressure and may actually be dangerous. Optic nerve sheath measurement with bedside ultrasound has eliminated these risks.

Conclusion:
In our patient we actually saw the ICP increase in the upright position while the patient was actively having a headache. This phenomenon reversed when her headache had resolved. To our knowledge this is the first demonstration of paradoxical intracranial orthostatic hypertension in a patient with joint hypermobility, and may be additional early evidence of the hypothesis that cervical spine instability causes cervical spine CSF flow obstruction and increased intracranial pressure with resultant headache.