Spinal CSF-Venous Fistulas in Morbidly and Super Obese Patients with Spontaneous Intracranial Hypotension

Abstract

Background and purpose: Spinal CSF-venous fistulas are increasingly recognized as the cause of spontaneous intracranial hypotension. Here, we describe the challenges in the care of patients with CSF-venous fistulas who are morbidly or super obese.

Materials and methods: A review was undertaken of all patients with spontaneous intracranial hypotension and a body mass index of >40 who underwent digital subtraction myelography in the lateral decubitus position to look for CSF-venous fistulas.

Results: Eight patients with spontaneous intracranial hypotension with a body mass index of >40 underwent lateral decubitus digital subtraction myelography. The mean age of these 5 women and 3 men was 53 years (range, 45 to 68 years). Six patients were morbidly obese (body mass indexes = 40.2, 40.6, 41, 41.8, 45.4, and 46.9), and 2 were super obese (body mass indexes = 53.7 and 56.3). Lumbar puncture showed an elevated opening pressure in 5 patients (26.5-47 cm H₂O). The combination of an elevated opening pressure and normal conventional spine imaging findings resulted in a misdiagnosis (midbrain glioma and demyelinating disease, respectively) in 2 patients. Prior treatment included surgical nerve root ligation for suspected CSF-venous fistula in 3 patients. Digital subtraction myelography demonstrated a CSF-venous fistula in 6 patients (75%). Rebound high-pressure headache occurred in all 6 patients following surgical ligation of the fistula, and papilledema developed in 3.

Conclusions: In our series, opening pressure was generally elevated in patients with morbid or super obesity. The yield of identifying CSF-venous fistulas with digital subtraction myelography in this patient population can approach that of the nonobese patient population. These patients may be at higher risk of developing rebound high-pressure headaches and papilledema.

FIG 1.

A, Anterior-posterior DSM demonstrates a CSF-venous fistula (BMI = 46.9 kg/m², weight 149 kg, height = 178 cm). B, Lateral DSM demonstrates a CSF-venous fistula (BMI = 40.6 kg/m², weight = 94.5 kg, height = 152 cm). C, Anterior-posterior DSM demonstrates a CSF-venous fistula (BMI = 40.2 kg/m², weight = 113 kg, height = 167 cm). D, Anterior-posterior DSM demonstrates a CSF-venous fistula (BMI = 53.7 kg/m², weight = 151 kg, height = 167 cm). E, Anterior-posterior DSM demonstrates a CSF-venous fistula (BMI = 41 kg/m², weight = 137 kg, height = 183 cm). F, Anterior-posterior DSM demonstrates a CSF-venous fistula (BMI = 45.4 kg/m², weight = 161 kg, height = 188 cm). In 2 other patients (BMI = 56.3 kg/m², weight = 149 kg, height = 163 cm and BMI = 41.8 kg/m², weight = 140 kg, height = 182 cm, respectively), DSM failed to demonstrate a CSF-venous fistula. Arrows indicates CSF-venous fistulas.

FIG 2.

Sagittal T2-weighted MRIs showing brain sagging and T2 signal change within the cervical spinal cord (presyrinx) (A) and resolution of the presyrinx after surgical ligation of the thoracic CSF-venous fistula due to resolution of brain sagging and cerebellar tonsillar herniation (B).