Association of Intracranial Hypertension With Calvarial and Skull Base Thinning.

OBJECTIVE

Determine if patients with increased opening pressure (OP) on lumbar puncture (LP) have thinner calvaria and skull bases.

STUDY

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral center.

PATIENTS: Patients (≥18 yr of age) who had a recorded OP on LP and high-resolution computed tomography imaging of the head. Patient age, sex, body mass index were calculated. Intracranial hypertension (IH) was defined with an OP≥25 cm-H2O and low intracranial pressure with an OP<15 cm-H2O.

INTERVENTION: Measurement of calvarial, zygoma, and skull base thickness when blinded to OP with three-dimensional slicer and radiologic calipers.

MAIN OUTCOME MEASURES: Association of calvarial, skull base, and zygoma thickness with OP and age.

RESULTS

Fifty-eight patients were included with a mean (SD) age of 53.1 (16.2) years and average (SD) body mass index of 30.1 (9.1) kg/m. Patients with IH had thinner mean (SD) calvaria (3.01 [0.81] versus 2.70 [0.58] mm; p = 0.036) and skull bases (5.17 [1.22] versus 4.60 [1.42] mm; p = 0.043) when compared with patients without IH. The mean (SD) extracranial zygoma thickness was similar between the two groups (5.09 [0.76] versus 5.00 [0.73] mm; p = 0.56). General linear model regression demonstrated advancing age was associated with increasing calvarial thickness in patients without IH and calvarial thinning in patients with IH (p = 0.038).

CONCLUSION

IH is independently associated with intracranial bone (calvaria and skull base) thinning and not extracranial (zygoma) thinning. Skull thinning occurs with IH and advancing age. These findings support a possible role of increased ICP in the pathophysiologic development of spontaneous cerebrospinal fluid leaks.