RESUMO
BACKGROUND: Short-lasting cough-associated headache (CAH) in patients with Chiari I malformation (CMI) is believed to be due to transient worsening of cerebrospinal flow (CSF) obstruction at the foramen magnum. We assessed changes in CSF flow in response to coughing in CMI patients with CAH and compared with those without CAH and healthy participants (HPs) using real-time magnetic resonance imaging. METHODS: Seventeen CMI patients (12 with CAH, 5 without CAH) and 6 HPs were prospectively assessed using real-time pencil-beam imaging magnetic resonance sequence. A 64-mm length pencil-beam imaging cylinder was placed at the craniocervical junction. CSF stroke volume (SVCSF) was assessed during resting, postcoughing, and relaxation phases via a 90-second scan. SVCSF was measured at 6 levels at 5-mm intervals between 10 and 35 mm below the foramen magnum. During each phase, SVCSF was compared between CMI with and without CAH and HPs and corrected for multiple comparisons. RESULTS: At multiple consecutive levels, postcoughing SVCSF was significantly lower in CMI with CAH compared with both CMI without CAH and HP (P < 0.05). No differences in postcoughing SVCSF were seen between CMI without CAH and HP. At rest or relaxation phase, no differences in SVCSF were seen between patients with and without CAH but minimal differences were seen between CMI with CAH and HP. CONCLUSIONS: A decrease in CSF flow after coughing in CMI patients with CAH supports the notion that CAH is caused by transient worsening of CSF flow obstruction at the foramen magnum.