Postpuncture CSF leakage: a potential pitfall of radionuclide cisternography.

Abstract

We sought to evaluate radioisotope cisternography (RICG)-related postpuncture CSF leakage by MRI. We conducted a prospective 3-day imaging study. Ten patients with orthostatic headache and other symptoms underwent pre-RICG brain and spinal MRI, magnetic resonance myelography (MRM), RICG, and post-RICG spinal MRI and MRM. For RICG, we used a 25-gauge pencil point spinal needle at the L3/4 or L4/5 level after which subjects took bed rest for 2.5 hours. On pre-RICG MRI and MRM, none of the 10 patients showed CSF leakage. However, 5 subjects (50%) showed epidural abnormalities suggesting CSF leakage on MRI after lumbar puncture for RICG. On RICG and subsequent MRM, 4 of the subjects showed definite findings of CSF leakage and 1 showed minimal leakage. RICG carries a risk of iatrogenic CSF leakage even with careful puncturing using a fine needle. This leakage produces abnormal RICG and MRM findings at the lumbosacral level. Therefore, abnormal RICG findings restricted to the lumbosacral level should be carefully interpreted when diagnosing SIH.