Monitoring ICP waveform dynamics non-invasively for Assessment and Treatment Response in CSF Hypotension: A case series

Introduction: Cerebrospinal fluid (CSF) hypotension due to spontaneous occult CSF fistulas is a condition that can cause debilitating symptoms such as headaches and neck pain. The non-invasive measurement of intracranial pressure waveform (nICPw) may provide a reliable way of assessing this condition. This study aims to evaluate the changes in P2/P1 ratios and time-to-peak (TTP) in different positions in patients with CSF hypotension due to spontaneous occult CSF fistulas and their response to treatment.

Methods: Three patients with CSF hypotension due to spontaneous occult CSF fistulas were evaluated using the P2/P1 ratio and TTP in different positions (supine, sitting, and standing) before and after treatment. All patients received specific treatment according to each case: one received an epidural blood patch, one received surgery and one received conservative treatment. The P2/P1 ratio was evaluated using a non-invasive device from brain4care®.

Results: The results showed that the P2/P1 ratios in all three patients varied up to 1.5 and bellow 0.6 in different positions before treatment, with TTP varying from 0.06 to 0.40. After each patient recieved specific treatment, the P2/P1 ratios and TTP returned to closer-to-normal levels and less variation in all patients, in different positions, while symptoms also improved.

Conclusion : The present study suggests that the non-invasive of ICP waveform and its associated parameters (P2/P1 ratio, TTP) may provide a reliable way of assessing CSF hypotension due to spontaneous occult CSF fistulas. The P2/P1 ratios and TTP in different positions varied before treatment, but returned to closer-to-normal levels after treatment. These findings may help further understading of other causes of CSF hypotension, such as shunt hyperdrainage. Further studies with larger sample sizes are needed to confirm these findings.