Introduction Lumbar puncture (LP) is routinely performed as part of the workup evaluation of suspected acute disseminated encephalomyelitis (ADEM). Mild pleocytosis and/or increased CSF protein concentration are common findings in ADEM. However, the CSF opening pressure, reflecting the intracranial pressure (ICP), has not been acknowledged to date in the literature.
Methods Chart reviews of paediatric patients hospitalised in the Tel-Aviv Sourasky medical centre, between 2005–2013, that were diagnosed with ADEM, were identified retrospectively.
Results Among 35 children diagnosed with ADEM, 20 who had documented CSF opening pressure comprised the study group. The mean age was 5.3 ± 4.1 years, ten males (50%); Mean CSF opening pressure was 27.8 ± 12.4 cmH2O, range 10–55 cmH2O. Considering the upper normal limit of CSF opening pressure in this age group (18 cmH2O), 15/20 (75%) patients had elevated pressure and one sample t-test comparison showed significant elevated CSF opening pressure among patients with ADEM (pv = 0.0023, 95% CI 3.9–15.6). Minimal pleocytosis was present in seven samples (median=2 cells/mm2). Eighteen out of twenty (90%) patients had clinical complaints/signs that can be explained by increased ICP (drowsiness/encephalopathy n = 18, vomiting n = 8, headache n = 8).
Discussion This study highlights that increased ICP is a prominent patho-physiologic change occurring in the CNS of ADEM patients. In our cohort, this was the most common CSF abnormal finding, independent of pleocytosis level. This observation is in line with the common non-focal neurological symptoms and signs and the beneficial effect of steroid treatment in ADEM. Furthermore, it suggests a potential efficacy of other reducing ICP treatments in ADEM.