Cases: Two patients with myelomeningoceles (MMC) and shunt-treated hydrocephalus are reported. At 5 and 7 years respectively, when they began presenting mental deterioration and behavioural disorders, sleep EEG showed continuous spike-waves during slow sleep (CSWS).
Discussion: These are the first cases of CSWS described in patients with MMC. The mechanisms of CSWS are considered. The role of hydrocephalus and the thalamic injuries found in one of the patients is discussed in detail. The usefulness of monitoring sleep EEG in patients with hydrocephalus or thalamic lesions is stressed, considering the effects of CSWS on the cognitive competencies and the soft or subclinical course that epilepsy complicated with CSWS may follow.