Expanding lacunae causing triventricular hydrocephalus - Report of two cases

Two patients are reported in whom the presence of triventricular hydrocepha lus and aqueductal obstruction or stenosis due to multiple expanding lacuna e in the mesencephalothalamic region possibly corresponds to abnormally dil ated perivascular spaces. Placement of a ventriculoperitoneal cerebrospinal fluid (CSF) shunt in one patient and the per formance of a third ventricle cisternotomy in the other reversed the hydrocephalic syndrome, but did not modify the complex neuroophthalmological disturbance and rubral tremor pre sumably related to the compressive effects of the lacunae on adjacent paren chyma. In one patient the number and size of the lacunae were increased 4 y ears after CSF shunt placement. A review of the literature revealed two cas es in which magnetic resonance imaging demonstrated a similar, poorly under stood pathological condition.