To the Editor: Leucoencephalopathy with vanishing white matter (LVWM) is a rare autosomal recessive disease, related to eIF2B subunit gene mutations.1–3 LVWM is a chronic, progressive disorder, dominated by spasticity, cerebellar ataxia, pyramidal signs, and mental impairment, with incomplete recovery and death normally within a few years.3 Typical findings include progressive white-matter rarefaction and cystic degeneration, various histopathophysiological abnormalities, and episodes of rapid and major neurologic deterioration after minor stress conditions, febrile infection, or mild head trauma.3 Although typical onset age is late infancy or early childhood, later reports have demonstrated a wider clinical spectrum of LVWM, affecting people of all ages. Milder variants, with later onset, less prominent neurologic deterioration, and protracted course have been reported.2,4,5 However, adult cases are also still rare, showing significant phenomenological variations. We present a case of an adult-onset LVWM with a prolonged course of 18 years, despite early major neurologic deterioration.