How many letters does the top answer for “inflammation of the brain and spinal cord” have?

The most common answer is encephalomyelitis (17 letters).

Crossword clue: inflammation of the brain and spinal cord

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

encephalomyelitis 17 letters wn-def

inflammation of the brain and spinal cord

inflammation of the spinal cord 75% similar → myelitis

of or relating to the brain and spinal cord 60% similar → cerebrospinal