Tachylalia or tachylogia[1] is extremely rapid speech.[2] Tachylalia by itself is not considered a speech disorder. Tachylalia occurs in many clutterers and many people who have speech disorders.
Tachylalia is a generic term for speaking fast, and does not need to coincide with other speech problems.
Tachylalia may be exhibited as a single stream of rapid speech without prosody, and can be delivered quietly or mumbled. Tachylalia can be simulated by stimulating the brain electronically.[3]
Tachylalia can occur with Parkinson's disease.[4]