What are pyramidal and extrapyramidal signs?

Pyramidal and extrapyramidal signs indicate nervous system abnormalities.  Pyramidal signs can be identified on neurological exam and can include weakness, hyperreflexia, and the Babinski reflex.  Extrapyramidal signs are involuntary muscle movements such as muscle contractions, muscle stiffness, facial contortions, an inability to sit still, and tremors.