Rubral tremor can be observed with midbrain injury and probably results from combined lesions of the superior cerebellar peduncle, substantia nigra, and red nucleus with interruption of the outflow pathway from the cerebellum to the motor thalamus. This tremor is present at rest but tends to be slower (3 to 5 Hz) than typical Parkinson tremor (5 to 7 Hz). It also persists unchanged or even increases with postural changes or goal-directed activity.