Definitions for "UMN"
Upper motor neuron. Neuron originating in the motor cortex or brain stem which synapses directly on -motoneurons (rare) or on local interneurons that synapse on -motoneurons (most); lesion typically results in spastic paralysis or paresis, increase muscle tone, increase reflex response (sometimes clonus, oscillating contraction following muscle stretch), Babinski sign
Upper motor nerve. Receives messages from the brain and transmits them to a lower motor neuron.
University of Minnesota, the developers of the Mapserver mapping server