A functional anomaly of the upper motor neuron. The upper motor neurons are neurons of the primary motor cortex which project to the brainstem and spinal chord via the corticonuclear, corticobulbar and corticospinal (pyramidal) tracts. They are involved in control of voluntary movements. Dysfunction leads to weakness, impairment of fine motor movements, spasticity, hyperreflexia and abnormal pyramidal signs. [ https://orcid.org/0000-0002-0736-9199 ]
Synonyms: Corticospinal tract dysfunction Pyramidal tract dysfunction
Term information
- UMLS:C1839042
- UMLS:C1504405
A functional deficit of the tract that conveys nervous impulses from the motor cortex of the brain to the spinal cord. The corticospinal tract mediates discrete voluntary skilled movements. Clinical features of corticospinal tract dysfunction may include spasticity and weakness, particularly affecting the lower limbs, as well as hyperreflexia, clonus at the ankles and knees, and extensor plantar responses (Babinski response).
Term relations
- has part some (
decreased functionality and
characteristic of some (
neuron and
part of some primary motor cortex) and
has modifier some abnormal)