An upper motor neuron lesion (also known as pyramidal insufficiency) Is an injury or abnormality that occurs in the neural pathway above the anterior horn cell of the spinal cord or motor nuclei of the cranial nerves.

[1] Upper motor neuron lesions occur in the brain or the spinal cord as the result of stroke, multiple sclerosis, traumatic brain injury, cerebral palsy, atypical parkinsonisms, multiple system atrophy, and amyotrophic lateral sclerosis.

These changes vary depending on the site and the extent of the lesion, and may include: These are the neural tracts which descend in the ventral horn of the spinal cord, carrying signals for voluntary movement of skeletal muscle.

From their origin in the primary motor cortex, these nerves pass via the corona radiata to gather in the internal capsule before crossing over to the opposite side (decussation) in the medullary pyramids and proceeding down the spinal cord to meet lower motor neurons in the anterior grey column.

During an exam, your doctor will look for signs of a nervous system problem by checking your: The treatment of an upper motor neuron lesion will be dependent on the underlying cause.