Are upper motor neurons cause spastic paralysis?

Extensive upper motor neuron lesions may also be accompanied by rigidity of the extensor muscles of the leg and the flexor muscles of the arm (called decerebrate rigidity; see below). read more

It is the severing of upper motor neurons (the pyramidal tract, starting from the precentral gyrus and ending at the anterior horn in de medulla spinalis) that causes spastic paralysis. read more

upper motor neuron disorders UMN paralysis" more accurate than attributing paralysis to just the CS/pyramidal pathway, since fibers from diff. tract mingle in corona radiata & IC. Preserves mvts that are invariably bilateral (eyes, pharynx,, thorax, abdomen) - bilaterally innervated mm. read more

Cause. Spasticity mostly occurs in disorders of the central nervous system (CNS) affecting the upper motor neurons in the form of a lesion, such as spastic diplegia, or upper motor neuron syndrome, and can also be present in various types of multiple sclerosis, where it occurs as a symptom of the progressively-worsening attacks on myelin sheaths and is thus unrelated to the types of spasticity present in neuromuscular cerebral palsy rooted spasticity disorders. read more