Difference between Upper and Lower motor neuron lesions

Key features of upper and lower motor neuron lesions

	Upper motor neuron	Lower motor neuron
Muscle tone	Increased	Decreased
Clonus	Present	Absent
Muscle fasciculation	Absent	Present
Tendon reflexes	Increased	Decreased or absent
Plantar reflex	Extensor (Babinski’s sign)	Flexor normal
Distribution	Extensor weakness and upper limb and flexor weakness in lower limb.	Weakness of muscle groups innervated by affected spinal segments/ root, plexus or peripheral nerve.