Upper motor neuron lesion will not cause:
Upper motor neurons lesions initially causes muscles to become weak and flaccid but eventually leads to spasticity, hypeonia, hyperactive stretch reflexes. Upper motor neurons include: Coicospinal tract or pyramidal tract Extrapyramidal tract: rubrospinal, tectospinal, vestibulospinal, reticulospinal Upper motor neuron paralysis lower motor neuron paralysis Affects whole groups of muscles - like hemiplegia, paraplegia, or monoplegia Single muscles affected No atrophy Severe atrophy No fasciculations Fasciculations present Rigidity Flaccid paralysis Increased tendon reflexes (Hyper-reflexia) Absent tendon reflexes Extensor plantar reflex (Babinski sign) Normal, if present Hypeonia Hypotonia
Hypeonia
Fasciculations
Positive Babinski
Hyper-reflexia
Motor System