Final answer:
Lower motoneuron lesions do not present with clasp knife spasticity. This sign is indicative of upper motoneuron disease. Lower motoneuron lesions usually result in hypotonicity, muscle weakness, and diminished reflexes.
Step-by-step explanation:
Do lower motoneuron lesions present with clasp knife spasticity? The answer is No. Clasp knife spasticity is a sign of upper motoneuron (UMN) disease which can be demonstrated by a resistance in the passive movement of a muscle followed by a sudden release to a lower state of resistance.
This characteristic reaction is termed the clasp-knife response and is associated with conditions such as cerebral palsy or multiple sclerosis (MS), or it may be the result of a stroke. On the other hand, lower motoneuron (LMN) lesions typically present with loss of muscle tone, weakness or paralysis of muscles, diminished reflexes, and significant muscle atrophy. These symptoms reflect hypotonicity or flaccidity rather than spasticity, as the LMN lesions inhibit action potential conduction that would usually maintain a basal level of acetylcholine in the neuromuscular junction.