National Certified Addiction Counselor, Level 2 (NCAC II) Practice Exam Exam

What do we call the involuntary muscle contractions and relaxation seen in Clonus?

1. Muscle Spasm

2. Myoclonus

3. Tremor

4. Hyperreflexia

The correct answer is: Myoclonus

Clonus is characterized by a series of involuntary muscle contractions and relaxations that occur in a rhythmic manner, typically in response to a sudden stretch applied to a muscle. The correct term that describes this phenomenon is myoclonus, which refers to rapid, involuntary jerking of a muscle or group of muscles. Myoclonus can be associated with various neurological conditions and is distinguished by its abrupt muscle contractions. In the context of the other terms: muscle spasms are generally more sustained and do not have the rhythmic quality; tremors are oscillating movements that occur at rest or during voluntary movement and are not specifically the same as clonus; hyperreflexia refers to an exaggerated reflex response and does not denote the rhythmic contraction and relaxation pattern characteristic of clonus. Thus, myoclonus is the accurate term for the involuntary muscle contractions and relaxation observed in this condition.