Which of the following is a negative sign in CNS lesions?

• A. Muscle weakness
• B. Hyperactive reflexes
• C. Spasticity
• D. Hypertonia

Answer: (A)

In CNS lesions, signs are categorized as negative or positive. Negative signs reflect a loss of normal function, such as the ability to generate force. Muscle weakness directly shows diminished strength from disrupted motor pathways, so it represents a loss of function.

The other options indicate increased activity or tone, which are positive signs: hyperactive reflexes show exaggerated reflex response, while spasticity and hypertonia reflect increased muscle tone due to altered neural control. These are not losses of function, but gains in abnormal activity.