Which of the following are NOT features of Coicospinal tract lesion? 1. Spasticity 2. Resting tremor 3. Exaggerated tendon reflexes 4. Extensor plantar response 5. Cogwheel rigidity
The options given are spasticity, resting tremor, exaggerated reflexes, extensor plantar response, and cogwheel rigidity. The correct answer is supposed to be the ones that are NOT features. Let me go through each.
Spasticity is a UMN sign, so that's a feature. Exaggerated tendon reflexes (hyperreflexia) are also UMN. Extensor plantar response (Babinski sign) is definitely a UMN sign. Resting tremor and cogwheel rigidity are more associated with lower motor neuron (LMN) issues or other conditions like Parkinson's. Wait, cogwheel rigidity is a Parkinsonian feature, which is extrapyramidal. So the ones not related would be resting tremor and cogwheel rigidity.
Looking at the options, the question asks which are NOT features. So the answer should include 2 and 5. Let me check the options again. The options are A, B, C, D, but the user didn't list them. But the correct answer is the combination that includes 2 and 5. So the correct answer would be the option that lists 2 and 5 as not features. Therefore, the answer is B, C, or D depending on how the options are structured. But since the user provided the correct answer as 2 and 5, the correct choice is the one that includes both.
Wait, the user's correct answer is listed as "2 and 5", so the options must be combinations of these numbers. The question is a multiple true/false type. The correct answer is the one that includes 2 and 5 as not features. So the answer is the option that lists 2 and 5 as the features not present in corticospinal lesions. Therefore, the correct answer is the one that includes 2 and 5. The user's correct answer is probably option B or C, but since the options aren't given, I need to focus on explaining why 2 and 5 are not features.
Resting tremor is a feature of Parkinson's disease, which is a basal ganglia disorder, not a UMN lesion. Cogwheel rigidity is also Parkinsonian, due to the combination of muscle rigidity and tremor. So both 2 and 5 are not associated with corticospinal lesions. Therefore, the correct answer includes these two. The other features (1,3,4) are UMN signs. So the answer is the option that includes 2 and 5.
**Core Concept**
The corticospinal tract (pyramidal tract) mediates voluntary motor control. Lesions cause upper motor neuron (UMN) signs like spasticity, hyperreflexia, and extensor plantar response. Resting tremor and cogwheel rigidity are extrapyramidal features of basal ganglia dysfunction, not UMN lesions.
**Why the Correct Answer is Right**
Resting tremor (2) and cogwheel rigidity (5) are hallmark features of Parkinson