Intention tremor is seen in
**Question:** Intention tremor is seen in
A. Parkinson's disease
B. Essential tremor
C. Multiple system atrophy
D. Wilson's disease
**Correct Answer:** C. Multiple system atrophy
**Core Concept:** Intention tremor is a type of postural tremor that worsens with voluntary muscle contraction and improves with muscle relaxation. It is a clinical sign associated with specific neurological disorders.
**Why the Correct Answer is Right:** Intention tremor is seen in multiple system atrophy (MSA) because this condition is characterized by a combination of parkinsonism and cerebellar dysfunction. The cerebellum plays a crucial role in controlling muscle tone, posture, and coordination. When the cerebellum is affected by MSA, patients experience intention tremors.
**Why Each Wrong Option is Incorrect:**
A. Parkinson's disease (PD) primarily affects the basal ganglia, leading to bradykinesia, rigidity, and resting tremors. PD does not cause intention tremors as seen in MSA.
B. Essential tremor (ET) primarily affects the cerebellum and is characterized by action tremors that worsen with voluntary muscle contraction and improve with muscle relaxation. Unlike ET, intention tremors in MSA are not related to cerebellar dysfunction but rather reflect the involvement of the basal ganglia.
D. Wilson's disease is a copper-related disorder affecting the basal ganglia and cerebellum, leading to chorea, dystonia, and parkinsonism. Wilson's disease does not cause intention tremors like MSA.
**Clinical Pearl:** The correct identification of intention tremors can help differentiate between various neurological disorders like Parkinson's disease, essential tremor, multiple system atrophy, and Wilson's disease. A detailed clinical history and neurological examination are crucial in reaching a proper diagnosis.