De Musset’s sign is seen in
**Question:** De Musset's sign is seen in
A. Motor neuron disease
B. Brainstem stroke
C. Amyotrophic lateral sclerosis (ALS)
D. Post-stroke spasticity
**Correct Answer:** De Musset's sign is seen in B. Brainstem stroke.
**Core Concept:** De Musset's sign is a clinical sign characterized by the patient's inability to speak or understand speech when the head is moved forward and backward rapidly. This phenomenon is caused by the disruption of the corticospinal tracts in the brainstem.
**Why the Correct Answer is Right:** De Musset's sign is present in brainstem stroke, particularly in lesions involving the pons or medulla oblongata. These areas are crucial for speech and language functions, as they contain important nuclei involved in these processes. When a stroke occurs in these regions, the corticospinal tracts get disrupted, causing De Musset's sign.
**Why Each Wrong Option is Incorrect:**
A. Motor neuron disease (amyotrophic lateral sclerosis, ALS) primarily affects motor neurons, leading to muscle weakness and atrophy, but does not cause speech difficulties or De Musset's sign.
B. Post-stroke spasticity (hypertonia) and fasciculations are common but De Musset's sign is not a feature of spasticity.
C. Although ALS can present with speech difficulties, the sign is not specific to ALS and can also be seen in other neurological conditions involving the brainstem.
**Clinical Pearl:** De Musset's sign is a valuable clinical sign for diagnosing brainstem lesions, particularly when combined with other neurological deficits. Early recognition and appropriate management of brainstem strokes can significantly improve patient outcomes.