A 50-year-old man presents with right-sided lower motor neuron facial palsy, failure of right lateral gaze, and weakness of the LEFT upper and lower limbs. The lesion responsible is located in the:
- A Right side of the caudal pons involving the facial nerve nucleus and fascicles ✓
- B Left side of the caudal pons
- C Right cerebral peduncle of the midbrain
- D Right internal capsule below the genu
Correct answer: A. Right side of the caudal pons involving the facial nerve nucleus and fascicles
Explanation
This is Millard-Gubler syndrome, a ventral caudal pontine lesion affecting the ipsilateral facial nerve fascicles (LMN palsy), the abducens nucleus or fascicles (ipsilateral gaze failure), and the crossing corticospinal fibres (contralateral hemiplegia). An internal capsular or midbrain lesion would give an upper motor neuron facial palsy with forehead sparing, which eliminates options C and D. The hemiplegia being left sided places the lesion on the right, killing option B.
Reference: Snell's Clinical Neuroanatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.