A 31-year-old woman presents with acute diplopia. Vital signs: BP 118/76, HR 88, RR 16, Temp 37.0°C, SpO2 98%. On examination, left gaze reveals failure of right eye adduction with left eye abduction nystagmus; convergence remains intact. MRI brain shows T2 hyperintensity in the medial longitudinal fasciculus. She denies recent fever or headache. Which structure is most likely affected?
- A)Edinger-Westphal nucleus
- B)Abducens nerve
- C)Oculomotor nerve nucleus
- D)Medial longitudinal fasciculusGABARITO
- E)Optic chiasm
Explicação
Medial longitudinal fasciculus is the correct answer because internuclear ophthalmoplegia results from a lesion in the MLF, disconnecting the abducens nucleus from the contralateral oculomotor nucleus and producing impaired adduction with abducting nystagmus. Ver explicação completa e trilha adaptativa →