44. A 67-year-old man is brought to the emergency department 2 hours after the onset of weakness and double vision. He has hypertension and hyperlipidemia treated with metoprolol, captopril, and atorvastatin. His blood pressure is 190/106 mm Hg. Neurologic examination shows left-sided facial weakness including the forehead. There is palsy of left
conjugate gaze, and the left eye fails to adduct on right gaze. Vertical eye movements are intact. Muscle strength is
3/5 in the right upper and lower extremities. Deep tendon reflexes are brisk, and Babinski's sign is present on the right. Which of the following is the most likely location of this patient's lesion?
A) Bilateral thalamic
B) Left frontal
C) Left pontine
D) Right caudate
E) Right midbrain
In my opinion, since there is involvement of a long tract and cranial nerves we must think of brain stem lesion. In this case since the CST is involved it suggests a medial brain stem lesion and this is coherent together with the abducens nerve lesion signs (gaze palsy to the left) for medial pontine syndrome.
As for the rest of the neurological signs:
- Facial nerve involvement is not uncommon in medial pontine syndrome especially if the lesion is caudally located. (left sided facial weakness)
- as for the last neurological sign: the fact that the left eye fails to adduct when looking towards the right suggests either CN III palsy on the left (which is inconsistent with the patients symptoms) or a left MLF lesion
So, i would choose C. left pontine lesion
even though it doesn't correlate to the last neurological sign (seen in bold) it fits with the rest