Clinical Reasoning: A patient with multiple cranial nerve palsies and areflexic paraparesis

A 62-year-old hypertensive man presented with 1.5-month history of bilateral facial nerve palsy evolving over 5 days, followed by double vision and restriction of eye movements for 1 month. He had progressive deterioration of vision of 20 days duration. His vital measures, except blood pressure (174/104 mm Hg), were normal. The patient was conscious, oriented, and obeyed commands and instructions. His vision was limited to appreciation of hand movements. Ophthalmoscopy revealed bilateral disk swelling with grade II hypertensive retinopathy. Pupils were dilated with a sluggish reaction to light. Cranial nerve examination further revealed bilateral third, fourth, sixth, and seventh cranial nerve palsies. Trigeminal nerve (V1-V3) sensations were intact. Hearing was normal. There was no tongue or palate weakness/asymmetry. Tongue bulk was normal. Sternocleidomastoid and trapezius were normal. Power in the upper limbs was normal. In the lower limbs, power in all groups of muscles was grade 3/5 (Medical Research Council grade). There was generalized areflexia. Planters were flexor. Sensory examination was normal. There was nuchal rigidity with a positive Kerning sign. Other systemic and general examinations were unremarkable.