Final answer:
Guillain-Barré Syndrome (GBS) is the most likely condition for a 70-year-old patient presenting with bilateral foot drop, blurred vision, and elevated CSF protein and cell count, due to its characteristic peripheral nervous system demyelination and acute presentation.
Step-by-step explanation:
The most likely neurological condition for a 70-year-old man from Fiji presenting with bilateral foot drop, blurred vision, and elevated cerebrospinal fluid (CSF) protein and cell count is Guillain-Barré Syndrome (GBS). GBS is a demyelinating disease of the peripheral nervous system, often triggered by an autoimmune reaction. This condition leads to motor deficits, such as foot drop, as well as sensory symptoms like blurred vision, being indicative of peripheral nerve damage. Elevated CSF protein and cell count are also consistent with GBS, which can involve inflammation of peripheral nerves, resulting in these characteristic cerebrospinal fluid changes. Other conditions such as Multiple Sclerosis tend to affect the central nervous system rather than the peripheral, Amyotrophic Lateral Sclerosis does not involve sensory deficits typically, and Chronic Inflammatory Demyelinating Polyneuropathy is more chronic in nature, unlike the acute presentation of GBS.