What is the likely diagnosis of a patient with diplopia and significant balance issues who has a history of Sjögren's syndrome?

The diagnosis of multiple sclerosis is strongly suggested in this case due to the combination of diplopia (double vision) and significant balance issues, particularly in a patient with a history of Sjögren's syndrome. Sjögren's syndrome is an autoimmune disorder that can be associated with various neurological manifestations, including an increased risk of developing multiple sclerosis.

In multiple sclerosis, the immune system attacks the protective covering of nerves, leading to demyelination. This demyelination can affect the cranial nerves that control eye movement, resulting in diplopia, as well as impair balance through effects on the vestibular pathways and cerebellum. The progressive neurological symptoms and the episodic nature of attacks can also align well with a diagnosis of multiple sclerosis.

While myasthenia gravis could also present with diplopia, it typically includes additional features such as fluctuating muscle weakness, particularly affecting the ocular muscles and muscle groups involved in daily activities. The history of Sjögren's syndrome is more directly linked to the pathophysiology seen in multiple sclerosis than with myasthenia gravis.

Wernicke encephalopathy, which results from thiamine deficiency, usually presents with a classic triad of confusion, ataxia, and ophthalmople