27th December 2023

Assess the brainstem

Diplopia can be a symptom seen in stroke patients where structures in the brainstem are affected. Therefore, when monocular diplopia is excluded, the logical next step would be to assess the brainstem and organise urgent imaging where indicated. Structures which may be affected include:

1. The diencephalon, a primary relay and processing centre for sensory (including visual) information
2. Nuclei or fascicles of the 3ʳᵈ, 5ᵗʰ, or 6ᵗʰ cranial nerves, each responsible for extraocular muscle function
3. The medial longitudinal fasciculus – a specialised nerve bundle involved in extraocular function
4. The vestibulo-ocular pathway – important in the gaze-stabilising reflex