Comparison of MRI finding in oculomotor cranial nerve palsies as a result of inflammation and ischaemia
Reviewed by Lauren Hepworth

This study aimed to explore the value of asymmetric enhancement of the cavernous sinus on MRI for differential diagnosis between ocular myasthenia gravis, ischemic or inflammatory oculomotor cranial nerve palsies. Three groups were recruited consecutively over a 30-month period and underwent a contrast enhanced MRI of the cavernous sinus. Each group had specific inclusion criteria. Ophthalmoplegia caused by infection, stroke, tumours, trauma, aplasia, carotid-cavernous fistulae, aneurysms and intracranial hypertension were excluded. All included cases were retrospectively reviewed and demographics, clinical presentation, inflammatory markers, imaging including reports, management and prognosis were extracted. A total of 243 individuals were included in the analysis, divided by group idiopathic inflammation (n=66), ischemic oculomotor cranial nerve palsies (n=117), and ocular myasthenia gravis (n=60). The idiopathic inflammation group were statistically significantly more likely than the ischemic group to have third and fourth cranial nerves involved, imaging findings of thickness of the cavernous sinus, thickening enhancement, enhancing adjacent lesions, and for there to be an inconsistency between the clinical and imaging findings. The authors acknowledge several limitations including atypical inflammation cases were excluded, potentially resulting in grouping bias and the lack of biopsy data to confirm pathological diagnosis. This study has outlined some imaging features which may help with differential diagnosis, however due to the variability, enhanced MRI should not be relied upon.

Cavernous sinus MRI findings in inflammatory and ischemic oculomotor cranial nerve palsies.
Yunqing W, Shilei C, Yong L, et al.
JOURNAL OF NEURO-OPHTHALMOLOGY
2024;44:236–41.
ORBIT