Thanks to Arturo Montano for presenting a fascinating case of a patient with monocular vision loss who was found to have GPA in her cavernous sinus.
Approach to multiple cranial neuropathies
- Start by documenting the distribution of all neuropathies and any other neurologic deficits. Is there a place where all of those nerves come together, such as the brain stem, skull foramen or cavernous sinus? Or is the distribution truly random?
- random distribution – think about systemic disease like viral infections, MS, guillain-barre and its friends, leptomeningeal spread of malignancy or diabetes
- anatomic distribution – think masses or strokes
- Always have a high index of suspicion for malignancy or mass – either a solid tumor or leptomeningeal spread of metastatic disease.
- in a case series of ~1K people with multiple cranial neuropathies, tumor or leptomeningeal spread caused 1/3 of cases
- when malignancies spread into the subarachnoid space. this should be distinguished from dural metastases, which are much more common.
- most common associated malignancies – breast, lung, GI and melanoma
- very difficult to diagnose! Often requires serial, large volume LPs. MRI with gad can also sometimes aid in diagnosis
- prognosis of 2 months or less.
Eye pain history
- Primary goal is to differentiate lesions within the globe from skin, soft tissue and bone lesions from neuromuscular lesions
- pain with extraocular movements make you concerned about either optic neuritis or a inflammation of the muscular cone that encases the eye
- optic classically presents with red desaturation – red objects look like they’ve been washed out
Cavernous sinus masses
A quick reminder of what runs through the cavernous sinus
- Cranial nerves III, IV, V1 & V2 branches and VI run through it
Ddx of cavernous sinous masses
- septic thrombosis
- Telosa-Hunt syndrome
- IgG4 dz
JR Keane Multiple Cranial Nerve Palsies: analysis of 979 cases.