Isolated trigeminal neuropathy as an initial manifestation of chronic inflammatory demyelinating polyradiculoneuropathy: A case report.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated disorder affecting the peripheral nerves and nerve roots. It typically presents with symmetrical weakness of both proximal and distal muscles. Although cranial nerve involvement is rare, it can occasionally occur before the typical peripheral neuropathy develops. We report an unusual case of a 37-year-old woman in whom cranial neuropathy preceded peripheral demyelinating neuropathy. She initially presented with painful vision loss caused by compressive optic neuropathy due to trigeminal nerve hypertrophy. She later developed lower limb weakness, and characteristic MRI findings of cranial nerve hypertrophy together with persistent demyelinating changes on nerve conduction studies over a 2-year follow-up confirmed the diagnosis of CIDP. This case highlights the importance of considering CIDP in patients with painful ophthalmoplegia and cranial nerve hypertrophy. Early recognition of these atypical presentations may lead to earlier diagnosis, timely treatment, and better outcomes.