To characterize the clinicoradiological features of cranial nerve (CN) involvement in neurosarcoidosis with a focus on treatment response.

CN involvement is prevalent in neurosarcoidosis, but few existing studies focus on this patient population. In particular, clinical and radiographic features at diagnosis and during the course of treatment offer a way to monitor disease course but have not been well-characterized and merit further investigation.

The charts of 42 patients with biopsy-proven sarcoidosis and cranial neuropathy symptoms were reviewed retrospectively. 35 patients had at least one MRI scan and 23 patients had MRI findings corresponding with cranial neuropathy symptomatology on initial presentation. Clinical and radiographic data for these 23 patients were analyzed using descriptive statistics.

Positive imaging findings included cranial nerve enhancement (52%), leptomeningeal enhancement (44%), enhancing parenchymal brain lesions (30%), non-enhancing parenchymal brain lesions (13%), pachymeningeal enhancement (9%), and hydrocephalus (9%). Cranial nerves most commonly affected were CN VII (39%), CN III (39%), CN VI (30%), CN IV (30%), and CN VIII (26%). 21 patients were treated with corticosteroids on presentation and 18 were additionally treated with biologic agents. 20 patients had a post-treatment MRI and of these, 35% had complete radiographic resolution while 65% had persistent radiographic findings of CN involvement. Of those with radiographic resolution, 57% had accompanying clinical resolution. Of those with persistent radiographic findings, 69% had persistent clinical symptoms. The mean time to radiographic resolution post-treatment was 41.3 months (SD = 33.2 months) and the mean time to clinical resolution post-treatment was 26.6 months (SD = 29.0 months).

Cranial neuropathies in sarcoidosis have variable clinical and radiographic features after treatment with corticosteroids and biologics. Patients with symptom resolution may have persistent MRI findings and vice versa. Clinical and radiographic resolution of disease can occur at different timepoints after treatment.