Following cranial nerve is most commonly involved in patients with sarcoidosis:

Ans: C (VII Cranial nerve) Ref: Harrison's Principles of Internal Medicine 18th edition. 2012. Chapter 329Explanation:Nervous System Involvement in SarcoidosisNeurologic disease is reported in 5-10%.Any part of the central or peripheral nervous system can be affected.The presence of granulomatous inflammation is often visible on MRI studies.The MRI with gadolinium enhancement may demonstrate space-occupying lesions, hut the MR! can be negative due to small lesions or the effect of systemic therapy in reducing the inflammation.The cerebral spinal fluid (CSF) findings include lymphocytic meningitis with a mild increase in protein.The CSF glucose is usually normal but can be iowr.Certain areas of the nervous system are more commonly affected in neurosarcoidosis.Cranial nerve involvementBasilar meningitisMyelopathyAnterior hypothalamic disease with associated diabetes nsipidusSeizures and cognitive changes also occur.Of ihe cranial nerves, seventh nerve paralysis can be transient and mistaken for Bell's palsy (idiopathic seventh nerve paralysis).Optic neuritis is another cranial nerve manifestation of sarcoidosis. This manifestation is more chronic and usually requires long-term systemic therapy, it can be associated with both anterior and posterior uveitis.