Cranial Neuritis

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Article initiated by:

Andrew Go Lee, MD, Chaow Charoenkijkajorn, M.D., Kais M. Karowadia, Mohammad Pakravan, Nagham Al-Zubidi, MD

All contributors:

Nagham Al-Zubidi, MD, Bayan Al Othman, MD, Chaow Charoenkijkajorn, M.D., Noor Laylani, M.D.

Assigned editor:

Bayan Al Othman, MD

Review:

Assigned status Update Pending

 by Bayan Al Othman, MD on May 17, 2024.

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Contributing Editors:	add

Disease Entity

Cranial neuritis is the inflammation of a cranial nerve. The inflammatory process may cause destruction and/or demyelination of the nerves. Involvement of multiple cranial nerves within the disease process can be classified as polyneuritis cranialis.

Etiology

Cranial neuritis documented in the literature focus on infectious and autoimmune etiologies, although cases of neoplastic, vascular, and idiopathic cause have also been reported.

Infectious

• Varicella Zoster Virus (VZV)
• Dengue Virus
• Epstein Barr Virus
• Borrelia burgdorferi (Lyme Disease)
• Mycobacterium tuberculosis
• Treponema pallidum (Syphilis)
• Francisella tularensis
• Cryptococcus neoformans
• Mucormycosis
• Aspergillosis
• SARS CoV-2

Autoimmune

• Polyarteritis nodosa
• Giant cell arteritis
• Granulomatosis with polyangiitis
• Eosinophilic granulomatosis with polyangiitis
• Microscopic polyangiitis
• Systemic lupus erythematosus
• Sarcoidosis
• Guillan-Barré (Miller-Fisher) syndrome
• Tolosa-Hunt syndrome
• Behçet disease
• Thyroid eye disease
• Myelin oligodendrocyte glycoprotein antibody disease(MOG-AD)
• Neuromyelitis optica (NMO)

Neoplastic

• Primary leptomeningeal neoplasm
• Metastatic neoplasms
  • Infiltrative
  • Compressive
• Chemotherapy induced neuritis (Immune checkpoint inhibitors)

Vascular

• Diabetes mellitus
• Sickle cell disease
• Vascular aneurysm compression

Idiopathic

• Idiopathic cranial polyneuropathy
• Idiopathic hypertrophic cranial pachymeningitis

Clinical Findings

The clinical findings may include but are not limited to:

• Third Nerve Palsy – diplopia, ptosis, pupillary involvement, deviation of eye downward and outward
• Fourth Nerve Palsy – vertical or torsional diplopia
• Fifth Nerve dysfunction (see Trigeminal Neuralgia)
• Sixth Nerve Palsy (see Abducens Nerve Palsy)
• Seventh Nerve Palsy– facial paralysis/asymmetry, facial droop, drooling, pain around jaw or behind ear ipsilaterally, headache, loss of taste, xerostomia, decreased tear production
• Eighth Nerve dysfunction – vertigo, tinnitus, nystagmus, sensorineural hearing loss
• Ninth Nerve Palsy – dysphagia, impaired taste on posterior third of tongue, loss of carotid sinus reflex, loss of gag reflex, and dysfunction of parotid gland
• Tenth Nerve Palsy – dysphagia, dyspnea, change in voice, loss of gag reflex, bradycardia, GI upset
• Eleventh Nerve Palsy – loss of shoulder shrug, drooping of shoulder, dull posterior shoulder pain
• Twelfth Nerve Palsy – atrophy, weakness, paralysis, and/or fasciculations of the tongue
• Headache
• Meningeal signs
• Increased ICP

Diagnosis

Ocular motor cranial neuritis produces symptoms and signs of ophthalmoplegia and diplopia. Although a non-contrast computed tomography (CT) scan may be the initial imaging, typically magnetic resonance imaging (MRI) of the brain and orbit with and without contrast is recommended for these cases. Concomitant or sequential CTA/MRA or catheter arteriography may still be needed if a vascular etiology is being considered. The distinctive radiographic feature of ocular motor cranial neuritis is contrast enhancement of the affected cranial nerve. Constructive interference in steady state (CISS) MRI sequences can help to visualize the cranial nerves better. Lumbar puncture and laboratory evaluation directed at the underlying etiologies in the differential diagnosis is recommended because the radiographic findings are not specific.

Treatment

The treatment of cranial neuritis depends on the etiology in each patient. Treating the underlying cause (e.g. acyclovir for HSV, steroids for inflammation) is recommended. The prognosis depends on the underlying etiology and effectiveness of therapy.