EBV can cause optic neuritis leading to visual disturbances. In other patients, it causes aseptic meningitis. These patients have fever, vomiting, pain over the top of the head, decreased consciousness, confusion, seizures, photophobia, and papilledema. Cranial nerve palsies are another manifestation of infectious mononucleosis in the central nervous system, mostly associated with cranial nerve 7 (facial nerve) or Guillain-Barre syndrome.
Facial palsy is characterized by the inability to close the eyelid, exposure keratitis, decrease tear production, dry eyes, dropping of the commissure of the lip, drooling, pain behind the ear, loss of nasolabial folds, facial muscle weakness on the affected side, hyperacusia (increased sensitivity to sound) and loss of taste sensation from the anterior one-third of the tongue.
Guillain-Barre syndrome is characterized by fever and muscle weakness in the limbs. Muscle weakness is ascending in nature and also symmetrical. Patients ultimately develop dyspnea due to respiratory muscle weakness, cranial nerve palsies, sensory loss and paralysis of the limbs. EBV can also lead to transverse myelitis, characterized by bilateral motor and autonomic dysfunction of the spinal cord, sensory loss below the level of the affected level of the spinal cord, and pleocytosis (leukocytes in the cerebrospinal fluid).