The definition of a biennium is a period of two years. Your two-year cell phone contract is an example of a biennium. noun.
Symptoms of vestibular neuritis are characterised by a sudden onset of a constant, intense spinning sensation that is usually disabling and requires bed rest. It is often associated with nausea, vomiting, unsteadiness, imbalance, difficulty with vision and the inability to concentrate.
1 Viruses that may cause labyrinthitis or vestibular neuritis include herpes viruses, influenza, measles, rubella, mumps, polio, hepatitis, and Epstein-Barr virus (EBV).  Meniere's disease is composed of a triad of symptoms including episodes of vertigo, ringing in the ears (tinnitus), and hearing loss.