Benign paroxysmal vertigo of childhood

Benign paroxysmal vertigo of childhood (BPVC for short) is a medical problem that happens in children. "Benign" means "harmless;" "paroxysmal" means something comes and goes suddenly; and "vertigo" means "dizziness." So BPVC is harmless dizziness in children that comes and goes suddenly.
The dizziness usually makes children feel like they are moving or spinning, or that the inside of their head is moving or spinning.
Usually, BPVC starts in children between two and five years old. It often goes away by the age of eight. But in some children, BPVC may start when they are much younger (as young as a few months old) or older (as old as 12 years old). 
BPVC is the most common cause of dizziness in children who do not have hearing loss or a diagnosed ear disease. It is a common problem that happens to about 2.6% of children (26 out of 1,000 children).
Causes.
Doctors don't know for sure what causes BPVC. Some doctors think it is related to problems of the inner ear that affect balance. For example, some doctors think BPVC is similar to a different disorder which often happens in adults over 50. This disorder is called "benign paroxysmal positional vertigo" (BPPV). BPPV is a "vestibular disorder" - a disorder in the inner ear which affects balance. 
Other doctors believe BPVC is related to migraine headaches, but most children with BPVC do not get headaches.
Diagnosis.
For a doctor to diagnose Benign Paroxysmal Vertigo of Childhood, all of these things must be true:
Differential diagnoses.
"Differential diagnoses" are different medical disorders which may cause the same symptoms. When a doctor asks what the differential diagnoses for BPVC are, she is asking "what other disease could cause these symptoms? What else could this be?" Before a doctor makes a final diagnosis, they must think of what other medical conditions have the same or similar symptoms, and make sure one of them is not the problem.
Some of the differential diagnoses for BPVC are: