health

The basic cause of a concussion is the rotation of the brain inside the
skull as well as compression of the brain tissue against the sides of the
skull when a person receives a blow on the head. Although the brain is
cushioned against minor bumps by cerebrospinal fluid (CSF), the
amount of fluid between the brain and the skull is not enough to absorb
the force of a heavy blow.
Doctors do not agree as to whether concussion is a disturbance of
brain function only or whether it involves damage to the structure of the
brain as well. It is presently thought that the forces from a blow to the
head disrupt the normal activity of the cells in the brain tissue, and that
it is this disruption that causes temporary alterations in consciousness.

The brain’s secretion of neurotransmitters (the chemicals that convey
signals from one nerve cell to another), its oxygen supply, and its
use of glucose (blood sugar) are all affected by concussion.
In addition, a small number of cells in the brain tissue may die as
a result of even temporary interruptions of blood flow to the parts of
the brain affected by the concussion.

The symptoms of a concussion include emotional and well as cognitive and physical
symptoms:

• Physical symptoms: Headache (the most common symptom of concussion),
  dizziness,loss of balance or coordination, nausea and vomiting, visual
  disturbances,ringing in the ears, seizures or convulsions.
  
• Cognitive: Temporary loss or alteration of consciousness, difficulty
  concentrating, memory loss, confusion, disorientation, difficulty
  thinking clearly, disturbed sleep patterns.
  
• Emotional: Moodiness, tearfulness, temper outbursts, emotions
  inappropriate to a specificsituation (such as laughing at a funeral),
  long-term personality changes.