Question: I've had a hard time with daily headaches, concentration, moodiness, and insomnia since having a car accident six weeks ago in which I hit my head on the steering wheel and blacked out for a few seconds. The MRI of my head was normal, but I still don't feel right. How long will I feel this way?

Answer: You have the classic symptoms of "post-concussion syndrome," also known as "mild traumatic brain injury." When the head is suddenly accelerated and/or decelerated during an accident, there are shearing forces on the brain's nerve fibers connecting one part of the brain to another. Also, the blow to the head from the steering wheel injury caused further nerve fiber injury. The end result of these forces is damage to the connections between nerve cells and the nerve fibers themselves, resulting in impairment of function.

People who have suffered post-concussion syndrome often show emotional instability and difficulty with concentration, memory and multitasking. There may be persistent headaches, anxiety, depression, personality changes, fatigue, and decreased libido. These symptoms can be misunderstood by the family doctor, the family, and even the affected person as either depression or anxiety.

It's thought that the head injury causes an alteration of the nerve chemical transmitters of the brain as well as altering the normal blood flow to select areas of the brain. Antidepressants can help in restoring the normal chemical balance, but can't correct or repair nerve cell injury.

The good news is that your brain will likely heal itself, and you should return to normal over the next few months.

A neurologist or a neuropsychologist can help you with the various symptoms you're still having as a result of your head injury.

The difference between true and false labor

A: During most of the months of pregnancy, the uterus undergoes periodic episodes of slow and weak contractions, as any expectant mother knows. They're called Braxton-Hicks contractions, and are what is meant by "false labor" contractions. Suddenly, at the end of pregnancy, these contractions become exceptionally strong, stretching the cervix and eventually forcing the baby through the birth canal.

What causes this sudden change from "false labor" to "true" labor? It's not up to the baby to decide when it's time to enter the world.

The proposed theory suggests that the stretching of the cervix by the baby's head finally becomes great enough to trigger a strong reflex that causes the uterus to contract. This pushes the baby forward, which stretches the cervix still more, initiating an even stronger contraction response from the uterus. This cycle continues again and again until the baby is delivered.

The difference between actual labor and false labor is that in false labor the contractions don't continually get stronger and stronger to cause the cycle of true labor to begin.