The pain occurs because fluid pressure in the skull decreases. This is literally a hypotension state in the brain. That is why the headache goes away when you lie down - the spinal fluid pressure goes back to normal in your skull. Most spinal headaches go away in a few days when the hole in the dura seals itself.
Cerebrospinal fluid is produced by the brain at a rate of 500-700cc every 24 hours. There are small arachnoid villi that function as one way valves. They allow the fluid to drain into the venous system to be reabsorbed within the body. At any one given time, you have between 140-270cc of fluid cushioning the brain and spinal cord. Anything less or more causes severe headaches.
Symptoms Of Spinal Headaches
Spinal headaches vary in intensity from mild to completely incapacitating. This can be frustrating when youre trying to devote time and energy for your new baby and the headache started after an epidural. The headache is typically severe and throbbing and located in the front of the head radiating toward the back. The pain typically gets worse when you sit up or stand and decreases or goes away when you lie down. These headaches are frequently associated with other symptoms including:
- Photophobia (light hurts your eyes)
- Neck stiffness
- Tinnitus or ringing in the ears
- Nausea and possible vomiting
- Changes in vision
It is important to realize that you do not have to have all of the symptoms of spinal headache to be diagnosed with one.
Neuroimaging In Spinal Headaches
Many times, patients will worry about this onset of a new type of headache. Generally speaking, if the symptoms do not resolve with treatment, then an MRI of the brain is warrented.
Why not a CT? Because the imaging of an MRI can get a look at the meninges. With low pressure situations, the meninges, or the tissue covering the braine, will look a little thicker and the ventricles in the center of the brain will look narrowed.
NOTE: A new onset of a severe headache during labor or immediately post-partum requires imaging as it may be an emergency type of headache.
Treatment Of Spinal Headache
There are ways to speed up the healing of the puncture in the spinal sac. The most common treatment for a spinal headache is a "blood patch". This may be done at the time of the tap or epidural if the doctor sees that he/she may have punctured the dura. If not it may be done several days later if the headache has not gone away. It involves taking a small amount of blood from a vein in your arm, mixing with a small amount of sterile saline, and injecting it into your back in the epidural space. The blood clots and "patches" the hole, giving it more time to complete healing.
For treatment of acute pain, we often do infusions of steroid and 300mg of caffeine. This has been shown to cut the severe pain of the headache as it may take up to 24 hours for a blood patch to have its full effect. If you are in the hospital after having delivered a baby, you may also be offered pain medication such as hydrocodone. In this specific case, we do recommend opioid treatment. Irritation of the meninges, for whatever reason, is one of the most excruiciating pain syndromes anyone could suffer from.
Read more about different types of headaches.