Humans have an average of 125ml to 150ml of cerebrospinal fluid at any given time. It is a clear and colorless fluid that can be found in both the brain and spinal cord. To help you understand better, you can look at this diagram that shows the circulation of cerebrospinal fluid. It functions to protect the brain by providing cushion to shield your brain from impact against your skull. The cerebrospinal fluid fills the ventricles, cisterns, and sulci of the brain. It also fills the central canal of the spinal cord. This means that your brain and spinal cord are essentially surrounded by a bag of fluid. In this analogy, the bag is called the dura mater and the fluid is the cerebrospinal fluid.
What Is A Spinal Anesthesia?
When a spinal anesthesia is given, a fine needle penetrates the dura mater to enter the subarachnoid space. It is generally done using a fine needle which is approximately 9cm or 3.5 inches long. IN obese patients, longer needles which are about 12.7cm or 5 inches are required. It is a common procedure used in various surgeries. In this case, it can be used in Caesarean sections or pain management for vaginal delivery. It is the first choice used in Caesarean section as it allows the patient to be conscious and present for the birth of their child without experiencing any pain. It also prevents the side effects of general anesthesia. Below is a diagram of how spinal anesthesia is done..
What Is An Epidural Anesthesia?
Epidural anesthesia is where the anesthetic drug is injected into the epidural space through a catheter. The site where the needle and catheter are inserted will first be numbed using a local anesthetic. After both the needle and catheter are inserted, the catheter is secured on the back, so more medication can be injected through the catheter if necessary. It is similar to spinal anesthesia and can be easily confused with each other.
What Causes the Headache In Spinal Anesthesia?
In spinal anesthesia, since the needle penetrates the dura mater to inject anesthesia into the subarachnoid space, some cerebrospinal fluid may leak out reducing the pressure in the space. In epidural anesthesia, the needle may also pass through the dura, but this depends on the experience of the anesthetist and several other factors. If the pressure in the subarachnoid space is reduced, it can cause a headache. The pressure reduces even more if you try to sit up. The pressure loss causes the brain to sag. This leads to the stretching of connective tissue in the cranium and is perceived as pain. Those who have experienced it usually describe is as a severe migraine that worsens when they try to sit or stand up. It is also known as a “post dural puncture” headache or spinal headache. It is as common as 1 in every 200 cases, but it also depends on individual circumstances and age. The headache usually starts between a day to a week after having the spinal or epidural anesthesia.
What Are the Symptoms of a Spinal Headache?
It is often described as “a headache like no other”. The pain is usually a dull and throbbing pain that can range from mid to debilitating. It is aggravated or more severe you are in an upright position (sitting or standing). It improves when you lie down. Some may even experience:
- Pain and / or stiffness in the neck
- >Photophobia (sensitivity to light)
- Phonophobia (sensitivity to sound)
- >Ringing in the ears (tinnitus)
- Blurry or double vision
What are the Risk Factors?
There are risk factors that could impact the severity of the headache experienced. The most common factors are outlined below:
- There is higher risk of spinal headaches in those who arstrong
- Between 18 to 30 years old
- Female gender
- Have a small body mass
- Having procedures that require larger needles or multiple punctures in the duration
How Can I Get Rid Of My Headache Spinal Anesthesia?
It will take several weeks or longer for the hole in the dura to heal. Some of the ways that you can alleviate the pain is by:
- Lying flat to avoid aggravating the headache as sitting or standing can worsen the pain
- Taking painkillers that are available over the counter such as Acetaminophen / Paracetamol or Ibuprofen
- Stay hydrated by drinking plenty of fluids and avoid any heavy exertion such as lifting and straining
- Your anesthetist may recommend an “epidural blood patch” if your headache is severe. This procedure takes about half an hour and involves your anesthetist taking your blood and injecting it near the hole in the dura so clotting occurs. This acts as a plug for the hole. It is effective in 60% to 70% of patients and relief is usually seen within 24 hours. A second blood patch may be required if symptoms persist. It is recommended that you lie flat after the blood patch procedure for about four hours and strenuous activities should be avoided for a minimum of two days. This procedure carries the risk of another accidental puncture.
- Intravascular caffeine may be recommended. This is where caffeine can be used to help relieve your spinal headache by delivering it directly into your bloodstream. You can usually feel relief within a few hours as your blood vessels in your head start to constrict.
- Ask for help from another person to assist you with your daily activities.
Difference Between Migraines Versus Spinal Headaches
If you suffer from migraines, you are not alone. It is estimated that approximately 12% of the population in the United States suffer from it as well. Migraines are recurring episodes of severe pain that is throbbing or pulsing on one side of the head. Besides the severe pain, patients are also sensitive to light and sound. They may also experience nausea and vomiting. It you have a history of migraines, you might be confused thinking that you are having an episode of migraine when you have a spinal headache since the symptoms are so similar. If in doubt, always consult your doctor so that you can receive the proper care. When you see your doctor, make sure to mention any recent procedures especially if you have had a spinal tap, spinal anesthesia, or epidural anesthesia. Your doctor may ask you to undergo a magnetic resonance imaging (MRI) scan to rule out other potential causes of your headache. Before going to your appointment, you should write down the symptoms you have been experiencing even if it may seem unrelated. You should also make a list of medications, vitamins, and supplements that you are currently or recently have taken. A friend or family member can be helpful as you may need help to remember certain information or simply to be there for you. Think of any questions you may have for your doctor and write it down, so you won’t forget.
Does a History of Migraines Increase My Chances of Spinal Headaches?
While popular belief dictates that individuals with a history of migraines have a higher risk of spinal headaches, two studies by van Oosterhout et al, 2013, and Munts et al, 2009, show that migraine patients do not have an increased risk or duration of spinal headaches. The research team led by van Oosterhout found that there is a low incidence of spinal headache in those with migraines. They were also able to confirm that younger age and low body mass index (BMI) are risk factors for spinal headache. Other findings include the observation that there is longer duration of spinal headache in those with a history of depression, multiple punctures into the dura, higher stress during the procedure.