Low pressure headache–I better lie down.

In this post I shall discuss a well described and not so uncommon cause of bothersome headaches–“low cerebrospinal fluid pressure headaches”. So what is low CSF pressure headache? To understand this better one needs to have a rudimentary knowledge of the anatomy of the central nervous system. The human brain is enclosed in a rigid bony skull which protects it from injury. The brain is composed of grey and white matter. The other contents of the skull include blood (carried in the arteries, veins and sinuses of the brain) and the cerebrospinal fluid (CSF). The CSF circulates around the brain and the spinal cord. So headache can occur whenever the pressure in the brain increases. Like for example the blood pressure shoots up–one complains of headache. If one suffers a bleed (hemorrhage) in the brain–patient may complain of headache. If the blood vessels of the brain go into spasm–one has headache. All this is easy to understand.

A not so uncommon cause of headache is when the pressure inside the skull suddenly drops.  Think of the brain as a ball floating in a bucket of CSF. The ball (brain) feels nice and happy when it is bobbing up and down in a full bucket of CSF. Now someone drills a small hole at the bottom of the bucket so that the CSF slowly starts leaking out.  As the amount of CSF in the bucket decreases and CSF pressure falls the brain is no longer bobbing. It sinks down as the CSF decreases and this puts pressure on the nerves which are at the base of the skull. So what happens next? Well the brain complains of a headache.  This in a simple way is what is called low CSF pressure headache.

Low CSF pressure headache has some defining characteristics. The headache is positional–meaning it is worse when the person is standing or sitting upright and abates when he lies down. Unlike migraines patients do not complain of throbbing unilateral headache accompanied by sensitivity to bright lights and loud sounds. Low CSF pressure headache is usually holocranial (whole head), dull, aching and like I said earlier positional. The positional component to the headache is its defining characteristic.

There can be many causes that lead to low CSF pressure headache. A common iatrogenic cause is a spinal tap (also called lumbar puncture). Let me give you a classical example. Let us assume you suffer from migraines  (though you may not be aware of it since it was never formally diagnosed by a doctor). One day you suffer a particularly severe and disabling headache episode (in the past you only had “minor” headaches). You end up going to the ER where the doctor orders a lumbar puncture to be carried out. Now you may ask why did the ER physician order a spinal tap in the first place. What was he looking for? Well the two most common conditions the ER physician wants to rule out is infection (meningitis) and subarachnoid hemorrhage (please see my post–thunderclap headache). So the lumbar puncture (spinal tap) is carried out by inserting the spinal tap needle into the lower part of the back. The needle pierces the dura and CSF starts flowing out. The sample is collected and sent to the lab. Soon enough the results are available and the ER physician comes back to update you. Good news the spinal fluid was clean. You do not have infection nor do you have subarachnoid hemorrhage. You just have a bad migraine attack. You are given pain medications for your headache and sent home.

You are relieved that it is nothing too serious. Next day however when you wake up you are bothered by a holocranial headache. Over the course of the next few days you realize that when you lie down the headache becomes better. It is worse when you are standing or sitting. After suffering through this for a few days two things may happen. The low CSF pressure headache may abate on its own and you are back to your good health or the low CSF pressure headache may persist and prompt a visit to your local neurologist.

The diagnosis is usually straight forward in someone who has the classical history which I have documented above. There are other less common causes of low CSF headache but I shall not dwell into that now.  No special investigations are needed. The neurologist advice is rest and drink plenty of fluids (water, caffeine, juices and so forth). I at times advice my patients to sleep on their tummy for a few nights.  The rationale of this advice–the CSF is leaking out of the small hole in the dura made by the spinal needle. The hole shall close on its own in a few days time. The CSF lost shall be replenished and the headache shall abate. Most of the times this advice works well. At times we prescribe the patient a pain killer containing Tylenol (acetaminophen) and caffeine.

In a few patients inspite of the above conservative treatment the headache persists. In these select patients a blood patch is extremely helpful. What is an epidural blood patch you may ask? Well we take about 10 cc of the patient’s own blood and inject into the epidural space (usually near the site where the original lumbar puncture was carried out). The blood clots and seals off the small opening in the dura. No more CSF leak and no more headache.

That is all about low CSF pressure headache for now folks. Now I too must lie down and enjoy my vacation in India. Miss my parents so it is always nice to be back home.

 

Nitin K Sethi, MD

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9 thoughts on “Low pressure headache–I better lie down.

  1. Hello.
    I just has an MRI “no contrast” on my Brain. Results saythe T2 and FLAIR sequence images show focal areas of bright signal change scatter in the deep white matter.
    Goes on the say, most likely consideration would be Chronic Ischemic change.
    A demyelinating process such as MS is less likely consideration in patient of this age.
    I always have a dull ache in the back of my head from the base of my scull to the top of my head..
    I am 67 years old. In April of this year I was told I have PMR/GCA.
    I have trouble walking. I walk toward the left and loose my balance.
    Light headed & dizzyness. I am not dizzy when walking..
    Lights are very bright. I have had sudden loss of vision & double vision..
    Would you please tell me what you think…Thank you

    1. Thank you Linda for writing in. My only advice is that you follow up with your doctor. He shall be the best person to determine if the MRI findings have any significance to your symptoms.

      Nitin K Sethi, MD

      1. Hello, My wife suffers from same condition, but still not diagnosed. She had a severe headache, admitted for severe back pain with headache, ortho was recommended and ruled out of any, ortho referred going for ENT clearance where she was admitted with severe headache (unbearable) had lot of fluids, subsided and it was fine, but It came again after 10 days with severe throbbing in nature, where she now has to lie down only. If she is upright the pain is severe. Went to neurologist, who advised rest and lot of fluids, advised MR venogram which showed no leak. He suggested to do another procedure called cisternogram to find out leak, but I went for second opinion with another well known neurologist, who recommended MR with thoracolumbar spine which showed no leak. She is feeling well when she has food, but headache returns back. Now, doctor has suggested us to go for a blood patch which will plug the leak which cannot be diagnosed sometimes in MRI. I want your opinion regarding this which might be helpful

  2. Hello, I am a 29 yr old female. 13 weeks pregnant. Since 7 days ago my head decided to give me this crippling pain. When I sit down the back of my neck stiffens and when I stand up it goes so bad that I feel my head is draining and if I stand for too long I feel sick.
    my blood pressure and blood test and baby scan are all ok///
    how long will I suffer this? please help..

  3. What do you do when you have all the same symptoms but you didn’t have a lumbar puncture and it happened spontaneously, But no leak is showing on MR myelography? Do you still do an epidural blood patch? Is there anything else that could cause the exact same symptoms with a postural headache? I’m having severe downward pressure on my brain in the upright position. The brain MRI is normal and we can’t find a leak in the spinal MRI. What else can be done to find the cause?

  4. i am glad i fond this blog. i have so many of these sypmtoms i red about and wish i could get an answer. i am tired of being tired, having headaches feel likes an absess tooth, throbbing non stop. i am confused, dizzy, had different diagnosis. i can feel something is not right, but i am just the patient. since 2009 i started getting electric scocks inmy body, numbness in feet and leggs, ice cold, feel im wearing a too small shoe and sit in nd ice iver. my feet are heavy and feels like water running off my leg, but is not. i walk and feel i walk on glass. pain so bad and burning i cannot let my linen touch me, have to wear socks mosly. now so bad i can even touch it myself. my leggs stared swelling like balloons last 4 weeks. have chronic pulmonary emboli. trapeze filter. had strokes. brain scans i dont understand. high signal intensities plaques were again demonstrated in both cerebral hemisheres, predominantly lef. small ischaemic foci. my physician said he thinks i have white matter disease. i have bulbar palsy, chock in food, spitum, drink vomit. cant breath. start chocking then begin to hiccup, stuff come through nose and i think i am gonna die. thank you for answers to others, i am sure i am not crazy. and i d not forget, it does not exist. it is black, new when they talk about it. to me a cap is a cap, if it fits or not, same with a lid.i will pour water in coffee tin iso cup, its a container in my mind, no comprehension. my body feels numb all over like local anastetic. i burn without feeling. i put my hand in running boiling water but dont realise i must use cold tap, put it back under the boiling water tap. is this normal Dr
    i hadbad falls and since i have water coming out of my nose and sometimes out of my ear. when the pain get bad i feel it going in through my ear behind my eyes like a hand above from my neck vertebra

  5. Hello, I have headaches that began ~1 year ago, with seasonal allergies. Very positional, in that it was very severe when I went from standing to bending over & back upright, I’d have to lay down it was so painful. Kept thinking it was allergies & treating for that. Now the allergist is telling me no, it’s not allergies right now. For the last couple of weeks, headache has been nearly constant, severity varies but almost always there. Only full relief when I lay down. Imitrex was tried once, but didn’t seem to do much. Had an MRI, and can see a Chiari malformation, so that plus finding this blog post about pressure headaches, makes me wonder if the Chiari is causing low CSF pressure headache, or something similar? Pain is not in the back of my head/neck really, more in the front. Have had 2 episodes of worse headache, nausea & vomiting, but otherwise am not dizzy ever really. Desperate to figure out what’s going on so any advice/resources/info would be appreciated!

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