Day 260 - Intracranial Hypertension

“In the 1890s, a German physician named Heinrich Quincke coined the term “pseudotumor cerebri” to describe a neurological disorder which he believed had all the symptoms of a brain tumor, but without the presence of an actual tumor. The “false brain tumor” that Quincke identified more than a century ago is known today as idiopathic intracranial hypertension (IIH).

There are two forms of chronic intracranial hypertension: idiopathic intracranial hypertension (IIH), whereby there is no identifiable cause that triggers the raised intracranial pressure, and secondary intracranial hypertension, which, in contrast to IIH, always has an identifiable cause (such as a head trauma, an underlying disease, a reaction to a certain drug). Intracranial hypertension literally means that the pressure of cerebrospinal fluid (CSF) within the skull is too high. “Intracranial” means “within the skull.” “Hypertension” means “high fluid pressure.”

Cerebrospinal fluid is one of three major components inside the skull; the other two are the blood supply that the brain requires to function and the brain itself. Under normal circumstances, these components work together in a delicate balance. Since the skull is made of bone and cannot expand, an increase in the volume of any one component is at the expense of the other two components. For example, if the brain swells and becomes enlarged, it simultaneously compresses blood vessels, causing the sub-arachnoid space to fill with more spinal fluid. This results in an increase in intracranial pressure (i.e. cerebrospinal fluid pressure), as well as a decrease in blood flow.

CSF has several important functions. It cushions the brain within the skull, transports nutrients to brain tissue and carries waste away. CSF is produced at a site within the brain called the choroid plexus, which generates about 400-500 ml. (one pint) of the fluid each day.

Chronic IH can cause both rapid and progressive changes in vision. Vision loss and blindness due to chronic IH are usually related to optic nerve swelling (papilledema), which is caused by high CSF pressure on the nerve and its blood supply. In addition, individuals with this disorder often suffer severe pain. The most common form is a chronic headache, which is generally unresponsive to the most potent pain medication.”*

*http://www.ihrfoundation.org/intracranial/hypertension/info/C16

As I type this post, my headache is surprisingly ‘good’. About 2/10 - excellent news! Hopefully by the end of the post it won’t have increased, given its moody temper.

Lately I have been trying to find out why my headache hurts much more the second I lie down (whether during the day or at night) - so far I have only come across one other person (on a forum) whose headache also worsens when lying down. He doesn’t know why this happens either, but he strongly suggested placing corn bags on my head at night. He explained that he has found some relief from wrapping very cold corn bags around his head, having left the bag in the fridge all day long.

A number of people have told me to look at Intracranial Hypertension, as apparently those who are afflicted with this illness also have a stronger headache when lying down.

Curiously, Intracranial Hypertension was first documented in the sixteenth century by a Dutch explorer, Gerrit de Veer, who identified the toxic effects of polar bear liver on early Artic explorers. Several men in his expedition developed secondary intracranial hypertension (SIH) and nearly died after consuming polar bear liver, which contains lethal levels of Vitamin A. Excessive ingestion of vitamin A is now a recognized SIH cause (no doubt children will be delighted to hear this).

When looking at the possibility of having Idiopathic Intracranial Hypertension, one must:

a) have signs and symptoms of increased intracranial pressure, such as papilledema and headache;
b) have no localizing findings on neurological examination (Localizing findings are findings that point to injury of specific brain areas. For instance, a localizing finding could be the inability to move a certain muscle.);
c) have a normal MRI/CT scan with no evidence of venous obstructive disease;

d) have high intracranial pressure of 250mm/H2O or above on a spinal tap, with no abnormalities of cerebrospinal fluid;

e) be awake and alert;

f) have no other cause of increased intracranial pressure found.

I can safely tick all of these but two (namely d and f, as I have not had either of these examined as yet).

Given that my unmitigated headache still remains a bit of a mystery to all, it could be an idea to also look into this condition. Just the thought of returning to my GP grates me - the fact that I have to re-explain everything from scratch pretty much every time is tedious enough, but more than anything what I find frustrating is that I know that deep down many of these doctors just think that I am a hypochondriac. If only they knew.