Cheryl presented with three months of daily headaches. She’d tried various combinations of over-the-counter painkillers, none of which had made the blindest bit of difference. It was getting ridiculous; she couldn’t go on like this; she had to have some help. As I listened to her opening remarks, it was clear that she’d been shouldering mounting anxiety and now that she’d finally decided to consult a doctor, it all came tumbling out in a rush of words.
This is a common scenario in general practice; one, furthermore, in which the subtitles to the consultation reel out a predictable script. Underlying the patient’s discourse is the dread that they have something sinister – a brain tumour – but they hardly dare voice the concern for fear it may, in fact, come true. For the doctor, knowing that brain tumours rarely occur with isolated headaches, the task is to draw out these anxieties into the open, so they can be addressed; and to establish the nature of the problem, which is usually something more prosaic.
In Cheryl’s case, it proved relatively easy to get to the nub of her concerns. She readily admitted that two relatives had suffered from brain tumours. She’d been living with these headaches, hoping they would pass, but as the weeks turned to months she had developed the near certainty that she was following in her unfortunate kin’s footsteps.
Now that her concerns were aired, I set about trying to establish the cause. Most headaches encountered in primary care are one of two types: tension headache or migraine. Tension headaches affect people at times of turmoil. Many of us sink our stresses into the muscles of our neck and shoulders, which gives rise to the pervasive pain of tension headache. A vicious circle ensues, with a growing fear as to the possibility of cancer aggravating the original stresses and compounding the physical symptoms. Cheryl was adamant, though: everything in her 21-year-old life was fine – a good job, happy relationships and no money worries.
I asked her about the features of migraine. There is usually a family history – there’s a genetic basis to the complaint – but no one in Cheryl’s family was a diagnosed migraineur. And migraines come with added “colour”. This might be vomiting, or transient paralysis of a limb, or a disturbance in vision – sometimes jagged lines in the visual field (fortification spectra) and sometimes the reversible loss of sight in one eye. Cheryl had none of these, but she did say that for the past few weeks her vision had been very blurred when she woke, though she said it became clearer as the morning wore on.
This piqued my attention. I asked more about the pattern of the headaches. They never woke her from sleep, she told me, but they were at their worst first thing, easing somewhat as the morning went on. Cheryl had noticed that the pain increased when she sneezed or leaned down to pick up something. These features suggested aggravation by postures or activities that cause a rise in the pressure in the head. Sinus congestion would be the commonest explanation, but Cheryl had no catarrhal symptoms. I then measured her height and weight, and put her body mass index (BMI) over 40. A healthy BMI lies between 18 and 25; anything over 35 indicates morbid obesity. Her blood pressure was normal, but an examination of the back of her eye showed papilloedema – blurring of the margins of the optic disc, which is the root of the nerve that takes the fibres from the retina back into the brain. Swelling of the disc indicates intracranial hypertension – that the fluid around the brain is under high pressure.
Intracranial hypertension is never an innocent finding and can indeed be a consequence of a brain tumour. I started to share some of Cheryl’s anxiety, but her age and her BMI pointed to a more perplexing cause. Idiopathic intracranial hypertension (IIH) was a mere footnote in the textbooks when I trained, but it is becoming ever more common with the obesity epidemic. It used to be considered benign but we now appreciate that, untreated, it can cause permanent damage to vision.
IIH affects young women with substantially raised BMIs. The term idiopathic means “no one knows the cause”. The mechanisms are still obscure, but some interaction between morbid obesity and the female hormone milieu results in chronically elevated pressure in the fluid around the brain and spinal cord (cerebrospinal fluid, or CSF). This in turn produces the pattern of headaches Cheryl was experiencing and, in more advanced cases, swelling of the optic disc, affecting eyesight.
I referred her urgently to a neurologist. A brain scan ruled out any tumour, and a lumbar puncture – inserting a needle into the space around the spinal cord – allowed relief of the elevated CSF pressure. Acetazolamide, a medication that slows production of cerebrospinal fluid, helps, but the only permanent resolution is with weight loss, which will take months. Once Cheryl attains a more normal BMI, the factors driving the rise in her CSF pressure will recede, curing the headaches and improving her health in many other ways besides.