The severe headache emergency – part 2
So you have been called to attend to a young lady complaining of severe headache. She has photophobia and is lying in bed in her darkened room. She has a history of migraine and has episodes like this before. Her pain is severe and has been unrelieved now, despite her doctor instructed self care plan, for several hours.
In your assessment you have decided to exclude more serious causes of headache before moving on to agreeing with her diagnosis of migraine. Though migraine is a bad enough problem in its own right, it isn’t as bad as a couple of other more sinister problems that can present similarly. You have considered and discounted stroke so far, including the life threatening subarachnoid haemorrhage.
The other serious cause of headache to consider is infection. Infection of the meninges or of the brain itself can lead to significant patient deterioration and poor outcome. Diseases such as meningitis or encephalitis are not common but always of concern. Management and outcome can depend on the underlying infection cause.
Infective cause headache may be similar to some of the stroke presentations. The headache can vary in severity. Consciousness may be impaired both through delirium or impaired brain function ranging from confusion to unconsciousness. Fever may be seen but this becomes less reliable in the elderly and sometimes in children. Nausea, vomiting, photophobia, neurological deficits and even seizures can all accompany the progression of infection on normal brain function.
It must always be remembered that if the patient is suspected of having meningeal infection, it could be caused a meningococcal bacteria. Once systemic, the patient could present with the highly infectious meningococcal septicaemia. There are three stand out implications to this. Firstly, the infectious nature dictates being safe with personal protection items including respiratory masks and eyewear. This is particularly so when performing airway procedures. Secondly, a broad spectrum antibiotic such as ceftriaxone is best administered as early as practicable. Thirdly, anticipate rapid patient deterioration and transport without delay.
The classic triad when assessing for meningeal infection is meningism. This is photophobia and headache accompanied by an inability of the patient to be able to flex their head forward because of neck muscle spasm. You can ask the patient to try to put their chin onto their chest if they can. This latter feature is nuchal rigidity. Meningism can be a good indicator of meningitis. However as it only indicates irritated meninges, it can also be observed in subarachnoid haemorrhage. In either case it is a serious finding. Other signs assessed for when considering meningeal infection are Kernig’s and Brudzinski’s signs. Both involve abnormal movement and reflexes of the legs in particular during assessment. However none of these assessment findings are absolutely reliable or definitive in diagnosis. For meningitis diagnosis, lumbar puncture is required. This makes prehospital differentiation of any combination of these findings in the patient with headache.15,16,17
Photophobia, not a fear of course but a strong sensitivity or even painful sensation caused by light, is not well understood. It appears in a number of conditions so is significant but not specific. It is common with migraine presentations and is likely due to stimulation of the trigeminal nerve given that this is a main mediator of head pain.18 This makes it also a finding with subarachnoid haemorrhage along with several other problems including tumour. Once again, it is an important finding but not definitive in diagnosis. Meningitis is a true neurological emergency that requires rapid diagnosis and antimicrobial or antiviral therapy as appropriate.
But we digress completely. Our patient does have a severe headache and is complaining of photophobia. She does not have fever or the other signs of meningism. The two major threats of subarachnoid haemorrhage and meningitis are possible causes but not stand out for suspicion. However the patient has told you about a long history of suffering migraines. She has a number of them every year with them sometimes lasting for more than a day. This presentation is pretty much the same as on other occasions. She normally manages her migraine herself. It is time to start considering the problem of migraine.
15. Accuracy of physical signs for detecting meningitis: A hospital-based diagnostic accuracy study Swati Waghdhare, Ashwini Kalantri, Rajnish Joshi, Shriprakash Kalantri Clinical Neurology and Neurosurgery 2010;112(9): pp 752–757
16. Diagnostic Accuracy of Clinical Symptoms and Signs in Children With Meningitis Amarilyo, Gil; Alper, Arik; Ben-Tov, Amir; Grisaru-Soen, Galia Pediatric Emergency Care: March 2011; 27(3): pp196-199
17. Bacterial meningitis. Heckenberg SG, Brouwer MC, van de Beek D. Handbook of Clinical Neurology 2014, 121:1361-1375