How to Diagnose Acute HeadacheAcute Headache accounts for about 3-8% of emergency room attendances, and for about 3% of emergency admissions to an acute medical ward.As a neurologist working in an acute general hospital I would see about 1-2 acute headache cases each week - about 100 per annum. In my own practice, the Headache Diagnosis in Hospitalised People is serious in about 6-8% of cases. Non-serious secondary headache accounts for about 25%, and primary headaches still account for over 60% of hospitalised headache diagnoses. Almost everyone will experience head pain at some point in their lives, as evidenced by studies of headache epidemiology. Epidemiology is the who, what and where of medical practice. Here's a guide on how make a headache diagnosis and sort out the serious from non-serious causes of acute headache. It is based upon a I gave to a Royal College of Physicians of Edinburgh Up-Date Meeting in 2008, 2009, and remains current for 2011. There are 5 steps to successful headache management which are discussed in detail below:
Step 1: Which acute headache category is it?When assessing the person with a headache emergency, it is important to realise that there are about 5 different categories of headache that present as an emergency.
About 15% of our acute headache cases have this abrupt onset of severe headache. Most people report onset to maximal headache within 2 seconds. About 15% of our acute cases have this. About 22% of our survey had this type of headache and the focal symptoms included: This was 19% of our own survey in our acute medical admissions unit, and is probably the hardest one to get right. 28% of our acute headache admissions had this type, and almost all will have a diagnosis of migraine at discharge. These 5 categories form the basis of your acute headache differential diagnosis. Once you have worked out which category you are in you are in a position to start your clinical neurological examination. In surveys in my own hospital, we found that only a minority of headaches presenting to A&E were subject to brain imaging (8%). 77% of those who did triage through to the Medical Admissions Unit had a CT Brain. In fact only 11% had no investigations once they reached the medical admissions unit, which proves the point that these cases are difficult and in the face of clinical uncertainty investigation can be helpful. Step 2: Perform a Quick Neurological ExaminationI have devised a quick screening examination - Forbes Quick Neurological Examination.In addition to the actions mentioned in the video, look for meningism and check for a Horner's Syndrome. It goes without saying that you have recored the vital signs of temperature, pulse rate, blood pressure and respiratory rate. If there is altered consciousness a Glasgow Coma Scale should be recorded too. Please download a pdf summary of Forbes Quick Neuro Exam here If you adopt it into your practice, please make sure you acknowledge this source!
Step 3: Make a Differential DiagnosisThe differential diagnosis is a term to describe the range of likely diagnoses that could explain the symptoms experienced by the headache sufferer.The differential diagnosis for each of the 5 categories in Step 1 is slightly different. Here are the options with the most common first, least common last:
These cases should have a CT Brain and Lumbar Puncture as a minimum. Recent literature suggests that MR angiography may also be helpful, but should only be interpreted by appropriately trained radiologists. The most reliable studies suggest that about 10% of thunderclap headache presenting to a general hospital will be due to subarachnoid haemorrhage. A CT performed within 12 hours has 98-99% sensitivity for detection of haemorrhage. If there is residual doubt, do a lumbar puncture, measure opening pressure and analyse for blood breakdown products ("xanthochromia") a minimum of 12 hours after the initial headache. Remember to protect CSF specimens from light if you are testing for xanthochromia. You can only diagnose this if other causes have been excluded. A CT Brain, LP and ECG are essential. Remember that there are known causes of Headache During Sex, and that treatment of sexual activity headaches is usually possible. This can either be a thunderclap headache caused by acute myocardial infarction, or an exercise induced headache more like angina, but with headache instead of chest pain. Aortic Dissection can also, very rarely, present with an acute headache. This is a rare cause of thunderclap headache, so always perform an ECG. There are very few cases of this reported in the medical literature. These can also present as an acute headache, and the provoking stimulus will be elicited from the history. These will still require CT brain as a minimum investigation. This form of stroke can present with a thunderclap headache too. Usually it is acute headache and loss of balance with vomiting. This usually presents with unilateral headache and a Horners Syndrome of a stroke associated with a unilateral headache. Thunderclap Headache can also occur. Always remember to start treatment for Temporal Arteritis with steroids while awaiting your temporal artery biopsy. The ESR and patients age are usually both greater than 50 (mm or years)! Intracranial Hypotension Diagnosis will require knowledge the criteria used by experts in the field. Many people will get better spontaneously, the mainstay of Intracranial Hypotension Treatment is the epidural blood patch procedure. A diagnosis of intracranial hypotension should always be sought if a CT Brain shows evidence of a Subdural Haematoma in a person who presents with Thunderclap Headache, postural headache or an exertional headache. This usually presents with a fairly longstanding headache, but cases that present acutely can be at an increased risk of visual loss and early neuro-ophthalmology input is advisable. This rare sinus problem accounts for <3% of sinusitis. It can present with a bad dull ache anywhere in the head that is severe, often worse at night or worse with changes in posture. Some unusual headache disorders can present acutely, causing other symptoms in addition to an acute headache: Sometimes called Occipital Neuralgia, but is a cause of severe pain in the side of the head. It is due to cervical spine facet joint disease which refers pain to the trigeminal nerve territory via trigemino-cervical pathways. You can read about management of common headache disorders in this Headache Guide. Step 4: Arrange Appropriate InvestigationsMost people with an acute headache that is not obviously a migraine headache, systemic illness headache, temporal arteritis nor cervicogenic headache will require a brain scan.A CT Brain Scan is usually sufficient, but there are some pitfalls for the unwary. Subarachnoid haemorrhage can be difficult to see if patient presents late or has a small amount of blood. Venous sinus thrombosis can also be overlooked if special attention is not paid to the venous drainage system of the head. There may be rare cases where an MRI Brain Scan is preferable, but MRI needs to be used intelligently, as it is a complex test to set up and perform. About 30% of people with acute headache will require a lumbar puncture procedure. This is usually to rule out haemorrhage by testing for xanthochromia, but is also needed to rule out high or low intracranial pressure and the presence or absence of infection. Detailed knowledge of a Lumbar Puncture Procedure is a core skill for any doctor practising emergency medicine. You can access the Lumbar Puncture Section from the Severe Headache Expert Home Page or the menu top left. A poorly performed LP can be a cause of significant patient discomfort and could yield misleading results. Step 5: Make a Final Headache Diagnosis and Complete TreatmentBased upon data from my own practice, the most common emergency headache diagnoses are primary headache disorders, such as migraine.About 25% of cases had a non-serious secondary headache associated with infection - so called systemic illness headache. Only 6% of acute headaches that were admitted to hospital had a life-threatening cause, including subdural haematoma, subarachnoid haemorrhage and venous sinus thrombosis. The treatment will depend upon your final headache diagnosis.
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NEW SURVEY: September 2011
What Colour is your Headache?
