Adult chickenpox: risk factors and management
GPs often have to decide whether a headache may be symptomatic of a serious condition requiring further investigation Dr Sean Kavanagh advises how good history taking is crucial to the process of elimination
Dr Sean Kavanagh advises how good history taking is crucial to the process of elimination
Mr P, a 35-year-old panel-beater, saw his GP, Dr S, as he'd developed sudden headache and neck pain while bending down to pick up a screwdriver. Dr S found Mr P's BP to be 150/88mmHg and recorded
'CNS clinically NAD'.
Dr S found some slight neck tenderness over C6-C7 and sent Mr P for a cervical spine X-ray and advised him to see an optician. Presumably, this was because Mr P had complained of visual symptoms, but Dr S kept no record of this. Mr P's
X-ray was unremarkable.
Mr P went to his optician, who found no ocular abnormality. Mr P's headache persisted and two weeks later he went to A&E. He gave a history of two weeks of severe headache with vomiting, photophobia and diplopia. It had started suddenly, with a further acute exacerbation prompting his attendance at A&E.
The pain was described as sharp and located in the occipital area, graded 10/10 for severity. Shortly after the worsening of his headache, Mr P had experienced unusual olfactory perceptions, then had a witnessed blackout.
From his wife's description, this was probably a generalised seizure. Mr P had no focal neurological signs.
The A&E doctor arranged an urgent CT scan which revealed evidence of a subarachnoid bleed, probably from the right middle cerebral artery. The next day Mr P was about to undergo cerebral angiography when he suddenly deteriorated and developed a left hemiparesis. Repeat CT revealed a substantial re-bleed and he was operated on as an emergency, undergoing craniotomy, clot evacuation and clipping of his aneurysmal right middle cerebral artery. Mr P was left with a disabling left-sided paralysis and epilepsy.
Mr P started legal proceedings against Dr S alleging negligence in that he had failed to consider the possibility of subarachnoid haemorrhage or refer for further investigations or follow-up. Dr S denied that he had been given any history of diplopia. However, he had asked Mr P to see an optician, and Mr P had given a very clear account of these symptoms in A&E, present from the start of his headache.
The Medical Protection Society settled the claim out of court for a sum equivalent to £500,000.
Told headache, think history
A GP expert brought in to look at the above case expressed concern at the lack of historical detail about associated symptoms that would raise the index of suspicion for subarachnoid haemorrhage.
It was felt that formal inquiry about nausea, photophobia and visual symptoms, recorded in the notes, represented the standard of reasonable care that would be expected by a responsible body of GPs.
The expert pointed out that the diagnosis is made largely on the basis of the history and that 'Dr S had not taken a sufficiently adequate history to rule out a vascular cause, which is necessary when there is a history of a sudden onset of headache'.
Dr S pointed out that he had considered the diagnosis but not seriously entertained it. The expert advised that: 'If Dr S considered the diagnosis, he should have sent the patient in.'
Neurosurgical opinion had some sympathy with Dr S, noting that some features of the history were atypical, but felt that the combination of sudden headache, neck pain and diplopia should have raised Dr S's suspicion of the diagnosis.
Had referral and surgery been carried out at first presentation, it was likely that Mr P would have escaped significant disability.
Lessons to be learned
Subarachnoid haemorrhage can be a difficult diagnosis to make. Where there is a history of a sudden headache, particularly if it is occipital and there is associated neck pain, it is wise to maintain a high index of suspicion for the diagnosis.
If there is any suspicion of the diagnosis in a primary care setting, you should have a very low threshold for referral for further assessment.
Careful documentation of the presence or absence of associated symptoms of meningism and other neurological symptoms is recommended when assessing acute headaches.
With a herald bleed, there will often be no neurological signs.
When a previously fit patient complains of a 'first and worst' acute headache, subarachnoid haemorrhage should feature prominently in your differential diagnosis.
Avoiding other headache pitfalls
Headache is a common symptom in primary and secondary care. The list of differential diagnoses numbers several hundred. Most are benign, but there are conditions it is imperative not to miss.
A useful template for taking a history in headache sufferers can be found at www.bash.org.uk (British Association for the Study of Headache's website). The history needn't be overly detailed, depending on one's confidence in this field. It is important to establish the nature of the headache's onset and whether or not this type of headache is novel to the patient. At a minimum, one should ascertain the standard 'sieve' of information relating to the nature, site, character and aggravating/relieving factors of the pain. Useful associated features to ask about include photophobia, nausea, syncope, seizures and visual symptoms.
The crucial thing is to assess the overall combination of symptoms and signs and come to the most likely diagnosis, with the 'not to miss' causes kept high in the differential list.
Often, intuition based on experience brings the clinician to the correct cause. A good rule to follow, if you feel you lack the pertinent expertise, is to ask yourself if any of the conditions in the 'not to miss' list (particularly the common ones) could possibly be to blame, referring the patient to a specialist if
the answer is 'yes'.
Sean Kavangh is clinical author for the Medical Protection Society
Causes of acute headache not to miss
Relatively common conditions
·Stroke haemorrhagic and ischaemic
·Meningitis and encephalitis
·Giant cell (temporal) arteritis
·Primary angle-closure glaucoma
Less common conditions
·Idiopathic intracranial hypertension (formerly benign intracranial hypertension/pseudotumour cerebri)
·Sub-acute carbon monoxide toxicity
·Dural tap or tear
·Cerebral venous/dural sinus thrombosis
·Mass lesions presenting acutely tumour, abscess,
parameningeal infection, intracranial haematoma of parenchymal, subdural or epidural types