Imaging in headache patients “Incidentalomas” Giles Elrington Barts & The London

To scan or not to scan Scan everyone Safe? Reassuring? Selective scanning How selective? Scan no-one Not recommended!

Where is the disease? SYMPTOMS PATHOLOGY ABNORMAL TESTS

BASH guidelines 2007 “Investigations, including neuroimaging, do not contribute to the diagnosis of migraine or tension- type headache. Some experts, but not all, request brain MRI in patients newly diagnosed with cluster headache. There are no data on the rate of abnormal findings. Otherwise, investigations are indicated only when history or examination suggest headache is secondary to some other condition.”

IHS classification 2004 Primary headache… Is not attributed to another cause; i.e. History and physical examination do not suggest any of the disorders listed in groups 5-12 (i.e. secondary headache), or history and/or physical and/or neurological examinations do suggest such disorder but it is ruled out by appropriate investigations, or such disorder is present but attacks do not occur in close temporal relationship to the disorder

Demography of headache 95% have headache in their lifetime 75% have headache in any year 20% of women have migraine 4% have headache on most days

Serious cause for headache Primary care Neurology clinic Accident & emergency 0.1% 1% 10%

Three cases All normal to examine Male 80. 3/12 R facial pain. Longstanding headache. Female yr episodic headache better off COC, worse 4yr, continuous 1yr. Female 74. Few months right craniofacial pain, partial response NSAID.

Unenhanced CT overlooks important secondary headaches Early tumours Early stroke Giant cell arteritis Venous sinus thrombosis Subarachnoid haemorrhage Subdural haematoma Tonsillar ectopia Colloid cyst Parameningeal suppuration Medication overuse headache

Imaging urgent: red flags tumour risk>1% Papilloedema Significant change consciousness, memory, confusion, coordination New epileptic seizure New cluster headache Cancer elsewhere

Imaging low threshold: orange flags tumour risk 0.1-1% New headache undiagnosed >8weeks Significant neurological findings Headache worse exertion/Valsalva Headache with vomiting Changed or crescendo headache New headache pt over 50 yrs Headache waking from sleep

Imaging yellow flags tumour risk % Migraine or TTH Weakness or motor loss Memory loss Personality change

Incidentalomas Age 20 –n= 2389 –¼ not strictly normal –¾ of these = normal variants Age –n=2000 –⅛ significant abnormality

One of these six has no headache…which one is it?

MRI result may be harmful... Female age 38 Migraine with aura Medication overuse MRI arranged in primary care

Two recent cases…

Headache imaging (n=2488)

Headache imaging (n=4971)

Incidentalomas Morris et al BMJ 2009;339: Systematic review and meta-analysis of MRI brain scans of 19,559 ‘normal’ subjects Neoplastic, structural vascular, inflammatory lesions, cysts, other structural lesions. Excluded: ‘white matter hyperintensities’, silent infarcts, microbleeds LesionPrevalence %‘NNS’ Neoplasms Meningioma0.29 ( )345 Pit. Adenoma0.15 ( )667 Low grade glioma0.05 ( )2000 TOTAL0.7 ( )143 Other2.0 ( )50 TOTAL2.737

Imaging for headache A&E: –low threshold –CT > MRI –Don’t forget LP, ESR(CRP) Office practice: –higher threshold –MRI > CT

Imaging for all Covers your back Improves provider income May temporarily reduce most patients’ anxiety Emotion based Expensive Scan only as good as the report Longer waits disadvantage those in urgent need Creates precedent Diminishes non-imaged diagnoses Causes harm to minority

Selective imaging Evidence based Economical Places clinical diagnosis first Allows prioritisation Incomplete precision Litigation risk Reduces provider income

Headache imaging: conclusions Suggest selective imaging policy Acute presentation: CT (NB LP, ESR) Non-acute: MRI First scan: –Patient (emotion) led Subsequent scan: –Doctor (evidence) led