Imaging in headache patients“Incidentalomas”

Giles Elrington

Barts & The London

elrington@aol.com

To scan or not to scan

Scan everyone• Safe?• Reassuring?

Selective scanning• How selective?

Scan no-one• Not recommended!

Where is the disease?

SYMPTOMS

PATHOLOGYABNORMAL 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 2004Primary 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 casesAll normal to examine

• Male 80. 3/12 R facial pain. Longstanding headache.

• Female 47. 30 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 flagstumour risk>1%

• Papilloedema

• Significant change consciousness, memory, confusion, coordination

• New epileptic seizure

• New cluster headache

• Cancer elsewhere

Imaging low threshold: orange flagstumour 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 flagstumour risk 0.01-0.1%

• 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 45-97– 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 1994-2001 (n=2488)

0

10

20

30

40

50

60

1 2 3 4 5 6 7 8

Year

%

MR & CT

MR

CT

Headache imaging 1994-2008 (n=4971)

0

10

20

30

40

50

60

1992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Year

%

%CT & MRI

% MRI

%CT

IncidentalomasMorris et al BMJ 2009;339:547-550

• 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

Lesion Prevalence % ‘NNS’

Neoplasms

Meningioma 0.29 (0.13-0.51) 345

Pit. Adenoma 0.15 (0.09-0.22) 667

Low grade glioma 0.05 (0.02-0.09) 2000

TOTAL 0.7 (0.47-0.98) 143

Other 2.0 (1.13-3.10) 50

TOTAL 2.7 37

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