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
ABNORMAL TESTS
PATHOLOGY
BASH guidelines 2007
“Investigations, including neuroimaging, do not
contribute to the diagnosis of migraine or tensiontype 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 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 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 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)
60
50
%
40
MR & CT
30
MR
CT
20
10
0
1
2
3
4
5
Year
6
7
8
Headache imaging 1994-2008
(n=4971)
60
50
%
40
%CT & MRI
30
% MRI
%CT
20
10
0
1992
1994 1996
1998
2000 2002
Year
2004
2006 2008
2010
Incidentalomas
Morris 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