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NEUROLOGY JOURNAL CLUB KSHITIJA KARI, MD PGY-III

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NEUROLOGY JOURNAL CLUB

KSHITIJA KARI, MD

PGY-III

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INTRODUCTION Which patients with headache disorders should undergo

neuroimaging?

UK & USA guidelines (National Institute for Health, American

Academy of Neurology) suggest selective policy for imaging as

prevalence of significant findings is low

High referral rate leads to increased discovery of

incidental findings on imaging

However, clinicians continue to refer such patients for

imaging for reassurance and patient satisfaction

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STUDY DESIGN Single center, prospective observational study over a

period of 5 years

Birmingham Headache Service

Outpatient consultation service

3 consultants

1 diagnostic headache nurse specialist

• Imaging performed in the same hospital and reported

by general radiologists.

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METHODS Patients referred to outpatient consultation service.

The nurse takes a headache and general medical history and performs a neurological exam.

Diagnosis based on ICHD-2 classification (International

Classification of Headache Disorders).

50% of new patients discussed with consultants regarding imaging.

Guidance for general practitioners on imaging in headache (Imaging patients with suspected brain tumor: guidance for primary care. Kernick DP, Br J

Gen Pract 2008).

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METHODSUrgent imaging ‘red flags’:

• raised intra cranial pressure

• focal neurological signs• epilepsy• cognitive disturbance• recent diagnosis of

cancer

Routine imaging ‘orange/yellow flags’:

• recent headache, change in character

• no diagnostic pattern, wakes from sleep

• Precipitated by coughing, straining, etc.

• hemiplegic migraine, cluster headache

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Significant abnormalities:

1º or 2º brain tumor

Chiari abnormality

Insignificant abnormalities:

Arachnoid cyst

cerebrovascular disease

white matter abnormalities

Normal findings.

METHODS

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RESULTS

• Aug 2004 – July 2009, 3655 new patients seen

• 69% female, mean age 42yrs

• 56% white, 34% Asian and 11% Afro-Caribbean

• Total of 530 of the 3655 patients were referred for

imaging

• Differences in proportion of patients imaged by the

3 consultants

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RESULTS530 Patients

Imaged

304 patients had MRI

9 significant

140 insignificant

155 normal

226 patients had CT scan

2 significant

63 insignificant

161 normal

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RESULTS Total 11 significant abnormalities (2.1%)

6 brain tumors:

4 clinically suspected

2 not suspected

167 Migraine patients imaged:

2 significant abnormalities (1.2%)

212 tension type headache:

2 significant abnormalities (0.9%)

55 Intracranial abnormalities:

3 significant abnormalities (5.5%)

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DISCUSSION 530 Headache patients with worrying features only

2.1% significant abnormalities.

Study showed more significant abnormalities with MRI compared with CT.

Selection of MRI over CT- reduce radiation exposure dose, better imaging quality, more sensitive

However, do not know if patients who were not imaged had any significant intracranial pathology

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OTHER STUDIES Meta-analysis of 11 studies of imaging migraine patients

with normal neuro exam & no red flags - 0.18% [1]

2 studies in tension-type headache - 83 pts. [1]

Spanish study: 1876 patients p/w non acute headache 1.2% (0.4% migraine & 0.8% tension) significant abnormalities. [2]

Meta-analysis of 16 studies of MRI in 19,559 normal people found 0.7% neoplastic & 2.0% of non-neoplastic incidental findings. [3]

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So, prevalence of significant findings in migraine

and tension headache is similar to that in normal

individuals.

MRI showed more frequent insignificant and

incidental findings in this study (occult CV disease).

Already worried patients may deteriorate if told of

such coincidental findings.

DISCUSSION

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Number of patients referred for imaging fell from 35%

to 13.5% the following year after results were

disclosed.

Feedback had an effect on consultants, as proportion

of patients imaged lowered than at the outset.

Excluding cases with known pre-existing pathology

and with unrelated pathology (meningioma, pineal

tumor) reduces incidence to 1.1% (Spanish-1.2%).

DISCUSSION

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Discussion Question

Can you think of any problems generalizing these

results to the population we serve?

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CONCLUSION

The study supports current UK and American

guidelines in advising the selective use of

neuroimaging in small proportion of headache pts

with sinister features either in history, exam or other

investigations.

The proportion of headache patients imaged by

consultants can be reduced by giving feed back on

data on their rate of imaging and its sensitivity.

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Thank YouDr. B. DesaiDr. A. AcharyaDr. N. NelsonDr. A. HaefnerDr. M. Do

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References References:

[1] The utility of Neuroimaging in the evaluation of headache in patients with

normal neurological examinations. American Academy of Neurology 2008

[2] Neurimaging in the evaluation of patients with non-acute headache.

Sempere AP, et al, Cephalalgia 2005

[3] Incidential findings on brain magnetic resonance imaging:systematic

review and meta-analysis. Morris Z, et al, BMJ 2009