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TRANSCRIPT
NEUROLOGY JOURNAL CLUB
KSHITIJA KARI, MD
PGY-III
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
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.
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).
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
Significant abnormalities:
1º or 2º brain tumor
Chiari abnormality
Insignificant abnormalities:
Arachnoid cyst
cerebrovascular disease
white matter abnormalities
Normal findings.
METHODS
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
RESULTS530 Patients
Imaged
304 patients had MRI
9 significant
140 insignificant
155 normal
226 patients had CT scan
2 significant
63 insignificant
161 normal
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%)
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
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]
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
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
Discussion Question
Can you think of any problems generalizing these
results to the population we serve?
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.
Thank YouDr. B. DesaiDr. A. AcharyaDr. N. NelsonDr. A. HaefnerDr. M. Do
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