The
question arose in rounds today about the utility of repeat imaging for patients
with persistence of headache after minor headache and initial negative head
CT. The case presented was of a woman
initially seen after a motor vehicle collision. Her CT head was negative, but
she had persistent headache. When her
headache worsened approximately three weeks after the initial injury, we were
prompted to re-scan her. However, we
sought to investigate if data or protocols would suggest that a patient with
persistent (but not escalating) headache be scanned purely for duration of
symptoms.
Posttraumatic
headache (PTH) is defined as a secondary headache. ICD-9 diagnostic criteria state that there be
a temporal relation to head injury and that headache develop within seven days
of the injury. However, it has been
reported in combat data that only as many as 27% may actually start outside the
seven day window (1). PTH is common,
with a reported prevalence of close to 30-40%.
Symptoms can last as long as three months to a year or longer. The estimated prevalence of PTH still present
at one year is estimated at 18-22% (1).
To
our review, the literature of a related disease process, that of concussion,
has little formal data to address our clinical question directly. In PTH and concussion, initial neuroimaging
is typically negative and the diagnosis is clinical (2). Most authors, including the Second
International Conference on Concussion in Sport acknowledge that repeat imaging
should be undertaken if there is a suspicion for an intracranial lesion and
offer disturbance of conscious state, focal neurologic deficit, or worsening
symptoms as a trigger (3). For
persistence of symptoms, MRI appears to be the preferred modality – functional
MRI shows promise for defining concussion injury and diffusion weighted imaging
on MRI is particularly sensitive for shear injury, a main component of the
pathophysiology of concussion (4). The
timing for these repeat imaging studies is not well-defined in the
literature. However, in personal
communication with concussion specialists, it seems that general practice
patterns suggests that repeat imaging is undertaken at 2-3 weeks post injury
with persistent symptoms.
In
terms of treatment, most episodes of PTH are treated with standard over the
counter medications. Some sources
recommend no ibuprofen or aspirin in the first 24 hours for the risk of
bleeding (2, 5). With persistence of
symptoms, triptans have shown promise in treating persistent PTH (1).
2 – Bracker MD, ed.
The 5-Minute Sports Medicine
Consult, 2nd ed.
Lippincott Williams and Wilkins, Philadelphia. 2011.
3 – McCrory P et al. Summary and agreement statement of
the 2nd International Conference on Concussion in Sport, Prague 2004. Br J
Sports Med. 2005 Apr;39(4):196-204.
4 – Pulsipher DT, et al. A critical review of neuroimaging
applications in sports concussion. Curr Sports Med Rep. 2011
Jan-Feb;10(1):14-20.
5 – Vargas BB, Dodick DW. Posttraumatic headache. Curr
Opin Neurol. 2012 Jun;25(3):284-9.
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