A 56-year-old woman comes to the emergency department due to a severe headache that has not responded to over-the-counter analgesics. The pain is generalized; it began 8 hours ago and worsened rapidly over several minutes. The patient has also experienced photophobia and an episode of vomiting, and she now describes vague discomfort in her neck and back. She has had tension headaches before, but they were not as severe. She has hypertension and takes lisinopril. The patient does not use tobacco, alcohol, or recreational drugs. She is an architect and reports high stress due to a large new project. Temperature is 37.3 C (99.1 F), blood pressure is 150/84 mm Hg, pulse is 94/min and regular, and respirations are 16/min. Pulse oximetry shows 98% on room air. The pupils are equal and reactive. Extraocular movements and funduscopy are normal. Neck stiffness is noted, but muscle strength, deep tendon reflexes, and sensation are normal in the bilateral upper and lower extremities. Downgoing plantar reflexes are present bilaterally. The remainder of the examination shows no abnormalities. Noncontrast CT scan of the head is normal. Which of the following is the best next step in management of this patient?
Clinical features of subarachnoid hemorrhage | |
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LOC = loss of consciousness; SAH = subarachnoid hemorrhage. | |
This patient has a sudden-onset, severe headache associated with photophobia, vomiting, and meningismus, suggesting subarachnoid hemorrhage (SAH). SAH is most commonly caused by rupture of an arterial berry (saccular) aneurysm and often results in a thunderclap headache, which is a sudden, severe pain reaching maximal intensity within seconds to minutes (as in this patient). Many patients describe it as "the worst headache of my life" or different from their usual headaches (eg, more intense, not responsive to typical medications). Nausea, vomiting, brief loss of consciousness, and other signs of meningeal irritation (eg, neck stiffness, often accompanied by back pain) are common.
SAH has high morbidity and mortality. Patients with thunderclap headache should undergo urgent noncontrast CT scan of the head, which may show blood in the basal cistern and cerebral sulci. CT scan is very sensitive for diagnosing SAH in the first few hours (~6 hr); however, minor bleeding and degradation of blood over time reduce its accuracy. Therefore, if CT scan results are negative, lumbar puncture (LP) should be performed in all patients with symptoms concerning for SAH (like this patient). LP findings in SAH include elevated opening pressure, xanthochromia (yellow or pink discoloration of cerebrospinal fluid due to hemoglobin breakdown), and a high red blood cell count that does not decline from the first collection tube to the last.
(Choice B) An MRI of the brain has similar sensitivity to CT for detecting SAH, so it is not a useful study after a negative CT scan. Performing an MRI would also delay LP, which should be done urgently to prevent morbidity and mortality from SAH.
(Choice C) Inhaled oxygen is the treatment for cluster headaches, which present as unilateral, stabbing periorbital pain associated with ptosis, lacrimation, or rhinorrhea (not seen in this patient).
(Choice D) Nonsteroidal anti-inflammatory drugs are used for tension headaches (bilateral, bandlike pain); although associated with stress, tension headaches are usually gradual in onset and only moderately painful. This patient requires LP to rule out SAH prior to trying other headache treatments.
(Choice E) Triptans (eg, sumatriptan) are abortive therapy for migraine headaches, which can cause photophobia and nausea. However, migraines are usually characterized by unilateral, throbbing pain. In addition, a first-time migraine in a patient age >50 is a red flag that should raise suspicion for a more serious intracranial process.
Educational objective:
Subarachnoid hemorrhage results in sudden-onset, severe headache with nausea and/or vomiting and other signs of meningeal irritation. Patients should be evaluated with urgent noncontrast CT scan of the head; if results are negative and a high suspicion for SAH remains, lumbar puncture should be performed.