Do I Need a Lumbar Puncture for Hemicrania Continua?

If your doctor suspects you have hemicrania continua, you do not automatically need a lumbar puncture (spinal tap). For the vast majority of people with typical hemicrania continua, a lumbar puncture is neither routine nor required to make a diagnosis ^[1][2]. Instead, doctors diagnose this condition based on your specific symptoms, a supervised trial of a specific medication, and brain imaging ^[1][3].

A lumbar puncture is generally only considered if there are unusual warning signs that suggest your headache is a “secondary headache”—meaning it is caused by an underlying infection, inflammation, or abnormal spinal fluid pressure ^[2].

How is Hemicrania Continua Typically Diagnosed?

Hemicrania continua is diagnosed clinically, meaning your doctor relies heavily on your medical history and an exam rather than a specific lab test or spinal tap ^[2]. The defining features of the condition include:

• Continuous, one-sided pain: Unrelenting background pain on one side of the head that has been present for at least three months, without switching sides, accompanied by periods of severe pain spikes ^[1][4].
• Autonomic symptoms: Symptoms during severe pain flares such as eye tearing, nasal congestion, or drooping eyelid on the same side as the pain ^[4][5].
• The Indomethacin Trial: Hemicrania continua is unique in that it must completely respond to indomethacin, a prescription nonsteroidal anti-inflammatory drug (NSAID) ^[1]. Do not attempt this trial on your own. A doctor must supervise the trial and individualized dosing, as indomethacin carries risks for stomach bleeding, kidney problems, and drug interactions ^[1]. If therapeutic doses completely eliminate your headache, this strongly supports the diagnosis, but it does not completely rule out secondary causes ^[1][6].

Even with a complete response to indomethacin, doctors still recommend brain imaging, such as an MRI (often with contrast or specific vascular views), to rule out mimics ^[3][6]. Structural or vascular issues (like tumors or blood vessel abnormalities) can mimic hemicrania continua and sometimes even respond to indomethacin ^[6][7].

When Might a Lumbar Puncture Be Necessary?

If your doctor recommends a lumbar puncture, it means they suspect an underlying medical condition rather than primary hemicrania continua ^[2]. The timing of a lumbar puncture depends on your symptoms—in an emergency, it may be done quickly (often after a CT scan to ensure it is safe), while in non-emergencies it is usually considered after an MRI.

Situations where a lumbar puncture may be necessary include:

• Suspected Infection: If you have a fever, neck stiffness, confusion, or a rapidly changing headache pattern, doctors may need to test your cerebrospinal fluid (the fluid surrounding your brain and spinal cord) for infections like meningitis or encephalitis ^[8][9].
• Abnormal Spinal Fluid Pressure: Some conditions cause abnormally high intracranial pressure. A lumbar puncture allows doctors to measure the “opening pressure.” However, if a low-pressure headache (like a spinal fluid leak) is suspected, a lumbar puncture is usually avoided as it can make the leak worse ^[10][11].
• Nerve or Inflammatory Issues: If you develop new neurological symptoms alongside your headache, a spinal tap can help check for inflammatory conditions in the nervous system ^[12].

Emergency Warning Signs (Red Flags)

Seek immediate emergency medical care if you experience any of the following, as they require urgent evaluation (and sometimes an urgent lumbar puncture) rather than waiting for an outpatient appointment ^[13]:

• A sudden, severe “thunderclap” headache
• Fever accompanied by a stiff neck, confusion, or altered mental status
• New neurological symptoms, such as sudden drooping eyelid, double vision, weakness, numbness, or trouble speaking
• Significant changes in your vision

(Note: New double vision or a drooping eyelid can signal an aneurysm or other vascular emergency. A prompt neurological or eye exam and specialized imaging are typically the first steps, rather than a routine spinal tap.)

What to Expect if a Spinal Tap is Recommended

During a lumbar puncture, a doctor carefully inserts a thin needle into the lower back to measure the pressure of your spinal fluid and collect a small sample for laboratory testing ^[2].

While generally safe, the procedure carries risks. The most common is a post-lumbar puncture headache, which can be severe and worsen when you stand up. Rare risks include bleeding, infection, and nerve irritation ^[2]. Because of bleeding risks, it is critical to tell your doctor about any blood thinners, anticoagulants, or bleeding disorders you have before the procedure.