Nummular Headache and Acupuncture: A Comprehensive Guide to Relief

 

Understanding Nummular Headache

What Is Nummular Headache?

Nummular headache, also known as coin-shaped headache, is a primary headache disorder first described in 2002 by the International Headache Society (IHS). It is classified under the International Classification of Headache Disorders (ICHD-3) as a distinct entity (code 4.8). NH is characterized by chronic or intermittent pain confined to a small, well-defined, circular or elliptical area of the scalp, typically 0.6 to 6 centimeters in diameter. The pain is often described as stabbing, sharp, pulsating, or burning and can vary in intensity from mild to severe.

Unlike migraines, which may involve systemic symptoms like nausea or light sensitivity, or tension-type headaches, which often affect both sides of the head, NH is highly localized and does not typically involve additional neurological symptoms. The condition is considered rare, though its prevalence may be underestimated due to underdiagnosis or misdiagnosis as other headache types.

Epidemiology and Prevalence

Nummular headache is relatively uncommon, with limited epidemiological data available. A 2008 study in China reported 21 cases over two years, suggesting it is not as rare as previously thought. The condition affects both men and women, with a slight female predominance (12 women vs. 9 men in the Oriental  study). It can occur at any age, with reported cases ranging from 18 to 63 years, and the average age of onset around 37 years. The headache duration varies widely, from days to decades, highlighting its chronic nature in some patients.

Causes and Triggers of Nummular Headache

The exact cause of nummular headache remains unclear, and research is ongoing to determine whether it originates from peripheral (e.g., scalp nerves) or central (e.g., brain) mechanisms. Several theories have been proposed:

• Peripheral Nerve Involvement: Some researchers suggest NH may result from irritation or dysfunction of peripheral nerves, such as branches of the trigeminal nerve or occipital nerves, in the affected scalp area. This is supported by cases where local nerve blocks provided temporary relief.
• Central Sensitization: Other studies propose that NH may involve central nervous system dysregulation, similar to migraines, where pain processing pathways become hypersensitive. A case report noted the reappearance of NH after surgical removal of the affected scalp area, suggesting a central component.
• Myofascial Trigger Points: Taut muscle bands in the scalp or neck, identified as myofascial trigger points, may contribute to NH pain, potentially overlapping with acupuncture’s mechanism of action.

Potential triggers include:

• Stress or emotional tension
• Trauma or injury to the scalp
• Infections or inflammation in the affected area
• Hormonal changes (e.g., in women during menstruation or menopause)
• Environmental factors like weather changes

However, many patients report no clear trigger, and the pain may occur spontaneously.

Symptoms of Nummular Headache

The hallmark of nummular headache is its localized pain, confined to a specific scalp area. Key symptoms include:

• Pain Characteristics: Stabbing (most common), sharp, pulsating, burning, or dull pain. In a series of 21 patients, 6 reported stabbing pain, 3 sharp, 3 pulsating, 5 exploding, and 3 light-dull pain.
• Location: Typically in the parietal (top of the head), occipital (back of the head), or temporal (side of the head) regions. The right or left side is equally affected, with rare cases in the midline.
• Size and Shape: Pain is confined to a circular area (0.6–6 cm) or elliptical area (1–2 cm x 1.5–3 cm).
• Intensity: Varies from mild (7/21 patients), moderate (8/21), to severe (6/21).
• Duration: Can be continuous or intermittent, lasting from days to years.
• Associated Symptoms: Unlike migraines, NH rarely involves nausea, photophobia, or phonophobia. Some patients report tenderness or sensitivity in the affected area.

Diagnosis of Nummular Headache

Diagnosing NH can be challenging due to its rarity and overlap with other headache disorders. The ICHD-3 diagnostic criteria for nummular headache include:

1. Continuous or intermittent head pain confined to a single, rounded or elliptical area of 1–6 cm in diameter.
2. Pain is mild to moderate but may have exacerbations of severe intensity.
3. No associated cranial autonomic symptoms (e.g., tearing, nasal congestion).
4. Not better accounted for by another ICHD-3 diagnosis (e.g., epicrania fugax or secondary headaches).

Diagnosis involves ruling out secondary causes, such as scalp infections, tumors, or nerve injuries, through:

• Medical History: Detailed history of pain characteristics, duration, and triggers.
• Physical Examination: Palpation of the scalp to confirm the localized pain area.
• Imaging: MRI or CT scans to exclude structural causes like tumors or lesions.
• Nerve Blocks: Temporary relief with local anesthetics may support a peripheral nerve etiology.

Misdiagnosis as tension-type headache, migraine, or epicrania fugax is common, emphasizing the need for specialist evaluation by a neurologist or headache expert.

Acupuncture: An Overview

Acupuncture is a TOM practice that involves inserting thin, sterile needles into specific points on the body, known as acupoints, to regulate the flow of Energy (vital energy) along meridians. It has been used for over 3,000 years to treat various conditions, including pain, stress, and neurological disorders. In modern practice, acupuncture is recognized for its potential to alleviate chronic pain, including headaches, with minimal side effects.

How Acupuncture Works

From a TOM perspective, acupuncture restores balance by clearing blockages in Energy flow. Western science offers complementary explanations:

• Neurotransmitter Release: Acupuncture stimulates the release of endorphins, serotonin, and other pain-relieving chemicals.
• Pain Modulation: It alters pain processing in the brain and spinal cord, reducing pain perception.
• Anti-Inflammatory Effects: Acupuncture may reduce inflammatory markers, which could benefit NH if inflammation plays a role.
• Myofascial Trigger Point Stimulation: Acupuncture may target taut muscle bands, overlapping with myofascial trigger points, to relieve localized pain.

Acupuncture’s low-risk profile makes it an appealing option for NH patients who experience side effects from medications like amitriptyline or NSAIDs.

The Effectiveness of Acupuncture for Nummular Headache

While research on acupuncture specifically for nummular headache is limited due to its rarity, evidence from studies on other primary headaches (e.g., migraines, tension-type headaches) and case reports on NH provides valuable insights. Below, we explore the effectiveness of acupuncture for NH, drawing on available data, mechanisms, and clinical considerations.

Scientific Evidence for Acupuncture in Nummular Headache

Direct evidence for acupuncture in NH is sparse but promising. A 2008 study of 21 NH patients in China reported that one patient achieved pain remission with acupuncture after ineffective trials of amitriptyline and paroxetine. This suggests acupuncture may be effective for some NH patients, particularly when conventional treatments fail.

Broader studies on acupuncture for headaches provide context:

• Tension-Type Headache (TTH): A 2021 data-mining study analyzed 128 studies and found that acupuncture, particularly at points like Fengchi (GB20), Baihui (GV20), and Hegu (LI4), significantly reduced TTH symptoms. The study highlighted acupuncture’s ability to target head and neck acupoints, which are relevant for NH due to its localized nature.
• Migraine: A 2024 meta-analysis found that acupuncture, including electroacupuncture, reduced migraine frequency, duration, and pain intensity more effectively than sham acupuncture or standard pharmacological therapy. This suggests acupuncture’s pain-modulating effects could extend to NH.
• General Headache Relief: The National Institutes of Health (NIH) and World Health Organization (WHO) recognize acupuncture as effective for chronic pain, including headaches, based on meta-analyses like a 2012 study in Archives of Internal Medicine.

While NH-specific studies are limited, the overlap in pain mechanisms (e.g., peripheral nerve irritation, central sensitization) between NH and other headaches suggests acupuncture’s potential efficacy.

Mechanisms of Acupuncture for Nummular Headache

Acupuncture’s benefits for NH likely stem from its effects on both peripheral and central pain pathways:

1. Peripheral Nerve Stimulation: Acupuncture at scalp acupoints (e.g., GB20, Taiyang) may modulate activity in trigeminal or occipital nerve branches, which are implicated in NH. This aligns with the temporary relief seen with local nerve blocks in some NH patients.
2. Endogenous Opioid Release: Acupuncture triggers the release of endorphins and enkephalins, which reduce pain perception. Electroacupuncture at 2 Hz enhances endorphin release, while 100 Hz promotes dynorphins, both relevant for chronic headache relief.
3. Serotonin and ATP Mediation: Acupuncture may increase serotonin (5-HT) release at acupoints, contributing to analgesia. This is particularly relevant for NH, as serotonin pathways are implicated in headache disorders.
4. Myofascial Trigger Point Relief: Acupuncture may target taut muscle bands in the scalp or neck, reducing localized pain and tension that contribute to NH.
5. Anti-Inflammatory Effects: By reducing pro-inflammatory cytokines, acupuncture may alleviate inflammation in the affected scalp area, if present.

Benefits of Acupuncture for Nummular Headache

• Localized Pain Relief: Acupuncture’s ability to target specific scalp acupoints makes it well-suited for NH’s focal pain.
• Minimal Side Effects: Unlike medications (e.g., amitriptyline, carbamazepine), acupuncture has a low risk of adverse effects, such as drowsiness or gastrointestinal issues.
• Complementary Approach: Acupuncture can be combined with medications or other therapies for enhanced relief.
• Holistic Benefits: Acupuncture reduces stress and promotes relaxation, addressing potential NH triggers like emotional tension.

Limitations and Considerations

• Limited NH-Specific Research: Most evidence for acupuncture in NH comes from case reports or studies on other headaches, necessitating further research.
• Variable Response: Not all NH patients respond to acupuncture, as seen in the 2008 study where only one patient achieved remission.
• Multiple Sessions Required: Acupuncture typically requires 6–12 sessions over weeks to achieve lasting benefits, which may affect cost and accessibility.
• Practitioner Expertise: The effectiveness of acupuncture depends on the skill of the practitioner in selecting appropriate acupoints for NH.

Patients with NH should consult a neurologist and a licensed acupuncturist to discuss whether acupuncture is suitable, especially if they have coexisting conditions like bleeding disorders.

Key Acupoints for Nummular Headache Relief

Acupoint selection is critical for effective acupuncture treatment, particularly for NH due to its localized pain. Based on studies of headache disorders and TOM principles, the following acupoints are commonly used for NH and related headaches, tailored to the affected scalp region (e.g., parietal, occipital, temporal).

General Acupoints for Headache Relief

Fengchi (GB20) – Gallbladder 20

• Location: At the base of the skull, in the depression between the sternocleidomastoid and trapezius muscles, just below the occipital bone.
• Benefits: A key point for all headache types, GB20 relieves pain in the head and neck, reduces tension, and modulates trigeminal nerve activity. It’s especially relevant for occipital NH.
• Application: Often combined with other points for synergistic effects.

Baihui (GV20) – Governor Vessel 20

• Location: At the top of the head, at the midpoint of the line connecting the tops of the ears.
• Benefits: Known as the “meeting point of all meridians,” GV20 calms the mind, reduces pain, and is ideal for parietal NH or stress-related headaches.
• Application: Stimulated to promote overall head pain relief.

Hegu (LI4) – Large Intestine 4

• Location: On the hand, in the webbing between the thumb and index finger.
• Benefits: A master point for pain relief, LI4 is effective for headaches, including NH, by reducing pain and inflammation. It’s particularly useful for frontal or temporal NH.
• Application: Used in combination with head-specific points.

Taiyang (EX-HN5) – Extra Head and Neck 5

• Location: In the temporal region, in the depression about one finger-width behind the midpoint between the lateral eyebrow and outer canthus of the eye.
• Benefits: A key extraordinary point for temporal headaches, Taiyang is highly relevant for NH affecting the temporal scalp. It reduces localized pain and tension.
• Application: Targeted for temporal NH or migraines.

Taichong (LR3) – Liver 3

• Location: On the foot, in the depression between the first and second metatarsal bones, about two finger-widths from the web of the toes.
• Benefits: LR3 regulates liver energy, reduces stress, and alleviates headache pain, particularly when emotional tension is a trigger.
• Application: Used for systemic balance and pain relief.

Acupoints for Specific NH Locations

Parietal Nummular Headache

Touwei (ST8) – Stomach 8

• Location: On the forehead, 0.5 cun within the anterior hairline, at the corner of the forehead.
• Benefits: Relieves pain in the parietal and frontal regions, making it suitable for parietal NH.

Sishencong (EX-HN1) – Extra Head and Neck 1

• Location: Four points located 1 cun anterior, posterior, and lateral to GV20 (top of the head).
• Benefits: Targets parietal and vertex pain, calming the mind and reducing localized discomfort.

Occipital Nummular Headache

Yuzhen (BL9) – Bladder 9

• Location: On the occipital region, 1.3 cun lateral to the midline, level with the upper border of the occipital protuberance.
• Benefits: Relieves occipital pain and stiffness, ideal for occipital NH.

Tianzu (BL10) – Bladder 10

• Location: On the nape, 1.3 cun lateral to the midline, below the occipital bone.
• Benefits: Supports GB20 in relieving occipital pain and neck tension.

Temporal Nummular Headache

Shuaigu (GB8) – Gallbladder 8

• Location: On the scalp, above the ear, 1.5 cun within the hairline.
• Benefits: Directly targets temporal pain, making it ideal for temporal NH.

Waiguan (TE5) – Triple Energizer 5

• Location: On the outer forearm, two finger-widths above the wrist crease.
• Benefits: Reduces temporal and facial pain, supporting Taiyang for NH relief.

Acupoint Selection and Treatment Protocols

Acupuncturists tailor treatments based on the NH location, pain characteristics, and TOM diagnosis (e.g., blood stasis, Energy stagnation). A typical session involves:

• Assessment: The practitioner evaluates the pain’s location, intensity, and triggers, often using pulse and tongue diagnosis.
• Needle Insertion: 4–10 acupoints are selected, with needles inserted for 15–30 minutes. For NH, local points (e.g., Taiyang for temporal pain) are combined with distal points (e.g., LI4, LR3).
• Adjunctive Techniques: Electroacupuncture, moxibustion (heat therapy), or cupping may enhance effects, particularly for chronic NH.
• Frequency: 1–2 sessions per week for 6–12 weeks, with maintenance sessions as needed.

Patients may experience a mild tingling or warmth, indicating Energy activation. Licensed acupuncturists with experience in headache disorders should be sought for optimal outcomes.

Practical Tips for Incorporating Acupuncture into NH Management

Finding a Qualified Acupuncturist

• Credentials: Choose a practitioner certified by a recognized body, such as the National Certification Commission for Acupuncture and Oriental Medicine (NCCAOM).
• Experience: Seek an acupuncturist with expertise in treating headaches or neurological conditions.
• Consultation: Discuss your NH symptoms, medical history, and treatment goals during an initial consultation.

Combining Acupuncture with Other Treatments

Acupuncture can complement conventional NH treatments, such as:

• Medications: Amitriptyline, carbamazepine, or NSAIDs, which were effective in some NH cases.
• Nerve Blocks: Local anesthetics like lidocaine may provide temporary relief, and acupuncture can extend benefits.
• Lifestyle Changes: Stress management, adequate sleep, and avoiding triggers like scalp trauma.

What to Expect During Acupuncture

• Session Duration: 30–60 minutes, including consultation and needle insertion.
• Sensation: Mild tingling or warmth is normal; acupuncture should not be painful.
• Results: Some patients experience immediate relief, while others require multiple sessions for noticeable improvement.

Safety and Side Effects

Acupuncture is safe when performed by a licensed practitioner. Minor side effects, such as temporary soreness or bruising, are rare. Avoid acupuncture if you have bleeding disorders, are pregnant (some points like LI4 are contraindicated), or have an infection in the affected scalp area.

Frequently Asked Questions About Acupuncture for Nummular Headache

Is Acupuncture Effective for Nummular Headache?

Limited evidence suggests acupuncture can help some NH patients, particularly when medications fail. Broader headache studies support its efficacy for pain relief.

How Many Sessions Are Needed?

Typically, 6–12 sessions over 6–12 weeks are needed for significant relief, with maintenance sessions for chronic NH.

Is Acupuncture Safe for NH?

Yes, when performed by a licensed practitioner, acupuncture is safe with minimal side effects. Discuss any medical conditions with your provider.

Can Acupuncture Replace Medications?

Acupuncture is not a cure but can complement medications or serve as an alternative for those intolerant to drugs.

Conclusion: Is Acupuncture Right for Your Nummular Headache?

Nummular headache is a unique and challenging condition due to its localized pain and limited treatment options. Acupuncture offers a promising, low-risk approach to managing NH symptoms, particularly for patients who experience side effects from medications or seek a holistic solution. By targeting key acupoints like Fengchi (GB20), Taiyang (EX-HN5), and Hegu (LI4), acupuncture may reduce pain intensity, frequency, and associated tension, improving quality of life.

While more research is needed to establish acupuncture’s efficacy for NH specifically, its proven benefits for other headaches and chronic pain conditions make it a viable option. Consult a neurologist and a licensed acupuncturist to develop a personalized treatment plan tailored to your NH symptoms. With the right approach, acupuncture could be a valuable tool in your journey to relief.