Hemicrania Continua: Symptoms, Causes, Treatment

What are the symptoms of hemicrania continua?

Hemicrania continua is a type of primary headache disorder characterized by continuous, unilateral (one-sided) head pain that varies in intensity but is present at all times. The symptoms typically include:

1. Continuous Headache: The hallmark symptom is a persistent, unremitting headache that affects one side of the head.
2. Severity Variability: The pain can fluctuate in intensity from moderate to severe without warning.
3. Response to Indomethacin: A distinguishing feature is that hemicrania continua almost always responds completely or significantly to indomethacin, a nonsteroidal anti-inflammatory drug (NSAID).
4. Autonomic Symptoms: Some individuals may experience accompanying autonomic symptoms such as tearing, nasal congestion, and drooping eyelid (ptosis) on the affected side.
5. Pain Characteristics: The pain is typically throbbing or piercing in nature and can be exacerbated by physical activity.
6. Unilateral Nature: The pain is predominantly on one side of the head and does not switch sides during attacks.

If you or someone you know is experiencing persistent one-sided headaches with these characteristics, consulting a healthcare professional for a proper diagnosis and management is recommended.

What are the causes of hemicrania continua?

The exact cause of hemicrania continua is not well understood, but it is classified as a primary headache disorder, meaning it is not caused by another underlying condition. Here are some potential factors and theories related to its causes:

1. Neurological Dysfunction: Abnormal functioning of pain-processing pathways in the brain and the trigeminal nerve (which is responsible for facial sensation) might play a role in hemicrania continua.
2. Genetic Factors: Although not well established, there might be a genetic predisposition that makes some individuals more susceptible to developing hemicrania continua.
3. Autonomic Nervous System: Dysregulation of the autonomic nervous system, which controls involuntary bodily functions, might contribute to the headache and associated autonomic symptoms.
4. Inflammatory Processes: Some researchers speculate that inflammatory processes in the brain could be involved, although this has not been definitively proven.
5. Chemical Imbalances: Imbalances in certain neurotransmitters or chemicals in the brain that regulate pain and other functions could be a factor.
6. Indomethacin Response: The significant response to indomethacin suggests that specific pathways and mechanisms that this drug affects are involved in the condition, although the exact mechanisms are still unclear.

Because the precise cause of hemicrania continua remains elusive, treatment focuses on managing symptoms, primarily through the use of indomethacin, which is highly effective in most cases. If you suspect hemicrania continua, consulting a healthcare professional for an accurate diagnosis and appropriate treatment plan is essential.

How is the diagnosis of hemicrania continua made?

The diagnosis of hemicrania continua (HC) is typically made through a combination of clinical evaluation, medical history, and diagnostic criteria. Here are the key steps involved in making a diagnosis:

1. Medical history: The patient is asked to provide a detailed account of their symptoms, including the frequency, duration, and pattern of their headaches. The healthcare provider will ask questions about the quality of the pain, any triggering factors, and any associated symptoms such as sensitivity to light or sound.
2. Physical examination: A thorough physical examination is performed to rule out other potential causes of headache pain, such as sinusitis, meningitis, or cervical spine problems.
3. Diagnostic criteria: The International Classification of Headache Disorders (ICHD-3) criteria for hemicrania continua are used to diagnose HC. The criteria include:
   • Unilateral headache pain (pain on one side of the head)
   • Continuous pain with periods of exacerbation and remission
   • Pain is typically felt on one side of the head, but may occasionally shift to the other side
   • Pain is often described as aching, throbbing, or pressing
   • No aura or migraine-like symptoms
   • No response to triptans or ergotamines
4. Exclusion of other conditions: The healthcare provider will rule out other conditions that can cause similar symptoms, such as:
   • Migraine without aura
   • Cluster headache
   • Trigeminal autonomic cephalalgia (TAC)
   • Sinusitis
   • Temporomandibular joint (TMJ) disorder
5. Imaging studies: Imaging studies such as CT or MRI scans may be ordered to rule out structural abnormalities in the brain or sinuses that could be contributing to the headaches.
6. Differential diagnosis: The healthcare provider will consider other conditions that can cause unilateral headache pain, such as facial neuralgia, dental problems, or cervical spine problems.
7. Confirmation of diagnosis: A diagnosis of hemicrania continua is confirmed when the patient’s symptoms meet the ICHD-3 criteria and other potential causes have been ruled out.

It’s important to note that the diagnosis of hemicrania continua can be challenging and may require a multidisciplinary approach involving neurologists, headache specialists, and other healthcare professionals.

What is the treatment for hemicrania continua?

The treatment for hemicrania continua (HC) typically involves a combination of medications and lifestyle modifications. The goal of treatment is to reduce the frequency, severity, and duration of headaches. Here are some common treatments used to manage hemicrania continua:

Medications:

1. Indomethacin: This is the most effective medication for treating HC. It’s often used as a first-line treatment and is typically started at a low dose and gradually increased as needed.
2. Triptans: While triptans are not effective for HC, they may be used in combination with indomethacin or other medications.
3. Topiramate: This anticonvulsant medication has been shown to be effective in reducing the frequency and severity of HC headaches.
4. Calcitonin gene-related peptide (CGRP) inhibitors: These medications, such as telcagepant, have been shown to be effective in reducing the frequency and severity of HC headaches.
5. Opioids: In some cases, opioids may be prescribed to help manage breakthrough pain or severe headache attacks.

Lifestyle modifications:

1. Pain management techniques: Techniques such as relaxation therapy, biofeedback, and cognitive-behavioral therapy can help patients manage their pain and reduce stress.
2. Sleep habits: Establishing consistent sleep habits and avoiding sleep disorders can help reduce headache frequency and severity.
3. Dietary changes: Some patients with HC may find that certain foods or food additives trigger or exacerbate their headaches. Keeping a food diary can help identify potential triggers.
4. Stress reduction techniques: Stress can trigger or worsen headaches. Practicing stress-reducing techniques such as meditation, yoga, or deep breathing exercises can help manage stress.
5. Physical therapy: Physical therapy can help improve posture, reduce muscle tension, and address any underlying musculoskeletal issues that may be contributing to headaches.

Other treatments:

1. Radiofrequency ablation: In some cases, radiofrequency ablation of the greater occipital nerve or the supraorbital nerve may be considered to reduce headache frequency and severity.
2. Sphenopalatine ganglion block: This procedure involves injecting a local anesthetic into the sphenopalatine ganglion to block pain signals from reaching the brain.

It’s important to work closely with a healthcare provider to develop a personalized treatment plan that addresses the individual’s specific needs and symptoms. In some cases, it may take several months to find the right combination of medications and lifestyle modifications that provide adequate relief from hemicrania continua symptoms.