Cluster Headache Specialty Program in Ottawa

Cluster headache is a severe primary headache disorder that is often mistaken for migraine. Accurate diagnosis is critical, because treatments for cluster headache are different — and highly effective when used correctly.

Our program is designed to provide accurate diagnosis, rapid symptom relief, and team-based structured preventive care for patients with suspected or confirmed cluster headache and TACs.

Cluster headache doesn't wait for a convenient opening in a schedule. What makes the Ottawa Headache Centre unique is our Team-Based Crisis Protocol. 

When you are in a "cluster bout," time is of the essence. Our program is designed to provide:

• Expedited crisis access: We have purposefully built this program to allow patients experiencing a cluster cycle to be scheduled now. When you are in a cluster bout, it essential to start acute, bridge, and preventive treatments expediently.

• Team-based synergy: Our cluster headache program is one of our team-based programs. To ensure capacity to treat patients in a cluster bout expediently, any of our available specialists assess patients in a cluster bout. You also benefit from the expertise of multiple experts through our "case rounds" aimed at continuously improving care.

A distinct neurological disorder requiring rapid, specialized treatment

Cluster headache is a primary headache disorder characterized by short-lasting but extremely severe attacks of pain, typically centered around one eye. Attacks tend to occur in clusters (bouts) lasting weeks to months, often followed by long symptom-free periods.

It is biologically and clinically distinct from migraine.

Because of its rapid attack profile and unique underlying mechanisms, cluster headache requires a different treatment strategy.

At the Ottawa Headache Centre, our Cluster Headache Program focuses on accurate recognition, rapid intervention, and structured long-term prevention.

Cluster headache and migraine are often confused, and are distinguished by their duration of attacks, presence of side-locked pain, presence of autonomic symptoms, and the behaviour during attacks.

Cluster headache management requires an expert structured plan that addresses:

1) Rapid attack termination

2) Transitional (“bridge”) control during a bout

3) Long-term prevention

Sumatriptan

Sumatriptan is rapid injectable triptan and highly effective for cluster headache when given as:

• Subcutaneous injection (fastest and most reliable)

Nasal spray may help some people, but oral tablets are often too slow for cluster attacks.

High-flow oxygen

High-flow 100% oxygen is one of the most effective treatments for an acute cluster headache attack.

How it is used:

• Delivered through a non-rebreather mask

• Typically at high flow (12–15 L/min)

• Used for 10–15 minutes at the start of an attack

What to do during an attack (step-by-step)

1. Start oxygen immediately at high flow

2. Use injectable sumatriptan if prescribed

3. Avoid lying flat if restlessness is severe

4. Track attack timing and response (consider using a tracker like MyCusters)

Prednisone (short course)

A short course of prednisone (steroid) may:

• Rapidly suppress cluster attacks

• Be used for days to weeks only

Steroids are not a long-term solution due to side effects, but can be very effective as a bridge.

Occipital nerve block

A greater occipital nerve block is a targeted injection that can:

• Reduce attack frequency

• Provide temporary relief during a cluster

• Help bridge until preventives work

First-line preventive: Verapamil

Verapamil is the most commonly used and most effective preventive medication for cluster headache.

Key points:

• Dose often needs to be increased gradually

• ECG monitoring is required (to ensure heart rhythm safety)

• Often started early in a cluster period

Verapamil is considered the standard first-line preventive.

Second-line option: Lithium (less preferred)

Lithium can be effective, especially in chronic cluster headache, but:

• Requires blood level monitoring

• Has more potential side effects

• Is generally used when verapamil is not tolerated or ineffective

CGRP-targeted therapy: Galcanezumab (Emgality®)

Galcanezumab (Emgality®) is a CGRP monoclonal antibody approved for episodic cluster headache.

It has been shown to:

• Reduce attack frequency early in treatment

• Be generally well tolerated

Next steps: moving from crisis to control

Symptoms checklist:

You may have cluster headache if your attacks:

• Are very severe and short-lasting

• Occur multiple times per day

• Always affect the same side

• Cause eye redness, tearing, or nasal symptoms

• Make you feel restless or unable to lie down

Moving from the exhaustion of a cluster bout to a structured plan is a process, but it’s one you don’t have to navigate alone. Here is how we start that journey together.

The referral

To join the program, we need a referral from your doctor or nurse practitioner.

The tracking

Consider keeping a simple record of your attacks. We will ask you about your attack frequency, their duration, and associated symptoms. Using a tool like MyClusters can make it easier to track cluster attacks.

The crisis protocol at the Ottawa Headache Centre

Once you are an active patient at the Ottawa Headache Centre, if a new bout starts, you (or your doctor) should contact us immediately. Our team-based model is designed to see you in an expedited way so we can start the treatment you need.

For clinicians

If you have a patient currently in the middle of a cluster bout, please flag the referral as "URGENT: Active Cluster" on your referral form.

Disclaimer

This material is provided for educational purposes and does not replace independent clinical judgment or institutional protocols. Management decisions remain the responsibility of the treating clinician.