RecruitingPHASE4INTERVENTIONAL

Cervicothoracic Sympathetic Block Evaluation for Post COVID Condition

This research is investigating a treatment called a cervicothoracic sympathetic block (CSB) for people experiencing long COVID. Long COVID, also known as Post-COVID Condition (PCC), can cause a range of ongoing symptoms like tiredness, difficulty thinking clearly (brain fog), and heart palpitations. These symptoms are often linked to a problem where the body's automatic nervous system isn't working correctly. The study involves injecting a local anaesthetic near specific nerves in the neck. The aim is to see if this can reduce the overactivity of these nerves, which might help ease long COVID symptoms. This trial is double-blind, meaning neither patients nor doctors will know who receives the real treatment and who gets a dummy treatment, to ensure fair and accurate results.

At a glance

Status

Recruiting

Phase

PHASE4

Sponsor

University Health Network, Toronto

Enrolment target

Start

19 May 2026

Estimated completion

01 Sep 2027

Autonomic Dysfunction

What is this study about?

Many people who have had COVID-19 continue to experience a variety of symptoms long after their initial infection. This condition is often called long COVID or Post-COVID Condition (PCC). Symptoms can be wide-ranging, from extreme tiredness and brain fog to heart palpitations and breathing difficulties, and they can significantly affect daily life. Scientists believe that a key reason for many of these symptoms is an issue with the body's automatic functions, specifically an overactive part of the nervous system called the sympathetic system. This overactivity can lead to ongoing inflammation and symptoms that make you feel unwell.

Current treatments for long COVID often have mixed results or can be difficult for some people to tolerate. Researchers are therefore looking for new and more effective ways to help reduce these persistent symptoms. One promising idea is a treatment called a cervicothoracic sympathetic block (CSB). This involves a doctor carefully injecting a local anaesthetic, similar to what a dentist might use, into an area of nerves in the neck.

The goal of this injection is to temporarily calm down the overactive sympathetic nerves. By doing this, it's hoped that it might improve blood flow to the brain and reduce inflammation, which could in turn help ease long COVID symptoms like fatigue and brain fog. Previous small studies have shown some positive results, but they haven't been rigorously tested. This new study is a crucial step to properly evaluate if CSB is truly effective and how much it can help people with long COVID.

Key takeaways

The study is for people with long COVID (Post-COVID Condition).
It tests a nerve injection called a cervicothoracic sympathetic block (CSB).
The aim is to help symptoms like fatigue, brain fog, and palpitations.
Participants will either get the active injection or a dummy treatment.
The study is designed to find out if this treatment really works safely.
Your participation could help others with long COVID in the future.

Who may be eligible?

To join this study, you need to be at least 18 years old and have been experiencing long COVID symptoms for at least three months since your COVID-19 infection. You should also be able to understand and communicate in English. The researchers will check for symptoms that suggest your automatic nervous system isn't working as it should be.

There are also some reasons why you might not be able to participate. For example, if you have certain existing health conditions such as recent heart problems, certain breathing difficulties, a history of glaucoma, or severe bleeding issues. You also can't join if you have an active autoimmune disease, problems with your automatic nervous system before you got COVID-19, or untreated mental health conditions that might need changes to your medication during the study.

Finally, if you've had major surgery or a stroke recently, or if you're allergic to local anaesthetics, you won't be able to take part. Also, if you can't comfortably move your neck (for example, due to severe arthritis) or have had this specific nerve block before, you won't be eligible.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you 18 years old or older?
Have you had long COVID symptoms for at least three months?
Can you read and understand English?
Have you been diagnosed with certain automatic nervous system problems?
Are you able to comfortably extend your neck?
Do you have any severe heart, lung, or bleeding issues?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you'll be randomly assigned to receive either the actual nerve block treatment or a dummy treatment (a sham group). This is similar to drawing lots, and neither you nor the doctors will know which one you receive. The main intervention involves a carefully guided injection of a local anaesthetic near nerves in your neck. The dummy treatment would involve a similar procedure but without the active medication.

Throughout the study, you'll have several visits to the clinic for assessments and to check how you're feeling. You'll complete questionnaires to track your symptoms, and doctors will monitor your health. If you are already taking any long COVID medications, you would need to be on a stable dose for at least four weeks before joining, and you should continue to take them as prescribed unless advised otherwise by the study team. The total duration of your participation in the study will be explained in detail by the study staff.

Potential risks and benefits

Taking part in this study might offer a potential benefit: if the nerve block is effective, you might experience an improvement in your long COVID symptoms. However, as with any medical procedure, there are potential risks, though these are generally considered small for nerve blocks. These can include pain or bruising at the injection site, or a temporary hoarse voice. The research team will explain all potential risks in detail. It's important to remember that you have the right to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (3)

Women's College Hospital
Verified postcode
Toronto, Canada· Not yet recruiting
Toronto Western Hospital
Verified postcode
Toronto, Canada· Recruiting
Toronto Western Hospital/UHN
Verified postcode
Toronto, Canada· Recruiting

Common questions

What is 'long COVID'?

Long COVID, also known as Post-COVID Condition (PCC), means you have symptoms that continue for a long time (usually at least 3 months) after you've had COVID-19, and can't be explained by other conditions.

What is a cervicothoracic sympathetic block (CSB)?

It's a procedure where a doctor injects a local anaesthetic near specific nerves in your neck to temporarily calm down an overactive part of your nervous system.

Will I know if I'm getting the real treatment or a dummy treatment?

No, neither you nor the study doctors will know if you're getting the actual nerve block or a dummy treatment. This is common in research to make sure results are fair.

What are the common symptoms of long COVID this study might help with?

This study is particularly looking at symptoms like persistent tiredness, difficulty thinking clearly (brain fog), and heart palpitations, which are thought to be related to nerves being overactive.

Is this a new treatment?

The general idea of nerve blocks isn't new, but using this specific type of nerve block (CSB) to treat long COVID symptoms is still being studied to see how effective and safe it is.

How to find out more

Emad Al Azazi, MD, PhD

emad.al-azazi@uhn.ca 4166035800 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.