Targeted injection, usually of local anaesthetic, used to investigate whether a structure contributes to pain.
Understanding the approach
A diagnostic block uses local anaesthetic to temporarily interrupt selected pain signals. In spinal care it may target medial branches supplying facet joints or another defined structure. Its main purpose is to test a clinical hypothesis rather than provide permanent treatment.
Indications and assessment
The specialist selects a target from the history, examination and available investigations. The patient may be asked to record symptoms during activities that are normally difficult. Duration of relief and the anaesthetic used must be interpreted together within the particular testing protocol.
Benefits, limitations and precautions
Substantial relief can support a facet-related explanation, but false positives occur through anaesthetic spread, unusual rest or contextual effects. A negative response also has more than one possible explanation. Risks include bleeding, infection, reaction to medication and temporary numbness; serious complications are less common.
Place in the care pathway
A qualified medical team performs the block, separately from TAGMED’s noninvasive treatments. Its report can assist coordination of care. A positive response does not automatically mean radiofrequency ablation is the best next step for that person.
Goals should be practical: walking farther, returning to a chosen activity or reducing symptoms that interfere with sleep. Improvement immediately after an intervention does not establish lasting benefit. Follow-up compares function with the starting point, records adverse effects and considers progress between appointments. An inadequate response should prompt a review of the clinical explanation or proposed approach, rather than an automatic extension of the same treatment.
Before starting, describe the outcome you want, treatments already tried and difficulties encountered. Ask how the response will be measured and when another option would be preferable. Available reports complement the discussion without replacing your current experience, priorities or preferences.
Frequently asked questions
How does it differ from a therapeutic injection?
The principal goal here is to assess a possible pain source.
Must symptoms be present during testing?
Usual symptoms need a meaningful comparison, without deliberately undertaking an unsafe activity.
Does a positive result prove everything?
No. It is one component of clinical reasoning and has limitations.
Why is a block sometimes repeated?
Some protocols use confirmation to reduce diagnostic uncertainty.
What should I record afterward?
Hourly symptom changes, activities performed and any unexpected effects.
Conceptual diagram of clinical reasoning; not an anatomical drawing to scale.
Role of TAGMED care
This entry describes a medical or specialist option; it does not mean the intervention is performed at TAGMED. The clinic can discuss how its conservative services might fit into coordinated care, considering prescribed treatment, reports and specialist restrictions. Medication should not be stopped or changed on the basis of this page.
Medical references
- NICE. Low back pain and sciatica in over 16s: assessment and management (NG59).
- NIH — NINDS. Pain.
References document the topic; their inclusion does not imply endorsement of TAGMED services by those organizations.
Educational information from The Spine Page. This entry does not replace an individual assessment. Documentary version: October 12, 2026. Sylvain Desforges, B.Sc., D.O., N.D., osteopath and naturopath.
TAGMED clinic contact details
For non-urgent consultations and information about available services.
Clinique TAGMED — Terrebonne
1150, rue Lévis, Suite 200
Terrebonne (Québec) J6W 5S6
450‑704‑4447
Clinique TAGMED — Montréal
1140, avenue Beaumont
Mont-Royal (Québec) H3P 3E5
1‑877‑672‑9060