Themamiddag ‘RSI concreet’ zaterdag 26 maart 2011, Den Haag de presentatie van dr. Andrew Dilley Ph.D.

Wie is Dr. Andrew Dilley Ph.D.? Universitair docent Anatomie en onderzoeker, Brighton and Sussex Medical School, University of Sussex, Brighton UK Deze universitair docent en onderzoeker van de University of Sussex doet onderzoek naar de mechanismes, die leiden tot veranderingen in zenuwen bij chronische pijn bij aandoeningen zoals a-specifieke RSI. Zijn onderzoek heeft hem al over drie continenten gevoerd, waarbij hij onder andere aan de prestigieuze Harvard universiteit heeft gewerkt. Hierbij maakt hij gebruik van beeldtechnieken om veranderingen in de zenuw zichtbaar te maken, zoals ultrageluid, en kan intrigerende filmpjes laten zien over verschillen tussen gezonde armen en RSI-armen. Zijn resultaten maken aannemelijk dat de bron van de pijn bij RSI de zenuw kan zijn en maakt concreet, dat er bij RSI wel degelijk iets fysieks gebeurt. Hij legt uit, hoe zijn bevindingen nuttig kunnen zijn voor de aanpak en behandeling van RSI.

the Presentation

“I’ve been told I have RSI, but where’s that pain coming from?” Dr Andrew Dilley Ph.D. Lecturer in Anatomy Brighton and Sussex Medical School

About me...  I’m not a clinician  I don’t see patients - But I am a scientist with an interest in RSI

About me...  Neurophysiologist and anatomist  Trained at University College London and Kings College London

About me... University College London Harvard Medical School Brighton and Sussex Medical School University of Sussex

The medical school  Research group at Brighton and Sussex Medical School Physiology laboratory Imaging laboratory

My research...  Peripheral nervous system “Wires of the nervous system” - Fibromyalgia - Complex regional pain syndrome - Repetitive strain injury  Chronic pain  Inflammation

Specifically... Non-specific arm pain [Chronic arm pain with no sign of injury using current clinical tests] Not: Carpal tunnel syndrome, tendinitis, tenosynovitis  Interested in an RSI subgroup

The reason  We do not understand the mechanism  Therefore it is not easy to treat Not enough high quality basic science research into repetitive strain injuries

What we need to know  MECHANISMS  Where does the pain come from?  What is causing the pain? “If we can understand the cause, we can develop better targeted treatments”

Where does the pain come from? Problem with the median nerve Non-specific arm pain

Median nerve  How do we know that there is a problem with the median nerve? 1. Changes in how the median nerve senses vibration Work with Professor Bruce Lynn and Dr Jane Greening at UCL

Median nerve  How do we know that there is a problem with the median nerve? 2. Light pressure with fingers over median nerve often causes pain

Median nerve  How do we know that there is a problem with the median nerve? 3. Median nerve movement tests are painful YES!! Nerves move “Nerves lengthen and shorten as joints are moved”

Peripheral nerves move..... Distal 10mm - Median nerve in the forearm during movement of the elbow

But why? Why are limb movements that stretch the median nerve painful in patients with NSAP?

Possible mechanism  Median nerve becomes stuck!! THEORY – “Restricted nerve sliding” Can not move easily Leads to pain (Common theory amongst physiotherapists)

Median nerve entrapment Neck/shoulder Forearm Carpal tunnel Possible sites of restriction

How to test this theory Compare median nerve movement in patients with normal subjects Brachialis 10mm ProximalDistal - Median nerve sliding in the upper arm during wrist extension

Results for wrist movements Median nerve movement during wrist extension Brachialis 10mm ProximalDistal Stretch 2.0% 1.1% 0.5% Shoulder angle: Elbow WristShoulder

Patient results... No restriction!! Wrist movements Finger movements Median nerve moves the same in patients as it does in normal subjects Elbow movements

Results Not even in carpal tunnel syndrome Finger movements Flexor digitorum profundus Flexor digitorum superficialis Proximal Distal

Interesting ProximalDistal A deep breath moves the median nerve

But not in NSAP! Pathology in the shoulder region

Radial Ulna * * * 10mm * Wrist movements causes the median nerve to move side-to-side Interesting

But not in NSAP! Pathology at the wrist

 These findings do not indicate a restriction  Suggest minor pathology at multiple sites Evidence for a pathology Neck/shoulder Carpal tunnel

We know:  Problem with the median nerve  Median nerve is not restricted from sliding  Evidence of pathology at multiple sites So what next?

Two more important questions What is the pathology? How does this pathology causes pain?

A role for inflammation Inflammation is a natural response to an injury Doesn’t switch off in non-specific arm pain?

MRI study Can visualize inflammation on MRI Examined median nerve at wrist, forearm and neck - Inflamed nerves appear bright

Non-specific arm pain Median nerve looks inflamed at wrist:

Not just the median nerve.... Ulnar nerve also looks inflamed at wrist:

And in the neck..... Consistent with ultrasound findings - Problem in neck and wrist “NSAP is diffuse”

And in fibromyalgia Fibromyalgia and non-specific arm pain may be similar?

Inflammation Inflammation of the median nerve looks like a possible cause of pain in NSAP

Laboratory based studies Successful treatments and therapies for NSAP require a full understanding of the mechanisms of pain How does inflammation causes pain? But such experiments can not easily be carried out in patients

Physiology experiments Looked at nerve cells that carry pain information What happens when these cells are inflamed? “The median nerve contains 1000’s of nerve cells conveying information in the form of electrical signals to and from the spinal cord”

Electrophysiology experiments Use electrophysiology to record electrical signals along nerve cells

Excitable nerve cells!! Inflammation causes nerve cells that carry pain information to fire on their own Important finding 1

Clinical significance Excitable nerve cells!! - Patients with non-specific arm pain complain of spontaneous pain (from deep tissues)

Sensitive nerve cells!! Inflammation causes nerve cells that carry pain information to fire to small stretches or light pressure Important finding 2

- Limb movements that stretch the median nerve can be painful Clinical significance - as well as pressure over nerves Sensitive nerve cells!!

In these experiments, the nerve cells recover as inflammation ends Signs of improvement - But not in NSAP... (inflammation doesn’t switch off)

In non-specific arm pain, we do not know what is causing the inflammation Problem If we know this, we could focus therapies (e.g. Physiotherapy)

We have identified important components of inflammation that may be responsible What about drug treatments? Such targets might lead to new drugs TNF CCL2 “Nerve cells showing targets (black) for specific inflammatory components”

What we’ve learnt….. Local inflammation can be detrimental to nerve function Our pharmacology studies have revealed essential details about the mechanism

But More complicated! Our focus is on the peripheral nervous system

But Changes to the peripheral nervous system Spinal cord Brain - Treatments need to target all parts of the mechanism

“I’ve been told I have RSI, but where’s that pain coming from?”

Well... Problem with the median nerve Not an entrapment Evidence of multiple sites of (minor) pathology Localised inflammation at these sites driving symptoms New targets and focused treatment

Acknowledgments Dr Jane Greening PhD (Brighton and Sussex Medical School) Professor Bruce Lynn PhD (University College London) Dr Geoffrey Bove PhD (Harvard Medical School) Ms Natalie Richards (Brighton and Sussex Medical School)

Dagvoorzitter drs. A.M. (Sandra) Oudshoff Voorzitter commissie Onderzoek, RSI-vereniging Sandra Oudshoff houdt zich vanuit de vereniging al vele jaren met het onderzoek naar RSI bezig. Zij is niet alleen ervaringsdeskundige maar volgt zoveel mogelijk het RSI-onderzoek in binnen- en buitenland en publiceert hierover regelmatig in Handvat (het kwartaal magazine van de RSI-vereniging). Zij neemt deel aan klankbordgroepen van RSI-onderzoeken en is lid van de programmacommissie van de stichting BON, waarin Nederlandse onderzoekers krachten bundelen voor RSI- onderzoek. Zij is ook lid van de kernwerkgroep voor de ontwikkeling van een multidisciplinaire richtlijn voor a- specifieke RSI-klachten. adres:

RSI-vereniging Stationsstraat 6b 3862 CG NIJKERK t e