Carpal Tunnel Syndrome

Carpal Tunnel Syndrome is a collection of symptoms which often gives symptoms of numbness, pins and needles or tingling in the hand.

Classically people wake at night with a tingling hand that they often will try and shake off, bang on something to try and “wake it up” or hang it over the side of the bed. Some patients run it under water to try and decrease their symptoms.

During the day it can commonly cause symptoms when driving, reading or on the telephone.  It can also cause difficulty with fine tasks like doing up buttons as the feeling in the finger tips can be altered. In particular, fine tasks when you can’t see what your fingers are doing (top buttons, backs of ear rings, picking coins from pockets) can be significantly effected.

The vast majority of people with carpal tunnel syndrome will have no underlying cause – this is a bit of a design problem with a tight tunnel containing 9 tendons and 1 nerve. The nerve is the softest structure in it and as such, suffers when space gets tight.

Potential causes (the minority of cases) include……

  • Broken Wrists (Distal Radius Fractures)
  • Underactive Thyroid Gland (Hypothyroidism)
  • Arthritis (Both Rheumatoid and Osteoarthritis)
  • Diabetes
  • Pregnancy
  • Renal Failure
  • Being overweight

For the majority of patients, the diagnosis is quite clear. However it should be remembered that there can be more than one problem going. There may be a trapped nerve elsewhere too contributing to symptoms which can be hard to distinguish from the carpal tunnel syndrome symptoms.

Sometimes it can be useful to send people for Nerve Conduction Studies. These are also called Neurophysiology, “Nerve Tests” or Nerve Conduction Velocities (NCVs).  Do remember that you can still have carpal tunnel, even if the nerve testing comes back as normal.

Treatment

In the majority, when there is no reversible cause and treatment normally follows a stepwise approach.

Splints – these are worn at night. They allow for the nerve to avoid being pinched with the wrist flexed or extended (bent) at the time that a lot of people can be bothered by their symptoms. I tell my patients to keep them on the bed side table and to put them on with their pyjamas at night and remove the splints in the morning.

Steroid Injections – these are a good “try before you buy” and can be used for therapeutic (make you feel better) and diagnostic (prove the diagnosis) reasons. These have a variable effect in various people for a number of reasons – how people metabolise steroid, how severe the nerve compression is etc.

I warn people of potential side effects of steroid injection being

  • Skin depigmentation – an unsightly patch of skin where the steroid “turns off” the pigment producing cells.
  • Fat Atrophy – the steroid can also turn of fat cells which produces a depression under the skin.
  • Steroid Flare – depending how people metabolise steroid, some people will get a temporary worsening of symptoms for a few days after the injection before it works.
  • Damage to nerve – very rare and most doctors would check for any increase in pins and needles before injecting steroid
  • Failure – that the steroid injection makes no difference to the symptoms. This can be for a variety of reasons – it isn’t carpal tunnel that we’re dealing with, the carpal tunnel syndrome was too severe for the steroid to have an effect etc.etc.

Surgery

What the surgery does – the operation releases the nerve and allows the blood supply to it to be improved. This allows the nerve to attempt to repair itself. Nerves are very specialised structures and don’t take damage very well. That’s why I always say the point of the surgery is to give the nerve the best chance to wake up, which can take a long time.

What to expect after surgery – I tell my patients that what goes pretty quickly is the pins and needles that wakes them up at night (unless severe carpal tunnel – see later).  However they swap one problem (pins and needles) for another, albeit temporary, set of problems.

  • The scar is in the palm and as such is very tender after surgery. Massage is essential to this scar to soften it and get it used to touch. This should be started once the sutures have been removed
  • Grip strength is decreased after surgery. This can continue to a symptomatic level for up to three months post surgery. You may lose the last 5-10% of you maximum grip strength permanently, though this is rarely noticed in the majority of patients.
  • Numbness may feel to have increased.  This is a strange thing to appreciate.  I try to explain it as the nerve isn’t all tingly or working normally or numb. Some of it will be each part. The tingling is a very strong sensation and so numbness is often not noticed.  As such, after the operation, once the tingling has gone, people can feel that they are more numb in their fingers than they were before the surgery.
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Carpal Tunnel Scar 5 days post operatively. Sutures still in situ. The purple lines a surgical marks with a temporary sterile pen. Patient Consent Obtained.

The Operation – in my practice, is performed under local anaesthetic. A tight band is placed around your upper arm to avoid bleeding and allow your surgeon to be able to see everything without there being blood to obscure the view.  In my practice, the procedure takes less than ten minutes. Obviously if more time is needed then more time will be taken! I have managed to sit with the tourniquet on myself for 20 minutes so I realise that it is quite unpleasant when it gets to that late stage!

You will have a big bulky bandage on the hand and wrist to protect the wound. The arm should be elevated as much as possible, including while at sleep.  This should minimise the swelling and bruising that any surgery will cause. Fingers should be kept moving as much as possible to minimise stiffness.  At between 10 and 14 days the sutures are removed and scar massage should commence.

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Carpal Tunnel Surgery Scar 6 weeks post op. This patient undertook early mobilisation of fingers, strict elevation of the hand and started with regular, vigorous scar massage on removal of the sutures. Patient Consent Obtained.

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Close up of same patients scar post carpal tunnel release. Patient Consent Obtained.