WHAT IS CARPAL TUNNEL SYNDROME (C.T.S.)?
It is a painful disorder of the hand caused by excess pressure on the Median nerve as it passes through a tunnel at the wrist.
The tunnel is formed by a tough membrane (Flexor Retinaculum) that makes a "roof' to a natural arch produced by the carpal (wrist) bones.
The Flexor retinaculum keeps the tendons and nerves that pass under it in place & provides protection for the nerve.
If structures in or around the tunnel swell then excess pressure on the nerve may cause nerve dysfunction. It is very common in the late stages of pregnancy.
Cross Section of the Wrist
WHAT CAUSES CTS?
Often many factors play a role but the major issue in pregnancy is fluid retention.
One may have many predisposing factors but no symptoms of the condition.
Fluid retention may therefore act as “the final straw”.
- Genetic - often mum also had CTS.
- Age – More common with older mothers
- Obesity – best predictor of developing CTS
- Diabetes or Family history of Diabetes
- Fluid retention
- Hormones – eg under-active Thyroid
WHAT ARE THE SYMPTOMS?
The symptoms typically include tingling and numbness in the hand which wakes you from sleep.
Pain may shoot up the arm from the wrist.
The fingers may feel swollen.
It may be relieved by shaking the hands or hanging them over the side of the bed.
Later – “Constant” Symptoms
- Numbness all day
- Weakness
- Dropping things
- Difficulty picking up small objects.
DIAGNOSIS:
The diagnosis is usually straight forward and is made after eliciting a typical history (as above) and an examination.
Nerve conduction tests are rarely required.
WHAT ARE THE RISKS?
It is usually not a serious problem and often settles when the baby is born.
If the symptoms develop early in pregnancy eg at 20 weeks then it may cause permanent nerve damage.
If the numbness is constant ie present night and day then it may take 12 months to recover.
If you have Gestational Carpal Tunnel Syndrome which settles once the baby is born you have an increased risk of developing CTS later in life.
WHAT IS THE TREATMENT?
-Night Splints (Grenace wrist brace holds wrist straight & opens up the tunnel). Can be obtained from the physiotherapist or from a chemist)
- Oedema Gloves ( control the swelling in the hand)
- Raising bed head to reduce the fluid shift from the legs to the hands at night ( Brick under bedhead)
- Controlling weight gain during pregnancy
-Aerobic Fitness training – You need to be very fit to have a baby. It is the hardest thing you will ever do!
-Cortisone injections
– are safe in pregnancy
- May control symptoms for 4 – 6 weeks
- Will not relieve Constant numbness – only “variable” symptoms
-Surgery
– Not Common
BUT – has been required more frequently in recent years due to:
1. Older mothers
2. Increased incidence of gestational Diabetes.
3. Onset of symptoms earlier in pregnancy
It is indicated when: The risk of permanent nerve damage is high:
1. Early onset in Pregnancy eg before 20 weeks
2. Diabetics
3. Severe symptoms where non-operative treatment is failing
Endoscopic release - involves cutting the membrane (Flexor retinaculum) to create more space in the tunnel for the nerve.
- See separate Information Sheet on this procedure
- The operation is undertaken in close consultation with your obstetrician.
- The operation is performed under local anaesthetic & sedation as a day only procedure.
- It may be less "Bad" to have surgery when pregnant than when you are dealing with a new baby.
- It is desirable to perform surgery before 30 weeks of pregnancy so you have time to recover before the baby arrives.
- Surgery is effective in relieving the symptoms of carpal tunnel syndrome in over 95% of cases.
- Recovery periods are variable but you can use the hand after surgery as Pain permits. You are NOT doing damage by using it.
- Note - If the numbness is constant it is likely to take 9 - 12 months for the nerve to recover.
The major problem with the surgery is persistent weakness or aching pain in the base of the hand when you lean on your hand or make a forceful grip ("Pillar pain").
See Hand Surgery Information and Hand Surgery Risks Handouts.
Recurrent carpal tunnel syndrome is possible but extremely uncommon.
14 / 5/ 2020