Numbness or pins and needles in the hands and carpal tunnel syndrome
Le canal carpien
Numbness or pins and needles in the hands amongst amyloidosis patients: is it carpal tunnel syndrome?
Numbness or pins and needles in the hands is typical of carpal tunnel syndrome. Symptoms like tingling or numbness affect the hands, more specifically the thumb, the index finger and the middle finger. These sensations can quickly turn painful and sometimes spread towards the forearms and elbows. Having this problem in both hands is very common. These symptoms usually show up at night and can disturb patients’ sleep, often in the early morning (around 3am). They usually disappear after a few minutes of shaking the hands. It is important to get this treated because if left, the motor fibres can become damaged and the thumbs’ ability to grip can deteriorate, making gripping objects, and consequently daily life, much more difficult.
The examination for this involves detecting symptoms of carpal tunnel syndrome such as difficulty recognising small objects when the eyes are closed or having reduced muscle mass at the base of the thumbs. Movements like applying pressure to the median nerve or flexing the wrist can prevent these problems from occurring or getting worse. Electromyograms are often used to confirm this diagnosis.
This syndrome is as a result of the median nerve being compressed in the wrist section of the carpal tunnel. The carpal tunnel does not stretch, and it contains the median nerve tendon which is surrounded by synovial fluid. This nerve is responsible for sensation in the flesh of the thumb, index finger and middle finger and also for motor function in certain muscles in the thumb, like the thenar muscles.
In amyloidosis patients, amyloid fibres are deposited in the synovial fluid, causing it to thicken and the carpal tunnel’s volume to increase despite its inability to stretch. The components of the carpal tunnel are then very tightly packed in. The first thing to be compressed is the median nerve because it is the most fragile. The electrical impulse which passes through also becomes weaker and the symptoms develop progressively as the amount of deposits increases.
Amyloidosis is not the only illness which causes carpal tunnel syndrome; it can also be linked to hypothyroidism, diabetes, rheumatoid polyarthritis and work which involves a lot of wrist movement.
Carpal tunnel syndrome can precede heart disease in amyloidosis patients by several years. It is common to find out that a cardiac amyloidosis patient had a bilateral procedure 5 to 10-years before other amyloidosis symptoms started.