Nerve conduction studies

The NCS show a grade 1 (out of 6) bilateral CTS so this is very mild. I tend to be very wary of surgery in grade 1 - the surgical outcomes are relatively poor and there are quite strong arguments for trying less risky alternatives first. The right hand is affected just because CTS is usually bilateral, and I doubt if work has much to do with it except as a trigger factor in someone who is probably destined to develop CTS in any case.

They did do some ulnar nerve studies on the left arm which looked normal at the wrist so they seem not to have bothered looking in more detail at the elbow. Given the results we do have it is not likely that there is a serious ulnar nerve lesion but there could be mild problems with the ulnar nerve at the elbow.

The sural nerve sensory potentials from your feet are normal (that's where you can see the -0.3 result but it is the other figures in that line which matter)

EMG is not usually a very good test for lumbar radiculopathy unless you have muscle weakness and wasting and if you have those then EMG is probably redundant anyway.

Given the very mild nature of the NCS abnormality the first thing to consider here is whether that abnormality is responsible for the symptoms but looking at your questionnaire answers it does seem at least fairly probable that you do have CTS. Given that, the obvious first aid measure would be a well fitted night splint for a few weeks - if you are lucky it might solve the problem and if not then you have lost very little. JB

Thank you for your reply, Dr. Bland.

Having had an appointment with neurologist yesterday, I am now totally confused. Neurologist undertook the physical tests for CTS, and all were negative. Due to this, plus the fact that my symptoms are not usual - i.e. whole hands affected, tingling and pain in left wrist despite nerve conductor test showing this area as normal, pain in elbow - his view is that these symptoms are not due to CTS.

I find that if I lie with either of my hands under my head (i.e. supporting my head) I experience severe pins and needles, and am not sure whether this is typical or atypical of CTS?

Because of additional tingling and lack of temperature control in feet, neurologist has advised a brain MRI to look at possibility of MS. At age 55, I thought I was too old to be diagnosed with this, but apparently not (previous brain scan 6 years ago was normal). I appreciate that it is not your remit to comment on this issue. Scan and next appointment will take two weeks, which will be a very anxious time. There is no sign of muscle/nerve weakness in feet or hands.

Neurologist said that the only way to be sure re carpal tunnel is to cut in order to view whether the median nerve is compressed. I am surprised that there is no other means, e.g. MRI of this area?

Neurologist also said that even when the nerve conductor tests assess CTS as mild, patient may experience symptoms which are at a severe level?

The physical tests for CTS are profoundly ureliable and should usually be ignored. The only examination findings which are reliable are sensory loss and weakness of the thenar muscles and by the time you have those it is too late - you need to recognise CTS before they develop really.

It's hard to know what to make of the hand under head story - what matters is the wrist position. Unless you set up a video camera to record what you do while you are asleep you are basically not going to know what sleeping position is actually related to the development of symptoms - it's not necessarily the one you wake up in.

MS can occur at any age and it has been mistaken for CTS but it's a lot rarer than CTS so on purely statistical grounds you are much more likely to have CTS than MS. There isn't much downside to MRI, though it does have a significant false positive rate and can sometimes show 'abnormalities' which will cause worry and further investigation even though the 'abnormality' is something which would never have caused you any problem if the MRI had not been done.

I'm afraid the idea that the only way to be sure about CTS is to cut is nonsense. Did the neurologist really say that? Visual assessment of the nerve at surgery is probably even more unreliable than the physical tests and the response of the symptoms to surgery cannot be relied upon either - some patients who do have CTS will not improve with surgery, while some patients who do not have CTS will improve I'm afraid - just because whatever they did have either remits spontaneously or responds to the two weeks of rest imposed by the operation.

The best (though not perfect) test for CTS is the nerve conduction studies. Second best, and sometimes abnormal when the NCS are normal, is ultrasound imaging. Third best, but by far the most expensive, is MRI.

The thing that the neurologist is right about here is that people with mild nerve conduction abnormalities can have subjectively severe symptoms. There is nothing surprising about this. Consider sticking your hand in a fire before and after cutting the nerves to the hand, before you sever the nerve you will have perfectly normal nerve function but will get  severe pain from the burn, after cutting the nerves you will have severely abnormal nerve conduction.... but no pain from burning the hand, ie there is no intrinsic linkage between the severity of symptoms and the severity of nerve damage.

Given symptoms which are partly suggestive of CTS (with some odd features that don't fit) and mild nerve conduction abnormalities I still think your quickest and safest course of action is to try some non-surgical treatment for CTS - splinting and/or injection. If the symptoms resolve then it adds a great deal of weight to the diagnosis of CTS. If the symptoms are unaffected then you have taken very little risk and can carry on looking for other explanations. JB

Thank you for your kind response, Dr. Bland. I was wondering that given the whole hands are affected, plus in particular tingling in little finger of left hand and pain in left elbow, if I might have cubital tunnel syndrome as well as CTS? I don't think the nerve conductor tests I had would have covered this possibility?

They didn't test comprehensively for cubital tunnel. However a fair proportion of patients who only have CTS do get symptoms outside the territory of the median nerve. We do see a few people with multiple nerve entrapments and you always wonder about there being an underlying cause such as diabetes in such cases. Pain in the elbow is not normally a major feature of ulnar nerve entrapment at the elbow. JB

Thank you once again for your help and patience, Dr. Bland.