Are certain parts of the body more susceptible to nerve damage than others?
 

I was wondering, are certain parts of the body, say peripheral nerves in the feet vs the fingers, more susceptible to crush related injuries?

Is there a place to find out which areas are more susceptible than others?

In a word, yes--
 

--although any nerve in any part of the body can be damaged if the blunt trauma or compressive forces are sufficient.

In general, nerve that are farther from the center of the body--in the periphery, such as feet and hands--are more prone to damage from systemic metabolic or toxic causes, though all nerves can be damaged by such things. This is because the longer the distance from the center of circulation, the more difficult it is for oxygen and nutrients to be transported to these nerves, and the harder it is for metabolic wastes or toxins to be transported out. That is why with things such as diabetic neuropathy the most typical presentation is a "die back"--symptoms occur in the extremities first and if there is progression gradually move towards the center of the body.

Now, having said that, there are specific areas of the body that are particularly prone to crush or compression injuries that are not necessarily at the periphery. These are generally anywhere nerves must pass thorough tightly constricted places and where it is easy for other structures to compress them. Among these are the carpal tunnel area of the wrist, the tarsal tunnel area near the ankle, the lower cervical vertebrae, for which the foraminal openings through which the nerves must pass are generally about a third smaller than those of the upper vertebrae, the lower lumbar vertebrae for a similar reason, the pelvic notch through which the lateral femoral cutaneous nerve of the outer thigh passes, the canal through which the pudendal nerve to the genital area passes, and even the ulnar slot by the elbow.

These are just some of the typical areas that many people experience narrow nerve transit symptoms; undoubtedly, with variation in individual anatomy, there are others for particular people.

And, due to the "double crush phenomenon", people with nerve compromise from systemic causes, if they then also experience compression in these or other areas, may have symptoms "greater than the expected some of the parts". In other words, nerves already damaged by something like diabetes may really act up if compressed as well. Spinal stenosis nerve symptoms tend to be more severe in diabetics, for example.

Thanks, you seem quite knowledgable.

I have a friend that does scalp massage for relaxation with both his hands and a wood bristle brush. He says he has gotten numbness in the fingertips but not the scalp itself. The numbness in the fingertips is isolated and there arent other carpal tunnel symptoms.

Does this mean that in his body his fingertips are more prone to pressure related nerve injury than his scalp?

In his case that might be--
 

--although the fingertips, being at the extremity from the center of circulation, would be a place that systemic neuropathy symptoms would be likely to manifest early.

The problem with many neuropathies is that there are so many possible causes for them--compressive included--that attempting to narrow down the cause can often be a long and difficult process, involving a lot of tests, time, and expense, and often being more a process of elimination procedure than anything more definitive. And, unfortunately, for a significant minority of patients, no direct cause is found and they remain stubbornly in the "idiopathic" category.

Thanks.

Would it be true that the scalp has more direct blood flow (so close to the carotid, etc) than the fingertips so therefore less prone to damage?

Optic Nerve?
 

Hi and I'm sorry if this is the wrong place for this question.
I have moderate-severe narrow vision Glaucoma and did the preventive laser iridotomy in 2012. I am checked every year to make sure the hole is still there and my pressure is ok. Last year a nerve scan showed thinning of my Optic Nerve. This has nothing to do with the narrow angle. No one in my family has Glaucoma. Could it have anything to do with my PN? My eye doctor says no but I want to see if anyone here knows. Thank you. Carol