Health Column August 2018
Home    |    HEALTH COLUMN    |    August 2018

Arm Numbness Medical Care Guide, Diagnosis, and Treatment
By Dr. Lin Xing-Qing & DPT Li Guan-Jie
 

Your arm feels numb and a bit painful, and it feels strange in a way that’s hard to describe. At first, it only felt numb in certain positions when exercising, but now the numbness is constant. In addition to numbness, the arm feels weakened and the muscles may have even shrunk; all of your previous weight training gone to waste.
These symptoms could very likely be a nerve pain problem, which may be indirectly caused by aging or long-term poor posture, or it could be the result of nerve injury or nerve compression stemming from a sports injury or car accident.
 
This article will tell you:
  1. If you encounter this type of problem, how should you see a doctor?
  2. How should you communicate with your doctor?
  3. How can you easily determine the possibility of arm numbness?
  4. What methods are there to check for nerve pain and nerve compression?
  5. Is surgery necessary? Other than surgery, what treatment options are available?

How should you see a doctor for arm numbness and nerve pain?

For arm numbness and nerve pain, you can choose to visit the Department of Rehabilitation, Neurology, or Neurosurgery. The following are important points you can discuss with your doctor in order to help them find the cause of your arm numbness:
  1. Where do you feel numbness? Where do you feel pain?
  2. How long ago did the symptoms start?
  3. How long do symptoms last during a flare-up?
  4. How does it become numb or painful? Which positions are uncomfortable and which are more comfortable?
  5. Is the numbness accompanied with weakness?
  6. Do you have any medical conditions? Have you ever had surgery? Are you taking medicine?
  7. Your lifestyle
 
These questions conform to the common"What, Where, When, How" ; it is recommended that you frequently keep a record of your physical status, as this will help you to communicate with your doctor as opposed to relying on memory. Please remember that when describing your condition to your doctor it is not necessary to start from the story of how your grandparents met; time is of the essence.

A Brief Introduction of Your Nervous System

Before talking about how doctors test and diagnose nerve pain, we will briefly talk about the nervous system. Your brain is the boss of your nervous system, and your nerves start from your brain, going through your spine before spreading to each part of your body. Nerves outside of your spine are called peripheral nerves, which can be divided into autonomic nerves, motor nerves, and sensory nerves. If a part of this long nerve is injured, compressed, or poorly treated, nerve pain will emerge. As nerves are both dense and long, how should you have them tested? Apart from the doctor's consultation mentioned in the previous section, the following will tell you about possible diagnostic methods and testing instruments.

Possible diagnoses for arm numbness and nerve pain

From the previous chart we learned that nerves spread downward like the branches of a tree, dividing and becoming thinner; moreover, every nerve fork controls a different sensory area and movement. Generally speaking, when the problem area is farther upstream (closer to the brain), the areas downstream will also have problems. For example:
  1. If both of your arms are numb, the problem is very likely in your spine.
  2. If one arm is numb from the top down, it could be that the nerve is compressed at the point it branches out from the spine.
  3. If the numbness is below the wrist, and the thumb, index and middle finger are numb, the median nerve could be compressed.
  4. If the ends of your hands and feet are numb, it could be multiple neuropathies caused by diabetes.
  5. If your arm becomes numb when raised, and the numbness subsides upon release, it could be thoracic outlet syndrome, in which your neck muscles temporarily compress a nerve or blood vessel​

In addition, medications, alcohol, kidney disease, tumors and more may cause arm numbness, so maintaining a healthy lifestyle is extremely important. If your arm goes numb when you wake up from a nap at your desk and the numbness quickly subsides, then I don’t think you need to be too worried, you simply placed pressure on your arm for too long.
Next, we will be discussing some medical devices that can help doctors find the root cause of the problem.

X-Ray and Magnetic Resonance Imaging (MRI)
X-rays can be used to check for normal spinal alignment, bone spurs, narrowing and thinning of intervertebral disks that can affect the nerve cavity, spinal ligaments calcification, tumors, and more. In more serious cases, MRI is used to look at structural issues, such as if nerves are being compressed by a protruding disk. However, the images taken using X-ray or MRI cannot definitively identify the cause of the problem, just like how bigger people are not necessarily stronger, they may just be taller.
 
Soft tissue ultrasound
If we suspect that your arm numbness could be caused by median nerve compression in your wrist or inflammation, then soft tissue ultrasound is a good choice. Most doctors using soft tissue ultrasounds have the ability to examine the median nerve in the wrist; although ultrasound cannot replace electromyogram (EMG) in testing for compression or inflammation swelling, it can be used to rule out compression caused by structural issues, choose the location of the injection, and help to make a diagnosis.
 
Electrical diagnosis
Usually, only hospitals will have electrical diagnostic testing, such as EMG, nerve conduction velocity, and muscular electrical stimulation.
Simply put, EMG examines what areas have uncontrolled electrical discharge, the level of injury to the nerve, whether it is an acute injury, if there has been recovery, and more. Using EMG, you can see what segment of your nerve conducts more slowly, or learn what segment of the nerve is decaying or growing based on the shape of the electrical waves. But (there's always a but), electrical testing is not always accurate. First, it relies heavily on the technique of the operator; second, if your arm numbness has multiple simultaneous causes it can be difficult to test; third, it can be difficult to test if your arm has not been numb for more than three weeks.
 

Treatment methods for arm numbness, nerve pain, and nerve compression

Treatment methods can be divided into surgical and nonsurgical (conservative treatment).
 
Surgical: Generally, the doctor will evaluate whether surgery is necessary. Generally speaking, if the muscle feels weak and atrophied or there are involuntary movements, following three to six months of conservative treatment follow-up EMG or images show that your nerves' condition continues to deteriorate or there is evidence of acute nerve necrosis, surgery is recommended; however, this recommendation is not a guideline, simply an expert's opinion.
 
Nonsurgical (conservative treatment): If your doctor determines that the problem is not serious, and there is no acute nerve damage or necrosis, conservative treatment will generally be administered.
  1. The most common conservative treatment is physical therapy covered by National Health Insurance (NHI), such as traction (e.g. neck pulling), which can relieve symptoms.
  2. A method with a higher level of supporting evidence is steroidal injection with a stabilizing splint to ease compression of peripheral nerves. If there is median nerve compression, such as carpal tunnel, we can try median nerve anesthetization, anti-inflammatory medicine, or nerve hydrodissection.
  3. Self-paid treatments include: Strength training, because strengthening the small muscles that stabilize and support the spine can open up more space for your nerves. Nerve mobilization is a common form of manual therapy, in which a special push-pull technique and pump effect is used to increase blood flow to the nerves while simultaneously decreasing nerve tension. This can be used complementarily to injection and splint treatments.
 
Please remember, these treatments should be assessed and performed by a professional physical therapist in order to prevent your condition from worsening; for example, those with carpal tunnel should be especially careful.

Retrieved from:好痛痛 - 復健科、骨科、物理治療醫療資訊
https://blog.easepain.tw/lin-hsin-chin/neuralgia/