My Hand is Numb

Numbness in the hand is one of the more frequently encountered symptoms in the medical field. While the brain and spinal cord can be the source of the patient’s numbness, this and similar symptoms will usually arise from the nerve roots or points further toward the hand. Pinched nerves in the neck definitely cause numbness in hands. Also, pressure at other sites such as the elbow or more commonly at the wrist (carpal tunnel syndrome) are the big players here.
The journey towards a solution of this clinical issue will likely start with the primary physician although orthopedists, neurosurgeons, neurologists or physiatrists are often the first stop. Generally, it is quite easy to determine the peripheral nature of the problem as a more central abnormality such as a brain or spinal cord lesion can be typically excluded based on the physical examination.

The source of the nerve problem is typically identified by electrophysiologic testing. Neurologists do two types of neurophysiological testing including EEG and EMG. EEG is also known as electroencephalography and is used exclusively for issues of the brain. Electromyography also known as EMG is a two-part examination that will almost always provide the answer for hand numbness as well as other symptoms such as weakness or pain.

The first part of the examination is called nerve conduction studies. Here, via surface electrodes, the condition of the nerve is tested by applying electric shocks at various sites along the course of the nerve. Measuring the distances and timing the response, the efficiency of the nerve transmission can be identified. The shocks can be a little bit unpleasant but are tolerated quite well even by small children. The second part of the examination is the so-called needle examination.
This part of the examination involves the placement of a very thin needle-type electrode in various muscles. The electrical activity is demonstrated on a screen next to the patient, and the signal is also transformed into an audible form that the examiner can hear simultaneously. The outcome of this type of examination will often be a very clear diagnosis that can guide therapeutic intervention such as an injection, surgery, splinting or occupational therapy.

Often abnormalities will be discovered for which the patient has no obvious symptoms. Numbness in the hand may be the first indication of a widespread nerve disease such as polyneuropathy which is seen in many conditions including certain toxicities, diabetes, thyroid disease, vitamin deficiencies such as B-12. This is very useful information as it will alert the clinician to begin a search for the various causes of neuropathy which may guide early therapy and prevent long-term complications.

Electromyography is a very valuable tool and is underutilized in the medical field. Mild nerve problems due to B-12 deficiency may inform the physician long before the serious brain symptoms appear. If you have numbness anywhere in your body that persists, please see your family doctor or other healthcare practitioner.
Getting help means you’re getting serious!

David Sudderth MD

Dr. Sudderth practices in Fort Myers Florida and his fellowship-trained in electromyography.