Symptoms of nerve damage to the shoulder and upper arms may include pain, weakness, paresthesias, or a tingling or prickling, pins-and-needles sensation when there are no known injuries to the affected area, according to the American Academy of Family Physicians. Johns Hopkins Medicine also lists avulsion pain, a burning and crunching type of pain, as a symptom that some patients experience. Symptoms can have either a sudden or progressively worsening onset.
Which symptoms a patient presents with can help to narrow the kinds of nerve injuries that a physician must consider. For example, an injury to the suprascapular nerve often causes weakness in a patient's shoulder or upper arm, but it rarely causes pain or complete numbness.
There are six different types of brachial plexus injuries, and they are categorized by the type of trauma that the nerve experiences, explains Johns Hopkins Medicine. These categories are avulsion, rupture, neurapraxia, axonotemesis, neurotemesis and neuroma. These different types of trauma to nerves have varying prognoses. Ruptures, for example, have a very good chance of healing; avulsions, however, have absolutely no chance of recovery.
Certain conditions that can destroy the myelin sheath, the protective coating that surrounds the nerves, include disorders that cause nerve inflammation throughout the body, deep infections, fractures of the upper arm bone, and shoulder dislocation. These conditions can lead to axillary nerve dysfunction, which presents as numbness over part of the shoulder and shoulder weakness, explains Johns Hopkins Medicine.