Focal Neuropathy

 
Print this page/section and all subsectionsPrint this page/section and all subsections
VIB.B.0

Lead Author(s): 

Jonathan S. Kirschner, MD, RMSK
Se Won Lee, MD

Supporting Author(s): 

Sylvia I. Watkins-Castillo, PhD

A focal neuropathy means only one or, at most, a few nerves are injured. Pain, numbness, and weakness are confined to a single limb or a small region of the trunk or head. Focal neuropathies are typically caused by compression or trauma. Carpal tunnel syndrome is an example of a focal neuropathy.  It is a common syndrome characterized by nighttime numbness and tingling in the hand, caused by compression of the median nerve in the wrist.

Mononeuropathy

Mononeuropathy is a form of neuropathy that affects a single nerve or, more rarely, a nerve group (mononeuritis multiplex). There may or may not be pain, followed by loss of sensation, strength, and overall function depending on the type. These types of neuropathies are typically due to injury, compression, aging, inflammatory disorders, or other systemic diseases. Examples of mononeuropathy include carpal tunnel syndrome, ulnar neuropathy, trigeminal neuralgia, radial neuropathy, peroneal neuropathy, radiculopathy and occipital neuralgia.

Mononeuropathy can develop if there has been a prolonged period of swelling or pressure placed on a specific point in the body such as the hands, feet or face. Symptoms of mononeuropathy include loss of feeling, tingling, burning, muscle weakness, and paralysis.

Carpal tunnel syndrome

Carpal tunnel syndrome is the most common mononeuropathy and is caused by entrapment of the median nerve in the carpal tunnel at the wrist. It is a slowly progressive condition causing tingling, numbness, and pain in the hand, typically the first 3.5 fingers (thumb to half of ring finger), with weakness and wasting of muscle in the thumb. Based on different studies, the incidence varies between 0.99 to 3.5 persons per 1,000 person-years.1,2 Higher incidence has been reported in women and working populations requiring repetitive wrist motions. Carpal tunnel syndrome is diagnosed based on the clinical information (history and physical examination) and confirmed by electrodiagnostic tests (EDx) consisting of nerve conduction studies (NCS) and electromyography (EMG).

Ulnar neuropathy

Ulnar neuropathy is the second most common entrapment neuropathy and most commonly occurs at the elbow, where it is known as “cubital tunnel syndrome”. It presents with weakness of the hand, along with tingling, numbness, and pain in the inner side of the hand and fingers (half of ring finger and pinky). It is often triggered from irritation of the “funny bone” where the nerve is exposed along the inner aspect of the elbow.  

Plexus Neuropathy

The brachial plexus is a network of nerves that originate in the neck region and branch off to form most of the other nerves that control movement and sensation in the upper limbs, including the shoulder, arm, forearm, and hand. The radial, median, and ulnar nerves originate from the brachial plexus.

Brachial plexus injury (BPI) is an umbrella term for a variety of conditions that may impair function of the brachial plexus nerve network. Most pediatric and adult brachial plexus injuries are caused by birth or trauma, such as high-speed vehicular or motorcycle accidents, blunt trauma, stabs or gunshot wounds. It can also be the result of inflammatory processes, compression (e.g., caused by a growing tumor, thickened muscles, or the collar bone), or genetic mutation. Symptoms are pain, loss of sensation, muscle weakness, and varying degrees of paralysis.

Root Neuropathy (Radiculopathy)

Radiculopathy is a nerve root disorder that can cause numbness, tingling, pain, and weakness.  It is typically caused by acute or chronic pressure on a nerve root as it exits the spinal canal. The most common cause is a herniated intervertebral disc in younger patients, and spinal stenosis, or narrowing of the spinal canal, in older patients,. There are also several less common causes such as meningitis, tumors, diabetes, and infections.

Cervical radiculopathy typically causes pain radiating form the neck to the arm or shoulder blade region., often accompanied by tingling, numbness or weakness. The prevalence of cervical radiculopathy is 3.3 cases per 1000, with average age-adjusted incidence rate of .8 cases per 1000 persons. Lumbosacral radiculopathy typically presents as “sciatica”, pain radiating from the lower back into the buttock, thigh and/or leg. It is more common than cervical radiculopathy with a prevalence of 3% to 5% of the adult population, which is evenly distributed between men and women.3 Most radiculopathies related to disc herniation are self-limiting with symptoms resolving over the course of weeks to months.4
 

  • 1. Wolf JM, Mountcastle S, Owens BD. Incidence of carpal tunnel syndrome in the US military population. Hand (NY) 2009;4(3):289-93.
  • 2. Nordstrom DL, DeStefano F, Vierkant RA, Layde PM. Incidence of diagnosed carpal tunnel syndrome in a general population. Epidemiology 1998;9(3):342-5.
  • 3. Tarulli AW and Raynor EM. Lumbosacral radiculopathy. Neurol Clin 2007;25(2):387-405.
  • 4. Casey E. Natural history of radiculopathy. Phys Med Rehabil Clin N Am 2011;22(1):1-5.

Edition: 

  • Fourth Edition

Chapter Graphs

To save an individual graph, right-click and select Save Image As

Topic Tables

Click on an image to view PDF