Nerve pain has many causes, including:
Nerve entrapment, or a pinched nerve, happens when pressure squeezes the affected nerve. This can happen in many areas of the body, including the wrist (carpal tunnel syndrome), elbow, arm, groin, knee, ankle, and foot.
Common examples include:
Median Nerve- at the wrist, Carpal Tunnel Syndrome -at the elbow between the heads of Flexor Digitorum Superficialis
Radial Nerve- at the arm in the radial groove between the humerus and triceps
Deep Radial Nerve- at the elbow between the Supinator muscles
Superficial Radial Nerve- at the wrist as it crosses over the 1st compartment tendons
Ulnar Nerve- at the elbow Cubital Tunnel between the heads of Pronator Teres muscle -at the wrist between the Pisiform bone and Ulnar artery
Ilioinguinal Nerve- at the Groin between the Internal Oblique/Transversus Abdominus
Genitofemoral Nerve Branches- also Groin- Genital br pubic tubercle; Fem br Fem Vein
Lateral Femoral Cutaneous Nerve- upper thigh between the Sartorius/Tensor Fascia Lata
Common Peroneal Nerve- Lateral knee/upper fibula
Posterior Tibial Nerve- inside ankle, Post Tarsal Tunnel- bottom of foot pain
Deep Peroneal Nerve- top of ankle, Ant Tarsal Tunnel- top of foot pain/first 2 toes
Superficial Peroneal N- Anterolateral Ankle pain
Sural Nerve- Lateral Foot pain
All of these may be considered for steroid injections. Most can be considered for Peripheral Nerve Stimulation. Many can be considered for Radiofrequency Ablation.
Another type of Nerve pain is a Neuroma. This results after a nerve has been cut after a trauma or after amputation of an extremity. This results in the nerve ending bundling up and sending ectopic transmissions causing pain. Many of these neuroma problems may also be considered for a steroid injection, PNS, and/or RFA. Chronic neuroma pain can develop into Chronic Regional Pain Syndrome Type II (see CRPS below). SCS/DRG may then be considered.
Other types of Nerve pain are referred to as Neuropathy. This is typically due to damage at or near the nerve endings. Examples of this are Peripheral Neuropathy, Diabetic Neuropathy, Charcot Neuropathy(due to extensive joint damage). Neuropathy problems can be very difficult to treat.
Chronic Neuropathy problems can develop into Complex Regional Pain Syndrome Type I (see CRPS below) When this occurs one may be a candidate for SCS or PNS.
Complex regional pain syndrome (CRPS)
CRPS has 2 types and is felt to be due to nerve injury, resulting in the dysfunction of the Sympathetic Nerves- which are part of your ‘fight or flight’ response.
The pain does not follow the pattern of a peripheral nerve or the pattern of a nerve root. The pain will cover a region of your body (most commonly the distal extremity). There will be autonomic symptoms with edema, stiffness, color changes, sweating or dry skin. The most common hallmarks of CRPS are Allodynia and Hyperalgesia, which is being extremely sensitive with severe pain with only ‘light touch’ and ‘light pressure’ on your skin, respectively.
CRPS Type I (historically called RSD- Reflex Sympathetic Dystrophy) occurs commonly after extremity injuries/fractures or surgeries for such problems. It is felt this is due to undetectable injuries at the end of the nerve fibers.
CRPS Type II (historically called Causalgia) commonly occurs with peripheral nerve or plexus injuries. Thus with Type II there is a known nerve injury, yet the pain pattern does not follow the nerve pattern.