Nerve Conditions of the Foot
The foot is composed of bones, ligaments, nerves, muscles, and tendons. Nerve conditions of the foot can range from minor nerve injuries to serious conditions like nerve entrapment and damage. A podiatrist is a doctor specializing in the treatment of foot problems including nerve conditions.
Types of Nerve Conditions
Morton’s neuroma is a nerve injury that occurs due to the thickening of the tissue between the toes, usually the third and fourth toes. Excess pressure is exerted on the nerves situated between the scar tissue and you feel like you are ‘walking on a marble’. Morton’s neuroma is more common in women than in men. Symptoms include pain in the ball of the foot (may also radiate to the toes), numbness in the affected toes and difficulty walking.
Tarsal Tunnel Syndrome
Tarsal tunnel syndrome is a condition where the posterior tibial nerve that lies within the tarsal tunnel is compressed and pinched. The tarsal tunnel is a gap that is formed between the underlying bones of the foot and the overlying tough fibrous tissue.
The exact cause of the condition is not known, but certain conditions, such as fractures, bone spurs, ganglions, benign tumors, muscle impingement or foot deformities, are known to increase the risk of developing tarsal tunnel syndrome. Other medical conditions such as arthritis can cause swelling of the joints that may compress the nerve. Scar tissue formed after an ankle injury and growth of abnormal blood vessels can press against the nerve, resulting in compression and pain.
Foot drop is difficulty lifting the front part of your foot resulting in dragging of the foot. You may lift up your knee higher than usual as if you were climbing stairs. Foot drop may also produce numbness and can affect one or both feet.
Foot drop may be caused by weakness or paralysis of the muscles of the foot, damage or compression of the nerve that supplies the foot muscles, or diseases of the muscles or nerves (muscular dystrophy), brain or spinal cord (stroke and multiple sclerosis).
Charcot-Marie-Tooth Disease is a neurological disorder characterized by damage to the peripheral nervous system which carries signals from the brain to various parts of the body and vice versa. This condition was named after 3 physicians Jean-Martin Charcot, Pierre Marie, and Howard Henry Tooth. The disease causes weakness of the foot, inability to walk or run, foot drop, curled toes and decreased sensation in your legs.
Peripheral neuropathy is a condition of nerve damage, usually in the lower extremities. It is a complication of uncontrolled diabetes which results in the diminished sensation of pain.
Peripheral neuropathy may cause Charcot neuropathy, which affects soft tissues, bones, and joints of the foot and ankle. Bones become fragile and can break or dislocate even with minor forces. Your foot may have redness, swelling, and warmth in the affected area. When left untreated, your foot may become deformed, leading to severe disability and may even require amputation in severe cases.
Plantar fasciitis is an inflammation of the thick band of fibrous tissue that runs along the bottom of your foot (Plantar fascia). It is caused due to repeated strain or overstretching that can result in tiny tears in the ligament, leading to pain and swelling which can make walking difficult.
Your doctor will take your medical history and perform a physical exam. Palpation of the foot and slight tapping of a specific nerve may be performed to identify the nerve condition.
Imaging studies (X-ray, MRI, CT-scan) may be ordered to identify any abnormalities such as overgrowths of bone or tumors that may be compressing the nerve. Nerve tests including electromyography and nerve conduction studies may be performed to examine the affected nerve and locate the area of damage.
Treatment depends on the type of nerve condition and may include:
- Anti-inflammatory medications and corticosteroid injections to help alleviate pain and inflammation.
- Resting your foot and application of ice packs over the inflamed area to reduce swelling.
- Supporting your foot with orthotics, such as specially designed shoe inserts, braces, splints, or change in footwear.
- Physical therapy to relieve pressure and improve the foot function
Surgery is considered if the symptoms fail to resolve with conservative treatments. It may involve the release of the compressed nerve or repair of the damaged nerve.