Tibial nerve neuropathy

 

Symptoms and Clinical Presentation of Tibial Nerve Neuropathy

Damage to the tibial nerve (sometimes referred to as tibial neuritis if inflammation is present) causes a characteristic set of motor and sensory deficits.

 

Motor Deficits

Paralysis or weakness of the muscles innervated by the tibial nerve leads to:

• Inability or Weakness of Foot Plantar Flexion: Difficulty pointing the foot and toes downwards (e.g., standing on tiptoes, pushing off during walking).
• Inability or Weakness of Toe Flexion.
• Weakness of Foot Inversion (turning the sole inward).
• Loss of the Achilles Reflex (Ankle Jerk): This reflex (S1-S2 mediated) is typically lost or significantly diminished in tibial nerve lesions at or above the ankle.

 

Sensory Disturbances

Sensory loss or alterations (numbness, tingling, paresthesias, pain) in tibial nerve neuritis typically occur on:

• The posterior aspect of the lower leg.
• The sole of the foot (plantar surface).
• The plantar surfaces of the toes.
• Often extending to the dorsal aspects of the terminal phalanges (fingertips of the toes).

Joint-muscular sense (proprioception) in the toes is generally not significantly affected by an isolated tibial nerve lesion if the function of the peroneal nerve (which also contributes to foot sensation and proprioception via some deep branches) is preserved. Proprioceptive loss is more prominent when both nerves are jointly damaged (e.g., in a complete sciatic nerve lesion) or with more proximal sciatic nerve trunk involvement.

 

Gait Abnormalities and Foot Deformity

• Gait Difficulty: While less dramatic than the "steppage gait" of peroneal neuropathy, tibial nerve palsy makes push-off during walking difficult, leading to a flat-footed or calcaneal gait (walking on the heel due to unopposed dorsiflexion from the peroneal nerve, and inability to plantarflex). The foot is often held in a position of dorsiflexion and eversion ("calcaneovalgus" deformity) due to the unopposed action of dorsiflexors and evertors innervated by the peroneal nerve.
• Muscle Atrophy: In chronic tibial nerve neuritis, muscle atrophy is usually significant and affects the posterior muscle group of the lower leg (calf muscles) and the intrinsic muscles of the sole of the foot. This can lead to a deepening of the arch of the foot and retraction (clawing) of the intertarsal spaces (though "claw toes" are more complex and involve imbalance with lumbricals/interossei).

 

Pain and Autonomic/Trophic Changes

Pain associated with tibial nerve neuritis (or neuralgia involving its fibers, especially within the sciatic nerve or at entrapment sites like the tarsal tunnel) is often extremely intense and can be burning or causalgic in nature. Injuries to the tibial nerve and its bundles within the sciatic nerve trunk are particularly prone to causing the **causalgic syndrome** (Complex Regional Pain Syndrome Type II), characterized by severe, persistent burning pain, allodynia, hyperalgesia, and autonomic dysfunction.

Vasomotor, sudomotor (sweat), and trophic (skin/nail) disorders are also usually significant with tibial nerve lesions, similar in some respects to those seen with median nerve injuries in the upper limb. This can include changes in skin color and temperature, altered sweating patterns, and dystrophic changes in the skin and nails of the sole and toes.

 

Specific Clinical Tests

Tests to determine movement disorders in tibial nerve neuritis include:

1. Inability to perform active plantar flexion of the foot and toes.
2. Inability to perform active inversion of the foot.
3. Inability to stand or walk on the toes.
4. Tinel's Sign: May be positive over the tarsal tunnel if entrapment is present there, eliciting pain or paresthesias into the sole of the foot.

 

Treatment of Tibial Nerve Neuropathy

The treatment for tibial nerve neuritis or neuropathy is selected individually for each specific case, taking into account the underlying cause, severity of symptoms, and duration of the condition. It typically includes a comprehensive set of conservative procedures, and surgical intervention may be considered in certain circumstances.

 

General Principles and Conservative Management

• Addressing the Underlying Cause: If a specific cause is identified (e.g., compression from a cyst or tumor, systemic disease like diabetes, trauma), treatment of that primary condition is paramount.
• Pain Management:
  • NSAIDs for inflammatory pain.
  • Neuropathic pain medications (gabapentin, pregabalin, tricyclic antidepressants, SNRIs) are often essential for nerve-related pain, especially causalgia.
  • Topical analgesics or capsaicin cream.
• Immobilization/Support:
  • Ankle splinting or orthotics (e.g., an AFO modified to prevent excessive dorsiflexion or to support the arch) may be used to protect the foot, prevent contractures (e.g., Achilles tendon shortening), and improve gait in some cases of weakness.
• Protection of Anesthetic Areas: Meticulous foot care is essential if there is significant sensory loss on the sole to prevent pressure sores, injuries, and infections.

 

Pharmacological Treatment

• Corticosteroids: A short course of oral corticosteroids or local corticosteroid injections (e.g., into the tarsal tunnel for entrapment) may be considered to reduce inflammation and swelling around the nerve.
• Vitamins: B-complex vitamins (B1, B6, B12), Vitamin C, and Vitamin E are often prescribed as supportive therapy for nerve health, although strong evidence for their efficacy in promoting nerve regeneration in all types of traumatic or compressive neuropathy is varied.
• Homeopathic Remedies: Some patients explore these options, but their effectiveness is not supported by robust scientific evidence for nerve regeneration or significant pain relief in established neuropathy.

 

Rehabilitative Therapies

Physical and occupational therapy are crucial for maximizing functional recovery.

• Physical Therapy:
  • Exercises to maintain or improve range of motion of the ankle and toes, preventing contractures.
  • Strengthening exercises for weakened plantar flexor, invertor, and intrinsic foot muscles as reinnervation occurs.
  • Balance and gait training.
  • Modalities to reduce pain and inflammation (e.g., heat/cold therapy, ultrasound).
• Acupuncture: Can be very effective for managing neuropathic pain and potentially improving nerve function and sensory symptoms in some individuals with tibial neuropathy.
• Nerve Stimulation and Muscle Stimulation:
  • Transcutaneous Electrical Nerve Stimulation (TENS) for pain control.
  • Neuromuscular Electrical Stimulation (NMES) to help maintain muscle mass, prevent disuse atrophy in denervated muscles, and potentially facilitate muscle re-education during nerve recovery. Neurostimulation (physiotherapy) can help eliminate paresthesias and pain, and aid in restoring strength in muscles affected by tibial neuropathy.

Surgical Intervention

Surgical treatment for tibial nerve neuropathy is considered if:

• Conservative management fails after an adequate trial period.
• There is a clearly identified and surgically correctable cause of nerve compression or injury (e.g., tumor, ganglion cyst, scar tissue entrapment in the tarsal tunnel, traumatic nerve transection).
• Progressive neurological deficit occurs despite conservative measures.
• Severe nerve damage is evident on electrodiagnostic studies with no signs of recovery.

Surgical procedures may include:

• Neurolysis: Surgical decompression of the nerve by releasing it from scar tissue, fibrous bands, or other compressive structures (e.g., tarsal tunnel release).
• Nerve Repair (Neurorrhaphy): Direct suturing of a transected nerve trunk.
• Nerve Grafting: If a segment of the nerve is severely damaged or missing, a nerve graft (often using the sural nerve) is used to bridge the gap.
• Excision of compressive lesions (e.g., tumors, cysts).
• Tendon transfers or other reconstructive procedures for permanent paralysis if nerve recovery is not expected.

 

Differential Diagnosis of Foot/Ankle Weakness and Sensory Loss

Symptoms of tibial neuropathy must be differentiated from other conditions causing similar deficits in the lower leg and foot:

Condition	Key Differentiating Features
Tibial Nerve Neuropathy	Weakness of plantar flexion, toe flexion, and inversion; sensory loss on sole of foot and posterior leg; Achilles reflex lost. Specific site of lesion (e.g., popliteal fossa, tarsal tunnel).
S1 Radiculopathy	Weakness of plantar flexion (gastrocnemius/soleus), often with back pain/sciatica radiating in S1 dermatome. Sensory loss in S1 dermatome. Achilles reflex often diminished/absent. Positive straight leg raise.
Sciatic Neuropathy (affecting both tibial and peroneal divisions)	Weakness of all muscles below the knee (foot drop + plantar flexion weakness), hamstring weakness (if lesion is high). Sensory loss in both peroneal and tibial distributions. Achilles reflex lost.
Lumbosacral Plexopathy	More widespread weakness and sensory loss in multiple lumbosacral nerve distributions, often asymmetrical.
Peroneal Nerve Neuropathy	Foot drop (weak dorsiflexion/eversion). Sensory loss on anterolateral leg/foot dorsum. Plantar flexion and inversion normal. Achilles reflex normal. (Antagonistic deficits to tibial neuropathy).
Peripheral Polyneuropathy (e.g., Diabetic, Alcoholic)	Usually symmetrical, distal "stocking" sensory loss, weakness, and reflex changes. Both tibial and peroneal (and other) nerves affected.
Compartment Syndrome (Posterior Compartment)	Severe pain, swelling, tenseness in calf, paresthesias, weakness of plantar flexion. Often after trauma or exertion. Pulses may be diminished. Medical emergency.
Achilles Tendon Rupture	Sudden severe calf pain, palpable gap in tendon, inability to plantarflex actively against resistance (though some weak plantarflexion by other muscles may be possible). Positive Thompson test.
Plantar Fasciitis	Heel pain, particularly with first steps in the morning or after rest. No primary neurological weakness or sensory loss (though nerve entrapment can co-occur).

 

Prognosis and Potential Complications

The prognosis for tibial nerve neuropathy depends on the cause, severity, and duration of the nerve injury, as well as the timeliness and effectiveness of treatment.

• Mild compressive or traction injuries (neurapraxia) often have a good prognosis with conservative management.
• More severe axonal damage (axonotmesis) allows for regeneration, but recovery can be slow (approx. 1 mm/day) and may be incomplete, especially for high lesions.
• Complete nerve transection (neurotmesis) has a poor prognosis without surgical repair, and even then, full recovery is often not achieved.

Potential complications include:

• Persistent weakness of plantar flexion and intrinsic foot muscles, leading to gait difficulties (e.g., inability to push off, calcaneal gait) and impaired balance.
• Chronic neuropathic pain (e.g., causalgia, tarsal tunnel syndrome pain).
• Permanent sensory loss on the sole of the foot, increasing the risk of unrecognized injuries, pressure sores, and neurotrophic ulcers.
• Muscle atrophy in the calf and foot.
• Foot deformities (e.g., clawing of toes, pes cavus due to intrinsic muscle imbalance).
• Joint contractures (e.g., ankle dorsiflexion contracture).

 

Prevention Strategies

Preventive measures are primarily aimed at avoiding trauma and managing underlying conditions:

• Careful positioning during surgery or prolonged immobilization to avoid pressure on the nerve in the popliteal fossa or around the ankle.
• Proper management of systemic conditions like diabetes.
• Avoiding direct trauma to the knee, leg, and ankle.
• Using appropriate footwear to prevent foot deformities that might predispose to tarsal tunnel syndrome.
• Awareness of activities that might put the tibial nerve at risk of compression or stretch.

 

When to Consult a Specialist (Neurologist, Neurosurgeon, Orthopedist)

Medical evaluation by a neurologist, neurosurgeon, orthopedic surgeon, or physiatrist is recommended if an individual experiences:

• Weakness in pointing the foot or toes downward, or difficulty standing on tiptoes.
• Numbness, tingling, or pain on the sole of the foot or posterior aspect of the leg.
• Changes in gait, such as difficulty pushing off or a tendency to walk on the heel.
• Symptoms suggestive of tarsal tunnel syndrome (pain/paresthesias in the sole radiating to toes, often worse at night or with activity).
• Following an injury to the knee, leg, or ankle that results in these symptoms.
• Development of foot deformities or non-healing ulcers on the sole.

Early diagnosis and appropriate management are essential to optimize recovery and prevent long-term disability from tibial nerve neuropathy.