Painful Legs and Moving Toes Syndrome - Causes, Diagnosis, and Treatment

Introduction:

Painful legs and moving toes syndrome (PLMT) is an uncommon movement disorder that causes diffuse pain along the legs and feet often accompanied by involuntary movements of the toes.

• This condition was initially reported in 1971 by Spillane and his colleagues as a pain syndrome.

• Only less than 200 cases have been reported of painful legs and moving toes syndrome till now.

• The clinical presentations of the cases with PLMTT have been updated and revised recently.

• Recent reports show its occurrence even in hands; the condition is also called the painful limbs and moving syndrome. This article will discuss the painful legs and moving toes syndrome, Its causes, symptoms, diagnosis, and treatment in detail.

What Are Painful Legs and Moving Toes Syndrome?

Painful legs and moving toes syndrome (PLMT) is considered to be a neurological movement disorder that is characterized by spontaneous irregular movements of one or more than one toe accompanied by severe diffuse pain along the feet and legs. Earlier it was believed to occur only in the legs, however, cases involving both legs and the hands are reported. The cause of the condition is still unknown. Since it is a very rare condition and there are only limited case reports, Hence there are no proper treatment guidelines for this condition.

What Are the Causes of PLMT?

The exact causes of Painful legs and moving toes syndrome (PLMT) is still debatable and under research. However, cases with PLMT show its association with neuropathic changes in the peripheral and central nervous system or the presence of a history of traumatic injuries. Here are the possible causes of PLMT.

1. Neuropathological Conditions:

• Post-traumatic peripheral nerve injury.

• Focal nerve injury (injury to a single nerve mostly peripheral nerves) such as carpel tunnel syndrome (The condition involves sensations of tingling or numbness in the hand resulting from compression of the median nerve.).

• Polyneuropathy (damage to multiple peripheral nerves).

• Restless leg syndrome manifests as a neurological disorder where individuals experience an uncontrollable urge to move their legs.

• Spinal Cord injuries.

• Cauda Equina (compression of the nerve roots of the lower back spine resulting in loss of sensation and movement).

2. Post-Operative complications.

3. Traumatic injuries of the bone or connective tissues of the foot.

4. Increased protein concentrations of cerebrospinal fluid.

5. History of stroke.

6. Parkinson's disease (a chronic degenerative movement disorder).

7. Wilson’s disease (a disorder that occurs due to the accumulation of copper in the parts of the body).

8. Virus infection-induced neuropathic changes in the nervous system in cases with HIV (Human Immunodeficiency Virus) or HV (Herpes Virus).

What Is the Pathogenesis of PLMT?

• The exact etiopathogenesis of PLMT is still not clear however, few hypotheses suggest the pathogenesis of the condition.

• Normally, The afferent nerve fibers carry sensory information from the receptors to the central nervous system.

• In the PLMT condition, it is believed that the pathologically induced nerve impulses (afferent fibers) from the injured nerve result in abnormal activation of the nerve cells in one of the divisions of the gray matter of the spinal cord (a vital butterfly-shaped structure with an anterior, lateral, and posterior horn).

• This unusual activation in the anterior horn of the spinal cord results in involuntary and irregular movements of the toes.

• Few cases of PLMT show a deficiency of adenosine levels in the blood.

What Are the Clinical Features of PLMT?

Most cases of PLMT are shown to occur more frequently in middle-aged female populations.

• This condition is characterized by pain along the feet and the legs followed by involuntary movements.

• In some cases, they may appear together also.

• The characteristics of pain are usually cramp-like, throbbing, and tearing.

• Numbness, tingling, or electric sensations in the feet.

• The intensity of the pain is usually moderate to severe.

• Sometimes, the pain becomes severe with walking and it gradually reduces when the painful leg is emersed in the water.

• The involuntary movements of the toes may show flexion (bending), extension (opposite of bending), adduction (towards the body’s midline), abduction (away from the midline), and rhythmic piano-like movements.

• The involuntary movements of the toes may be seen in both legs (bilaterally) and rarely do involve the ankle and legs as well.

• Cases with similar spontaneous movements with no pain in the upper extremities are also reported.

How Is PLMT Syndrome Diagnosed?

The diagnosis of PLMT is based on the clinical manifestations of the disease in the patients.

• The doctor will perform detailed history-taking regarding the previous history of trauma, neuropathological conditions, pre-existing diseases, and chronic diseases.

• The physician will examine for indications and symptoms such as widespread and intense pain in the legs and feet accompanied by involuntary movements involving one or more toes.

• The doctor conducts a comprehensive physical examination to assess the magnitude and severity of the involuntary movements.

• Other neurophysiological examinations such as electroneurography (ENG), or electromyography (EMG) may be performed on the patients to examine for possible underlying neuropathological conditions.

How Is PLMT Syndrome Treated?

The obscure pathogenesis of PLMT results in the lack of proper guidelines in the management of PLMT. The treatment of PLMT is primarily focused on the relief of pain in these patients. There are pharmacological and non-pharmacological interventions in the management of PLMT.

Pharmacological Interventions:

• Oral Medications: The primary drug of choice in the treatment of PLMT includes GABA (Gamma-Amino Butyric Acid), beta-blockers, antiepileptic agents, benzodiazepines, atypical antipsychotic drugs, corticosteroids, calcitonin, analgesics.

• In patients with adenosine deficiency, infusion of Adenosine Triphosphate (ATP) was shown to be effective.

• Botulinum Neurotoxin (a biological substance produced from the bacterium Clostridium botulinum): Local injections of botulinum neurotoxin A are used for the reduction of pain in these patients.

Non-pharmocological Interventions:

• In severe cases of PLMT epidural spinal cord stimulation is performed for the management of pain in these patients. In this technique, electrodes are positioned in the dorsal region of the spinal cord, and electrical stimulation is applied through these electrodes to achieve epidural stimulation.

• Patients experiencing moderate to severe pain are additionally recommended to consult a physical therapist for pain management.

• When conservative treatment fails to respond in patients with nerve root compression, they may require surgical interventions such as sympathectomy (surgical dissection and removal of a specific segment of a sympathetic ganglion) or surgical decompression to treat the underlying cause of the PLMT.

Conclusion:

Painful legs and moving toes syndrome is an uncommon condition affecting the feet and legs and involves involuntary movement of the toes. The etiology of the condition is still unknown. However, it is believed to occur as a result of neuropathological conditions or traumatic nerve injuries. In patients with the underlying cause of nerve root compression, the most recommended treatment option is the surgical decompression of the affected nerve root.