Unilateral painful legs and moving toes syndrome with moving fingers--evidence for distinct oscillators

Peripherally-induced Movement Disorders: An Update

Background

Peripherally-induced movement disorders (PIMD) should be considered when involuntary or abnormal movements emerge shortly after an injury to a body part. A close topographic and temporal association between peripheral injury and onset of the movement disorders is crucial to diagnosing PIMD. PIMD is under-recognized and often misdiagnosed as functional movement disorder, although both may co-exist. Given the considerable diagnostic, therapeutic, and psychosocial-legal challenges associated with PIMD, it is crucial to update the clinical and scientific information about this important movement disorder.

Methods

A comprehensive PubMed search through a broad range of keywords and combinations was performed in February 2023 to identify relevant articles for this narrative review.

Results

The spectrum of the phenomenology of PIMD is broad and it encompasses both hyperkinetic and hypokinetic movements. Hemifacial spasm is probably the most common PIMD. Others include dystonia, tremor, parkinsonism, myoclonus, painful leg moving toe syndrome, tics, polyminimyoclonus, and amputation stump dyskinesia. We also highlight conditions such as neuropathic tremor, pseudoathetosis, and MYBPC1-associated myogenic tremor as examples of PIMD.

Discussion

There is considerable heterogeneity among PIMD in terms of severity and nature of injury, natural course, association with pain, and response to treatment. As some patients may have co-existing functional movement disorder, neurologists should be able to differentiate the two disorders. While the exact pathophysiology remains elusive, aberrant central sensitization after peripheral stimuli and maladaptive plasticity in the sensorimotor cortex, on a background of genetic (two-hit hypothesis) or other predisposition, seem to play a role in the pathogenesis of PIMD.

Painful legs and moving toes

The syndrome of painful legs-moving toes (PLMT) is an adult-onset, rare disorder characterized by pain, typically of a neuropathic quality, in the feet or legs, associated with writhing movements of one or more toes. It is the pain which usually brings the patient to medical attention. The syndrome may be unilateral or bilateral. Identical toe movements may occur without pain, referred to as: "painless legs-moving toes," and a similar condition affects the upper limbs: "painful arms-moving fingers." The pathophysiology of PLMT and its variants is not known but most reports suggest an association with a peripheral lesion, usually at the level of the root or nerve, though in many cases no cause is found. It has been suggested that a peripheral lesion causes aberrant input leading to "central reorganization," probably at the level of the spinal cord, and that the latter is responsible for the pain and movement. Treatment is often unsatisfactory and many drugs commonly used for neuropathic pain have been reported anecdotally to help (e.g., gabapentin). Other anecdotal therapies include spinal blocks, spinal cord stimulation, and local injection of botulinum toxin.

Case reports: Painful limbs/moving extremities: report of two cases

BACKGROUND

Painful limbs/moving extremities is a relatively rare condition characterized by aching pain in one limb and involuntary movement in the affected fingers or toes. Its pathomechanism is unknown. We report two patients with painful limbs/moving extremities. In one patient with a painful arm and moving fingers, the symptoms were resolved after surgery.

CASE DESCRIPTIONS

Patient 1 was a 36-year-old man with a painful arm and moving fingers. Treatment with administration of analgesics was not effective. Postmyelographic CT showed stenosis of the right C5/C6 foramen attributable to cervical spondylosis and a defect of the contrast material at the foramen. He was treated with cervical foraminotomy. Patient 2 was a 26-year-old woman with a painful leg and moving toes. The pain and involuntary movement appeared 2 weeks after discectomy at L5/S1. Lumbar MRI and myelography showed no indications of nerve root compression. She was treated with a lumbar nerve root block. The pain and involuntary movement completely disappeared in both patients after treatment.

LITERATURE REVIEW

Numerous studies report treatments for painful limbs/moving extremities, but few report successful treatment. Recently, botulinum toxin A injection and epidural spinal cord stimulation have been used and are thought to benefit this condition. Successful surgical treatment previously was reported for only one patient.

PURPOSES AND CLINICAL RELEVANCE

If imaging indicates compression of nerve tissue, we believe surgical decompression should be considered for patients with painful limbs/moving extremities who do not respond to nonoperative treatment.

Painful limbs/moving extremities

Painful limbs/moving extremities (PLME) is a disorder characterized by spontaneous, complex, slow (1-2 Hz) involuntary toe or finger movements. The movements that can be bilateral or unilateral are usually accompanied by pain in the affected limbs. Painless variants are less common. PLME has been associated with peripheral and central nervous system disease although idiopathic cases have been reported. Its etiopathogenesis is unknown and treatment approaches remain largely empirical. Nerve blocks and botulinum toxin type A injections as well as oral medication have had some measure of success. Current theories suggest that central oscillator(s) at the spinal or supraspinal levels may be involved. Future research in PLME should include prospective electrophysiological and functional imaging studies as well as clinical trials with botulinum toxin injections and oral pharmacological agents.

A case report of painless moving toes syndrome

This is the first report of a case of painless moving toes syndrome with radiculopathy. The patient presented with bilateral painless moving toes and unilateral subclinical sacral (S1) radiculopathy. Bilateral movements with the unilateral lesion, and fluctuation with postural changes and distant muscle contraction suggest that the underlying pathomechanism was a central reorganization in the spinal level.

Posterior spinal cord stimulation in a case of painful legs and moving toes

A 59-year-old woman with a 5-year history of right lower limb pain is reported. Symptoms developed initially when walking and progressively became bilateral, appeared at rest and involuntary movements of the toes became evident. A diagnosis of painful legs and moving toes was made. As several drug therapies proved unsuccessful, a therapeutic test with a tetrapolar epidural lead to stimulate the spinal cord dorsal tracts was performed. Due to the marked improvement the device and generator were implanted and she has responded satisfactorily to this therapy for the past 13 months.

A musculoskeletal model of low grade connective tissue inflammation in patients with thyroid associated ophthalmopathy (TAO): the WOMED concept of lateral tension and its general implications in disease

Background

Low level connective tissue inflammation has been proposed to play a role in thyroid associated ophthalmopathy (TAO). The aim of this study was to investigate this postulate by a musculoskeletal approach together with biochemical parameters.

Methods

13 patients with TAO and 16 controls were examined. Erythrocyte levels of Zn, Cu, Ca²⁺, Mg, and Fe were determined. The musculoskeletal evaluation included observational data on body posture with emphasis on the orbit-head region. The angular foot position in the frontal plane was quantified following gait observation. The axial orientation of the legs and feet was evaluated in an unloaded supine position. Functional propioceptive tests based on stretch stimuli were done by using foot inversion and foot rotation.

Results

Alterations in the control group included neck tilt in 3 cases, asymmetrical foot angle during gait in 2, and a reaction to foot inversion in 5 cases. TAO patients presented facial asymmetry with displaced eye fissure inclination (mean 9.1°) as well as tilted head-on-neck position (mean 5.7°). A further asymmetry feature was external rotation of the legs and feet (mean 27°). Both foot inversion as well as foot rotation induced a condition of neuromuscular deficit. This condition could be regulated by gentle acupressure either on the lateral abdomen or the lateral ankle at the acupuncture points gall bladder 26 or bladder 62, respectively. In 5 patients, foot rotation produced a phenomenon of moving toes in the contra lateral foot. In addition foot rotation was accompanied by an audible tendon snapping. Lower erythrocyte Zn levels and altered correlations between Ca²⁺, Mg, and Fe were found in TAO.

Conclusion

This whole body observational study has revealed axial deviations and body asymmetry as well as the phenomenon of moving toes in TAO. The most common finding was an arch-like displacement of the body, i.e. eccentric position, with foot inversion and head tilt to the contra lateral side and tendon snapping. We propose that eccentric muscle action over time can be the basis for a low grade inflammatory condition. The general implications of this model and its relations to Zn and Se will be discussed.

A case of painless arms/moving fingers responsive to botulinum toxin a injections

Painless arms/moving fingers is a rare variant of the painful limbs/moving extremities syndrome (PLME) characterized by slow involuntary movements of the toes or fingers. Its typical form is associated with limb pain. We report the first case of painless arms/moving fingers and describe its favorable response to botulinum toxin A injections. The presence of dystonic symptoms in our case argues in favor of a possible implication of a dystonic mechanism in at least some cases of PLME.

Sympathetic nervous system involvement in the syndrome of painful legs and moving toes

The objective of this study is to investigate sympathetic nervous system involvement in 2 patients with painful legs and moving toes. The first case was studied several years after the initiating trauma produced a peripheral nerve lesion and demonstrated the characteristic sequence of progression of pain and moving toes from the injured leg to the contralateral leg. The second case was initially studied within 3 months of an injury that did not produce definitive signs of a peripheral nerve lesion. Pain increased when the patients were startled and subsided temporarily after sympathetic blockade. In the first patient, toe movements and allodynia to light tactile stimulation persisted during sympathetic blockade, and pain sometimes returned before the vascular effects of blockade disappeared. In the second patient, pain and toe movements could be provoked reproducibly by light tactile stimulation of the affected foot and by sympathetic arousal. These symptoms and signs disappeared after lumbar sympathectomy, and re-emerged when signs of sympathetic reinnervation were detected. We concluded that sympathetic neuronal discharge may provoke pain by activating an impulse generator in the affected limb. Sympathetic involvement in the painful legs and moving toes syndrome appeared to be greater in the second case than the first, presumably due to differences in the initial injury or stage of the condition.

Painful legs and moving toes syndrome associated with herpes zoster myelitis

A 75-year-old woman developed painful legs and moving toes syndrome (PLMT) 16 months after the onset of herpes zoster (HZ) myelitis. Although the scattered extensive lesions due to HZ myelitis were observed to be eccentric near the posterior horn on MRI, these changes had disappeared upon the development of PLMT. Combined median and tibial nerve somatosensory evoked potentials demonstrated abnormal findings only in the tibial nerve stimuli, suggesting that a severe alteration occurred in the somatosensory fibers coming selectively from the lower legs. These findings suggest plasticity in the ascending somatosensory pathway including the posterior horn cells, probably involving the interneuron networks, for the lower legs may underlie the development of PLMT associated with HZ myelitis.

Painful arm and moving fingers: clinical features of four new cases

The syndrome of painful arm and moving fingers associates pain in one arm or hand with involuntary movement of one or several fingers. In the four cases described, an association between a central and a peripheral nervous system lesion is demonstrated or suspected. Treatment of the condition is disappointing.

Bilateral painful hand-moving fingers: electrophysiological assessment of the central nervous system oscillator

We describe a 35-year-old woman who presented with the syndrome of painful hand-moving fingers on the right side. Eight months later, she developed similar finger movements and hand discomfort on the left side. She had a history of hand trauma and recurrent shoulder dislocation on the right side. Kinesiologic electromyography suggested a common central oscillator for finger movements in both hands. Electrophysiological assessment of spinal alpha motor neuron excitability, reciprocal inhibition, and Renshaw cell inhibition failed to show any abnormalities. Somatosensory evoked potential test showed marked attenuation of N20 potential recorded from the left somatosensory cortex; paired transcortical magnetic stimulation of the left motor cortex suggested failure of cortical facilitation. The data suggest that the central oscillator responsible for finger movements is located above the spinal cord level in this patient.