Selective neurotomy of the tibial nerve in the spastic hemiplegic child: an explanation of the recurrence

[Surgical procedures for treatment of spasticity]

BACKGROUND

The causes of spasticity are various and include cerebral palsy, spinal cord injury, stroke, multiple sclerosis or other congenital or acquired lesions of the central nervous system (CNS). While there is often a partial functional component, spasticity also results in varying degrees of impairment of the quality of life.

OBJECTIVE

A review of surgical treatment options for spasticity.

MATERIAL AND METHODS

A systematic PubMed review of the literature on epidemiology and treatment options with a focus on neurosurgical interventions for spasticity and developments in the last 20 years as well as inclusion of still valid older landmark papers was carried out. Illustration of indications, technique, follow-up, and possible pitfalls of the different methods for the surgical treatment of spasticity.

RESULTS

Depending on the affected region, the number of muscle groups, and the extent of spasticity, focal (selective peripheral neurotomy, nerve transfer), regional (selective dorsal rhizotomy), or generalized (baclofen pump) procedures can be performed. The indications are usually established by an interdisciplinary team. Conservative (physiotherapy, oral medications) and focally invasive (botulinum toxin injections) methods should be performed in advance. In cases of insufficient response to treatment or only short-term relief, surgical methods can be evaluated. These are usually preceded by test phases with, for example, trial injections.

CONCLUSION

Surgical methods are a useful adjunct in cases of insufficient response to conservative treatment in children and adults with spasticity.

Botulinum toxin type A or selective neurotomy for treating focal spastic muscle overactivity?

OBJECTIVE

To discuss the effectiveness, indications, limitations and side effects of botulinum toxin type A and selective neurotomy for treating focal spastic muscle overactivity to help clinicians choose the most appropriate treatment.

METHODS

Expert opinion based on scientific evidence and personal experience.

RESULTS

Botulinum toxin type A can decrease muscle tone in different types of spastic muscle overactivity, which allows for treating a large variety of spastic patterns with several etiologies. The toxin effect is sometimes insufficient to improve functional outcome and is transient, thereby requiring repeated injections. Selective neurotomy is a permanent surgical treatment of the reflex component of the spastic muscle overactivity (spasticity) that is effective for spastic equinovarus foot. The neurotomy provides a greater and more constant reduction in spasticity. However, the long-lasting effect on the non-reflex muscle overactivity, especially dystonia, is doubted. The effectiveness, clinical indications, advantages, side effects and limitations of both techniques are discussed.

CONCLUSION

Botulinum toxin type A has the highest level of evidence and the largest range of indications. However, the botulinum toxin effect is reversible and seems less effective, which supports a permanent surgical treatment such as selective neurotomy, especially for the spastic foot. Further research is needed to compare the effect of botulinum toxin type A and selective neurotomy for the different types of spastic muscle overactivity and clinical patterns.

Anatomy of psoas muscle innervation: Cadaveric study

Hip flexion weakness is relatively common after lateral transpsoas surgery. Persistent weakness may result from injury to the innervation of the psoas major muscles (PMMs); however, anatomical texts have conflicting descriptions of this innervation, and the branching pattern of the nerves within the psoas major, particularly relative to vertebral anatomy, has not been described. The authors dissected human cadavers to describe the branching pattern of nerves supplying the PMMs. Sixteen embalmed cadavers were dissected, and the fine branching pattern of the innervation to the PMM was studied in 24 specimens. The number of branches and width and length of each branch of nerves to the PMMs were quantified. Nerve branches innervating the PMMs arose from spinal nerve levels L1-L4, with an average of 6.3 ± 1.1 branches per muscle. The L1 nerve branch was the least consistently present, whereas L2 and L3 branches were the most robust, the most numerous, and always present. The nerve branches to the psoas major commonly crossed the intervertebral (IV) disc obliquely prior to ramification within the muscle; 76%, 80%, and 40% of specimens had a branch to the PMM cross the midportion of the L2-3, L3-4, and L4-5 IV discs, respectively. The PMMs are segmentally innervated from the L2-L4 ventral rami branches, where these branches course obliquely across the L2-3, L3-4, and L4-5 IV discs. Knowledge of the mapping of nerve branches to the PMMs may reduce injury and the incidence of persistent weak hip flexion during lateral transpsoas surgery. Clin. Anat. 30:479-486, 2017. © 2017 Wiley Periodicals, Inc.

Pediatric tone management

Tone management is one of the primary roles of a pediatric physiatrist. Hypertonicity frequently inhibits normal movement patterns in children with central nervous system lesions but at times can reinforce muscle group firing and be useful for a child's function. Treatment approaches should be individualized based on functional goals, degree of impairment, interference with care, and type and location of hypertonicity. Treatment plans should be created in collaboration with all individuals caring for the child. There are many causes of hypertonicity as well as many nonsurgical and surgical treatments. Historical and current evidence-based treatments are reviewed.

Direct neurectomy of the motor branches of the tibial nerve in hemiplegic adults: an assessment with a mean follow-up period of 11 years

INTRODUCTION

Neurectomy of the tibial nerve plays a major role in the relief of disabling spasticity, which is refractory to drug treatment and physiotherapy. Although the immediate postoperative results are generally satisfactory, few evaluations of the procedure's long-term efficacy have been published.

OBJECTIVE

To estimate the long-term efficacy of total or partial neurectomy of the motor branches of the tibial nerve (combined with additional orthopaedic surgery in some cases).

METHOD

A descriptive, retrospective study of 25 brain-damaged patients having undergone neurectomy at least 4 years ago.

RESULTS

The mean post-neurectomy follow-up period was 11 years. Twenty patients became less dependent on the use of walking aids. Of the 18 patients unable to walk barefoot before surgery, 11 could do so after surgery. Of the 12 patients unable to walk on uneven ground before surgery, seven could do so afterwards. The walking distance increased for 20 patients. In 22 cases, the spasticity disappeared immediately after the operation and did not reappear in the long-term. In three other cases, spasticity persisted postoperatively and, in the long-term, affected the soleus (the denervation of which had been incomplete or not performed). Eighty-three percent of the patients were satisfied with the operation's outcome.

CONCLUSIONS

The observed maintenance of the benefits of total or partial neurectomy after an average follow-up period of 11 years confirms the value of this procedure. The few mediocre outcomes (observed in cases of partial neurectomy of the soleus) are in agreement with literature reports and emphasize the role of the soleus in this pathology.

Intrathecal administration of GABA agonists in the vegetative state

Gamma aminobutyric acid (GABA) is an inhibitor neurotransmitter that plays many important roles in the central nervous system. Because the half-life time of GABA is very short in vivo, GABA itself is not used for clinical practice. An analogue of GABA, baclofen, is an agonist of GABA-B receptor, and has very strong antispastic effect by acting to the posterior horn of the spinal cord. However, baclofen poorly crosses through the blood brain barrier, and the antispastic effect is modest when administered orally. Therefore, direct continuous infusion of small doses of baclofen into the cerebrospinal fluid (intrathecal baclofen therapy, ITB) has become an established treatment for control of otherwise intractable severe spasticity. Spasticity is clinically defined as hypertonic state of the muscles with increased tendon reflexes, muscles spasm, spasm pain, abnormal posture, and limitation of involuntary movements. Spasticity is a common symptom after damage mainly to the pyramidal tract system in the brain or the spinal cord. Such damage is caused by traumatic brain injury, stroke, spinal cord injury, multiple sclerosis, and so on. Patients in persistent vegetative state (PVS) usually have diffuse and widespread damage to the brain, spasticity is generally seen in such patients. Control of spasticity may become important in the management of PVS patients in terms of nursing care, pain relief, and hygiene, and ITB may be indicated. Among PVS patients who had ITB to control spasticity, sporadic cases of dramatic recovery from PVS after ITB have been reported worldwide. The mechanism of such recovery of consciousness is poorly understood, and it may simply be a coincidence. On the other hand, electrical spinal cord stimulation (SCS) has been tried for many years in many patients in PVS, and some positive effects on recovery of consciousness have been reported. SCS is usually indicated for control of neuropathic pain, but it has also antispastic effect. The mechanism of SCS on pain is known to be mediated through the spinal GABA neuronal system. Thus, ITB and SCS have a common background, spinal GABA neuronal mechanism. The effect of GABA agonists on recovery of consciousness is not yet established, but review of such case studies becomes a clue to solve problems in PVS, and there may be hidden serendipity.

Selective peripheral neurotomy (SPN) for spasticity in childhood

OVERVIEW

Excess spasticity leads to disability that is marked by impaired locomotion, handicapping deformities and, if not controlled, discomfort and pain. Selective peripheral neurotomy in the child is indicated for severe focal spasticity, when botulinum toxin injections cannot delay surgery any longer.

MATERIALS AND METHODS

Preoperative motor blocks mimicking the outcome of the surgical procedure are essential to establish the objectives of neurotomy. In the lower limb, obturator neurotomy is indicated for spasticity in the adductor muscles, hamstring neurotomy for the knee flexion and tibial neurotomy for the spastic foot. Anterior tibial neurotomy is indicated for the extensor hallucis spasticity and femoral neurotomy for spasticity in the quadriceps. In the upper limb, neurotomy of the pectoralis major and teres major nerves is indicated for spasticity of the internal rotators of the shoulder. Neurotomy of the musculocutaneous nerve is indicated for spasticity of the flexors of the elbow, and neurotomy of median and ulnar nerves are indicated for spasticity of the pronators and flexors of the wrist and fingers.

CONCLUSION

Selective peripheral neurotomy is a valuable neurosurgical procedure in well-trained surgical hands for severe focalised spasticity.

The role of neurosurgical interventions for control of spasticity in neurorehabilitation: new findings on functional microanatomy of the tibial nerve

Harmful spasticity after cerebral or spinal damage disturbs functional recovery in neurorehabilitation, but neurosurgical interventions for relief of spasticity are not widely performed, at least in Asian countries including Japan. We have been performing various types of neurosurgical treatment for spasticity such as selective peripheral neurotomy, selective dorsal rhizotomy, microsurgical DREZotomy, and intrathecal baclofen administration. We deal with both children and adults. From our experience of tibial neurotomy, in particular, we describe functional microsurgical anatomy of the tibial nerve in the popliteal fossa. This is the first report on this regional functional anatomy.

Long term course of the H reflex after selective tibial neurotomy

OBJECTIVES

This study was conducted to evaluate the long term clinical and electrophysiological outcome by recording the H reflex in a consecutive series of six patients treated by selective tibial neurotomy for spastic equinus foot.

METHOD

The amplitudes of Hmax reflexes, Mmax responses, and Hmax:Mmax ratio were recorded in six patients with chronic lower limb spasticity, before and after surgery, at day 1 and 8 months and 24 months after selective tibial neurotomy. The passive range of movement, the stretch reflex score according to the Tardieu scale, the osteoarticular and tendon repercussions, and the quality of motor control of dorsiflexion were evaluated preoperatively and postoperatively.

RESULTS

At the end of the study, all patients presented a reduction of equines. Gait and Tardieu's score of spasticity had improved in all patients. Active dorsiflexion of the ankle was unchanged in four patients, but two improved by 5 degrees to 12 degrees. In five cases, fascicular resection of the superior nerve to soleus was, alone, sufficient to reduce spastic equinus foot, without recurrence, for a mean follow up of 28 months. Two patients were reoperated on, one for remaining spasticity related to an underestimated spasticity of the gastrocnemius muscles, and the other for painful claw toes. Hmax, Mmax, and Hmax:Mmax ratios were significantly lower the day after surgery. The reduction of Hmax and Hmax/Mmax ratio remained stable over time and was still statistically significant two years after the operation. However, the value of Mmax eight months postoperatively was no longer significantly different from the preoperative value.

CONCLUSION

This study shows the long term efficacy of the selective tibial neurotomy as treatment of spastic equinus foot. Neurotomy confined to fibres supplying the soleus muscle is sufficient in most cases and acts by decreasing sensory afferents without significant long term motor denervation.

The surgical treatment of spasticity

Many neurosurgical procedures have been designed for or applied to the treatment of spasticity arising from different disorders, including cerebral palsy; traumatic, ischemic, or hypoxic brain injury, multiple sclerosis, and spinal cord injury. Neurosurgical procedures are primarily aimed at reducing spasticity by interrupting the stretch reflex at various sites along the spinal reflex arc or attempting to increase the centrally mediated inhibitory influence on the pool of motor neurons in the anterior horn. Surgical interventions for spasticity can be classified into peripheral ablative procedures, such as rhizotomy or peripheral neurectomy, and central ablative procedures, such as cordectomy, myelotomy, or stereotactic procedures. Non-ablative procedures include peripheral nerve or motor point blocks, the implantation of cerebellar or spinal stimulators, and the implantation of subdural catheters for infusion of pharmacologic agents to increase inhibitory activity. Several proposed mechanisms for spasticity are reviewed so that the rationale for the various surgical interventions for spasticity described may be better understood.