**2.5 Alcohol and phenol**

Localised and loco-regional spasticity may effectively be treated by selective neurolysis. Coagulation and denaturing of proteins induced by phenol perineurally injected lead to cellular and axonal damage. Unfortunately, this chemical denervation is irreversible; moreover, the effects of phenol are not selective because also vascular and sensory structures can be destroyed [62]. In fact, the main recommendation choosing this approach is to identify preferably the nerves to be treated with a low sensory activity and a high motor predominance (i.e. obturator or musculocutaneous nerves, etc.). However, this focal treatment is usually not used as a first-line therapy, except in the case of particularly problematic overactivity affecting a big area under a single motor nerve control, for example, musculocutaneous nerve for biceps brachii muscle or obturator nerve for thigh adductor muscles. This may allow to use in the same patient BTX to treat other muscles, without the risk of an overdose. Electrical stimulation is used to identify a nerve, in order to perform injection on it. Firstly, a transient motor block may be a plan, in order to evaluate if chemical neurolysis might be significantly effective and safe. In fact, the efficacy and/or advantages eventually deriving from alcohol or phenol treatment could be evaluated before, in particular with respect

to surgery (above all, tissue fibrosis induced by alcohol or phenol, which may hamper surgery approach). Advantages are the low cost and the long duration of effect. In clinical practice, 5–7% concentrations of phenol in aqueous solution are administered.

### **2.6 Intrathecal baclofen**

Intrathecal baclofen (ITB) is a long-term treatment with continuous, intraspinal administration via an implanted pump that reduces spasticity, especially in spinal injury patients and in multiple sclerosis [63, 64]. For this reason, ITB has become the first choice in intractable generalised spasticity, especially when oral administration fails to be effective. ITB efficacy in reducing spasticity was demonstrated by several studies [65]. Through direct infusion into the cerebrospinal fluid, the baclofen can be concentrated regionally, avoiding liver metabolism, so it is totally available for its therapeutic effects. In fact, with respect to oral baclofen administration, the ITB, bypassing the blood–brain barrier entirely, needs much lower dose in order to obtain the same CSF concentrations; it has been determined that the ITB dose is 100–1000 times smaller than the oral daily dose. Depending on the pump model, it is possible to modify infusion rate, according to the patient's needs. In several studies ITB was shown as safe and effective in reducing spasticity. The complication rate was found to be low, and the efficacy was maintained over time [64]. A reduction in the Ashworth scale from 3 to 4 to 1 after ITB implantation was reported in several studies. Also spasm frequency significantly decreased. Some activities of daily living, in particular the ability to sit in a wheelchair and nursing care, improved after ITB implant. In some cases, authors showed that patients with less severe disability experienced an improvement in the ability to transfer, thanks to ITB effect [66]. Side effects, such as vertigo, nausea, nystagmus, dysmetria, mouth dryness, headache, amnesia, bladder, and sexual dysfunction, have been described in about 4% of patients and mainly are not life-threatening. As a red flag, it is notable that concerning gastrointestinal function, ITB could affect peristalsis, which could be severely slowed down to paralytic ileus. Nevertheless, constipation has previously been reported as an infrequent ITB-induced adverse effect, ranging from 3 to 10% of treated patients [67], rarely leading to death [68]. Therefore, recognition of constipation in patients treated with ITB is very important, not only because constipation is a possible side effect, being reported in some study, but also because it may be also a life-threatening complication. ITB has been used in patients with leg diffuse muscle overactivity. This type of treatment should be used above all in patients, in which muscle overactivity impaired posture, nursing, and personal independence or causes pain [63]. Several assessments are required before planning a definite pump implantation, performing drug test injection via lumbar puncture or via a temporary access device. Efficacy may be evaluated during the following 3–4 h. The first test dose is usually recommended up to 50 μg in adults, picking up gradually to a maximum dose of 150 μg, eventually reached after 3 days. A risk of overdose should be always evaluated, in particular regarding the effects on consciousness level and respiratory disorders. So, a specialised medical team is needed in order to monitor patient after and during the 4 h following the test. Only after the end of this test, if the treatment has been well-tolerated and effective, the team may make the decision to implant the pump. It is important to monitor the patient during the entire follow-up period, in order to prevent and/or detect collateral effects related to the procedure (displacement and/ or obstruction of the catheter, infection, etc.), which may induce a serious withdrawal syndrome. ITB is often recommended for the treatment of spasticity, with a strong evidence of efficacy [42].

**125**

*Spasticity and Dystonia: A Brief Review DOI: http://dx.doi.org/10.5772/intechopen.91780*

**3. Treatment options of dystonia**

**3.1 Indications of treatment**

**3.2 Cholinergic system agents**

Surgery may play an important role in the treatment of chronic muscle overactivity or for the after-effects induced by spasticity that become functional impairments (e.g. irreducible equinovarus foot), but it is not the first-line treatment. Because of its potential adverse events and its definite effects, surgical techniques should be reserved only in selected patients in order to reach different goals:

hygiene, standing, transferring, walking, and the use of assistive devices. It involves neurosurgery and orthopaedic surgery. Surgical procedures may include one or more of the techniques described below. Peripheral neurotomy may include partial or segmental resection of a motor nerve, involving spastic muscles. In order to balance agonists and antagonists overlapping the muscle activity, a selective peripheral neurotomy is recommended to maintain a "functional" muscle tone. Collateral branches of the posterior tibial nerves and obturator nerves are commonly the main targets for the legs (e.g. ankle clonus, equinus, inversion of the foot). For the arms, neurotomy of the musculocutaneous, median, and ulnar nerves showed good results regarding efficacy and safety [69]. Other surgery techniques, such as rhizotomies, although used, have potential collateral effects and complications [70]. Musculoskeletal surgery, performed on the muscle or the tendon itself, aims to treat spasticity consequences, such as contracture and joint deformities. Tendon transfers (e.g. *tibialis* anterior) and lengthening are conservative treatments commonly proposed [69]. Tenotomy may be considered in the case of muscle contracture without active functional objectives [69]. Hip displacements and foot deformities induced by severe spasticity may be sometimes treated with osteotomies [69]. Arthrodesis may be the only solution to stabilise joints, notably ankle and foot joints in case of severe paresis associated with strong muscle overactivity and hypoesthesia [69].

Treatment options of the management of dystonia include pharmacological therapies, injections, and surgical interventions. The main pharmacological therapies are anticholinergics (particularly trihexyphenidyl), baclofen, benzodiazepines (particularly clonazepam), and dopamine-related medications. However, medical therapy in dystonia is largely empiric and at times may seem anecdotal. Three main neurotransmitter systems are involved: cholinergic generally acting as antagonist at postsynaptic M1 receptor, GABAergic-like baclofen, and dopaminergic systems. Dopaminergic treatments can be divided into two: levodopa and dopamine reducing medications like presynaptic dopamine depleters such as tetrabenazine and postsynaptic dopamine-blocking agents, such as clozapine or neuroleptics. The therapeutic strategy, carried out by Fahn [71], is to "start low and go slow": medications should be started at a low dose and upped slowly to the lowest effective dose, in order to reduce symptoms without side effects. The rate of titration may depend on age: every 3–4 days in children, compared to every 1 week in adults. A combination approach is used when monotherapy achieves a "good" dose, but symptom control is incomplete. The question is which medications should be started first?

In 1952, beneficial effects of trihexyphenidyl in writer's cramp and "dystonia musculorum deformans" were first reported [72, 73]. The first open-label study of

**2.7 Surgery**

*Spasticity and Dystonia: A Brief Review DOI: http://dx.doi.org/10.5772/intechopen.91780*

### **2.7 Surgery**

*Neurostimulation and Neuromodulation in Contemporary Therapeutic Practice*

administered.

**2.6 Intrathecal baclofen**

to surgery (above all, tissue fibrosis induced by alcohol or phenol, which may hamper surgery approach). Advantages are the low cost and the long duration of effect. In clinical practice, 5–7% concentrations of phenol in aqueous solution are

Intrathecal baclofen (ITB) is a long-term treatment with continuous, intraspinal administration via an implanted pump that reduces spasticity, especially in spinal injury patients and in multiple sclerosis [63, 64]. For this reason, ITB has become the first choice in intractable generalised spasticity, especially when oral administration fails to be effective. ITB efficacy in reducing spasticity was demonstrated by several studies [65]. Through direct infusion into the cerebrospinal fluid, the baclofen can be concentrated regionally, avoiding liver metabolism, so it is totally available for its therapeutic effects. In fact, with respect to oral baclofen administration, the ITB, bypassing the blood–brain barrier entirely, needs much lower dose in order to obtain the same CSF concentrations; it has been determined that the ITB dose is 100–1000 times smaller than the oral daily dose. Depending on the pump model, it is possible to modify infusion rate, according to the patient's needs. In several studies ITB was shown as safe and effective in reducing spasticity. The complication rate was found to be low, and the efficacy was maintained over time [64]. A reduction in the Ashworth scale from 3 to 4 to 1 after ITB implantation was reported in several studies. Also spasm frequency significantly decreased. Some activities of daily living, in particular the ability to sit in a wheelchair and nursing care, improved after ITB implant. In some cases, authors showed that patients with less severe disability experienced an improvement in the ability to transfer, thanks to ITB effect [66]. Side effects, such as vertigo, nausea, nystagmus, dysmetria, mouth dryness, headache, amnesia, bladder, and sexual dysfunction, have been described in about 4% of patients and mainly are not life-threatening. As a red flag, it is notable that concerning gastrointestinal function, ITB could affect peristalsis, which could be severely slowed down to paralytic ileus. Nevertheless, constipation has previously been reported as an infrequent ITB-induced adverse effect, ranging from 3 to 10% of treated patients [67], rarely leading to death [68]. Therefore, recognition of constipation in patients treated with ITB is very important, not only because constipation is a possible side effect, being reported in some study, but also because it may be also a life-threatening complication. ITB has been used in patients with leg diffuse muscle overactivity. This type of treatment should be used above all in patients, in which muscle overactivity impaired posture, nursing, and personal independence or causes pain [63]. Several assessments are required before planning a definite pump implantation, performing drug test injection via lumbar puncture or via a temporary access device. Efficacy may be evaluated during the following 3–4 h. The first test dose is usually recommended up to 50 μg in adults, picking up gradually to a maximum dose of 150 μg, eventually reached after 3 days. A risk of overdose should be always evaluated, in particular regarding the effects on consciousness level and respiratory disorders. So, a specialised medical team is needed in order to monitor patient after and during the 4 h following the test. Only after the end of this test, if the treatment has been well-tolerated and effective, the team may make the decision to implant the pump. It is important to monitor the patient during the entire follow-up period, in order to prevent and/or detect collateral effects related to the procedure (displacement and/ or obstruction of the catheter, infection, etc.), which may induce a serious withdrawal syndrome. ITB is often recommended for the treatment of spasticity, with a

**124**

strong evidence of efficacy [42].

Surgery may play an important role in the treatment of chronic muscle overactivity or for the after-effects induced by spasticity that become functional impairments (e.g. irreducible equinovarus foot), but it is not the first-line treatment. Because of its potential adverse events and its definite effects, surgical techniques should be reserved only in selected patients in order to reach different goals: hygiene, standing, transferring, walking, and the use of assistive devices. It involves neurosurgery and orthopaedic surgery. Surgical procedures may include one or more of the techniques described below. Peripheral neurotomy may include partial or segmental resection of a motor nerve, involving spastic muscles. In order to balance agonists and antagonists overlapping the muscle activity, a selective peripheral neurotomy is recommended to maintain a "functional" muscle tone. Collateral branches of the posterior tibial nerves and obturator nerves are commonly the main targets for the legs (e.g. ankle clonus, equinus, inversion of the foot). For the arms, neurotomy of the musculocutaneous, median, and ulnar nerves showed good results regarding efficacy and safety [69]. Other surgery techniques, such as rhizotomies, although used, have potential collateral effects and complications [70]. Musculoskeletal surgery, performed on the muscle or the tendon itself, aims to treat spasticity consequences, such as contracture and joint deformities. Tendon transfers (e.g. *tibialis* anterior) and lengthening are conservative treatments commonly proposed [69]. Tenotomy may be considered in the case of muscle contracture without active functional objectives [69]. Hip displacements and foot deformities induced by severe spasticity may be sometimes treated with osteotomies [69]. Arthrodesis may be the only solution to stabilise joints, notably ankle and foot joints in case of severe paresis associated with strong muscle overactivity and hypoesthesia [69].
