**Chronic Headache and Neuromodulation**

**Chronic Headache and Neuromodulation**

DOI: 10.5772/intechopen.72150

Vicente Vanaclocha-Vanaclocha, Nieves Sáiz-Sapena, José María Ortiz-Criado and Leyre Vanaclocha Nieves Sáiz-Sapena, José María Ortiz-Criado and Leyre Vanaclocha Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.72150

Vicente Vanaclocha-Vanaclocha,

#### **Abstract**

The immense majority of patients with chronic headaches can be controlled with medical treatments. However, there is a subset of them with poor response, and it is for those patients that new therapeutic strategies are being designed. Neuromodulation has been used for chronic pain management in many areas for the past 50 years. The application of these techniques to the treatment of the most refractory chronic headache disorders has offered hope to these patients. There is a large variety of different techniques, each of them particularly suitable to specific types of chronic headaches. The surgically implanted devices are still in use in some particularly recalcitrant cases. Nevertheless, new percutaneous devices allow new treatment strategies. Percutaneous devices do not always show the same effectivity as surgically implanted stimulating devices, but they are user friendly and have no serious adverse effects. Thus, they are becoming the treatment of choice once the pharmacological means are no longer effective. In case of failure, the surgical procedures would still be available as a last resort.

**Keywords:** chronic headache, chronic migraine, cluster headache, neuromodulation, neurostimulation

#### **1. Introduction**

Chronic headache is one of the most frequent pain syndromes, affecting 3% of the population. It can be rather disabling [1, 2], particularly for young people who are most affected by it. The International Classification of Headache subdivides headaches into 300 different entities [3], each of those with a different pathophysiology and involving different anatomical structures. Pain can originate from the central nervous system, the cranium or the cervical area [4].

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Primary headaches like tension headache, migraine (CM) or trigeminal autonomic cephalagias (TACs) show the highest incidence. TACs are particularly incapacitating [5]. Most cases can be controlled with medication and physiotherapy. Abuse of medication is common with these patients, via the dose, the drugs or both [6]. When the pharmacological and conservative treatments fail, surgery may be considered. In the past, ablative surgical techniques have been applied. These techniques have been replaced by neuromodulation techniques. In them, the anatomical structures are not lesioned, but instead, the electric impulses block the nervous structures in a reversible fashion [7]. These techniques can be subdivided into two broad categories: noninvasive and invasive [1]. The noninvasive options include transcranial stimulation either electric [8–10] or magnetic [11–13] and transdermal stimulation of occipital [14, 15], supraorbital [9, 14–19] or vagus [20–23] nerves. Invasive procedures include stimulation of occipital [5, 17, 24, 25–35], supraorbital [19, 31, 36], infraorbital [31] or greater auricular [37] nerves as well as sphenopalatine ganglion [38–44], cervical spinal cord [45–48] or hypothalamus [4, 25, 27, 49–52].

of CM [63]. The first case reported with cervical spinal stimulation (SCS) in the treatment of CH was in 2008 [64]. The first report on stimulation of the sphenopalatine ganglion was presented at 2009 [38]. Ever since, there has been an explosion of reports on the effectiveness, indications and AEs of all these techniques. Simultaneously new devices that allow percuta-

Chronic Headache and Neuromodulation http://dx.doi.org/10.5772/intechopen.72150 125

The first step is to diagnose the patient and select an appropriate treatment by an experienced team that is familiarised with all available treatments. Neuromodulation techniques are indicated in cases that have failed all other medical treatments available for this specific headache

The next step is to attempt noninvasive neuromodulation techniques particularly useful in this type of chronic headache. Should all fail, a period of temporary trial stimulation is suitable [33]. Patients showing no response are not implanted and are redirected to other forms of treatment. This temporary stimulation also helps to predict the results to be expected if the

This technique involves applying a low amperage continuous electric stimulation directly to the scalp [10]. In most cases, the electric stimulus spreads out of the area covered by the electrodes [10]. AEs have been moderate, such as skin burns due to inadequate electrode skin contact, fatigue or local prickling and burning sensation during the stimulation [8, 10]. Its

A magnetic field is applied to the head, inducing depolarization and electrical activity of the underlying brain cortex [65, 66]. Most have applied it to the left frontal motor area [11, 67, 68], but some have done it to the occipital region, particularly in migraine patients [69]. In chronic headache related to mild posttraumatic head injury (MTHI-H), it has shown ≥50% improvement in pain intensity and frequency in 58.3% of the patients [11]. In migraine, some have reported a reduction of 31.2% in pain frequency and 37.8% in attack duration [70] in two-third of the patients [66]. The acute variant, with or without aura, seems to have a better response than the chronic one [67–72]. There seems to be a cumulative effect, so that the longer this treatment modality is applied, the greater is the attack duration reduction [69]. In migraine

neous stimulation have reached the market, allowing new solutions to old problems.

type. It is also recommended that patients receive a psychological assessment.

**3. Indications for neuromodulation**

definitive implant is attempted [32, 46].

*4.1.1. Transcranial electric stimulation (TES)*

effectivity and experience are limited [8, 10].

*4.1.2. Transcranial magnetic stimulation (TMS)*

**4.1. Noninvasive procedures**

**4. Classification of the different techniques**

Noninvasive neuromodulation techniques are user friendly and have low costs and few and minor side effects [8–15, 19–23]. Unfortunately, their effectivity is lower than their invasive counterparts. Invasive neuromodulation is reserved for the most refractory cases, as they are associated with increased aggressiveness, more severe adverse events (AE) and higher costs [7].

All costs have to be taken into consideration. The full cost of neuromodulation would include the disability grants, as well as further possible treatments for AEs [33, 34, 53].

Taking the net expenditure into consideration, some have reported that the reductions in cost are evident at 5-year postimplantation [53]. In any case, invasive neuromodulation must only be used in the most refractory cases and only after all other medical and noninvasive treatments have failed [46]. This is particularly important due to the high incidence of AEs and the possibility of new surgical procedures to solve them [29, 33]. A trial of temporary stimulation is required to evaluate the possible response of a definitive implant [45, 46, 54] to avoid wasting time and resources.

These techniques present promising new treatment strategies. The available evidence will be analysed, describing the possible future trends.
