Pharmacological versus microvascular decompression approaches for the treatment of trigeminal neuralgia: clinical outcomes and direct costs

Journal of Pain Research Dovepress open access to scientific and medical research O r i g i n al R e s e ar c h Journal of Pain Research downloaded from https://www.dovepress.com/ by 37.59.46.207 on 12-Jul-2018 For personal use only. Open Access Full Text Article Pharmacological versus microvascular decompression approaches for the treatment of trigeminal neuralgia: clinical outcomes and direct costs This article was published in the following Dove Press journal: Journal of Pain Research 23 August 2011 Number of times this article has been viewed Laurinda Lemos 1,2 Carlos Alegria 3 Joana Oliveira 3 Ana Machado 2 Pedro Oliveira 4 Armando Almeida 1 Life and Health Sciences Research Institute (ICVS), School of Health Sciences, Campus de Gualtar, University of Minho, Braga, Portugal; 2 Hospital Center of Alto Ave, Unit of Fafe, Fafe, Portugal; 3Department of Neurosurgery, Hospital São Marcos; 4 Products and Systems Engineering, Campus de Azurém, University of Minho, Guimarães, Portugal 1 Abstract: In idiopathic trigeminal neuralgia (TN) the neuroimaging evaluation is usually normal, but in some cases a vascular compression of trigeminal nerve root is present. Although the latter condition may be referred to surgery, drug therapy is usually the first approach to control pain. This study compared the clinical outcome and direct costs of (1) a traditional treatment (carbamazepine [CBZ] in monotherapy [CBZ protocol]), (2) the association of gabapentin (GBP) and analgesic block of trigger-points with ropivacaine (ROP) (GBP+ROP protocol), and (3) a common TN surgery, microvascular decompression of the trigeminal nerve (MVD protocol). Sixty-two TN patients were randomly treated during 4 weeks (CBZ [n = 23] and GBP+ROP [n = 17] protocols) from cases of idiopathic TN, or selected for MVD surgery (n = 22) due to intractable pain. Direct medical cost estimates were determined by the price of drugs in 2008 and the hospital costs. Pain was evaluated using the Numerical Rating Scale (NRS) and number of pain crises; the Hospital Anxiety and Depression Scale, Sickness Impact Profile, and satisfaction with treatment and hospital team were evaluated. Assessments were performed at day 0 and 6 months after the beginning of treatment. All protocols showed a clinical improvement of pain control at month 6. The GBP+ROP protocol was the least expensive treatment, whereas surgery was the most expensive. With time, however, GBP+ROP tended to be the most and MVD the least expensive. No sequelae resulted in any patient after drug therapies, while after MDV surgery several patients showed important side effects. Data reinforce that, (1) TN patients should be carefully evaluated before choosing therapy for pain control, (2) different pharmacological approaches are available to initiate pain control at low costs, and (3) criteria for surgical interventions should be clearly defined due to important side effects, with the initial higher costs being strongly reduced with time. Keywords: trigeminal neuralgia, carbamazepine, gabapentin associated with ropivacaine, microvascular decompression, clinical outcomes, direct costs Introduction Correspondence: Armando Almeida Life and Health Sciences Research Institute (ICVS), School of Health Sciences, Campus de Gualtar, University of Minho, 4710-057 Braga – Portugal Tel +351-253-604808 Fax +351-253-604809 Email submit your manuscript | www.dovepress.com Dovepress http://dx.doi.org/10.2147/JPR.S20555 Powered by TCPDF (www.tcpdf.org) Trigeminal neuralgia (TN) is a neuropathic pathology considered one of the most painful experiences patients can report, and no universal treatment is capable of reverting completely and definitely its intermittent paroxysmal excruciating pain crises.1 TN is associated with impairment of daily functionality, reduced quality of life,2,3 and depression,4 to which contributes the overwhelming fear that pain can suddenly return again. Although the huge impact of pain in TN, which has an incidence of 4–5 per 100,0005 or even higher,6 and a high prevalence in older patients should have been capable of resulting in clinical standards for TN treatment, this Journal of Pain Research 2011:4 233–244 © 2011 Lemos et al, publisher and licensee Dove Medical Press Ltd. This is an Open Access article which permits unrestricted noncommercial use, provided the original work is properly cited. 233 Journal of Pain Research downloaded from https://www.dovepress.com/ by 37.59.46.207 on 12-Jul-2018 For personal use only. Lemos et al pathology is far from being well known and treated. In most cases the pathophysiology underlying TN is unknown or incompletely understood. Classical or idiopathic TN includes all cases without an established etiology (most of them) as well as those with potential vascular compression of the trigeminal nerve, whereas symptomatic TN results secondarily to cases such as tumors or multiple sclerosis.7 TN is not controlled by classical analgesics, but the first-line therapy is pharmacological, being based on anticonvulsants (ACs), usually considered adjuvant analgesics in other pathologies but essential for neuropathic pain. Phenytoin in the past8,9 and now carbamazepine (CBZ)1,10–12 are first-line drugs in TN, followed by several second-line ACs such as lamotrigine,11,13 oxcarbazepine,14 gabapentin (GBP),1 and CBZ or GBP associated with peripheral block of triggerpoints with the local anesthetic ropivacaine (ROP);3,15 these treatments changed the management of TN, as previously it was almost exclusively surgical. Surprisingly, combination therapies, although common in epilepsy, have not been explored for TN management.3,15,16 Surgical intervention for TN is usually reserved for patients with intractable pain refractory to an adequate trial of at least 3 drugs including CBZ.1 The decision to perform a surgical approach should be based on the clinical presentation (including co-morbilities) of the patient and not primarily or exclusively on neuroimaging,1 as craniotomy is not without risks and fine detail alone at actual MRI spatial resolution cannot distinguish the pathological from the incidental when a vessel course is along the trigeminal nerve root.17,18 However, some patients may request surgical treatment due to intractable pain or strong adverse side effects.1 Microvascular decompression (MVD) of the trigeminal nerve root is a well established and superior method of choice among neurosurgical procedures19 in immediate (91%–97%) and long-term (53%–70%) relief of TN,12,20–22 but is associated with several risks, including different degrees of facial sensory loss as well as a small risk of mortality.1 Other surgical options include Gasser ganglion compression, glycerol gangliolysis, and radiofrequency thermocoagulation of the nerve, with the last producing initial pain relief in more than 90% and a complete pain relief after 5 years reaching 57% of patients;23 however, these cases are associated with a risk of an (...truncated)