Comparative Study Between Valproate and Memantine in the Prophylactic Management of Episodic Migraine.
Comparative Study Between Valproate and Memantine in the Prophylactic Management of Episodic Migraine.
Migraine is one of the three most disabling diseases worldwide. Constituted by recurrent
 episodes of headache, characterized by unilateral location, throbbing character, moderate or
 severe intensity, worsening with physical activity, and association with nausea or
 photophobia and/or phonophobia. There are two types of drug treatment: abortifacient and
 prophylactic. The American Academy of Neurology classifies sodium valproate as level A;
 however, some patients do not obtain a satisfactory response rate and/or have adverse
 effects. Therefore, the search for new pharmacological treatments continues. In 2015, a
 double-blind, randomized clinical trial with a placebo was carried out to assess Memantine's
 efficacy in the prophylactic treatment of migraine without aura, which reported a reduction
 of 2.3 migraine attacks per month compared to the placebo group. Memantine could be a new
 effective treatment alternative, which is why we will compare the efficacy of Memantine
 against sodium valproate as a prophylactic migraine treatment.

 Main objective: To compare the efficacy of Memantine at a rate of 20mg divided into two doses
 a day against sodium valproate (VPA) at a rate of 1000mg divided into two doses a day
 prophylactic treatment of migraine for three months.

 Study design: a prospective controlled, randomized, double-blind clinical trial. Inclusion
 criteria: Men and women aged 18 to 65 years with a diagnosis at least one year before the
 study must present at least 2 to 8 migraine attacks per month and less than 15 days with
 headache per month, which should not be receiving prophylactic treatment for migraine and
 sign an informed consent

 Sample size calculation and statistical analysis:

 It is calculated using the normal distribution model, where the recommended sample size is
 196 participants. Since a pilot study will be conducted, 10% of the sample size will be taken
 to make it representative, a sample size of 20 participants is decided for each group.
Migraine is a primary headache, currently one of the three most disabling diseases globally.
 It has an annual and lifetime prevalence of 18% and 33% in women, and 6 to 13% in men,
 respectively, with a predominance in women (3: 1). The age of onset with the highest
 prevalence is between 25 and 55 years.

 Migraine is described by the International Headache Society (IHS) as recurrent episodes of
 headache lasting 4 to 72 hours, characterized by unilateral location, pulsatile character,
 moderate or severe intensity, worsening with physical activity, and association with nausea
 or photophobia and phonophobia. The IHS also classifies migraine based on the frequency of
 attacks: episodic migraine when the headache occurs on less than 15 days a month, and chronic
 migraine, when the headache occurs 15 or more days a month for three months and at least
 eight days a month with characteristics of migraine headache.

 The subtypes of migraine concerning their clinical presentation are migraine with aura and
 without aura.4 Up to one-third of patients present migraine aura, with visual symptoms being
 the most frequent.

 Four phases have been identified during a migraine: prodromal phase, aura, headache, and
 postdrome. The prodromal phase is characterized by premonitory symptoms hours before the
 headache, including difficulty concentrating, irritability, fatigue, repetitive yawning,
 stiff neck, and photophobia.

 Recurrent episodes characterize the aura, lasting from 5min to 60min, with transient
 unilateral visual, sensory, or other CNS symptoms that develop progressively, usually precede
 headache and symptoms associated with migraine.4 The aura's genesis is activated by the NMDA
 (N-methyl-D-aspartate) receptor and disseminated cortical depression. Disseminated cortical
 depression is an extreme depolarization of the cell membranes of the glia and neurons that
 produce an alteration of the ionic gradient, an increase in extracellular potassium
 concentrations, glutamate release, and a transient increase followed by a decrease in
 cerebral blood flow.

 The pain phase in migraine is due to the activation and sensitization of the
 trigeminovascular pain pathway, which innervates intracranial structures, including the eye,
 the dura mater, large braincases, and the venous sinuses. It has been shown to involve
 neuronal presynaptic activation by ID serotonin receptors (5-HT 1D), resulting in the release
 of the calcitonin gene (CGRP) and pituitary adenylate cyclase-activating polypeptide
 (PACAP-38), which are neuroinflammatory peptides. The post-synaptic effect on the meninges
 includes the activation of the arachidonic acid cascade, which conditions inflammation and
 vasodilation, stimulates the nociceptive afference of pain first branch of the trigeminal
 nerve.

 The diagnosis of migraine is clinical and must meet the criteria of the IHS International
 Classification of Headaches (ICH-3), which are for migraine without aura:

 At least five crises that meet criteria B-D. A. Headache episodes are lasting 4 to 72 hours
 (untreated or unsuccessfully treated).

 B. The headache has at least two of the following four characteristics:

 1. Unilateral location.

 2. Pulsatile character.

 3. Pain of moderate or severe intensity.

 4. Made worse by or conditions the abandonment of habitual physical activity (e.g., walking
 or climbing stairs).

 C. At least one of the following during the headache:

 1. Nausea and vomiting.

 2. Photophobia and phonophobia. D. No better explanation by another diagnosis of ICHD-III.

 The non-pharmacological treatment of migraine goes hand in hand with the pharmacological one;
 one is to avoid the triggers of the migraine attacks and carry out the lifestyle
 modifications. Pharmacological treatment is divided into acute (administered at the time of
 headache) and prophylactic (administered daily to reduce the chances of migraine episodes).

 The objective of prophylactic treatment is to reduce the frequency, duration, and severity of
 migraine attacks, improve the response to acute treatment, improve functionality, and reduce
 disability.

 The American Academy of Neurology recommends initiating prophylactic treatment in patients
 with migraine with one or more of the following characteristics9

 1. Recurrent migraine, which interferes with the patient's daily life and quality of life.

 2. Frequent headaches.

 3. That they have an inadequate response or contraindication to abortive treatment.

 4. Adverse events to abortion treatment.

 5. Uncommon migraine conditions: ophthalmoplegic migraine, basilar migraine, hemiplegic,
 prolonged aura, migraine infarction.

 The IHS defines the response to treatment as a decrease equal to or greater than 50% in the
 frequency of migraine attacks compared to the baseline situation.

 The American Academy of Neurology guideline for the prophylactic drug treatment of episodic
 migraine classifies divalproex sodium, valproate sodium (VPA), topiramate, metoprolol
 propranolol as level A (Drugs with established efficacy ).

 Valproic acid (2-propylpentaenoic acid) was first synthesized in 1882 as an analog of valeric
 acid, naturally found in valerian. Anyone of Valproic acid, sodium valproate, or a mixture of
 the two (sodium valproate) has a mechanism of action characterized by increasing or improving
 GABA neurotransmission, blocking voltage-gated sodium channels, and T-type calcium channels.
 In 2013, Cochrane conducted the review: Valproate for the prophylaxis of episodic migraine
 (Linda et al.), where they evaluated ten clinical trials. Two crossover clinical trials for
 sodium valproate demonstrated a significant reduction in headache frequency than placebo (MD
 -4.31 95% CI -8.32 to -0.30), which shows us in clinical terms an approximate reduction of
 four headaches for every 28 days. Jensen 199413 showed that sodium valproate is superior to
 placebo (OR 4.67; 95% CI 1.54 - 14.14), suggesting that patients are three times more likely
 to present a reduction equal to or greater than 50% in the frequency of headaches compared to
 placebo. The recommended dose for migraine headaches is 500-1000mg per day. The most common
 adverse effects are asthenia, fatigue, dizziness/vertigo, nausea, tremor, and weight gain.

 In recent years, interest has increased in glutamate receptor antagonists for migraine
 prophylaxis, such as memantine. Within the pathophysiology of migraine, glutamate is
 implicated in disseminated cortical depression, trigeminal-vascular activation. Other studies
 corroborate its role by reporting elevated glutamate levels in the cerebrospinal fluid in
 patients with chronic migraine in the ictal period and elevated serum levels in migraine
 patients. Besides, after experimental stimulation in the dura and the ventral-posteromedial
 thalamic nucleus structures, elevated levels of glutamate in the trigeminal-cervical complex
 have been evidenced. fifteen

 In 2008 Bigal and colleagues conducted the first open clinical trial, a pilot study to
 evaluate memantine's efficacy and safety as a prophylactic treatment in patients diagnosed
 with refractory migraine. A sample of 28 participants who had a baseline frequency of
 headache days of 21.8 days per month received memantine from 10mg to 20mg per day for three
 months. A decrease in the frequency of headache days was obtained to 16.1 (P <0.01).
 Therefore, the authors concluded that memantine as a prophylactic treatment is safe and
 effective in refractory migraines. In 2015, Noruzzadeh and colleagues conducted the first
 randomized, double-blind, placebo-controlled clinical trial to evaluate memantine's efficacy
 as a prophylactic treatment of migraine without aura With a sample of 52 participants, 25
 with memantine (10 mg/day) and 27 with placebo. The memantine group had a more significant
 reduction in the frequency of migraine attacks compared to placebo, which was a difference of
 2.3 attacks per month with a P <0.001.14
Inclusion Criteria:

 1. Men and women from 18 to 65 years old.

 2. Diagnosis of migraine according to the ICHD-III of the IHS at least one year before
 the study.

 3. You must have at least 4-14 migraine attacks per month.

 4. Not receiving prophylactic treatment for migraine

 5. Sign informed consent

 Exclusion Criteria:

 1. Pregnant or lactating patients.

 2. Patients with another type of non-migraine headache.

 3. Allergy to Sodium Valproate and/or Memantine

 4. Being a carrier of systemic disease (infectious, immunological, or metabolic
 processes) or cardiovascular (myocardial, coronary, or valvular disease) prevents
 their participation in the study.