An analysis of the "carry-over effect" following successful short-term treatment of transformed migraine with divalproex sodium

The sense of stopping migraine prophylaxis

INTRODUCTION

Migraine prophylactic therapy has changed over recent years with the development and approval of monoclonal antibodies (mAbs) targeting the calcitonin gene-related peptide (CGRP) pathway. As new therapies emerged, leading headache societies have been providing guidelines on the initiation and escalation of such therapies. However, there is a lack of robust evidence looking at the duration of successful prophylaxis and the effects of therapy discontinuation. In this narrative review we explore both the biological and clinical rationale for prophylactic therapy discontinuation to provide a basis for clinical decision-making.

METHODS

Three different literature search strategies were conducted for this narrative review. These include i) stopping rules in comorbidities of migraine in which overlapping preventives are prescribed, notably depression and epilepsy; ii) stopping rules of oral treatment and botox; iii) stopping rules of antibodies targeting the CGRP (receptor). Keywords were utilized in the following databases: Embase, Medline ALL, Web of Science Core collection, Cochran Central Register of Controlled Trials, and Google Scholar.

DISCUSSION

Reasons to guide decision-making in stopping prophylactic migraine therapies include adverse events, efficacy failure, drug holiday following long-term administration, and patient-specific reasons. Certain guidelines contain both positive and negative stopping rules. Following withdrawal of migraine prophylaxis, migraine burden may return to pre-treatment level, remain unchanged, or lie somewhere in-between. The current suggestion to discontinue CGRP(-receptor) targeted mAbs after 6 to 12 months is based on expert opinion, as opposed to robust scientific evidence. Current guidelines advise the clinician to assess the success of CGRP(-receptor) targeted mAbs after three months. Based on excellent tolerability data and the absence of scientific data, we propose if no other reasons apply, to stop the use of mAbs when the number of migraine days decreases to four or fewer migraine days per month. There is a higher likelihood of developing side effects with oral migraine preventatives, and so we suggest stopping these drugs according to the national guidelines if they are well tolerated.

CONCLUSION

Translational and basic studies are warranted to investigate the long-term effects of a preventive drug after its discontinuation, starting from what is known about the biology of migraine. In addition, observational studies and, eventually, clinical trials focusing on the effect of discontinuation of migraine prophylactic therapies, are essential to substantiate evidence-based recommendations on stopping rules for both oral preventives and CGRP(-receptor) targeted therapies in migraine.

Prognosis Following Discontinuation of OnabotulinumA Therapy in "Super-responding" Chronic Migraine Patients

OBJECTIVE

To determine whether the successful treatment of chronic migraine (CM) with onabotulinumA (BotoxA) may be followed by a continued respite from headache once therapy has been discontinued.

BACKGROUND

The optimal duration of prophylactic therapy for migraine generally and for CM treated with BotoxA specifically is unknown.

METHODS

We conducted a prospective cohort study evaluating a series of patients with CM at a university-affiliated headache subspecialty clinic in Reno, Nevada, all of whom were treated according to a uniform protocol involving serial injections of BotoxA. We followed all positively responding patients who met our stopping rule for a minimum of 6 months after discontinuation of BotoxA, and we assessed the incidence of clinical worsening in that group.

RESULTS

A total of 105/131 patients (80%) for whom complete follow-up was available reported no clinical worsening or need to resume prophylactic therapy over the 6 months following discontinuation of BotoxA therapy. Patients with pre-treatment baseline chronic daily headache (CDH) of greater than 6 months duration were more likely to report clinical deterioration within 6 months of stopping treatment, as compared to patients with CDH of less than 6 months. A greater number of BotoxA treatments required to achieve our stopping rule correlated with clinical deterioration within 6 months of stopping treatment.

CONCLUSIONS

In many CM patients who experience an especially positive response to serial BotoxA injection therapy, clinical improvement may be sustained for a period of at least 6 months following discontinuation of prophylactic therapy.

Clown-care reduces pain in children with cerebral palsy undergoing recurrent botulinum toxin injections- A quasi-randomized controlled crossover study

Objective

We investigated the impact of clown-care on pain in 45 children with cerebral palsy who underwent recurrent Botulinum-toxin injections (age 7.04± 4.68 years). Participants were randomized to receive either clown (n = 20) or standard (n = 25) -care.

Methods

Pain Visual-Analogue-Scale (range 1–5) was reported before and after procedures. Pain assessment was lower for children undergoing Botulinum-toxin injections with clown-care (2.89± 1.36) compared to standard-care (3.85± 1.39; p = 0.036) even though pain anticipated prior to procedures was similar (~3).

Findings

Children who underwent the first procedure with clown-care reported lower pain even after they crossed-over to the following procedure which was standard (p = 0.048). Carryover effect was more prominent in injection-naïve children (p = 0.019) and during multiple procedures (p = 0.009). Prior pain experience correlated with pain in subsequent procedures only when first experience was standard-care (p = 0.001).

Conclusions

Clown-care alleviated pain sensation during Botulinum-toxin injections and initial clown-care experience reduced pain during subsequent injections even though clowns were not present.

Trial registration

clinicaltrials.gov ID # NCT01377883.

Sodium valproate in migraine without aura and medication overuse headache: a randomized controlled trial

OBJECTIVE

To assess the efficacy, safety and tolerability of sodium valproate (800mg/die) compared with placebo in medication-overuse headache patients with a history of migraine without aura.

METHODS

This is a multicenter, randomized, double-blind, placebo-controlled study enrolled medication-overuse headache patients for a 3-month treatment period with sodium valproate (800mg/day) or placebo after a 6 day outpatient detoxification regimen, followed by a 3-month follow-up. Primary outcome was defined by the proportion of patients achieving ≥50% reduction in the number of days with headache per month (responders) from the baseline to the last 4 weeks of the 3-month treatment. Multivariate logistic regression models were used on the primary endpoint, adjusting for age, sex, disease duration, comorbidity and surgery. The last-observation-carried-forward method was used to adjust for missing values.

RESULTS

Nine sites enrolled 130 patients and, after a 6-day detoxification phase, randomized 88 eligible patients. The 3-month responder rate was higher in the sodium valproate (45.0%) than in the placebo arm (23.8%) with an absolute difference of about 20% (p=0.0431). Sodium valproate had safety and tolerability profiles comparable to placebo.

CONCLUSIONS

The present study supports the efficacy and safety of sodium valproate in the treatment of medication overuse headache with history of migraine after detoxification.

Targeting the epigenome: effects of epigenetic treatment strategies on genomic stability in healthy human cells

Epigenetic treatment concepts have long been ascribed as being tumour-selective. Over the last decade, it has become evident that epigenetic mechanisms are essential for a wide range of intracellular functions in healthy cells as well. Evaluation of possible side-effects and their underlying mechanisms in healthy human cells is necessary in order to improve not only patient safety, but also to support future drug development. Since epigenetic regulation directly interacts with genomic and chromosomal packaging density, increasing genomic instability may be a result subsequent to drug-induced epigenetic modifications. This review highlights past and current research efforts on the influence of epigenetic modification on genomic stability in healthy human cells.

The effect of sodium valproate on chronic daily headache and its subgroups

The objective of the study was to assess the efficacy and tolerability of sodium valproate (VPA) on chronic daily headache (CDH) in a prospective, double-blind, randomized, placebo-controlled trial. Seventy patients were included in the study. Twenty-nine had chronic migraine (CM) and 41 had chronic tension-type headache (CTTH). VPA and placebo were applied for 3 months to 40 and 30 patients, respectively. Visual analog scale (VAS) and pain frequency (PF) were used for evaluation. VPA decreased the maximum pain VAS levels (MaxVAS) and PF at the end of the study (P = 0.028 and P = 0.000, respectively), but did not change general pain VAS (GnVAS) levels (P = 0.198). In CM patients, the decreases in MaxVAS, GnVAS and PF parameters were more in VPA treated patients (P = 0.006, P = 0.03, and P = 0.000, respectively). VPA treatment caused more reduction in PF than placebo in the CTTH subgroup (P = 0.000). VPA is effective in the prophylactic treatment of CDH by reducing MaxVAS levels and PF. It was more effective in CM than in CTTH.

Sodium valproate prophylaxis in childhood migraine

Migraine is a cause of recurrent headache in childhood. The efficacy of sodium valproate is well known in the prophylactic treatment of adult migraine, but there are few studies involving the drug's effect in pediatric migraine.

OBJECTIVE

To determine the efficacy of sodium valproate in the prophylactic treatment of childhood migraine.

METHODS

Fifteen children with migraine according to International Headache Society criteria were included in the study. Headache severity was measured and assessed by Algology unit by a using visual analog scale and a numerical rating scale. All of the subjects were asked to keep a headache diary for 8 weeks. Three subjects who had no headache attacks during the baseline period and two cases who were lost to follow up were excluded. Thus, sodium valproate was initiated in 10 subjects (six boys, four girls), 500 mg/night, and the daily dose was increased up to 1000 mg according to blood levels. Their ages ranged from 9 to 17 (mean age 13.6 +/- 3.2 years). Therapy continued for at least 12 weeks.

RESULTS

Headache severity as measured via the mean visual analog score was 6.8 +/- 1.8 at baseline and was 0.7 +/- 1.2 at the end of the treatment period (P = 0.000). Mean headache attacks per month were 6 +/- 4.2 at baseline and were 0.8 +/- 1.9 at the end of the treatment period (P = 0.002). The duration of headache was significantly decreased from a mean of 5.5 +/- 3.9 hours to 1.1 +/- 2.5 hours with treatment (P = 0.001). The observed side effects were dizziness, drowsiness, and increase in appetite; none required drug withdrawal. In two cases, headache attacks recurred after the cessation of valproate, and therapy was restarted. Headache control lasted for six months following cessation of the drug in the remainder of the subjects.

CONCLUSION

Sodium valproate appears to be effective and safe in selected patients with childhood migraine.