Effects of topiramate on neurophysiological and neuropsychological tests in migraine patients

Narrative Review of Topiramate: Clinical Uses and Pharmacological Considerations

Due to the diverse mechanisms of action of antiseizure drugs, there has been a rise in prescriptions of these drugs for non-epileptic pathologies. One drug that is now being used for a variety of conditions is topiramate. This is a narrative review that used PubMed, Google Scholar, MEDLINE, and ScienceDirect to review literature on the clinical and pharmacologic properties of topiramate. Topiramate is a commonly prescribed second-generation antiseizure drug. The drug works through multiple pathways to prevent seizures. In this regard, topiramate blocks sodium and calcium voltage-gated channels, inhibits glutamate receptors, enhances gamma-aminobutyric acid (GABA) receptors, and inhibits carbonic anhydrase. Topiramate is approved by the Food and Drug Administration (FDA) for epilepsy treatment and migraine prophylaxis. Topiramate in combination with phentermine is also FDA-approved for weight loss in patients with a body mass index (BMI) > 30. The current target dosing for topiramate monotherapy is 400 mg/day and 100 mg/day to treat epilepsy and migraines, respectively. Commonly reported side effects include paresthesia, confusion, fatigue, dizziness, and change in taste. More uncommon and serious adverse effects can include acute glaucoma, metabolic acidosis, nephrolithiasis, hepatotoxicity, and teratogenicity. Related to a broad side effect profile, physicians prescribing this drug should routinely monitor for side effects and/or toxicity. The present investigation reviews various anti-seizure medications before summarizing indications of topiramate, off-label uses, pharmacodynamics, pharmacokinetics, adverse effects, and drug-drug interactions.

Does cognitive dysfunction correlate with dizziness severity in patients with vestibular migraine?

OBJECTIVE

To characterize the relationship between dizziness severity and cognitive dysfunction in vestibular migraine (VM) patients.

METHODS

Dizziness Handicap Inventory (DHI) and Cognitive Failures Questionnaire (CFQ) scores were compared pre- and post-treatment in a cohort of definite VM patients who underwent evaluation in a multidisciplinary clinic from 2016 to 2020.

RESULTS

44 patients were included. DHI reduction of 11.96 (SD 11.49) (p < 0.001) from an initial mean of 58.36 (22.05) and CFQ reduction of 4.57 (12.20) (p = 0.017) from an initial mean of 47.66 (19.12) were demonstrated. Both pre- and post-treatment DHI scores correlated with pre- and post-treatment CFQ scores (r = 0.537, p < 0.001 and r = 0.667, p < 0.001, respectively). Change in DHI score correlated with change in CFQ score (r = 0.351, p = 0.019).

CONCLUSIONS

Cognitive dysfunction in VM patients is correlated with dizziness severity. The DHI may fail to thoroughly assess cognitive dysfunction in VM patients. Additionally, multidisciplinary treatment of VM reduces both dizziness severity and cognitive dysfunction.

Differences in Frontal Lobe Dysfunction in Patients with Episodic and Chronic Migraine

Neuroimaging and neuropsychological investigations have indicated that migraineurs exhibit frontal lobe-related cognitive impairment. We investigated whether orbitofrontal and dorsolateral functioning differed between individuals with episodic migraine (EM) and chronic migraine (CM), focusing on orbitofrontal dysfunction because it is implicated in migraine chronification and medication overuse headache (MOH) in migraineurs. This cross-sectional study recruited women with CM with/without MOH (CM + MOH, CM − MOH), EM, and control participants who were matched in terms of age and education. We conducted neuropsychological assessments of frontal lobe function via the Trail Making Test (TMT) A and B, the Wisconsin Card Sorting Test (WCST), and the Iowa Gambling Task (IGT). We enrolled 36 CM (19 CM + MOH, 17 CM − MOH), 30 EM, and 30 control participants. The CM patients performed significantly (p < 0.01) worse on the TMT A and B than the EM patients and the control participants. The WCST also revealed significant differences, with poorer performance in the CM patients versus the EM patients and the control participants. However, the net scores on the IGT did not significantly differ among the three groups. Our findings suggest that the CM patients exhibited frontal lobe dysfunction, and, particularly, dorsolateral dysfunction. However, we found no differences in frontal lobe function according to the presence or absence of MOH.

Information Processing in Migraine: A Review of Studies on P300

Subjective cognitive dysfunction is common among migraineurs. The aim of this review is to evaluate the usefulness of psychophysiology by means of the P300 component of the event-related potential in the understanding of subtle and sub-clinical changes in cognition that may occur during and between migraine episodes. Some P300 studies suggest a potential impairment of information processing, as reflected by only few findings of interictal decreased amplitude and prolonged latency, ictal augmented amplitude and prolonged latency, changes in cognitive habituation, and limited capacity to relocate attention away from painful stimuli. P300 may represent a valuable aid for clinicians to identify patients at risk of chronicization and cognitive weakening due to neurovascular complications; in this perspective a research agenda may be planned involving larger numbers of patients undergoing psychophysiological studies.

Severity of Topiramate-Related Working Memory Impairment Is Modulated by Plasma Concentration and Working Memory Capacity

Drug side effects that impair cognition can lead to diminished quality of life and discontinuation of therapy. Topiramate is an antiepileptic drug that elicits cognitive deficits more frequently than other antiepileptic drugs, impairing multiple cognitive domains including language, attention, and memory. Although up to 40% of individuals taking topiramate may experience cognitive deficits, we are currently unable to predict which individuals will be most severely affected before administration. The objective of this study was to show the contributions of plasma concentration and working memory capacity in determining the severity of an individual's topiramate-related cognitive impairment. Subjects were enrolled in a double-blind, placebo-controlled crossover study during which they received a single dose of either 100, 150, or 200 mg topiramate. Working memory function was assessed using a modified Sternberg working memory task with 3 memory loads administered 4 hours after dosing. After adjustment for differences in working memory capacity, each 1 μg/mL of topiramate plasma concentration was associated with a 3.6% decrease in accuracy for all memory loads. Placebo effects occurred as a function of working memory capacity, with individuals with high working memory capacity experiencing less severe placebo-related impairment compared with those with low working memory capacity. Our results demonstrate that severity of topiramate-related cognitive deficits occurs as a function of both drug exposure and baseline cognitive function. By identifying patient- and exposure-related characteristics that modulate the severity of cognitive side effects, topiramate dosing strategies may be individually tailored in the future to prevent unwanted cognitive impairment.

Subjective cognitive complaints and migraine characteristics: A cross-sectional study

OBJECTIVES

Subjective cognitive complaints by patients with migraine have been associated with memory impairment. However, whether the severity of memory impairment relates to migraine characteristics, such as attack frequency and aura, remains undetermined. We investigated the relationship between subjective cognitive complaints and migraine characteristics.

MATERIALS AND METHODS

This cross-sectional study recruited 669 clinic outpatients from Taiwan. We stratified them by migraine frequency and the presence or absence of aura, and we controlled the data for confounding variables. We performed multivariable linear and logistic regressions to investigate whether different migraine frequencies are associated with subjective cognitive complaints, which were evaluated by the subjective memory complaints scale and the Ascertain Dementia 8 (AD8) questionnaire.

RESULTS

Total subjective memory complaints scores tended to increase with the migraine attack frequency (P = .022) in patients with migraine with aura; similar results were obtained for AD8 scores in women with migraine with aura. Poor sleep quality was associated with a higher total subjective memory complaint (B = 0.08, 95% confidence interval [CI] = 0.03-0.14) and AD8 (B = 0.07, 95% CI = 0.02-0.11) scores. In addition, more severe depression was associated with higher total subjective memory complaints and AD8 scores (B = 0.05, 95% CI = 0.02-0.09; B = 0.08, 95% CI = 0.05-0.11, respectively).

CONCLUSIONS

Subjective cognitive complaints tend to increase with the frequency of migraines with aura, and this interrelation is substantially influenced by depression severity and sleep disturbances.

Evaluation of cognitive functions in migraineurs treated with topiramate

Topiramate for the treatment of migraine prophylaxis may cause side effects such as cognitive dysfunction. We aimed to investigate the topiramate's efficacy in migraineours and effect on cognitive functions. 24 migraine patients (Group 1) and 24 healthy participants (Group 2) were included. In both groups event-related potentials P300 Latency, Amplitude and N200 Latency, Amplitude's were evaluated. Topiramate treatment was ordered to group 1. Two months after treatment, the same parameters were evaluated. Monthly number of attacks, painful days, analgesic-triptan use and VAS scores were compared before and 2 months after treatment. Evaluation between group 1 and group 2 showed no difference. Group1's before and after treatment values were compared; all parameters after treatment were statistically significantly better. Group 1's number of attacks in a month, the number of painful days in a month, VAS score, the number of analgesic use, the number of triptan use had all decreased after treatment. 100 mg topiramate was effective in the treatment of migraine. However, electrophysiological studies showed that cognitive functions are also affected adversely.

Topiramate modulates trigeminal pain processing in thalamo-cortical networks in humans after single dose administration

Migraine is the sixth most common cause of disability in the world. Preventive migraine treatment is used to reduce frequency, severity and duration of attacks and therefore lightens the burden on the patients' quality of life and reduces disability. Topiramate is one of the preventive migraine treatments of proven efficacy. The mechanism of action underlying the preventive effect of topiramate in migraine remains largely unknown. Using functional magnetic resonance imaging (fMRI) we examined the central effects of a single dose of topiramate (100mg) on trigeminal pain in humans, compared to placebo (mannitol). In this prospective, within subject, randomized, placebo-controlled and double-blind study, 23 healthy participants received a standardized nociceptive trigeminal stimulation and control stimuli whilst being in the scanner. No differences in the subjective intensity ratings of the painful stimuli were observed between topiramate and placebo sessions. In contrast, topiramate significantly decreased the activity in the thalamus and other pain processing areas. Additionally, topiramate increased functional coupling between the thalamus and several brain regions such as the bilateral precuneus, posterior cingulate cortex and secondary somatosensory cortex. These data suggest that topiramate exhibits modulating effects on nociceptive processing in thalamo-cortical networks during trigeminal pain and that the preventive effect of topiramate on frequent migraine is probably mediated by an effect on thalamo-cortical networks.

Differences in executive functions applied to memory processes in people with migraine: a cross-sectional study

The aim of this cross-sectional study was to identify differences in memory processes and the role of executive functions in memory, in people with migraine and in a control group. Neuropsychological evaluation was made in one session on 63 participants distributed into interictal migraine-with-aura (n = 24), interictal migraine-without-aura (n = 16) and control (n = 23) groups. ANOVAs on the individual tasks revealed statistically significant differences between groups on Rey-Osterrieth direct and percentile copy strategy and recall (both p < 0.001). Differences were identified between control and migraine groups in performance on the Rey-Osterrieth Complex Figure, but not on other memory tasks, suggesting the existence of brain dysfunctions in people with migraine affecting organizational and planning abilities that are necessary for visual memory.

Clinical Utility of the Mig-SCog

BACKGROUND

Mig-SCog is a 9-item questionnaire developed to quantify attack-related cognitive complaints in migraine (M). The items relate to executive function and language, and the total Mig-SCog score is the sum of those scales.

OBJECTIVE

To evaluate the Mig-SCog scores regarding cognitive symptoms during a variety of conditions.

METHODS

We conducted a prospective comparative study of the Mig-SCog scores (1) between migraine and tension-type headache (TTH) patients during a headache; (2) in migraine patients between migraine attacks, non-headache pain and pain-free status; (3) in migraine patients during and outside a migraine attack.

RESULTS

One hundred forty-nine patients (98 M and 51 TTHA). Total Mig-SCog score was higher in migraine patients than TTH (8.0 ± 4.1 vs 3.4 ± 3.2, P < .0001). Sixty-three patients took part in the next part of the study. Migraine patients rated the Mig-SCog higher for migraine (7.9 ± 4.6) than for non-headache pain (2.3 ± 2.9, P < .0006) or pain-free (1.6 ± 2.4, P < .0006). In the final phase of the study, 38 patients Mig-SCog scores were not significantly different whether obtained during or outside an M attack (P = .26).

CONCLUSIONS

Attack-related subjective cognitive symptoms, assessed by Mig-SCog scores, differed between migraine and TTH patients. The Mig-SCog scores from migraine patients were found to be higher during migraine than during non-headache pain or pain-free conditions. Patient scoring from memory for usual attacks was not significantly different to scoring within attacks, We believe this demonstrates negligible recall bias.

The impact of cognitive symptoms on migraine attack-related disability

Background

The socio-economic impact of migraine is mostly related to work loss either by absenteeism or decreased work performance. Migraine-associated cognitive dysfunction during an attack may contribute to these difficulties.

Objective

The objective of this article is to analyze the presence and relevance of cognitive symptoms during migraine attacks and to relate their intensity and symptom-related disability with other migraine-defining symptoms.

Methods

Consecutive migraine patients of a headache clinic completed diaries scoring each migraine symptom (including cognitive symptoms) intensity and symptom-related disability.

Results

Of 100 consecutive patients included in this study, 34 (all females, age average 31.8 ± 8.8 years) returned information on 229 attacks, on average 6.7 per participant. Every symptom’s intensity was always rated slightly higher than the disability it caused. Pain was the symptom scored with the highest intensity and disability, followed by cognitive symptoms (difficulty in thinking and worsening with mental effort) and photo- and phonophobia. Scoring was independent of any of the clinical variables. Attack intensity and disability scores correlated with intensity and disability from pain and from worsening with mental effort.

Conclusions

Attack-related cognitive symptoms are intense and disabling. Some attack-related cognitive symptoms correlate to intensity and disability subjectively attributed to the migraine attack. Cognitive performance should be addressed as a valuable secondary endpoint in trials of acute migraine treatment.

Efficacy of zonisamide in migraineurs with nonresponse to topiramate

This study investigated another type of carbonic anhydrase inhibitor and antiepileptic drug, zonisamide, in order to evaluate its potential effectiveness for migraine prophylaxis refractory to topiramate, and to assess intolerability to adverse events, paresthesia in particular. This is an open-labeled retrospective single center study. We included headache patients who met the requirement of migraine without aura and were refractory to topiramate. Patients were treated only with zonisamide 100 mg/day, directly switching from topiramate. Patients were monitored every month for three months. A positive response to treatment (responders) was defined as a 50% or greater reduction in headache days at three months after study commencement, compared with baseline. One hundred and twenty migraineurs who were refractory to topiramate were recruited. Compared with baseline, headache days with zonisamide showed a decrease, compared with baseline (P < 0.01). Two patients complained of adverse effects, such as paresthesia. These results suggest that zonisamide is effective for migraine prophylaxis refractory to topiramate, or intolerable patients due to topiramate-induced paresthesia.

Topiramate: Effects on cognition in patients with epilepsy, migraine headache and obesity

This paper reviews the clinical implications of topiramate (TPM)-induced cognitive deficits in patients with epilepsy, migraine headache, obesity, and in normal populations, followed by reviews of the literature describing the reversal of such deficits upon medication discontinuation. It also discusses animal investigations of TPM's role of neuroprotection in brain injury. TPM's most intolerable adverse effects (AEs) are on verbal fluency and reaction time, resulting in high discontinuation rates in patients taking it for epilepsy and migraine headache. However, because TPM is so effective in the treatment of epilepsy and migraine headache, its use is expected to continue. There appears to be greater tolerance of TPM's cognitive AEs when it is used in the treatment of obesity, perhaps because of the lower doses required. Research attempting to predict the populations most vulnerable to the cognitive effects caused by TPM is ongoing. Studies suggest that one such population may include patients with a past psychiatric history. Slow titration and administration of the lowest possible doses may decrease risk of cognitive deficits.

New drugs in migraine treatment and prophylaxis: telcagepant and topiramate

Although the triptan drugs provide effective relief from migraine for many patients, a substantial number of affected individuals are unresponsive to these compounds, and such therapy can also lead to a range of adverse effects. Telcagepant represents a new class of antimigraine drug-the calcitonin gene-related peptide receptor blockers. This compound exerts its effects by blocking receptors for the calcitonin-gene-related peptide at several sites in the trigeminal and central nervous systems, resulting in pain relief. Telcagepant does not cause vasoconstriction, a major limitation in the use of triptans. Comparisons with triptans in clinical trials for acute treatment of migraine attacks revealed clinical effects similar to those of triptans but better than those of placebo. Telcagepant might provide hope for those who have a poor response to, or are unable to use, older drugs. In patients who need prophylaxis because of frequent attacks of migraine, topiramate is a first-line drug for migraine prevention in many countries; it is generally safe and reasonably well tolerated. Data suggest that topiramate could aid reversion of chronic migraine to episodic migraine.