Migraine and handedness

Handedness in Alzheimer Disease: A Systematic Review

Handedness has been a topic of scientific interest for many years. However, false and misleading ideas have dominated this field with a still limited amount of research into the association with clinical disorders like Alzheimer disease (AD). In accordance with PRISMA guidelines, PubMed, Embase, and Cochrane Library were searched for studies regarding the association of handedness and AD. Twelve articles were included. Case-control studies show that left-handedness is not a risk factor for late-onset AD (LOAD). However, nonright handedness was found to be more prevalent in patients with early-onset AD (EOAD). Moreover, handedness does not seem to affect neuropsychological performance. We also show that collapsing versus separating mixed and left-handedness may yield different results. Future research on the relation between handedness and AD may provide new insight into disease pathogenesis, improve rehabilitation, and help identify patients who will progress, aiding the design of prevention trials.

Comparison of migraine with left- versus right-sided headache: A cross-sectional study

OBJECTIVE

The goal of this study was to clarify whether clinical differences exist between patients with migraine who experience headache that is typically left-sided ("left-migraine") versus right-sided ("right-migraine") during attacks.

BACKGROUND

Migraine has been associated with unilateral headache for millennia and remains a supportive trait for the clinical diagnosis of migraine of the International Classification of Headache Disorders. It is currently unknown why headache in migraine is commonly unilateral, and whether headache-sidedness is associated with other clinical features.

METHODS

This is a cross-sectional study comparing left- versus right-migraine using all available intake questionnaires of new patients evaluated at an academic tertiary headache center over a 20-year period. Eligibility was based on patient written responses indicating the typical location of headache during attacks. In our analyses, the side of headache (left or right) was the predictor variable. The outcomes included various migraine characteristics and psychiatric comorbidities.

RESULTS

We identified 6527 patients with migraine, of which 340 met study eligibility criteria. Of these, 48.8% (166/340) had left migraine, and 51.2% (174/340) had right migraine. When comparing patients with left- versus right-migraine, patients with left migraine experienced 3.6 fewer headache-free days (95% confidence interval [CI] 1.3-5.9; p = 0.002) and 2.4 more severe headache days (95% CI 0.8-4.1; p = 0.004) in the previous 4 weeks. No significant differences in age, sex, handedness, migraine characteristics, or psychiatric comorbidities were identified between the two groups.

CONCLUSIONS

Patients with migraine with typically left-sided headache during attacks reported a higher burden of headache frequency and severity than those with typically right-sided headache during attacks. These findings may have implications for our understanding of migraine pathophysiology, treatment, and clinical trial design.

The volume of the thalamus and hippocampus in a right-handed female episodic migraine group

Background/aim

Migraine is a disabling headache with clinical and radiological complications. The aim of this study was to investigate the volume of the thalamus and hippocampus in migraineurs, the role of white matter lesions (WMLs), and the migraine characteristics in volume changes.

Methods

Brain MRIs of 161 right-handed female episodic migraine patients and 40 right-handed, age-related, healthy women were performed. Left and right thalamus segmentation was performed on the 3D MPRAGE images using the Freesurfer 5.3 image analysis suite. Hippocampal subfield segmentation was based on a novel statistical atlas built primarily upon ultra-high-resolution ex vivo MRI data.

Results

The left hippocampus had a smaller and the left thalamus had a larger total volume than the right one in both the control (p < 0.001) and migraine groups (p <0.001). Patients with white matter lesions (L+) showed smaller right thalamus and right hippocampal tail volumes than patients without lesions (L-) (p = 0.002 and p = 0.015, respectively) and controls (p = 0.039 and p = 0.025, respectively). For the right hippocampal body, we found significantly smaller volume in L+ patients when compared to L- patients (p = 0.018) and a similar trend when compared to the control group (p = 0.064). Patients without aura (A-) showed a larger right hippocampus (p = 0.029), right hippocampal body (p = 0.012), and tail volumes (p = 0.011) than patients with aura (A+). Inverse correlations were found between attack frequency and the volumes of the left and right hippocampal tails (p = 0.018 and p = 0.008, respectively).

Conclusion

These findings indicate that WMLs may influence the volume of the right thalamus and hippocampus, while migraine aura and attack frequency may lead to volume changes in different parts of the hippocampi in migraine patients. These data support the necessity of effective migraine management to limit subcortical volume loss in migraineurs.

Left- vs right-sided migraine: a scoping review

BACKGROUND

Migraine is a historically unilateral head pain condition, the cause of which is not currently known. A growing body of literature suggests individuals who experience migraine with left-sided headache ("left-sided migraine") may be distinguished from those who experience migraine with right-sided headache ("right-sided migraine").

OBJECTIVE

In this scoping review, we explore migraine unilaterality by summarizing what is currently known about left- and right-sided migraine.

METHODS

Two senior medical librarians worked with the lead authors to construct and refine a set of search terms to identify studies of subjects with left- or right-sided migraine published between 1988, which is the year of publication of the first edition of the International Classification of Headache Disorders (ICHD), and December 8, 2021 (the date the searches were conducted). The following databases were searched: Medline, Embase, PsycINFO, PubMed, Cochrane Library, and Web of Science. Abstracts were loaded into Covidence review software, deduplicated, then screened by two authors to determine study eligibility. Eligible studies were those involving subjects diagnosed with migraine (according to ICHD criteria) in which the authors either: a) compared left- to right-sided migraine; or b) described (with analysis) a characteristic that differentiated the two. Data were extracted by the lead author, including ICHD version, the definition of unilateral migraine used by the authors, sample size, whether the findings were collected during or between attacks, and their key findings. The key findings were grouped into the following themes: handedness, symptoms, psychiatric assessments, cognitive testing, autonomic function, and imaging.

RESULTS

After deduplication, the search yielded 5428 abstracts for screening. Of these, 179 met eligibility criteria and underwent full text review. 26 articles were included in the final analysis. All of the studies were observational. One study was performed during attack, nineteen between attacks, and six both during and between attacks. Left- and right-sided migraine were found to differ across multiple domains. In several cases, reciprocal findings were reported in left- and right-migraine. For example, both left- and right-sided migraine were associated with ipsilateral handedness, tinnitus, onset of first Parkinson's symptoms, changes in blood flow across the face, white matter hyperintensities on MRI, activation of the dorsal pons, hippocampal sclerosis, and thalamic NAA/Cho and NAA/Cr concentrations. In other cases, however, the findings were specific to one migraine laterality. For example, left-sided migraine was associated with worse quality of life, anxiety, bipolar disorder, PTSD, lower sympathetic activity, and higher parasympathetic activity. Whereas right-sided migraine was associated with poorer performance on multiple cognitive tests, a greater degree of anisocoria, changes in skin temperature, higher diastolic blood pressure, changes in blood flow through the middle cerebral and basilar arteries, and changes on EEG.

CONCLUSION

Left- and right-sided migraine differed across a wide range of domains, raising the possibility that the pathophysiology of left- and right-migraine may not be identical.

Cerebral perfusion variance in new daily persistent headache and chronic migraine: an arterial spin-labeled MR imaging study

BACKGROUND AND PURPOSE

New daily persistent headache (NDPH) and chronic migraine (CM) are two different types of headaches that might involve vascular dysregulation. There is still a lack of clarity about altered brain perfusion in NDPH and CM. This study aimed to investigate the cerebral perfusion variances of NDPH and CM using multi-delay pseudo-continuous arterial spin-labeled magnetic resonance imaging (pCASL-MRI).

METHODS

Fifteen patients with NDPH, 18 patients with CM, and 15 age- and sex-matched healthy controls (HCs) were included. All participants underwent 3D multi-delay pCASL-MRI to obtain cerebral perfusion data, including arrival-time-corrected cerebral blood flow (CBF) and arterial cerebral blood volume (aCBV). The automated anatomical labeling atlas 3 (AAL3) was used to parcellate 170 brain regions. The CBF and aCBV values in each brain region were compared among the three groups. Correlation analyses between cerebral perfusion parameters and clinical variables were performed.

RESULTS

Compared with HC participants, patients with NDPH were found to have decreased CBF and aCBV values in multiple regions in the right hemisphere, including the right posterior orbital gyrus (OFCpost.R), right middle occipital gyrus (MOG.R), and ventral anterior nucleus of right thalamus (tVA.R), while patients with CM showed increased CBF and aCBV values presenting in the ventral lateral nucleus of left thalamus (tVL.L) and right thalamus (tVL.R) compared with HCs (all p < 0.05). In patients with NDPH, after age and sex adjustment, the increased aCBV values of IFGorb. R were positively correlated with GAD-7 scores; and the increased CBF and aCBV values of tVA.R were positively correlated with disease duration.

CONCLUSION

The multi-delay pCASL technique can detect cerebral perfusion variation in patients with NDPH and CM. The cerebral perfusion changes may suggest different variations between NDPH and CM, which might provide hemodynamic evidence of these two types of primary headaches.

Regular Practice of Autogenic Training Reduces Migraine Frequency and Is Associated With Brain Activity Changes in Response to Fearful Visual Stimuli

Several factors can contribute to the development and chronification of migraines, including stress, which is undoubtedly a major trigger. Beyond pharmacotherapy, other treatment methods also exist, including behavioral techniques aiming at reducing patients’ stress response. However, the exact brain mechanisms underlying the efficacy of such methods are poorly understood. Our pilot study examined whether the regular practice of autogenic training (AT) induces functional brain changes and if so, how it could be associated with the improvement of migraine parameters. By exploring neural changes through which AT exerts its effect, we can get closer to the pathomechanism of migraine. In particular, we investigated the effect of a headache-specific AT on brain activation using an implicit face emotion processing functional MRI (fMRI) task in female subjects with and without episodic migraine. Our focus was on migraine- and psychological stress-related brain regions. After a 16-week training course, migraineurs showed decreased activation in the migraine-associated dorsal pons to fearful compared with neutral visual stimuli. We also detected decreasing differences in supplementary motor area (SMA) activation to fearful stimuli, and in posterior insula activation to happy stimuli between healthy subjects and migraineurs. Furthermore, migraineurs reported significantly less migraine attacks. These brain activation changes suggest that AT may influence the activity of brain regions responsible for emotion perception, emotional and motor response integration, as well as cognitive control, while also being able to diminish the activation of regions that have an active role in migraine attacks. Improvements induced by the training and the underlying neurophysiological mechanisms are additional arguments in favor of evidence-based personalized behavioral therapies.

Prenatal oestrogen-testosterone balance as a risk factor of migraine in adults

BACKGROUND

Migraine is a common neurological disease with extremely debilitating, but fully reversible symptoms. Women suffer from migraine more often than men. It was assumed that fluctuation of oestrogen level during menstrual cycle is one of many factors responsible for more frequent migraine attacks. The second-to-fourth digit ratio (2D:4D) is considered as an indicator of prenatal sex steroids. Balance of prenatal androgens (testosterone) and oestrogen has been studied in numerous diseases that are affected by hormones. However, the relationship between migraine and the sex steroids balance in prenatal development is still unexplained. The aim of this paper is to provide an evidence of relationship between prenatal oestrogen and testosterone exposure following 2D:4D digit ratio, and migraine prevalence in adults.

METHODS

We examined a group of 151 adults (33 males, 118 females) with migraine and a control group of 111 adults (45 males, 66 females). 2D:4D digit ratio of both hands was measured using sliding Vernier calliper.

RESULTS

Significant differences were found in the right hand. Female migraineurs had lower value of 2D:4D ratio than the control group and the right 2D:4D was lower than left 2D:4D (Δ2D:4D), suggesting prenatal testosterone dominance. The opposite relationship was observed in males. Male migraineurs had higher value of 2D:4D ratio and Δ2D:4D was greater than the control group, suggesting prenatal oestrogen dominance.

CONCLUSIONS

Our results suggest that depending on sex, different proportion of prenatal sex steroids might be a risk factor of migraine in adults. Women with migraine were presumably exposed in prenatal life to higher testosterone levels relative to oestrogen, while men with migraine were probably exposed in prenatal life to higher levels of oestrogen relative to testosterone.