Is palinopsia in migraineurs an enhanced physiological phenomenon?

Topographic localization of migraine triggers and its association with headache frequency and severity

OBJECTIVE

Internal biological rhythm with or without external trigger may precipitate migraine. Classifying exogenous and endogenous triggers to a topographic localization may help in understanding the migraine. We report topographic localization of migraine triggers and its influence on headache frequency and severity.

METHODS

588 migraineurs, aged 16-69 years were included. Various endogenous and exogenous triggers were categorized to topographic localization- hypothalamic, pituitary, auditory, visual, somato-sensory, olfactory and gustatory. The relationship of topographic localization of triggers with episodic versus chronic migraine, and moderate versus severe headache were analyzed using univariate followed by multivariate analysis.

RESULTS

All migraineurs had triggers 584(99.9%) except 4(0.1%) patients. Presence of multiple triggers (99.4%), and combination of both endogenous and exogenous triggers (97.7%) was the rule. On topographic localization, hypothalamic trigger was the commonest (98.1%) followed by visual (84.1%), auditory (82.1%), somatosensory (76.1%), olfactory (26.2%), pituitary (24.1%), and gustatory (6.6%). 98.6% patients had combination of hypothalamic with pituitary triggers. Hypothalamic [Adjusted odds ratio (AOR) 4.50] and auditory triggers (AOR 0.34) independently predicted chronic migraine, and auditory (AOR 0.55) and gustatory (AOR 2.41) triggers predicted severity of headache.

CONCLUSION

Hypothalamic triggers are the commonest suggesting an innate susceptibility of migraine. Auditory trigger may precipitate frequent and severe headache.

Impact of comorbid psychogenic non-epileptic seizures on migraine: An observational study

Objectives

There is a bidirectional and complex interplay between psychiatric comorbidities and migraine. Migraine has been observed in 50-60% of patients with psychogenic non-epileptic seizures (PNES). Studies describe migraine as a medical comorbidity in PNES. However, there are limited studies on impact of PNES on migraine. We aim to see the impact of PNES on migraine.

Materials and Methods

This cross-sectional and observational study was conducted at a tertiary-care center from June 2017 to May 2019. Fifty-two patients with migraine with PNES and 48 patients with migraine without PNES were included on the study. Migraine and PNES were diagnosed based on International Classification of Headache Disorders-3 (ICHD-3) and International League Against Epilepsy (ILAE) criteria, respectively. Headache intensity was assessed using visual analog scale. Comorbid depression, anxiety, and somatoform-symptom-disease were assessed using the Generalized Anxiety Disorder-7 Scale, Patient Health Questionnaire-9, and DSM-5 criteria, respectively.

Results

Females were common in both groups and the difference was statistically insignificant. Headache frequency was significantly more in patients with migraine with PNES (P < 0.05). However, headache intensity was similar in both groups. Patients with headaches and PNES identified triggers less commonly except for stress. Depression and somatoform symptom disorder were significantly more common in patients with migraine with PNES. Abnormal neurocircuitry involving frontal, limbic, and thalamic regions due to comorbid PNES may cause central sensitization, resulting in frequent migraine headaches which is further augmented by coexisting depression and somatoform-symptom-disease.

Conclusion

Migraine with PNES patients suffers more frequent headaches than patients with migraine without PNES. They differ in various headache triggers, with mental stress being the predominant trigger.

Migraine triggers in Asian countries: a narrative review

Background

Migraine is one of the most common neurological disorders worldwide. Clinical characteristics of migraine may be somewhat different across ethnic groups. Although factors such as stress, lack of sleep, and fasting are known as migraine triggers, the discussion about geographical differences of migraine triggers in Asia is lacking.

Methods

In this study, we performed a narrative review on migraine triggers in Asia. We searched PubMed for relevant papers published between January 2000 and February 2022.

Results

Forty-two papers from 13 Asian countries were included. Stress and sleep are the most frequently reported migraine triggers in Asia. There were some differences in migraine triggers in Asian countries: fatigue and weather common in Eastern Asia and fasting common in Western Asia.

Conclusion

Majority of the common triggers reported by patients with migraine in Asia were stress and sleep, similar to those reported globally, thus showing they are universally important. Some triggers linked to internal homeostasis are influenced by culture (e.g., alcohol, food/eating habit), and triggers related to environmental homeostasis, such as weather, are highly heterogenous between regions.

Is Palinopsia in Migraineurs a Phenomenon of Impaired Habituation of Visual Cortical Neurons?

Palinopsia in migraine has been reported recently, which may be due to the dysexcitability of visual cortical neurons. In this cross-sectional study, we report the correlation of neuronal dysexcitability with palinopsia using pattern shift visual evoked potential (PSVEP) in 91 migraineurs and 25 healthy controls. The presence of palinopsia was evaluated using a novel objective method, and revealed more frequent palinopsia in the migraineurs compared to the controls (53 of 91 [58.2%] vs 3 of 25 [12%]; P < .001). Five consecutive blocks of PSVEP were recorded for the evaluation of sensitization and impaired habituation. Amplitudes of N75 and P100 in block 1 were considered for sensitization. Impaired habituation of N75 and P100 was considered if any amplitudes in blocks 2 to 5 were higher than block 1. Impaired habituation was more frequent in migraineurs compared with the controls, and was more marked in wave N75 (81.3% vs 32%; P < .001) than wave P100 (63.7% vs 44%; P = .12). Impaired habituations of wave N75 (81.7% vs 58.9%; P = .008) and wave P100 (71.7% vs 46.4%; P = .008) were more frequent in those with palinopsia compared with those without. There was a lack of suppression of P100 amplitude in block 3 in the palinopsia group compared to the controls. The duration of palinopsia correlated with the extent of impaired habituation of N75. It can be concluded that the impaired habituation of PSVEP waveforms is a biomarker of palinopsia in migraine.

Visual Snow: Updates on Pathology

Purpose of Review

Until the last 5 years, there was very little in the literature about the phenomenon now known as visual snow syndrome. This review will examine the current thinking on the pathology of visual snow and how that thinking has evolved.

Recent Findings

While migraine is a common comorbidity to visual snow syndrome, evidence points to these conditions being distinct clinical entities, with some overlapping pathophysiological processes. There is increasing structural and functional evidence that visual snow syndrome is due to a widespread cortical dysfunction. Cortical hyperexcitability coupled with changes in thalamocortical pathways and higher-level salience network controls have all shown differences in patients with visual snow syndrome compared to controls.

Summary

Further work is needed to clarify the exact mechanisms of visual snow syndrome. Until that time, treatment options will remain limited. Clinicians having a clearer understanding of the basis for visual snow syndrome can appropriately discuss the diagnosis with their patients and steer them towards appropriate management options.

Illusions, hallucinations, and visual snow

Illusions and hallucinations are commonly encountered in both daily life and clinical practice. In this chapter, we review definitions and possible underlying mechanisms of these phenomena and then review what is known about specific conditions that are associated with them, including ophthalmic causes, migraine, epilepsy, Parkinson's disease, and schizophrenia. We then discuss specific syndromes including the Charles Bonnet syndrome, visual snow syndrome, Alice in Wonderland syndrome, and peduncular hallucinosis. The scientific study of illusions and hallucinations has contributed significantly to our understanding of how eye and brain process vision and contribute to perception. Important concepts are the distinction between topologic and hodologic mechanisms underlying hallucinations and the involvement of attentional networks. This chapter examines the various ways in which pathological illusions and hallucinations might arise in relation to the phenomenology and known pathology of the various conditions associated with them.

Symptoms related to the visual system in migraine

Migraine is a common headache disorder characterized by often-severe headaches that may be preceded or accompanied by a variety of visual symptoms. Although a typical migraine aura is not difficult to diagnose, patients with migraine may report several other visual symptoms, such as prolonged or otherwise atypical auras, "visual blurring", "retinal migraine", "ophthalmoplegic migraine", photophobia, palinopsia, and "visual snow". Here, we provide a short overview of these symptoms and what is known about the relationship with migraine pathophysiology. For some symptoms, the association with migraine is still debated; for other symptoms, recent studies indicate that migraine mechanisms play a role.

Comparison of chronic daily headache with and without medication overuse headache using ICHD II R and ICHD 3 beta criteria

OBJECTIVE

To evaluate the frequency of Medication Overuse Headache (MOH) in the patients with Chronic Daily Headache (CDH) using International Classification of Headache Disorder II Revision (ICHD II R) and International Classification of Headache Disorder 3 Beta (ICHD-3 beta) criteria. We also compare the CHD patients with and without MOH using both the criteria.

PATIENTS AND METHODS

Consecutive CDH patients from neurology service between 2014 and 2015 were included. The patients with CDH was categorised to MOH was based on ICHDIIR and ICHD-3 beta criteria. Their demographic and headache characteristics including frequency, duration, severity and disability were noted. Severity of headache was assessed using Visual Analogue Scale (VAS). Predictors of MOH were evaluated by multivariate analysis. Demographic and headache characteristics of CDH patients without MOH were compared with those with MOH.

RESULTS

202 patients were included whose median age was 32 (range 18-65) years, and 151(74.8%) were females. 12.3% patients fulfilled ICHDIIR criteria for MOH and 46.5% fulfilled ICHD-3 beta criteria. The predictors of MOH were female gender (OR = 3.72; 95% CI 1.72-8.02, p = 0.001), low education level (OR = 1.07, 95%CI 1.02-1.13; p = 0.007) and higher VAS score (OR = 0.67, 95%CI 0.51-0.88; p = 0.004). MOH patients as per ICHD-3 beta criteria had higher education (p = 0.02) and consumed lesser abortive drugs (p = 0.03) as compared with ICHDIIR criteria.

CONCLUSION

The frequency of MOH increases by four-fold when using ICHD-3 beta criteria instead of ICHDIIR criteria. Females with lower education level predispose to MOH.

Neurology at Sanjay Gandhi PGI: Beginning, progress and hope

High quality publications, patient care and educational standard have made Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow, India a favored destination for the patients and medical students, for getting treatment and education, respectively. The current article traces the history and milestone of the Department of Neurology, SGPGIMS, Lucknow and summarizes its achievements and facilities. The uniqueness of the department lies in being sensitive to the expectation of the patients, students and its faculty's own aspirations in research, keeping the patient as the center of focus.