Multisensory hallucinations and other unusual sensory experiences in the context of migraine: a systematic review

OBJECTIVE AND BACKGROUND

Visual auras in migraine have been extensively studied, but less is known about multisensory hallucinations or other unusual sensory experiences, including whether these should be diagnostically considered as part of aura symptoms. The current study aimed to conduct a systematic review and synthesis to bring together existing empirical evidence on these non-visual perceptual experiences, focusing on their phenomenological descriptions and clinical correlates.

METHODS

Forty-eight relevant studies were included based on a systematic search across PsycINFO APA and Web of Science, for peer-reviewed publications in the English language, from 1980 to the present. These comprised a mix of case reports/series (n = 19) and group design studies (n = 29).

RESULTS

Reports of complex multisensory hallucinations, beyond typical established aura symptoms, were numerous and varied in nature. Yet there were limited data on how this related to patient distress and functional interference. Other sensory distortions or hypersensitivities across non-visual domains were also evident, and generally more common in those with established aura symptoms.

CONCLUSION

Our findings provide preliminary evidence that multisensory hallucinations and other unusual perceptual experiences in migraine are likely more common than previously believed. Further investigations are needed to appropriately account for these symptoms within current nosological systems. Increased clinician-patient awareness is important for managing distress (where necessary), and potentially for offering a holistic therapeutic approach to migraine management.

Multisensory Hallucinatory Experiences in Migraine: A Preliminary Basis for Olfactory, Somatic-Tactile, and Gustatory Auras

Background and Objectives

Visual auras in migraine have been extensively studied, but less is known about unusual experiences in other sensory domains, including whether they should be diagnostically considered as part of aura symptoms. This study aimed to examine the prevalence of multisensory aura experiences in migraine and their phenomenologic and clinical correlates.

Methods

Respondents were 729 participants with probable migraine, who completed an online study examining unusual sensory experiences. These comprised aura experiences in the auditory, visual, olfactory, somatic-tactile, and gustatory domains. Basic demographic and clinical information and migraine symptomatology were also collected. To facilitate groupwise comparisons, participants with probable migraine were divided into those with and without (visual) aura experiences.

Results

Endorsement of visual aura experiences was the highest (42.1%), whether in a single modality (44.2%) or multiple (55.8%) modalities, followed by somatic-tactile (32.0%), gustatory (21.9%), olfactory (18.6%), and auditory (11.0%) domains. Phenomenologic similarities, for instance, in frequency, personification, and controllability, existed across sensory domains. Somatic-tactile and gustatory auras conversely exhibited greater duration and negative emotional valence. Participants with probable migraine with visual aura tended to report significantly more severe migraine symptoms relative to those with nonvisual or no aura.

Discussion

Our findings provide preliminary indication that unusual olfactory, somatic-tactile, and gustatory experiences in migraine are common and could be clinically significant as aura symptoms. Increased clinician and patient awareness and effective management of these symptoms are essential for a holistic therapeutic approach to migraine.

Various presentations of the olfactory hallucination in two patients with migraine disease: Case report

OBJECTIVES

To report two different presentations of migraine with the olfactory hallucinations. A case with the typical hallucinatory olfactory symptoms preceding migraine headaches and another case with longstanding olfactory hallucinations.

BACKGROUND

Migraine prevails in about 12% of the general population, with the migraine aura accountable for at least one-third of these cases. The most common aura is the visual aura, followed by the sensory aura, speech, and motor auras. Olfactory hallucinations preceding the headache phase of migraine are rare. To date, the International Classification of Headache Disorders (ICHD) has not recognized them as a subset of migraine aura.

RESULTS

This report presents a patient with a typical Phantosmia (PO) aura before her migraine headache and a patient who experiences a longstanding PO aura.

CONCLUSION

The olfactory hallucination may present differently in patients with migraine disease. Based on the clinical significance of migraine with olfactory hallucinations, we propose that the ICHD classify this phenomenon as a subtype of aura in the future. However, larger studies are still required to better assess the pathophysiology of this phenomenon.

Pathophysiology and Therapy of Associated Features of Migraine

Migraine is a complex and debilitating disorder that is broadly recognised by its characteristic headache. However, given the wide array of clinical presentations in migraineurs, the headache might not represent the main troublesome symptom and it can even go unnoticed. Understanding migraines exclusively as a pain process is simplistic and certainly hinders management. We describe the mechanisms behind some of the most disabling associated symptoms of migraine, including the relationship between the central and peripheral processes that take part in nausea, osmophobia, phonophobia, vertigo and allodynia. The rationale for the efficacy of the current therapeutic arsenal is also depicted in this article. The associated symptoms to migraine, apart from the painful component, are frequent, under-recognised and can be more deleterious than the headache itself. The clinical anamnesis of a headache patient should enquire about the associated symptoms, and treatment should be considered and individualised. Acknowledging the associated symptoms as a fundamental part of migraine has permitted a deeper and more coherent comprehension of the pathophysiology of migraine.

Topiramate-Induced Suicidal Ideation and Olfactory Hallucinations: A Case Report

Antiepileptic drugs prescribed in the context of migraine have been reported to be potentially linked with an increased risk of suicidal ideation and behavior. Meta-analyses support the evidence that amongst antiepileptic drugs, Topiramate has the greatest potential for facilitating the occurrence of suicidal ideation and behavior. Studies indicate that this occurs via the increased incidence of mood disorders amongst the population with migraines using Topiramate as a treatment, with a slow and progressive onset of suicidal ideation (if any). We discuss the unique case of a 43-year-old man known to have chronic migraines, who presented with intense rapid-onset suicidal ideation and olfactory hallucinations, three weeks after the introduction of Topiramate for chronic migraines. After a negative extensive investigation panel to rule out common organic diseases, Topiramate was ceased. The suicidal ideation and olfactory hallucinations resolved in less than 24 h without further interventions. This case report highlights that rapid-onset suicidal ideation and olfactory hallucinations could be linked as an unusual side effect to the introduction of Topiramate. The removal of Topiramate from the patient’s pharmacological treatments prevented further psychological distress linked to ego-dystonic suicidal ideation and a resolution of olfactory hallucinations. He was discharged 48 h later.