New Year… Brain Function Nor on Animal Studies
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EDITORIAL 1 Neurologists, Psychiatrists, and Neuro- ....................................................................................... surgeons. Papers should be of direct clinical relevance and so we will not J Neurol Neurosurg Psychiatry: first published as on 16 December 2004. Downloaded from generally publish papers on normal New year… brain function nor on animal studies. We hope that these changes will provide M N Rossor, M G Hanna a quick decision for our authors whilst reducing the burden on reviewers. ................................................................................... Nevertheless prioritising between good papers remains very difficult and to assist this we have established a weekly editorial meeting. ast year we said goodbye to Ian burden we have tried to make an early As we enter 2005 we reiterate our Whittle whom we thank for all his decision on priority for the journal with thanks to reviewers and authors and Lhard work and welcome Peter the result that over a third of papers do hope to continue to attract similar high Warnke from Liverpool as our new not go out to review. This will include quality manuscripts to those we have Associate Editor for Neurosurgery. We many papers that are well conducted handled over the last year. also say goodbye to many members of and worthy of publication but which we J Neurol Neurosurg Psychiatry 2005;76:1 the editorial board and welcome new consider are not best suited to the JNNP, faces. The vitality of the journal rests usually because they are too specialised. ...................... with its reviewers and authors. We In order to assist authors with the Authors’ affiliations listed our reviewers in the December decision of whether to submit to the Martin N Rossor, Michael G Hanna, Institute issue and reiterate our thanks to them. journal we have revised the web- of Neurology, Queen Square, London WC1N With over two thousand submissions a site guidelines. In summary we wish 3BG, UK year the burden on unpaid reviewers to attract papers of general interest Correspondence to: Professor Martin Rossor; forever increases. In order to reduce the to the multi-disciplinary readership of [email protected] EDITORIAL ....................................................................................... Migraine Anxiety disorders Migraine2anxiety related dizziness (MARD): a new disorder? J M Furman, C D Balaban, R G Jacob, D A Marcus http://jnnp.bmj.com/ ................................................................................... Balance disorders izziness is a common complaint Thus, it is not surprising that some that can result from abnormalities patients with dizziness may suffer from Figure 1 Venn diagram of the interfaces of the vestibular apparatus of the a combination of a balance disorder, among migraine, anxiety, and balance on October 1, 2021 by guest. Protected copyright. D disorders. The central sector, which denotes the inner ear and of those portions of the migraine, and an anxiety disorder, a three way interface, represents an hypothesised central nervous system (CNS) that symptom complex that we propose to new ailment, migraine2anxiety related process information from the peripheral name migraine2anxiety related dizzi- dizziness (MARD). vestibular system and other senses, ness (MARD) (fig 1). The general particularly vision and somatosensation. recognition of MARD may be limited Recently, two CNS disorders, migraine because of the fragmented nature of our DEFINITIONS: DISORDER, and anxiety, have been recognised as healthcare system, where specialists in SYNDROME, DEFINING being commonly associated with dizzi- one field, such as psychiatry or neurol- SYMPTOMS, AND ASSOCIATED ness.12 These associations may be an ogy, fail to recognise phenomena known SYMPTOMS expression of an aetiological relation- to specialists in other fields, such as Medical conditions are diagnosed by a ship, for example, dizziness caused by otoneurology. variety of signs and symptoms. Specific migraine, or dizziness caused by anxi- This editorial will focus on the patho- constellations of signs and symptoms ety; alternatively, migraine or anxiety physiology and clinical issues relating to are usually called syndromes, whereas a may influence the presentation of a MARD, including the interfaces among disorder is ideally identified by specific balance disorder. For example, chronic balance disorders, migraine, and anxi- pathophysiological mechanisms. Some dizziness may become more disabling ety. We use current epidemiological data diagnostic systems distinguish between during the added stress of a migraine and studies of pathogenesis to develop symptoms necessary for the diagnosis of headache or panic attack. In addition, comorbidity models. These models serve the disorder (defining symptoms),6 and dizziness occurs comorbidly with both as hypotheses that may lead to possible those that are associated but not defin- migraine headache and anxiety disor- treatment options for many patients ing (associated symptoms). Although ders.34Finally, there is increased comor- with dizziness, including those with associated symptoms occur with bidity between anxiety and migraine.5 MARD. increased prevalence in a disorder, they www.jnnp.com 2 EDITORIAL but not in patients with tension-type Spreading headache.13 Conversely, migraine was depression reported by 38% of 200 consecutive J Neurol Neurosurg Psychiatry: first published as on 16 December 2004. Downloaded from patients with the primary complaint of Pain and aura dizziness, compared with 24% in a comparison group of orthopaedic Neocortex patients.1 A similar study evaluating Vertigo migraine in patients with isolated ver- tigo (n = 72) compared with orthopae- Passive coping dic controls identified migraine in 61% Thalamus of the vertigo patients but only 10% of orthopaedic patients.14 Clinical labora- tory vestibular tests in migraineurs unselected for the presence or absence of dizziness show a variety of abnorm- alities, including both peripheral and central abnormalities;12 13 15 however, Sterile "Trigeminovascular reflex" inflammation these vestibular abnormalities are more (extravasation) prominent in patients with migraine associated with dizziness.9 13 16–20 Vasodilation PAG The link between vestibular symp- of cerebral and toms and migrainous symptoms and the labyrinthine increased prevalence of vestibular test vessels abnormalities in migraineurs suggests Ophthalmic that migraine related dizziness is based Activate division Trigeminal on a specific pathophysiology—that is, trigeminal Nuc. caudalis that migraine related dizziness is a bona afferents C1/C2 dorsal horn fide disorder. In fact, Neuhauser, et al Peptide have established specific diagnostic cri- release into teria for migraine related dizziness, inner ear and which they term ‘‘migrainous vertigo’’.1 interstitial fluid Activate Vestibular A validated structured diagnostic inter- vestibular nuclei view for migrainous vertigo using these afferents criteria may help to identify this condi- tion.21 Using the Neuhauser criteria, Modulate sensitivity of: migrainous vertigo was diagnosed in 1. "Trigeminovascular reflex" 9% of migraine headache patients. In 2. Pain pathways DRN RMag 45% of these patients, migraine head- (5-HT) (5-HT) 3. Affective reactivity ache episodes were regularly accompa- http://jnnp.bmj.com/ LC (NE) LTeg (NE) nied by vestibular symptoms, and in another 48%, vestibular symptoms co- occurred irregularly.1 The influence, if any, of migraine aura on the link Figure 2 Pathogenetic model for migraine related dizziness. The core of the diagram represents between migraine and vestibular symp- pathogenetic mechanisms in migraine related pain, shown as unshaded boxes. The vestibular 4 toms is unknown. We speculate that linkages to migraine mechanisms are shaded. Adapted from Furman et al. 5-HT, 5- some episodes of vertigo in patients hydroxytryptamine (serotonin); DRN, dorsal raphe nucleus; LC, locus ceruleus; LTeg, lateral tegmental noradrenergic neurones; NE, norepinephrine; PAG, periacqueductal grey; RMag, with MARD represent migraine aura on October 1, 2021 by guest. Protected copyright. nucleus raphe magnus. without headache. do not in themselves identify the dis- (including serotonin, norepinephrine Pathophysiology of migraine order. For example, dizziness occurs as (noradrenaline), and dopamine) and related dizziness an integral or defining symptom in cutaneous allodynia, representing aber- Reflecting the uncertainty regarding the Meniere’s disease7 and panic disor- rant neurophysiology during migraine.11 pathophysiology of migraine headache, der—that is, dizziness during a panic In addition to these defining features of the pathophysiology of migraine related attack.8 Dizziness can also be considered migraine, patients often describe a dizziness is largely unknown. In fig 2, an associated symptom for migraine9 or variety of additional migraine associated we provide a framework that integrates generalised anxiety disorder.6 symptoms. One of the most common the possible neuroanatomical pathways migraine accompaniments is dizziness with the clinical manifestations of MIGRAINE RELATED DIZZINESS or balance disturbance. Dizziness occurs migrainous vertigo. Fundamental to The term ‘‘migraine’’ refers to both a in 28230% and vertigo in 25226% of the pathophysiology of migraine is the syndrome and a disorder. The diagnosis patients with a primary complaint of trigeminovascular reflex. This is a para- of migraine syndrome requires the pre- migraine.912The