Diagnosis and Management of Vestibular Migraine

In summary, when the criteria for MD are met together with documented audiometric abnormalities, MD should be diagnosed, even if migraine symptoms occur during the vestibular attacks [18]. Only patients who experience 2 different types of attacks, one fulfilling the criteria for VM and the other for MD, should be labelled as Meniere’s disease/migraine overlap syndrome. It is hoped that future revisions of diagnostic criteria will include this overlap entity.

Migraine and Benign Paroxysmal Positional Vertigo

VM patients can experience brief positional dizziness and therefore VM may mimic BPPV. It is therefore important to perform positional testing to look for nystagmus typical for BPPV. Certainly the positional characteristics are distinct from BPPV with regard to the duration of attacks (often as long as the head position is maintained in VM rather than seconds in BPPV). BPPV may also produce attacks of vertigo that can act as triggers for migraine headaches. In these patients, treatment of the BPPV will reduce headache frequency [30].

Transient Ischemic Attacks

Transient ischemic attack (TIA) is a cerebrovascular disease with temporary neurological symptoms [43] and is differentiated from VM mainly from the characteristics of reported symptoms. Being a vascular phenomenon, one would expect TIA symptoms to have a sudden onset, with a brief duration of symptoms (typically short minutes), followed by a rapid improvement to baseline, as well as correspond to a vascular territory. The other important message is that stereotyped, frequently recurrent symptoms are less likely to be TIAs, with the exception of capsular warning syndrome [44] and limb shaking TIAs [43] described elsewhere.

Migraine and Motion Sickness

In an individual patient it may be difficult to differentiate between motion sickness and acute attacks of VM induced by motion stimuli. The distinction may be helped by observing nausea and dizziness improving after cessation of motion which points more towards motion sickness, as oppose to the persistent vertigo after the motion stimulus has ended, thus pointing more towards VM.

Episodic Ataxia Type 2

Of the various episodic ataxias, episodic ataxia type 2 would be the most important subtype in the differential diagnosis of VM given it presents with episodic vertigo and is the most frequently occurring subtype. It is a rare autosomal dominant inherited neurological disorder resulting from mutations of the calcium channel gene CACNA1A [45]. The clinical manifestations include recurrent disabling attacks of imbalance, vertigo and ataxia, which can be provoked by physical exertion or emotional stress. Patients may have downbeat nystagmus interictally. A slow progression of cerebellar signs accompanied by atrophy of midline cerebellar structures and a response to acetazolamide or 4-aminopyridine can help distinguish it from VM.

Migraine, Dizziness, and Comorbid Psychiatric Disorders

Particularly in patients with protracted symptoms, it is difficult to tease out the difference between the symptoms of migraine and dizziness from the symptoms of certain psychiatric disorders given their bidirectional associations. Migraine is a risk factor for first-onset major depression [46] and panic disorder [47]. Patients with VM have very high rates (30%–65%) of coexisting psychiatric illness, especially anxiety and depression, with frequencies higher than that associated with other migraine or vestibular disorders [48,49]. Vestibular migraine patients who have a positive history of psychiatric disorders have a comparatively higher risk of developing somatoform dizziness [48]. The unpredictability of recurrent vestibular symptoms could be a factor leading to elevated distress in VM patients. It is not uncommon to see a premature diagnosis of psychogenic dizziness to be given to patients without objective abnormalities. On the contrary, a diagnosis of psychogenic dizziness can rarely be made with certainty due to multiple reasons. Disabling vertigo leading to physical symptoms and avoidance of social activities can easily be misconstrued to have panic disorder with or without agoraphobia. Moreover, dizziness is the second most common symptom of a panic attack after palpitations [50].