Journal of Clinical Outcomes Management. 2015 October;22(10)
References
Unfortunately, there are no objective tests that can reliably discriminate vestibular syndromes from psychiatric syndromes in patients with dizziness. The SVQ is not specific enough to differentiate symptoms of VV from the space and motion discomfort symptoms often found in agoraphobic patients [25]. Experimentally, agoraphobia patients may have a more surface-dependent strategy rather than a visual-dependent strategy on CDP [51]. It is unclear whether the vestibular system is causally linked to emotion processing pathways.
Chronic Subjective Dizziness
Chronic subjective dizziness is an entity characterised by chronic unsteadiness or nonvertiginous dizziness accompanied by hypersensitivity to motion stimuli and poor tolerance for complex visual stimuli lasting for 3 months or more without objective abnormalities [52]. These vestibular symptoms are often difficult to distinguish from symptoms of VM. This condition is thought to be a spatial sensory analog of allodynia experienced by some chronic migraine headache sufferers [8].
Dizziness Due to Side Effects of Migraine Prophylactic Medications
Dizziness is often listed as a side effect in the product information of various medications including those used for migraine prophylaxis. It is important to take an accurate history of the suspected offending drug in terms of its temporal relationship to vestibular symptoms. Tricyclic antidepressants (TCAs) can cause drowsiness, lightheadedness, fatigue and blurred vision [53]. Beta-blockers can cause orthostatic hypotension [53]. All the above effects could be confused with vestibular symptoms.
Treatment of Vestibular Migraine
Current treatment options for VM are mainly limited to expert opinion rather than inferred from randomized controlled trials (RCTs) [54]. Below we have offered our consensus on how VM should be managed, with concepts based on the guidelines of treatment for typical migraine [55]. Avoidance of migraine triggers should always be the first avenue of treatment. In addition, any vestibular disorder that is triggering migraine attacks should be identified and treated in its own right. Pharmacotherapy can be abortive for acute episodes and prophylactic.
Lifestyle Advice
The key first task in management is the correct diagnosis and educating the patient about the condition. A thorough explanation of the migraine origin of the attacks can address patients fear and expectations. Nonpharmaceutical approaches in the treatment of VM should not be neglected, even though only a very small proportion of patients may derive a benefit. Advice on dietary manipulation is routinely given; however, its efficacy in VM is questionable. Dietary advice includes healthy eating at regular intervals to prevent skipped meals as well as avoidance of excess caffeine and rich foods. A retrospective study found that lifestyle intervention alone resulted in 13 of 81 patients experiencing significant relief from vestibular symptoms with migraine. The remaining cohort of patients required a multifaceted approach including pharmacotherapy to achieve similar benefit [56].
Acute Abortive Treatments
Drugs classes described for acute abortive treatment include triptans, antiemetic medications, and simple analgesics. Triptans are used to provide acute relief for moderate to severe migraine, or mild to moderate attacks unresponsive to nonspecific analgesics ( Table 2 ). There is 1 small RCT specific to acute abortive treatments in VM patients [57]. This study suggests benefit from zolmitriptan in 38% (3 of 8 episodes) of patients with VM whereas in the placebo group a positive effect was observed in only 22% (2 of 9 episodes), albeit with wide confidence intervals. We recommend triptans for infrequent moderate to severe attacks. The pharmokinetics of each triptan may affect the choice of drug. Triptans have vasoconstrictive properties but a recent Cochrane review has concluded that available studies do not suggest obvious cardiovascular safety issues with triptans as compared to the potentially more harmful ergotamine [58]. However, we would still advocate that caution should be exercised in patients with ischemic heart disease, stroke, uncontrolled hypertension or hemiplegic or basilar migraine.
Oral antiemetics are commonly prescribed for motion sickness and acute migraine, however there is no evidence supporting their effectiveness in VM (Table 2). Patients should be counselled about avoiding overuse of antiemetics given their risk of causing extrapyramidal side effects [53].