This case illustrates the importance of inquiry of neurological symptoms, in particular headache, in patients with bipolar disorder. Patients with bipolar disorder have a greater-than-twofold risk of having migraine, as compared with the general population.1 Treatment for migraine, irrespective of mood disorder, includes amitriptyline, valproate, topiramate, and beta-blockers.2 In patients with bipolar disorder and migraine, judicious use of treatments for both disorders should be considered. Lamotrigine was used for this patient because valproate, although approved for both disorders,3 did not ameliorate the migraine symptoms. For bipolar disorder, lamotrigine is efficacious in the prevention of depressive episodes and, possibly, rapid-cycling type.4 Less evidence supports its use in acute depression or mania.4 For migraine, lamotrigine was not beneficial in a placebo-controlled trial, but had some effectiveness in two open pilot studies for the treatment and prevention of migraine aura.2
Lamotrigine is generally well tolerated, with an acceptable side-effects profile (mainly dizziness, nausea, and insomnia), and may be considered for a patient with aura nonresponsive to other medication. Slow and low dose increase is recommended for side-effects monitoring, especially for severe rashes and Steven's Johnson syndrome. In our patient, lamotrigine was increased to 200 mg twice daily. Use of lamotrigine with valproate may increase lamotrigine concentrations by up to 200% because of increased lamotrigine clearance inhibition,3,5 and valproate levels may also decrease.3 The patient's headache duration eventually decreased to 1 hour nightly, and he returned to work full-time with a 45-minute nap.