Cluster headache and
trigeminal neuralgia are relatively rare but debilitating neurologic conditions. Although they are clinically and diagnostically distinct from
migraine, many of the same pharmacologic agents are used in their management. For many patients, the attacks are so frequent and severe that abortive
therapy is often ineffective; therefore, chronic preventive
therapy is necessary for adequate
pain control.
Cluster headache and
trigeminal neuralgia have several distinguishing clinical features.
Cluster headache is predominantly a male disorder;
trigeminal neuralgia is more prevalent in women. Individuals with
cluster headaches often develop their first attack before age 25; most patients with
trigeminal neuralgia are between age 50 and 70.
Cluster headaches are strongly associated with tobacco smoking and triggered by alcohol consumption;
trigeminal neuralgia can be triggered by such stimuli as shaving and
toothbrushing. Although the
pain in both disorders is excruciating,
cluster headache pain is episodic and unilateral, typically surrounds the eye, and lasts 15 to 180 minutes; the
pain of
trigeminal neuralgia lasts just seconds and is usually limited to the tissues overlying the maxillary and mandibular divisions of the trigeminal nerve.
Cluster headache is unique because of its associated autonomic symptoms. Although the pathophysiology of
cluster headache and
trigeminal neuralgia are not completely understood, both appear to have central primary processes, and these findings have prompted investigations of the effectiveness of the newer
antiepileptic drugs for
cluster headache prevention and for the treatment of
trigeminal neuralgia. The traditional
antiepileptic drugs phenytoin and
carbamazepine have been used for the treatment of
trigeminal neuralgia for a number of years, and while they are effective, they can sometimes cause central nervous system effects such as drowsiness,
ataxia,
somnolence, and
diplopia. Reports of studies in small numbers of patients or individual case studies indicate that the newer
antiepileptic drugs are effective in providing
pain relief for
trigeminal neuralgia and
cluster headache sufferers, with fewer central nervous system side effects.
Divalproex has been shown to provide effective
pain control and to reduce
cluster headache frequency by more than half in episodic and
chronic cluster headache sufferers.
Topiramate demonstrated efficacy in a study of 15 patients, with a mean time to induction of
cluster headache remission of 1.4 weeks (range, 1 day to 3 weeks). In the treatment of
trigeminal neuralgia,
gabapentin has been shown to be effective in an open-label study. When added to an existing but ineffective regimen of
carbamazepine or
phenytoin,
lamotrigine provided improved
pain relief; it also may work as monotherapy.
Topiramate provided a sustained
analgesic effect when administered to patients with
trigeminal neuralgia. The newer
antiepileptic drugs show considerable promise in the management of
cluster headache and
trigeminal neuralgia.