Abstracts

Trigeminal neuralgia (TN) is one of the most excruciating neuropathic pain syndromes known. Although the course of TN is typically that of spontaneous exacerbations and remissions that occurs over months and years, TN can become refractory to medical treatment and so may require invasive measures including ablative and surgical techniques. More effective and safer treatments are needed. Since the mainstay of medical treatment for TN are the antiepileptic drugs (AEDs), it is a rational consideration to try levetiracetam (LEV), a new AED for the treatment of TN. Since neuropathic pain involves mechanisms similar to that of epileptic mechanisms but in a different location in the nervous system, the use of AEDs for neuropathic pain is rational. We treated 9 consecutive, unselected patients who were suffering from TN with LEV. Five were female, 4 male with a mean age of 62 years (range 34 to 78 years). Causes of their TN were idiopathic in 5, multiple sclerosis (MS) in 3 and Arnold-Chiari Syndrome in one patient. The mean duration of symptoms was 6.8 years (range 0.3 to 23 years). In 5 patients LEV was begun with a gradual titration. LEV was begun at an initial dose of 500 mg twice daily in 4 patients and at 250 mg twice daily in one patient. In 4 patients who presented with severe suffering at the time of initial evaluation, an initial dose of 2000 mg was given in the office and a maintenance dose of 1000 mg twice daily was immediately begun. Three of the TN patients had not previously been treated with any specific agent such as an AED. The others had been treated with carbamazepine (CBZ), oxcarbamazepine (OXC), gabapentin (GBP), baclofen, amitriptyline and various analgesics, usually opioid. Patients were titrated rapidly up to a dose that controlled their pain to a maximum of 2000 mg twice daily if needed. All 3 of the new TN patients experienced complete relief of pain within 48 hours and they had no recurrence of pain during the observation period of 6 months. One severely disabled MS patient who was in pain despite a 3 month treatment trial of CBZ developed complete relief of pain within 3 weeks on 500 mg bid LEV. The CBZ was tapered and discontinued over the next 3 weeks without return of pain. In the 5 patients with severe, long-standing and refractory TN, all 5 had good relief of pain but in 2 relief was temporary. One had recurrence of refractory pain after one year and the other had recurrence of refractory pain after one month. Those 2 patients required microvascular decompression for pain relief. LEV appears effective in treating the neuropathic pain associated with TN. LEV may have a unique ability for rapid and total relief of the pain of newly occurring or recurrent TN since LEV can be rapidly increased or even [lsquo]loaded[rsquo] to achieve effective CNS levels without debilitating side effects. In refractory patients, LEV appears to add significant relief and may eliminate in need for invasive procedures in some patients. (Supported by UCB)