| Article Access Statistics|
| Viewed||10339 |
| Printed||239 |
| Emailed||7 |
| PDF Downloaded||273 |
| Comments ||[Add] |
| Cited by others ||2 |
Click on image for details.
|LETTER TO EDITOR
|Year : 2004 | Volume
| Issue : 3 | Page : 394-396
Intravenous valproate in post-anoxic myoclonic status epilepticus: A report of ten patients
R Patel , S Jha
Department of Neurology, Sanjay Gandhi PGIMS, Lucknow, India
|Date of Acceptance||12-Nov-2003|
Department of Neurology, Sanjay Gandhi PGIMS, Lucknow, India
|How to cite this article:|
Patel R, Jha S. Intravenous valproate in post-anoxic myoclonic status epilepticus: A report of ten patients. Neurol India 2004;52:394-6
Post-anoxic myoclonic status epilepticus (MSE) is difficult to treat. Valproate (VP) is an established antiepileptic drug (AED) with broad-spectrum efficacy in generalized and partial seizures., Clinical trials with intravenous VP have shown encouraging results in myoclonic epilepsy and status epilepticus., Intravenous VP has been shown to be effective in terminating MSE in a patient with juvenile myoclonic epilepsy. We present our observations on the effect of intravenous VP in post-anoxic MSE.
We studied the efficacy of intravenous VP in 10 patients who developed MSE following anoxic cerebral injury in the peri- and postoperative (within 24-48 hrs) period. The clinical details, the primary disease for which the operation was done, and the type of anesthesia were recorded in all the patients. Informed consent was taken from the relatives for the drug administration. Initial loading dose of VP was 20 mg/kg at a rate of 20 mg/minute. This was followed by 10mg/kg bolus every 6 hours for 24 hours (the total dose in the first 24 hours: 60 mg/kg). Patients were then given a maintenance dose of 10 mg/kg every 6 hours till the patient was shifted to oral VP., The infusion was continued till MSE was terminated. The frequency of seizures and the time taken for the termination of MSE were noted. Metabolic (hepatic, renal and pancreatic function tests), hemodynamic (heart rate, blood pressure, respiratory rate and electrocardiographic changes) and hematological parameters were monitored. Arterial blood gases and oxygen saturation were also monitored. Serum valproate levels were not measured.
The clinical characteristics of the patients are given in [Table - 1]. There was a significant reduction in the frequency of seizures in all the 10 patients. MSE was terminated with intravenous VP alone in 6 patients and the time duration for the termination of MSE ranged between 2-10 hours. Four patients needed 30 mg/kg and 2 patients needed 40 mg/kg of VP to terminate MSE. An additional infusion of a second AED, intravenous diazepam or lorazepam, one each was required in 2 patients to terminate MSE. The time taken for the termination of MSE was 26 and 38 hours. The remaining 2 patients continued to have seizures, but with a reduced frequency (approx 25% reduction). During intravenous VP therapy, no adverse effects, including reaction at the infusion site, respiratory depression, cardiac arrhythmia or hypotension were observed. There was no change in hemodynamic parameters. Two patients died. Six patients recovered completely and 2 patients were left with significant neurological deficits. [Figure - 1]
Introduction of the parenteral form has facilitated the use of VP in situations like seizures in the operative or postoperative phase., Several advantages are evident with intravenous VP: a physiological pH, ready-to-use preparation, non-requirement of any organic solvent, no incompatibility with other intravenous solutions and high stability at room temperature., A high success rate of intravenous VP has been observed in various studies., Excellent control of myoclonus in a patient after cardio-pulmonary arrest, with intravenous VP has also been documented when other antiepileptics had failed., Similar results have been described in post-anoxic myoclonus. It is well tolerated and safe in children with refractory epilepsy and in the elderly, even in the setting of concurrent hypotension, labile cardiovascular function or severe illness., Though the Food and Drug Authority recommends an infusion rate of 20 mg/min of intravenous VP, excellent tolerability has been reported with higher rates.
Anoxic brain injury and MSE are life-threatening and notoriously refractory to AEDs. Their long duration is associated with poor outcome and high mortality, hence must be treated promptly. The available conventional intravenous AEDs may induce or exacerbate hypotension and cause respiratory depression requiring intensive monitoring. Hypotension associated with intravenous AED administration may adversely affect the general cardiovascular status by limiting the timely and adequate delivery of the AEDs (since these complications have to be managed by slowing the infusion rate)., The mechanism postulated for the efficacy of intravenous VP is rapid penetration of the drug into the brain tissue., Recently, levetiracetam has been found to be effective in myoclonic epilepsy, which may emerge as an alternative therapy.
Our observations with intravenous VP in post-anoxic MSE are preliminary and the study has many limitations. Continuous EEG monitoring was not done and serum valproate levels were not measured. Larger, multicentric and controlled studies are required for intravenous VP to be considered as first- line therapy for post-anoxic MSE.
| » References|| |
|1.||Schmidt D. Diazepam. In: Levy RH, Mattson RH, Meldrum BS, editors. Antiepileptic drugs. 4th Ed. New York: Raven Press 1995. p. 705-24. |
|2.||Bourgeois BFD. Valproic acid: Clinical use. In: Levy RH, Mattson RH, Meldrum BS, editors. Antiepileptic drugs. 4th Ed. New York: Raven Press 1995. p. 633-9. |
|3.||Chapman AG. Valproate and myoclonus. Adv Neurol 1986;43:661-74. |
|4.||Yamamoto LG, Yim GK. The role of intravenous valproic acid in status epilepticus. Pediatr Emerg Care 2000;16:296-8. |
|5.||Sheth RD, Gidal BE. Intravenous valproic acid for myoclonic status epilepticus. Neurology 2000;54:1201. |
|6.||Chez MG, Hammer MS, Loeffel M, et al. Clinical experience of three pediatric and one adult case of spike-and-wave status epilepticus treated with injectable valproic acid. J Child Neurol 1999;14:239-42. |
|7.||Uberall MA, Trollmann R, Wunsiedler U, et al. Intravenous valproate in pediatric epilepsy patients with refractory status epilepticus. Neurology 2000;54:2188-9. |
|8.||Ruggero GF, Varsi M, Smith MC. Valproic acid: mechanisms of action In: Levy RH, Mattson RH, Meldrum BS, editors. Antiepileptic drugs. 4th Ed. New York: Raven Press 1995. p. 581-8. |
|9.||Loscher W. Valproate: A reappraisal of its pharmacodynamic properties and mechanisms of action. Prog Neurobiol 1999;58:31-59. |
|10.||Adin J, Arteaga R, Herranz JL, et al. The use of intravenous valproate. Rev Neurol 1999;29:744-53. |
|11.||Czapinski P, Terczynski A. Intravenous valproic acid administration in status epilepticus. Neurol Neurochir Pol 1998;32:11-22. |
|12.||Liron L, Chambost M, Depierre P, Peillon D, Combe C. Effectiveness of valproic acid for postanoxic action myoclonus. Ann Fr Anesth Reanim 1998;17:1247-9. |
|13.||Bruni J, Willmore LJ, Wilder BJ. Treatment of postanoxic myoclonus with valproic acid. Can J Neurol Sci 1979;6:39-42. |
|14.||Uberall MA, Trollmann R, Wunsiedler U, Wenzel D. Intravenous valproate in pediatric epilepsy patients with refractory status epilepticus. Neurology 2000;54:2188-9. |
|15.||Sinha S, Naritoku DK. Intravenous valproate is well tolerated in unstable patients of status epilepticus. Neurology 2000;55:722-4. |
|16.||Nita A, Limdi EF. The Safety of Rapid Valproic Acid Infusion (Brief Communication). Epilepsia 2000;41:1342-5. |
|17.||Lowenstein DH, Alldredge BK. Status epilepticus. N Engl J Med 1998;338:970-6. |
|18.||Perucca E. The new generation of antiepileptic drugs: Advantages and disadvantages. Br J Clin Pharmacol 1996;42:531-43. |