AAN Releases New Clinical Recommendations About Stroke and Epilepsy

November 1, 2005
Dee Rapposelli

Two new recommendation papers--one on the use of serum prolactin (PRL) in the differential diagnosis of epileptiform seizures and the other on use of carotid endarterectomy (CE) in stroke prevention--were released this past September by subcommittees of the American Academy of Neurology (AAN).

Two new recommendation papers--one on the use of serum prolactin (PRL) in the differential diagnosis of epileptiform seizures and the other on use of carotid endarterectomy (CE) in stroke prevention--were released this past September by subcommittees of the American Academy of Neurology (AAN).

SERUM PRL ASSAY FOR DIFFERENTIATING EPILEPTIC SEIZURES

Although the use of serum PRL assay in the differential diagnosis of epileptiform seizures is being upstaged by the recent availability of video-electroencephalographic (EEG) monitoring, the AAN believes that the assay is still clinically relevant and is especially useful in clinics that do not have ready access to video-EEG technology. Recommendations for the use of serum PRL assay in the differential diagnosis of epileptic seizure (ES) and psychogenic nonepileptic seizure (PNES) are as follows:

•Serum PRL assay is a useful adjunctive modality for the differential diagnosis of ES.

•A diagnosis of complex partial seizure (CPS) or generalized tonic-clonic (GTS) seizure in adults and older children is probable when an elevated serum PRL level is recorded 10 to 20 minutes after a suspected epileptic event. Most laboratory studies put the normal upper limit of serum PRL at 18 to 23 ng/mL.

•Because the sensitivity and predictive value of the assay are low, a measurement in the normal range is not diagnostic for PNES, and CPS and GTS cannot be ruled out.

•Serum PRL levels that are taken more than 6 hours after a suspected event should be considered baseline measurements.

WHEN TO CONSIDER CE TO PREVENT STROKE

The new recommendations on the use of CE to prevent stroke take into account data from several multicenter trials that have been completed over the past 15 years. The guideline authors concluded that:

•CE is beneficial for patients who have displayed symptoms of stroke within the past 6 months (recent symptoms), including 70% to 99% stenosis of the internal carotid artery (ICA). The procedure should be performed "without delay, preferably within 2 weeks of the . . . last symptomatic event." Patients should have at least a 5-year life expectancy and a perioperative risk of stroke or death of less than 6%.

•Asymptomatic patients between the ages of 40 and 75 years with 60% to 99% stenosis of the ICA also are candidates for CE if they have at least a 5-year life expectancy and a perioperative risk of stroke or death of less than 3%.

•Patients with 50% to 69% stenosis are candidates for CE, but additional clinical variables need to be taken into account. For example, the data suggest that women with 50% to 69% ICA stenosis do not benefit from CE and that CE is more useful in patients who have had a hemispheric transient ischemic attack or stroke than in patients who have had a retinal ischemic attack. The authors also pointed out that CE is of little benefit in asymptomatic patients whose radiographic findings show contralateral occlusion but that it provides "persistent benefit" in symptomatic patients. The procedure does, however, place the patient at increased risk during surgery. The guidelines' authors discouraged use of CE in patients with less than 50% stenosis and instead recommended medical management.

•To decrease the risks of stroke, myocardial infarction, and death, aspirin at a dosage of either 81 or 325 mg/d should be taken preoperatively and for at least 3 months after surgery by both asymptomatic and symptomatic patients.

The citations for these guidelines articles are:

•Chen DK, So YT, Fisher RS. Use of serum prolactin in diagnosing epileptic seizures. Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2005;65: 668-675.

•Chaturvedi S, Bruno A, Feasby T, et al. Carotid endarterectomy--an evidence-based review. Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2005;65:794-801. *