Visual P300 latency predicts treatment response to modafinil in patients with narcolepsy.
OBJECTIVE
To evaluate the hypothesis that visual P300 latency (VL) predicts treatment response to modafinil (a new wake-promoting agent) in patients with narcolepsy.


METHODS



METHODS
Comparison of responders and non-responders in a double-blind randomized placebo-controlled trial.


METHODS
Private practice referral sleep disorders center.


METHODS
Twenty one patients with narcolepsy (ages 17-65 years).


METHODS
Auditory and visual P300 testing using 31 evenly spaced scalp electrodes, and baseline polysomnograms and objective and subjective tests of daytime sleepiness, followed by modafinil treatment for 9 weeks. Polysomnograms and tests of sleepiness were then repeated.


METHODS
The Maintenance of Wakefulness Test (MWT). Response defined as a final MWT > 7.3min (normative sample mean - 3 SD), plus an increase > 1SD based on normative sample (3.6 min) over baseline MWT.


RESULTS
Non-responders had longer age-adjusted 31-electrode mean VL (448.4 ms vs. 410.8 ms, P = 0.024), and larger auditory P300 amplitude, with no topographical P300 differences. Non-responders and responders did not differ on any other baseline clinical variable. Using a cut-off of 0.5 SE from normal regression constant, shorter age-adjusted VL predicted modafinil response, with specificity of 0.71 and sensitivity of 0.86.


CONCLUSIONS
VL predicts treatment response to modafinil in patients with narcolepsy.
Sleep Disorders Institute and Sangal Research Foundation, Troy, MI, USA.
R B
RB
Sangal
J M
JM
Sangal
C
C
Belisle
D000293:Adolescent; D000328:Adult; D000368:Aged; D001559:Benzhydryl Compounds / Q000627:therapeutic use*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D004311:Double-Blind Method; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077408:Modafinil; D009290:Narcolepsy / Q000188:drug therapy* / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011930:Reaction Time / Q000502:physiology
D001559:Benzhydryl Compounds; D000697:Central Nervous System Stimulants; D000077408:Modafinil