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.
Sangal
R B
RB
Sleep Disorders Institute and Sangal Research Foundation, Troy, MI, USA.
Sangal
J M
JM
Belisle
C
C
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