Effect of modafinil on cerebral blood flow in narcolepsy patients.
BACKGROUND
To investigate the effects of modafinil on regional cerebral blood flow (rCBF) in narcolepsy, we performed 99mTc-ethylcysteinate dimer single photon emission computed tomography (SPECT) before and after modafinil or placebo medication.


METHODS
Brain SPECT was performed twice during the awake state before and after modafinil or placebo administration for 4 weeks in 43 drug-naive narcoleptics with cataplexy (M/F = 23/20, 29.5 +/- 5.8 years). For SPM analysis, all SPECT images were spatially normalized to the standard SPECT template and then smoothed using a 12-mm full width at half-maximum Gaussian kernel. The paired t-test was used to compare pre- and post-modafinil or placebo SPECT images.


RESULTS
The mean modafinil dose used was 207.8 +/- 62.3 mg/day. Modafinil significantly reduced Epworth Sleepiness Scale scores from 20.3 +/- 2.1 to 5.2 +/- 3.1 (P < 0.01), while placebo did not. Compared to the off-modafinil condition, the on-modafinil condition showed significantly increased rCBF in the right dorsolateral and bilateral medial prefrontal cortices. Conversely, after modafinil administration, rCBF was decreased in bilateral precentral gyri, left hippocampus, left fusiform gyrus, bilateral lingual gyri, and cerebellum. There was no significant rCBF change after placebo administration.


CONCLUSIONS
By a chronic administration of modafinil in narcoleptic patients, rCBF increased in the bilateral prefrontal cortices, whereas it decreased in left mesio/basal, temporal, bilateral occipital areas, and cerebellum.
Department of Neurology, Samsung Medical Center Sungkyunkwan University School of Medicine, Seoul, Korea.
Eun Yeon
EY
Joo
Dae Won
DW
Seo
Woo Suk
WS
Tae
Seung Bong
SB
Hong
D000293:Adolescent; D000328:Adult; D001559:Benzhydryl Compounds / Q000627:therapeutic use*; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000187:drug effects*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002560:Cerebrovascular Circulation / Q000187:drug effects; D003545:Cysteine / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077408:Modafinil; D009290:Narcolepsy / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D015609:Organotechnetium Compounds; D017286:Polysomnography; D019275:Radiopharmaceuticals; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon
D001559:Benzhydryl Compounds; D000697:Central Nervous System Stimulants; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C059659:technetium Tc 99m bicisate; D003545:Cysteine; D000077408:Modafinil