Prepulse inhibition of acoustic startle and the influence of methylphenidate in children with ADHD.
OBJECTIVE
ADHD is common among children with comorbidity of enuresis. Findings concerning prepulse inhibition (PPI) of startle reflexes are controversial. Although PPI is improved through desamino-arginine vasopressin (dDAVP) in enuresis, some patients also improve concomitant ADHD through dDAVP. This study aims to evaluate whether methylphenidate (MPH) also improves PPI in ADHD.


METHODS
Nineteen ADHD patients were investigated in a prospective, double-blind, crossover study with MPH versus placebo. PPI was measured as a reduction of acoustic startle reflexes. Subgroups of gender, ADHD subtype, and baseline PPI were analyzed.


RESULTS
Median baseline PPI of ADHD patients (51.7%) was below the value of age-matched normal controls (73%, p = .090). MPH showed no improvement in the whole group, or the subgroups gender or subtype. Reduced baseline PPI was significantly improved (22.5%-39.3%, p = .039).


CONCLUSIONS
Heterogeneity of ADHD is confirmed with a wide range of baseline PPI. The improvement of reduced baseline PPI through MPH suggests impaired sensorimotor gating in this subgroup.
1University Hospital Schleswig-Holstein, Campus Kiel, Germany.
Sebastian
S
Schulz-Juergensen
Anja
A
Thiemann
Julia
J
Gebhardt
Alexander
A
Baumgarten-Walczak
Paul
P
Eggert
D000161:Acoustic Stimulation; D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D018592:Cross-Over Studies; D003894:Deamino Arginine Vasopressin / Q000627:therapeutic use; D004311:Double-Blind Method; D004775:Enuresis / Q000188:drug therapy / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D011446:Prospective Studies; D011931:Reactive Inhibition; D013216:Reflex, Startle / Q000187:drug effects* / Q000502:physiology; D016896:Treatment Outcome
D000697:Central Nervous System Stimulants; D008774:Methylphenidate; D003894:Deamino Arginine Vasopressin