This project is a maturational study of startle modulation during childhood and an application of the normative data to the syndrome of attention-deficit hyperactivity disorder (ADHD). The major aim of this proposal is to continue our studies of startle modulation in ADHD along lines suggested by current literature and our own data, namely that pathophysiology in ADHD is likely to be located in structures rostral to brainstem regions. To explore this hypothesis, startle will be used as a probe to evaluate the sustained attention of ADHD during a continuous performance task (CPT). ADHD children have shown attentional deficits on the CPT, and startle attenuation can reflect the degree of attentional engagement and downstream cortical control of brainstem sensory processing mechanism. Additionally this proposal continues our normative maturational studies, extending them to CPT attenuation of startle, by studying this type of startle modulation in preschool children. Since 30 percent of our ADHD subjects had primary nocturnal enuresis, and it was those ADHD boys with enuresis who showed significantly reduced inhibitory prestimulation modulation of startle (PMS), a new aim of this proposal is to study PMS in definitive groups of boys with ADHD with and without nocturnal enuresis and boys with pure nocturnal enuresis. These groups will be large enough so that their dimensional characteristics (severity of ADHD, and frequency of nocturnal enuresis) and expected comorbidity (oppositional defiant disorder in ADHD, daytime wetting and encopresis in nocturnal enuretics, and specific development disorders in both groups can be evaluated. Because there is a strong familial component to primary nocturnal enuresis, both parents of each pure enuretic boy will be tested for PMS. Hence, this proposal will explore the possibility of a familial neurophysiologic marker in enuresis. A feature of this proposal is the evaluation of diagnostic and functional neuroanatomic specificity. This will be achieved by comparing the enuretic and ADHD populations not only with normal controls but also with each other on both the PMS and CPT attenuation of startle experiments. It is anticipated that the enuretics will show deficient inhibitory PMS and normal CPT attenuation of startle, suggesting a primary brainstem dysfunction, while ADHD boys will show the opposite, suggesting cortical dysfunction, with downstream effects on startle modulation.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
2R01HD014193-09A1
Application #
3312511
Study Section
Human Development and Aging Subcommittee 3 (HUD)
Project Start
1981-09-01
Project End
1996-06-30
Budget Start
1992-08-01
Budget End
1993-06-30
Support Year
9
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Type
Other Domestic Higher Education
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Gehricke, Jean-Guido; Ornitz, Edward M; Siddarth, Prabha (2002) Differentiating between reflex and spontaneous blinks using simultaneous recording of the orbicularis oculi electromyogram and the electro-oculogram in startle research. Int J Psychophysiol 44:261-8
Ornitz, E M; Gehricke, J G; Russell, A T et al. (2001) Modulation of startle and the startle-elicited P300 by the conditions of the cued continuous performance task in school-age boys. Clin Neurophysiol 112:2209-23
Ornitz, E M; Russell, A T; Gabikian, P et al. (2000) Prepulse inhibition of startle, intelligence and familial primary nocturnal enuresis. Acta Paediatr 89:475-81
Ornitz, E M; Russell, A T; Hanna, G L et al. (1999) Prepulse inhibition of startle and the neurobiology of primary nocturnal enuresis. Biol Psychiatry 45:1455-66
Bailey, J N; Ornitz, E M; Gehricke, J G et al. (1999) Transmission of primary nocturnal enuresis and attention deficit hyperactivity disorder. Acta Paediatr 88:1364-8
Ornitz, E M; Gabikian, P; Russell, A T et al. (1997) Affective valence and arousal in ADHD and normal boys during a startle habituation experiment. J Am Acad Child Adolesc Psychiatry 36:1698-705
Hanna, G L; Ornitz, E M; Hariharan, M (1996) Urinary catecholamine excretion and behavioral differences in ADHD and normal boys. J Child Adolesc Psychopharmacol 6:63-73
Hirano, C; Russell, A T; Ornitz, E M et al. (1996) Habituation of P300 and reflex motor (startle blink) responses to repetitive startling stimuli in children. Int J Psychophysiol 22:97-109
Ornitz, E M; Russell, A T; Yuan, H et al. (1996) Autonomic, electroencephalographic, and myogenic activity accompanying startle and its habituation during mid-childhood. Psychophysiology 33:507-13
Hanna, G L; Ornitz, E M; Hariharan, M (1996) Urinary epinephrine excretion during intelligence testing in attention-deficit hyperactivity disorder and normal boys. Biol Psychiatry 40:553-5

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