Startle modulation was induced by prestimulation in 43, 6-11 year old boys with attention-deficit hyperactivity disorder (ADHD), 13 of whom were or had been enuretic, 17 age-matched enuretic boys, and 42 age-matched normal boys, using 60-ms and 120-ms prestimulation intervals and a 4000-ms continuous tone. There was a significant multivariate effect of enuresis on startle amplitude modulation. This effect was attributed primarily to the reduction of amplitude inhibition following the 120-ms prestimulation interval regardless of whether or not enuresis was associated with ADHD. There was no effect of ADHD on startle modulation by prestimulation. The inhibition following the 120-ms prestimulation interval in the enuretic boys was reduced to the level of 5-year-old normal children, suggesting a maturational component of the deficient startle inhibition. The neurophysiologic dysfunction underlying the deficient startle inhibition in enuresis, but not ADHD, is discussed in terms of a possible dysfunction of mesopontine reticular mechanisms mediating preattentive processing of signals associated with spinal reflexes involved in urinary bladder control.

We studied acoustic startle response and its modulation by prestimulation and by short-term and long-term habituation in 54 autistic patients and 72 normal age-matched controls. The startle response was measured as the amplitude and onset latency of the integrated orbicularis oculi EMG. There were no consistent significant differences between the autistic and control subjects in startle modulation by inhibitory or facilitatory prestimulation, short-term habituation of startle amplitude, long-term habituation of either startle amplitude or latency, or unmodulated startle amplitude. Differences between autistic and control subjects were limited to prolongation of unmodulated startle onset latencies in the autistics in all of the experimental paradigms (significant p = .005 only in the context of short-term habituation) and a statistically significant (p < .05) slower rate of short-term habituation of startle onset latency in the autistic patients, relative to the controls. Results provide only limited support for hypotheses of brainstem pathophysiology and no support for hypotheses of cerebellar pathophysiology in autism.

SUMMARY This study examinec the presurgical 2‐deoxy‐2[18F]‐fluoro‐D‐glucose positron emission tomography (PET) patterns of regional cerebral glucose metabolism in the non‐resected hemisphere of 13 children who underwent hemispherectomy for early‐onset intractable seizures. These patterns were compared with the rate of change in the children's non‐verbal communication scores, measured before and after surgery. Irrespective of the side of surgery, the pre‐operative glucose metabolism in the non‐resected prefrontal cortex correlated significantly with the postoperative rate of change in the children's ability to focus the attention of an adult on an object or event (joint attention). These preliminary findings suggest that pre‐operative PET patterns might be associated with certain aspects of the developmental outcome of children undergoing hemispherectomy. RÉSUMÉ Hémisphérectomie pour crises irréducribles à debur précoce: mérabolistne préchirurgical du glucose cérébral et allures postchirurgicales des communications non verbales Cette étude apprécie les aspects de la tomographie préchirurgicale àémission de positron au 2‐désoxy‐2[18F] fluoro‐D‐glucose résvélant le métabolisme cérébral régional du glucose dans I'hémisphère non réséqué de 13 enfants chez qui fut pratiquée une hémisphérectomie pour crises irréductibles a début précoce. Ces aspects ont été comparés avec I'importance des modifications des scores de communication non verbale, mesurés avant et après chirurgie. Quel que soit le cǒté de I'hémisphérectomie, il y avait une correlation significative entre le métabolisme pré‐opératoire du glucose dans le cortes préfrontal non réséqué et I'importance de la modification post‐opératoire dans la capacité des enfants à fixer leur attention sur un adulte, un objet ou un événement (attention jointe). Ces données préliminaires suggérent que les aspects PET pré‐opératoires peuvent ětre associés á certains aspects du devenir développemental d'enfants ayant subi une hémisphérectomie. ZUSAMMENFASSUNG Hemisphärekromie bei früh einsetzenden therapieresistenten Anfällen: pröperativer cerebraler Glukosenterabolismirs und posroperative non‐verbale Kommunikationsmuster In dieser Studie wurden die präoperativen 2‐deosy‐2[18F] fluoro‐D‐glucose positron emission tomography (PET) Muster des cerebralen Glukosemetabolismus in der nicht resezierten Hemisphäre bei 13 Kindern untersucht, bei denen eine Hemispärektomie wegen früh einsetzender, therapieresistenter Anfälle durchgeführt wurde. Diese Muster wurden mit den Veränderungen bei den non‐verbalen Kommunikationsscores der Kinder verglichen, die vor und nach der Operation gemessen worden waren. Man fand eine signifikante Korrelation zwischen dem präoperativen Glukosemetabolismus im nicht resezierten präfrontalen Kortex und den postoperativen Veränderungen in der Fähigkeit der Kinder, die Aufmerksamkeit eines Erwachsenen auf ein Objekt oder einen Vorgang zu lenken (joint attention), unabhängig davon welche Seite operiert worden war. Diese vorläufigen Befunde lassen ver...

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Primary nystagmus was evoked by constant angular acceleration at near-threshold levels (0.2, 0.4, and 0.6 degree/s2) in 34 normal human subjects (25 children aged 2-11 years and 9 young adults aged 17-21 years). Acceleration was carried out in complete darkness, and with subjects' eyes open. Analysis of response latencies showed that all subjects responded to acceleration magnitude as low as 0.2 degrees/s2. A decrease in response latency was associated with an increase in acceleration magnitude, and there was no significant effect of age on response latency or its relationship to acceleration. However, a relationship was found between age and the percentage of trials showing the presence of a set of three successive beats during acceleration: a significant increase in the frequency of such trials occurred with increasing age. The relationship of these findings to brainstem vestibular modulatory mechanisms is discussed.