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Biomedical subjects

R R Clancy

Publications and source records attributed to R R Clancy.

50 records · Page 3Linked to original sources

Cerebral cortical function in infants at risk for sudden infant death syndrome.

Cerebral cortical function was prospectively examined by electroencephalography (EEG) in 3 subgroups of 257 infants at risk for sudden infant death syndrome (SIDS). Group 1 consisted of apparently healthy infants with near-miss SIDS episodes; Group 2 consisted of siblings of SIDS victims; and Group 3 consisted of neurologically suspect infants with apnea. The usual abundance and distribution of sharp EEG transients (SETs) were determined from 69 Group 1 infants. EEGs were interpreted as abnormal in the presence of ictal apnea, excessively abundant SETs, or immaturity of EEG background for conceptional age. Ninety percent of infants in Group 1 had entirely normal EEGs. There was no significant difference in the abundance or distribution of SETs between infants with normal breathing patterns and those with excessively periodic respirations. Nonictal apnea was recorded in 7% of Group 1 infants. The unexpected diagnosis of ictal apnea was confirmed in 2 Group 1 infants (1.2%), and 5 (2.9%) had excessive SETs but no recorded seizures. Only 4 infants (2.3%) had abnormally immature EEGs for conceptional age. Nonictal apnea occurred in 5 of 33 (15.2%) Group 3 infants and ictal apnea was confirmed in 2 others (6.1%). We conclude that the majority of Group 1 and 2 infants have normal cerebral cortical activity between and during apnea and that central nervous system cortical immaturity, as measured by EEG, plays no important role in the pathogenesis of SIDS. SETs are commonly recorded in these infants and must be conservatively interpreted. However, an EEG examination was critical in establishing the unexpected diagnosis of ictal apnea in a small percentage of Group 1 and 3 infants and materially influenced subsequent evaluation, management, and prognosis.

Apnea↗

Neonatal theophylline neurotoxicity.

Despite the frequency with which theophylline is administered to premature infants, there are few reported cases of neurotoxicity. We describe a theophylline-treated premature infant with chronic bronchopulmonary dysplasia and hepatitis who displayed a focal seizure and irritability followed by other systemic signs of theophylline intoxication, at a postnatal age of 5 months. An unrecognized accidental drug overdose combined with a prolonged elimination half-life were responsible for clinical intoxication. The potential mechanisms of theophylline's neurotoxicity are discussed briefly.

Bronchopulmonary Dysplasia↗

Positive rolandic sharp waves in the electroencephalograms of premature neonates with intraventricular hemorrhage.

Seventy-eight electroencephalograms (EEGs) recorded from 44 premature infants with documented intraventricular hemorrhage (IVH) were retrospectively reviewed. Positive rolandic sharp waves (PRS) were observed in 13 of 44 (29.5%) patients. Among infants with grades 3 and 4 IVH, the incidence of PRS was 60% (9 of 15). During the period of study, typical PRS appeared in two EEGs of one premature infant who did not suffer an IVH. PRS were usually associated with moderately abnormal EEG backgrounds and with grades 3 and 4 IVH. Beta activity was superimposed on an average of 21.5% of PRS (beta-PRS). Infants with grades 3 and 4 IVH had a higher incidence of beta-PRS than those with smaller hemorrhages. PRS first appeared in early postnatal life, increased in abundance and then eventually disappeared from the records by 3-4 weeks of age. The field of distribution of PRS was centered at the central parasagittal region (Cz) with generous anteroposterior spread into the frontal and parietal vertices (Fz and Pz) and symmetric lateral spread into the rolandic areas (C3 and C4). Asymmetric involvement of PRS at C3 and C4 may signify differential hemispheric injury. The majority of infants whose EEGs contained PRS died or suffered serious neurologic sequelae. However, their outcomes were not significantly inferior to those without PRS.

Brain↗

EEG in premature infants with intraventricular hemorrhage.

Seventy-eight EEGs from 44 premature infants with CT- or autopsy-verified intraventricular hemorrhage (IVH) were reviewed retrospectively. The patient's most abnormal EEG was a reliable predictor of outcome, independent of the estimated gestational age, 1- and 5-minute Apgar scores, and IVH grade. Nine of 12 infants who had all normal or mildly abnormal EEGs had favorable outcomes. The nine infants whose worst EEGs were moderately abnormal experienced mixed outcomes, ranging from normal survival to death. All 23 infants with one or more markedly abnormal EEGs suffered unfavorable outcomes. Positive rolandic sharp waves, a highly specific EEG pattern for IVH in premature infants, occurred in only 29.5% of the patients. The degree of EEG abnormality correlated significantly with the patient's mental status, but not with the IVH grade. Subarachnoid hemorrhage, hypoxia-ischemia, and focal parenchymal lesions caused electrographic seizures in 14 patients, 12 of whom died (85.7%). This study suggests that EEG has limited value in the diagnosis of IVH. However, it may play an important role in the neurologic assessment of the premature infant with established IVH by confirming clinically suspected seizures and providing reliable prognostic information.

Brain↗

The neuropathology of propionic acidemia.

The neuropathology in two biochemically documented cases of propionic acidemia is presented. While spongiform changes in white matter were seen in the infant who died at 12 days, no such changes were evident in an older patient who died at age 23 months. These findings are compared with other aminoacidemias.

Amino Acid Metabolism, Inborn Errors↗

Clinical variability in congenital fiber type disproportion.

Congenital Fiber Type Disproportion (CFTD) has recently been described as a consistent and stereotyped clinicopathological entity, including congenital nonprogressive hypotonia and weakness, contractures, kyphoscoliosis, high arched palate, dislocated hips, short stature, and feet deformities. Our personal experience with this condition suggests a wider disparity in the physical appearance and associated abnormalities of affected individuals than the well-defined clinical syndrome previously described. We are presenting 5 cases, including 2 siblings, whose muscle biopsies satisfy the major histological and statistical criteria for the diagnosis. Although each child clearly had hypotonia and weakness consistent with a congenital myopathy, only 3 had a sufficient number of other similarities to establish the diagnosis clinically. The clinical spectrum of the other cases ranged from one infant whose only abnormality was mild hypotonia in the legs to another whose problems included severe motor impairment, marked mental retardation, growth failure, frontal bossing, abnormal hair, and scoliosis. Even in retrospect, the diagnosis of CFTD could not have been supported on clinical grounds alone. Therefore, CFTD is a congenital myopathy whose diagnosis can be made only by muscle biopsy, rather than a distinct syndrome whose diagnosis can be assumed on the basis of clinical characteristics alone.

Child, Preschool↗

Recent advances in the diagnosis, treatment, and prognosis of neonatal seizures.

Current knowledge about the diagnosis, treatment, and prognosis of neonatal seizures is reviewed. The pitfalls in establishing the diagnosis are emphasized and the usefulness of new electrodiagnostic techniques is discussed. A protocol for treating neonatal seizures is suggested. Finally, the clinical and electroencephalographic variables which are relevant in determining neurologic outcome are discussed.

Anticonvulsants↗

Prognostic value of EEG in neonatal meningitis: retrospective study of 29 infants.

Neonatal meningitis is associated with significant neurologic sequelae. Previous studies from our laboratory and others demonstrated electroencephalography (EEG) to be a useful tool in predicting long-term neurologic outcome in at-risk neonates. We, therefore, retrospectively studied 29 infants with culture-proved neonatal meningitis who died in the neonatal period or survived to follow-up at a mean of 34.4 months. Seventy-five EEGs were obtained during the acute phase of infection; the degree of EEG background abnormality proved to be an accurate predictor of outcome. Infants who had normal or mildly abnormal backgrounds had normal outcomes, whereas those with markedly abnormal EEGs died or manifested severe neurologic sequelae at follow-up. When the EEG was considered with the presence or absence of seizures and the level of consciousness, an accurate prediction of neurologic outcome was obtained in 27 infants (93%). Although the EEG patterns were generally nonspecific, some abnormalities, such as positive rolandic sharp waves, persistent hemispheric or focal voltage attenuation, suggested more specific pathology (i.e., deep white matter necrosis, large-vessel infarction and abscess, respectively). EEG was also valuable for the recognition of subtle and subclinical seizures. Therefore, we conclude that EEG is a valuable tool for predicting the long-term prognoses of infants with neonatal meningitis.

Birth Weight↗

Cerebral venous thrombosis in neonates and children.

Twenty-five patients (10 neonates, 15 children) with cerebral venous thromboses diagnosed by magnetic resonance imaging or computed tomography over a 10-year period were reviewed retrospectively. Two groups were analyzed separately because of their differing modes of presentation and outcome. Eighty percent of neonates presented with seizures and the outcomes were unfavorable in more than 50%. Thrombosis usually was associated with an acute systemic illness, such as shock or dehydration. In comparison, headache was the most common mode of presentation in the older children (excluding infants) and their outcomes generally were favorable. Thrombosis in this group usually occurred in the setting of a hypercoagulable state or an infectious process. In both groups, global or focal neurologic findings on initial examination unrelated to increased intracranial pressure correlated with the presence of an infarction on computed tomography or magnetic resonance imaging. Infants and children with infarction due to a deep venous thrombosis often had persistent neurologic disability at subsequent examination. No sequelae were observed in those children and neonates only with thrombosis or with superficial venous infarction. Treatment for both groups was conservative. No patient was anticoagulated specifically for the thrombosis. The good outcomes in most patients suggest that acute anticoagulation may not be indicated.

Adolescent↗

The exact ictal and interictal duration of electroencephalographic neonatal seizures.

The temporal behavior of neonatal seizures caused by diverse acute encephalopathies in 42 patients with 487 seizures was studied. All 487 seizures were confirmed by typical ictal electroencephalogram (EEG) patterns. Neonatal seizures are relatively brief events, which usually last about 2 min. They are recurrent and are separated by interictal recovery periods of variable duration, on the average, about 8 min. Solitary prolonged seizures are rare and do not represent the usual behavior of neonatal seizures.

Brain↗

Occult neonatal seizures.

Forty-one infants with neonatal seizures frequent enough to be captured by randomly recorded routine EEG examinations were studied to determine how often their electrographic seizures were occult (subclinical) and to examine the effects of seizure duration and mental status on their clinical visibility. Seizures were the result of diverse etiologies and most infants had received one or more antiepileptic drug prior to the EEG recordings. The majority of electrographic seizures were occult: only 84 of 393 (21%) were accompanied by distinctive clinical seizure activity; the remaining 79% were occult. There was no significant difference between the duration of EEG seizures with distinctive clinical signs and those without. There was no significant difference in the proportion of occult seizures in neonates with preserved consciousness compared with lethargic or comatose infants. We conclude that unaided visual inspection of infants seriously underestimates true seizure frequency. Long-term EEG monitoring may be necessary in many infants to determine their real seizure frequency and to judge the adequacy of antiepileptic drug treatment.

Anticonvulsants↗

Postnatal epilepsy after EEG-confirmed neonatal seizures.

We examined infants whose neonatal seizures were confirmed by randomly recorded ictal EEG tracings to determine the types and frequency of postnatal epilepsy (PNE)--unprovoked, recurring postnatal seizures. Perinatal and postnatal clinical and EEG variables were also examined for their relevance to PNE. Forty infants with EEG-documented neonatal seizures of diverse etiologies were studied. The 27 survivors were followed for a mean of 31 months. PNE developed in 56% (15 of 27) of the cohort. The first seizure appeared at a mean-corrected age of 12.7 months and occurred despite ongoing antiepileptic medication in 60% (9 of 15) of the group. Seizures were classified as infantile spasms or minor motor (7 patients), complex partial (4 patients), or generalized tonic-clonic (4 patients). Perinatal variables that significantly correlated with PNE included the presence of coma but not the age at seizure onset, the estimated gestational age, or Apgar scores. PNE occurred in 68% (13 of 19) of patients with moderately or markedly abnormal EEG backgrounds but in only 25% (2 of 8) without (p = 0.035). There was a strong trend for PNE to develop in patients with greater than 10 electrographic seizures per hour but in only 45% (9 of 20) of infants with fewer seizures (p = 0.058). Several postnatal variables were significantly related to PNE--the presence of cerebral palsy (CP), mental retardation (MR), CP with MR, and follow-up EEGs. PNE occurred in only 27% (3 of 11) of patients without spikes or sharp waves on postnatal EEGs performed at age 3 months but in 100% (3 of 3) of patients with spikes or sharp waves (p = 0.022).(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗