Henry W. Baird

Application of digital filtering and automatic peak detection to brain stem auditory evoked potential

A method to establish optimal parameters for automatic analysis of the BAEP was proposed. Spectral analysis of a set of BAEP trial averages yields criteria for the selection of the optimal bandwidth for digital filtering, establishes a lower limit for the number of averaged responses required for accurate determination of BAEP wave shape and permits accurate estimation of the amplitude and latency of BAEP peaks. Estimation of phase variance proved to be an effective procedure for selection of the optimal frequency band for automatic peak detection. Complete representation of the BAEP should include unfiltered and digitally filtered signals, an accuracy estimate of the filtered signal, and computer peak detection. High stability of detected peak latency values, as a result of using a digital filter with optimal parameters, will allow a reduction in the number of responses which must be averaged to obtain an accurate estimate of BAEP morphology. This should be of particular value where closely spaced serial observations are desirable, as in intra-operative monitoring. Procedures analogous to those described herein should permit reduction of the sample size required for accurate estimation of the morphology of far-field somatosensory evoked potentials, and for cortical potentials evoked by any stimulus modality. The consequent increase in the speed with which reliable measurements can be obtained can be expected to increase the practical application of all evoked potential techniques.

The relationship of oxygen consumption to cerebral functional activity

Summary 1. An adaptation of the Kety nitrous oxide method for the determination of cerebral blood flow has been described. It is practical and safe for use in infants and children. 2. Studies of thirty-three infants and children, most of whom had defects of the central nervous system, indicate that a direct correlation exists between cerebral oxygen consumption and mental ability. 3. Some of the theoretical aspects of the relation of cerebral metabolism to cerebral functional activity have been discussed. 4. The potential usefulness of studies of this nature in the evaluation and prognosis of children with neurological disorders and mental retardation has been emphasized.

Infantile myoclonic seizures.

Summary 1. Fifty-one of eighty children whohad a hypsarhythmia on their electroencephalogram had infantile myoclonic seizures either alone or with some other convulsive disorder. 2. The presence of infantile myoclonic seizures suggests that the child will be significantly retarded in his intellectual abilities. 3. Although meprobamate (Miltown)has shown some promise, drug therapy for the control of infantile myoclonic seizures is unsatisfactory. 4. Some infants who manifest myoclonic seizures have a history of normal motor development during early infancy. In later life the capacity of these children to relate to their environment is much more limited than are their motor abilities. 5. Although a large number of infantilemyoclonic seizures seem to be prenatally determined, some would appear to have their origin in encephalopathies of various etiologies. In the latter group, pertussis immunization should be considered as an etiological possibility.

Kindred showing congenital absence of the dermal ridges (fingerprints) and associated anomalies

Complete absence of dermatoglyphics (finger, palm, and toe prints) in more than one member of a family has not been described previously. Various studies of 24 members in one kindred are reported here. The 13 affected members also show bilateral partial flexion contractures of the fingers and toes, bilateral webbing of the toes, and transient congenital milia.

Cytoplasmic inclusions in juvenile amaurotic idiocy

Several forms of neuronal and glial cytoplasmic bodies have been observed with the electron microscope in cerebral biopsies from patients with juvenile amaurotic idiocy. In this study, another cytoplasmic inclusion, with contents resembling fingerprint markings, 8 has been found in neurons and astrocytes in 4 cases of juvenile amaurotic idiocy. These studie suggest that juvenile amaurotic idiocy is the manifestation of several distinct cellular disorders.

Electronic Data Processing of Medical Records

THE need for better means of recording and retrieving data for medical records has become increasingly apparent.1 2 3 The tremendous accumulation of data reflects the use of more sophisticated labo...

Electroencephalographic changes in children with artificially induced hyperthermia

Summary 1. The electroencephalographs of twelve children were recorded following the intravenous administration of typhoid vaccine. 2. Seven children had a history of three or more convulsions with fever; three had no family or personal history of convulsions of any kind; one had a history of a previously abnormal electroencephalogram; and one had a twin brother who had febrile convulsions. 3. Electroencephalographic changes consisting of high-voltage slow waves, increase delta activity, spike-and-wave formations, and some seizure discharges occurred in all tracings. 4. The fact that otherwise normalchildren have electroencephalographic changes during and shortly after a febrile episode without convulsions should be considered in the interpretation of electroencephalographic changes following a febrile convulsion.

Relationship of serum phenylalanine levels and ability of phenylketonurics to hydroxylate tryptophan.

Summary 1. Following a decrease in serum phenylalanine levels (induced by feeding of a low-phenylalanine diet) phenylketonurics excrete increased amounts of 5-hydroxyindoleacetic acid. 2. The ratio of urinary 5-hydroxyindoleacetic acid to creatinine is about 5-fold greater for young phenylketonuric children, fed a low-phenylalanine diet for 4–10 months, than for untreated phenylketonurics. 3. Oral administration of L-tryptophan to untreated phenylketonuric was followed by increase in 5-hydroxyindoleacetic acid excretion. 4. Following oral administration of 5-hydroxytryptophan, 10–15% was excreted as urinary 5-hydroxyindoleacetic acid by an otherwise untreated phenylketonuric.

Normative values for brain stem auditory evoked potentials obtained by digital filtering and automatic peak detection

A BAEP test which uses constant, high level click stimulation was developed for preliminary screening of patients with known or suspected problems in auditory information processing. Digital filtering and automatic peak detection were employed to aid in the analysis of BAEP component latencies. The results of 148 BAEP tests allowed us to select a set of normative measures: absolute peak latency, interpeak latency and left-right peak latency difference. The set of threshold values was developed for selected BAEP measures, in order to evaluate test results.

Microphthalmos, corneal opacity, mental retardation, and spastic cerebral palsy. An oculocerebral syndrome

Three sisters with microphthalmos, severe mental retardation, and spastic cerebral palsy are described. A review of the literature has revealed several nonfamilial examples of this triad. Each patient also had various degrees of corneal opacity in the absence of cataract or coloboma. Their normally intelligent mother had unilateral microphthalmos and marginal dysplasia of Descemets membrane. The frequent association of microphthalmos with nonocular congenital defects is discussed from the viewpoint of the genetic counselor.