Intestinal pseudo-obstruction as the presenting manifestation of small-cell carcinoma of the lung. A paraneoplastic neuropathy of the gastrointestinal tract.

A 58-year-old woman who had presented with intestinal pseudo-obstruction died 9 months later from rapidly progressive neurologic symptoms and autonomic insufficiency. Her gastric emptying had been markedly delayed and transit of markers had been slowed throughout the small bowel. A 5-hour manometric recording of the antrum and duodenum had shown absence of the normal interdigestive motor complex, which was replaced by irregular contractile activity of reduced amplitude. A small-cell carcinoma of the lung was found at autopsy. Pathologic study of the gut showed widespread degeneration of the myenteric plexus, which was infiltrated by plasma cells and lymphocytes and contained significantly reduced numbers of neurons. The extra-intestinal nervous system had neuronal loss and lymphocytic infiltrates in dorsal root ganglia. Thus, a gastrointestinal neuropathy causing intestinal pseudo-obstruction may be the presenting manifestation of a paraneoplastic syndrome associated with small-cell carcinoma.

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.

Neurometric evaluation of epileptic children who do well and poorly in school.

The neurometric examination is a way of obtaining quantitative electrophysiological data which can be analyzed statistically and compared with similar information from control groups. Statistically significant differences were found among 4 groups of children: group I -- 'epileptic achievers', children with a history of seizures who are functioning at grade level, group II -- 'epileptic under-achievers', children with a history of seizures who are not functioning up to grade level, group III -- 'healthy achievers', children without a history of seizures who are functioning at grade level, and group IV --'healthy underachievers', children who do not have a history of seizures and who are not functioning at grade level. 'Epileptic achievers' and 'epileptic underachievers' both showed sharp waves, severe and widespread. However, 'epileptic underachievers' displayed more 'beta bursts', excessive theta and beta activity in the resting EEG, and greater hyper-reactivity of evoked responses to visual and auditory stimuli in the frontal and frontopolar regions. 'Epileptic achievers' and 'healthy achievers' both had little abnormality in the frequency spectrum. However, the 'epileptic achievers' showed more theta activity, more asymmetry and lower coherence. 'Epileptic underachievers' showed a lower incidence of EEG asymmetries than 'healthy underachievers' but more theta and beta activity. 'Healthy underachievers' showed more abnormal spectral bands, more areas with abnormal spectral bands, greater asymmetry, lower coherence, and a higher incidence of sharp waves than 'healthy achievers'. When the 'epileptic achievers' and 'underachievers' were combined, they were found to have a significantly higher incidence of sharp waves, theta and beta excess, EEG asymmetry, low coherence, and hyper-reactive evoked responses than the 'healthy achievers'.