Extracranial and extraspinal nerve sheath tumors: computed tomographic evaluation.

Thirty-five patients with 37 peripheral nerve sheath tumors (NST) (16 schwannomas, 11 neurofibromas, 5 plexiform and 1 diffuse neurofibroma, and 4 malignant NST) were studied respectively. The benign NST usually appeared on CT as well-defined oval, spherical or fusiform masses, centered at the expected anatomic location of a cranial, spinal, autonomic or peripheral nerve with characteristic displacement of adjacent muscles and blood vessels. None of the schwannomas appeared homogeneously hypodense on IV enhanced CT, whereas close to half of neurofibromas and plexiform neurofibromas were so. This fact, which had not been reported in the past, may be related to differences in inherent vascularity and blood-nerve barrier (fenestrated blood vessels) between schwannomas and neurofibromas and may be a useful distinguishing CT feature. The most reliable, though not infallible criterion of malignant NST was poor definition of their margins. Ninety-two per cent of NST (34 out of 37) were diagnosed or included in a limited differential pre-operatively.

Cystic lesions of the adrenals: diagnosis and management.

Until recently, adrenal cysts were diagnosed at surgery or autopsy. Current imaging methods allow accurate preoperative diagnosis in symptomatic patients and may obviate surgery in the asymptomatic. Eighteen cystic lesions of the adrenal glands are described. Computed tomography was the most useful diagnostic test. Many cysts had typical appearances of a thin-walled, fluid-filled lesion with or without thin septa and mural calcification. Atypical features included central densities, which may be characteristic of intracystic hemorrhage, and wall thickening which should initiate a search for endocrinopathy and tumor.

Maintenance and generalization of 40-Hz EEG biofeedback effects.

Maintenance of conditioning of 40-Hz EEG activity was investigated in six adults 1 to 3 years after they had experienced biofeedback training to increase 40-Hz EEG. Subjects were first retrained to alternately increase and suppress 40-Hz EEG. All six subjects achieved a preset performance criterion in 16-20 minutes. Five of these subjects also subsequently demonstrated significant control of 40-Hz EEG without feedback. The sixth subject did not demonstrate control after 76 minutes and four sessions of attempted retraining with feedback. Transfer of 40-Hz EEG control to a problem-solving task was tested in all subjects in a final session. Cognitive test items were presented and subjects were instructed to alternately increase and suppress 40-Hz EEG while solving the problems. Rates of 40-Hz EEG in suppression periods during problem solving wer significantly greater than during suppression periods without problems. No significant differences in problem-solving performance were found comparing 40-Hz increase and suppression periods. This study supports previous research suggesting an association between 40-Hz EEG and mental activity, and suggests methods for further study of transfer of EEG biofeedback effects.

Percutaneous catheter drainage of liver abscess: an alternative to open drainage?

Percutaneous catheter drainage is still a new concept. Only 4 cases have been reported thus far and this paper reports 2 further cases. The technique of percutaneous catheterization of a liver abscess under CAT scan control is described, and the management of the catheter by a closed irrigation system is set out. Unless there is another compelling reason to do a laparotomy, we feel that this procedure is well worth a trial in view of the high mortality still associated with open drainage. Further experience may well prove percutaneous catheter drainage to be the procedure of choice for liver abscess.

Hypersomnia with simultaneous waking and sleep patterns in the electroencephalogram. A case report with neurotransmitter studies.

A mildly dyslexic boy of 11 years, with no neurological deficit or history of epileptic seizures, had marked hypersomnia for 2 years, which was most pronounced in the morning hours. Repeated EEG studies and power spectral analysis revealed simultaneous posterior alpha rhythm and sleep patterns (spindles, vertex waves, K complexes) over vertex and frontocentral regions, while the patient was behaviorally awake. Bilateral synchronous anterior spikes were frequently noted in association with sleep patterns. A polysomnogram over 24 h confirmed excessive sleep, night and day (especially morning hours) and there was evidence of a large REM sleep percentage (on EMG and EOG basis) while the EEG had predominantly non-REM sleep patterns. Special neurotransmitter studies were performed in view of a presumed disturbance affecting the neurobiochemical sleep regulation. These studies were based on CSF metabolite levels and provided evidence for a high serotonin metabolite (5HIAA) level. It is tempting to hypothesize that the biochemical disturbance has led to encroachment of non-REM sleep patterns on both wakefulness and REM sleep. Further discussion deals with the bilateral-synchronous spike activity and its relationship to arousal patterns in sleep.

Experimental analysis of EMG feedback in treating cerebral palsy.

Three subjects diagnosed as having severe choreoathetoid cerebral palsy were trained in the use of EMG feedback procedures. Both between- and within-session controls, including reversals of baseline, attempted muscle control with feedback, and muscle control without feedback, were employed to analyze the contribution of feedback procedures to improvements in muscle control. The data (1) indicate that feedback enhanced muscle control and (2) provide evidence of generalization of feedback effects to no-feedback conditions and untrained muscles.

Experimental analysis of EMG feedback in treating dystonia.

Recent clinical reports have suggested that electromyographic feedback offers promise as a palliative therapy for neuromuscular disorders. This study utilized a single-subject experimental analysis to evaluate the effects of EMG feedback training on a 20-year-old man with adult-onset idiopathic dystonia to achieve control of orofacial dysfunctions. Feedback training produced reductions in levels and variability of tension in facial and forearm muscles, as measured by EMG. Reliable blind observations of facial control indicated that feedback training enabled the patient to produce normal facial relaxation in extraclinical environments.

Biofeedback training of 40-Hz EEG in humans.

This study was a preliminary evaluation of biofeedback training of human subjects to control high-frequency EEG responses in the 35- to 45-Hz (40-Hz) and 21- to 31-Hz ranges. A total of 22 adult males divided into three groups were successfully trained for increases or suppression of 40-Hz EEG, or increases of 21- to 31-Hz EEG. Dissociation of rates of 40-Hz EEG recorded from scalp leads and 40-Hz EMG responses from prominent muscle contaminators, and partial dissociation of 40-Hz and 21- to 31-Hz EEG responses were noted. After biofeedback training, 8 subjects demonstrated increase and suppression of 40-Hz EEG without feedback. No consistent descriptors of subjective experiences accompanying EEG changes were reported by subjects in any of the groups. The study suggests the utility of biofeedback procedures in research on high-frequency EEG activity.

Behavioral and electroencephalographic correlates of 40-Hz EEG biofeedback training in humans.

Two groups of eight adults successfully trained with biofeedback for increases in 40-Hz EEG responses in left or right hemispheres also demonstrated significant 40-Hz EEG increases during baseline periods, and increases in the contralateral hemisphere during training periods. No changes in heart rate, 40-Hz EMG, or 21- or 31-Hz beta, alpha, or theta EEG occurred over training days. Three subjects returning for additional training demonstrated suppression of 40-Hz EEG. A group of four subjects experiencing daily bidirectional training produced substantial within-session control of 40-Hz EEG but no changes over days. Data from posttraining tests without feedback for successful subjects in both groups indicated significant control of 40-Hz EEG responses in the initial parts of these sessions, and some correlated changes in other EEG responses. Measures of successful subjects' experiences during training and control tests indicated awareness of changes in subjective concomitants of EEG responses. This study suggests further strategies for research on behavioral correlates of EEG activity.

Considerations in the analysis and treatment of dietary effects on behavior: a case study.

Scientific and public interest in the effects of diet of behavior disorders has recently increased. This paper argues that (1) the experimental analysis of behavior offers an effective scientific methodology for assessing the effects of dietary substances on behavior problems, and that (2) such analysis permits behavioral consequences to be considered as an alternative treatment to dietary control. A case study of a 9-year-old retarded boy with autistic behaviors is presented. Suspected dietary substances were demonstrated to be effective influences on the child's behavior, whereas a simple behavior modification program improved his problem behaviors. Also discussed are issues and problems which arise in research on dietary effects on behavior and in selection of effective and ethical treatments.

Early diagnosis of breast cancer: experience in a consultant breast clinic.

Of 2839 women referred to a consultant breast clinic for clinical, mammographic and thermographic examination, 480 underwent biopsy and 126 were found to have cancer. Ten percent of the tumours were occult and were classified as very early biologic disease; they were identified by routine mammography in women whose breasts were clinically normal. Biopsy of solid mass lesions non-suspicious on mammography identified 20% of the cancers; half these lesions, classified as early biologic disease, were discovered by doctors at routine annual clinical breast examination, though the earliest cancers were detected by women who were confident and competent in monthly self-examination of the breasts. Biopsy of solid mass lesions suspicious on mammography identified 70% of the cancers; these were classified as late biologic disease. Skin or nipple dimpling or retraction was evident in two thirds of the patients; their lesions seemed to be later biologically than the lesions of the patients without clinical signs, and 75% had discovered the lesions themselves accidentally.