Left Earlobe Research Articles

Spatiotemporal changes of EEG activity during waking-sleeping transition period.

To evaluate the spatiotemporal changes of EEG during waking-sleeping transition or hypnagogic period, spectral analysis of the five scalp EEG on the midline (Fpz, Fz, Cz, Pz and Oz) referenced to the left ear lobe was carried out on seven young male subjects. Power spectra from consecutive samples of 5.12 sec period with 0.2 Hz resolution were studied from 10 min before the manually scored stage 1 onset to 30 min after the onset of stage 1. The average power spectra over 1 min segments and corresponding coefficient of variation (CV) were determined for the frequency bands of delta (1-3 Hz), theta (4-7 Hz), alpha (8-12 Hz), sigma (13-15 Hz) and beta (16-19 Hz). The latency score was defined as the time elapsed from the onset of stage 1 to the first epoch when the frequency band power, using the ANOVA significantly increased (or decreased) in comparison with the average level at the onset of stage 1. Median latency scores for each band were similar to the Cz scores, with a ranking, from early to late, of: alpha (2 min), theta (3 min), delta (5 min) and sigma (5 min). Significant change was not observed on the beta band activity. In terms of the EEG areas, the shortest latency was found in the theta band activity of the Fz EEG (2 min), and the longest was the sigma band activity of the Fpz and Oz EEG (8 min). The average stage 2 latency was 3.5 min when it was measured as time elapsed between the onset of stage 1 and 2. The average curves of delta, theta and alpha band CVs, started to increase just before or immediately after stage 1 onset and continued to increase for about 10 min. If the increased CV or unsteadiness of EEG activity is taken as a characteristic of the hypnagogic period, hypnagogic states may be considered to have continued until about 10 min after the stage 1 onset. Delta-theta activity showed a rapid rise in power after the onset of stage 1 for all areas. Delta power at the occipital, however, increased more gradually, and consistently remained at a lower level. The differences of delta power between Oz and other four electrode sites became clear at 7 min after the onset of stage 1. These regional differences may reflect the termination of hypnagogic effects.(ABSTRACT TRUNCATED AT 400 WORDS)

第一さい裂由来の側けいろうの一例

Anomaly of the first branchial cleft is relatively rare when compared with those of the second. Aronsohn showed that the incidence of this anomaly was less than 1% of all the branchial anomalies.A case of the first branchial anomaly occurring in a girl aged 5 years is presented. She was admitted to Mie University Hospital on November 1, 1979, because of painful swelling beneath and posterior to the left ear lobe, and an abscess adjacent to the hyoid bone which had been incised and drained. A contrast X-ray study was carried out and revealed a tract of 7cm in length extending down from the postauricular region to the left part of the hyoid bone. The diagnosis of the fistula of the first branchial cleft was made. On November 13, 1979, the fistula was dissected under general anesthesia. The fistula lay deep to the main trunk of the facial nerve, extended down along with the stylohyoid muscle and ended in the left part of the hyoid bone. The upper part of the fistula ended blindly at the cartilage of the external auditory canal. The excised fistula was 7cm in length and 0.5cm in diameter. Histopathological examination revealed a sinus tract lined by stratified squamous epithelia containing hair bulbs and sweat glands.Seventy one cases of the first branchial cleft anomaly collected from the international literature were analyzed in terms of histopathological findings and the relationship of the fistula to the facial nerve based on the classification proposed by Belenky and Medina. The case of a first branchial anomaly reported here is believed to be the 14th such case ever reported in the Japanese literature.

Central somatosensory conduction in man: Neural generators and interpeak latencies of the far-field components recorded from neck and right or left scalp and earlobes

Early somatosensory evoked potential (SEP) components to median nerve or finger stimulation were recorded with non-cephalic references in normal young adults. Detailed topographic data over scalp and neck were related to anatomical observations on the actual conduction distances in dorsal column, medial lemniscus and thalamo-cortical parts of the somatosensory pathway. The extrapolation of afferent conduction velocity (CV) measured from sensory nerve potentials along the peripheral nerve to the C6-C7 spinal segments identified the spinal entry time with the onset of the neck N11 or scalp P11 (far field 2 or FF2). The first far field (FF1) is generated in the nerve proximal to axilla. The definite latency shift of the spinal negativity along the neck indicates a CV of 58 m/sec. Data about the maximal diameter of lemniscal axons in man were used to calculate a CV of 40.5 m/sec. Consideration of transit times from spinal entry to cortex and of synaptic delays clarified the arrival times of the afferent volley at various relay nuclei, and also suggested a thalamo-cortical CV of about 33 m/sec. Interpeak and onset-to-peak measures on scalp far fields suggest that FF3-FF4 are generated in medial lemniscus rather than above the thalamus. Consistent differences in amplitude, but not in wave form, were recorded at right and left earlobes for FF2 (larger ipsilaterally) and FF3-FF4 (larger contralaterally). The scalp topography of far fields was analysed in detail.

Delayed hypersensitivity during casein-induced murine amyloidosis

Cellular immunity has been studied in mice at various times during the induction of amyloidosis following multiple injections of casein. The assay system used was one which measured delayed hypersensitivity (DH) in vivo, by injecting antigen into the left ear lobe of sensitized mice, followed by the intravenous administration of 125I-deoxyuridine ( 125I-UdR). The ears were then cut off and the L R 125I-UdR ratio provided a measure of DH. It was found that DH to casein appeared in pre-amyloidotic mice, remained through the stages of mild and moderate amyloidosis and disappeared in severely amyloidotic mice. DH to fowl IgG disappeared after three injections of casein and remained absent at all times thereafter, likely due to antigenic competition. In contrast, DH to DNFB persisted at all times, even in the face of severe amyloidosis. These results have been interpreted to indicate that, using this assay, DH is normal during casein-induced murine amyloidosis.

The effect of test conditions on the early components of the averaged electroencephalic response.

The effect of test conditions on the early components of the averaged electroencephalic response was examined in 12 normal hearing subjects between the ages of 21 and 43. Clicks at 50 dB SL were presented to the right ear at the rate of 9.6/sec while the subject was (1) sitting in the dark with eyes closed, (2) sitting quietly in the light with eyes open, and (3) reading. Order of presentation was counter-balanced with each condition repeated three times. 1024 clicks were used in obtaining each of the nine averaged responses. Electroencephalic activity was recorded from an electrode on the vertex referred to the left earlobe. The polyphasic response pattern was relatively consistent, characterized by a configuration with mean peak latencies of (N o ) 7.6 msec, (P o ) 16.5 msec, (N a ) 26.9 msec, (P a ) 40.6 msec, and (N b ) 54.0 msec. No significant differences occurred in either latency or amplitude of the response with the different test conditions. Latency and amplitude of the response did not differ as a function of order, although the first response was usually larger than the mean of the remaining eight.

Stability of the early components of the averaged electroencephalic response.

The early components of the averaged electroencephalic response (AER) were examined at three-hour intervals in eight normal hearing adults over a single, sleepless 24-hour span. During each of the eight sessions, three series of clicks at 50 dB SL were presented to the right ear of the subject as he sat reading. 1024 clicks at the rate of 9.6/sec were used in obtaining each averaged response. Electroencephalic activity was recorded from an electrode on the vertex referred to the left earlobe. The response pattern was very stable, characterized by a polyphasic configuration with mean peak latencies of (P o ) 13.3 msec, (N a ) 22.0 msec, (P a ) 32.3 msec, and (N b ) 45.1 msec. An earlier negative peak (N o ) with a mean peak latency of 8.3 msec occurred in many of the responses. At the conclusion of the 24-hour span, three of the subjects were tested with the same stimuli during various stages of sleep. The early components of the AER remained consistent even during sleep. Threshold searches were successfully carried out on two of the sleeping subjects. The long-term stability of the early components of the AER in the awake and sleep states makes them practical as a response index for electroencephalic audiometry. Their characteristics are more compatible with a neurogenic than with a myogenic theory of their origin.

Early components of averaged evoked responses to rapidly repeated auditory stimuli.

Averaged evoked responses to clicks were elicited from 20 normal-hearing subjects between the ages of 16 and 41. Two thousand clicks were presented to the right ear at the rate of 10 per sec at 60, 30, 10, 5, 0, −5, and −10 dB SL. Sensation levels were varied randomly. In each series two control conditions without stimulation were randomly interspersed. Electroencephalic potentials were recorded from an electrode on the vertex of the skull referred to the left earlobe. The response pattern was relatively consistent with a vertex-negative peak (N a ) at about 20–24 msec, and a vertex-positive peak (P a ) at about 31–35 msec. Another vertex-negative peak (N b ) at about 46–50 msec was seen less frequently. Criteria for response were established on the basis of the occurrence of N a and P a within prescribed latencies as well as the interval between the two peaks of about 12–13 msec. The number of identifiable responses diminished with diminishing sensation levels but responses were observed in about one-half of the subjects as low as −5 dB SL.