We studied the clinicoradiological characteristics of patients with Wallenberg syndrome by lateral medullary infarction．
Seventeen patients with Wallenberg syndrome were divided into a normal group（N）and dysphagia group（D）according to the results of a water swallowing test．We examined for the following 7 symptoms： vertigo or dizziness，gaze nystagmus，cerebellar ataxia，dissociated sensory loss including the range from Hayakawa's classification，Horner's syndrome，hoarseness and hiccups．Magnetic resonance imaging（MRI）was done within 7 days of the first neurological examination．Lesions were located in 3 parts，classified into the rostral， middle and caudal portions．
7 patients belonged to group N and 10 patients belonged to group D，and 59％ of the patients showed dysphagia． All patients showed vertigo or dizziness， gaze nystagmus， cerebellar ataxia and dissociated sensory loss． All cases of Horner's syndrome（57％ of group N and 90％ of group D），hoarseness（29％ of group N and 90％ of group D），and hiccups（43％ of group N and 80％ of group D） were more frequent in group D，and hoarseness was the only statistically frequent clinical symptom．Only 1 patient in group N and 7 patients in group D showed all 7 symptoms．Of the 7 patients in group N，3 were placed in Hayakawa class 1 and 4 in Hayakawa class IV．Meanwhile，7 of the 10 patients in group D were placed in Hayakawa class 1 and the other 3 in Hayakawa class ll ． Radiologically，the lesions were located in the middle portion in 3 patients in group N and in the caudal portion in the other 4 patients．ln group D，the lesions were located in the rostral portion in 5 patients and the middle portion in 5 patients．
The more symptoms appeared，the more often the swallowing functions were disturbed in patients with Wallenberg syndrome．Hoarseness was the symptom most related to dysphagia．Of the patients exhibiting lateral medullary infarctions，dysphagia was more common in patients with infarctions in the rostral portion of the medulla．
This paper describes the study of a method of extracting a contrast medium in a low-contrast image of videofluorography （VF） for swallowing in a personal computer．
Histograrn analysis shows that pixel values for the regions of interest are distributed in different ways depending on the region； the pixel values for the oral cavity are distributed in the low range， and those for the pharynx in the midrange． An algorithm is therefore proposed in which difiierent types of contrast enhancement are applied depending on the region． The image of barium passing through the region connecting the mandible and the pharynx cannot be made distinct if the image has been processed as a whole． On the other hand，by changing the parameters of contrast enhancement depending on the region of interest， the image of barium is distinctly shown in each region． The image processing program applied separately to the three regions， the mandible， the pharynx and the esophagus， is shown to be usefu1 in clinical diagnosis．
It is suggested that conventional patient doses can be reduced by up to 45％ if the VF system installed with the newly proposed algorithm is used．
Mandibular movement was examined to clarify the effect of food texture on masticatory dysfunction． The subjects consisted of 10 normal volunteers． Five test foods were chosen based on physical properties with two different sizes． Mandibular movement during mastication was affected by the properties and sizes of the test foods． The maximum speed during mastication ranged from 102mm/sec to 258mm/sec， the mean speed ranging from 64mm/sec～131mm/sec． These rates were 10 times faster than the compression speed of the texture analyzer of food．Measurement conditions affect levels of food properties， which should therefore be examined under similar conditions during mastication．
Motor aspects of swallowing have been intensively studied by several kinds of methods (for example, EMG, ultrasonic, and videofiuoroscopic examinations), but far fewer investigations have focused upon sensory aspects, thus many problems remain unresolved. Since it is scientifically and clinically important to understand how swallowing of bolus is perceived by individuals, the present study was designed to examine 1）the optimal volume for a swallow (OVS), 2) the maximum volume for a swallow (MVS), and 3) changes in the subjective ease of swallowing (SES) in relation to bolus volumes. A total of 67 healthy young females were subjects in the present experiment, and they were divided into ExperimentⅠ (Exp I , n＝28) and Experiment II (Exp II, n＝39). A kind of tea at room temperature was used as a ‘simulated’ bolus. ln Experiment Ⅰ, OVS and MVS were measured by a free access condition, and the obtained values were 17.9 ± 1.58 mL (mean ± SEM) and 35.4 ±2.26 mL, respectively. Changes in SES caused by increasing or decreasing the volume of a swallow were measured by the magnitude estimation method in both experiments. OVS in each subject in Experiment I was adopted as the standard stimulus (SS), and 7 volumes varying from (SS - 6) mL to (SS + 6) mL of the SS were used as the comparative stimuli (CS). In Experiment II，18 mL (averaged OVS in Exp I) was adopted as the SS in all of the subjects, and 7 volumes varying from 6 mL to 24 mL were used as the CS．ln both experiments， the sublects were initially instructed to quantify the SES for the SS as ‘10’ , and were then instructed to evaluate the SES for the CS by integers in comparison with that of the SS. The major findings were that：1) the SES decreased by both decreasing and increasing bolus volume，2）a reversed‐U curve was plotted at the center of which was the SES for the volume of 15 mL, and 3）the SES for (SS + 6) mL in ExperimentⅠand those for 6 mL and 24 mL in Experiment II were significantly smaller than that for the SS. The present study provides experimental evidence with a psychometric method for the experiential fact that an extremely small or large volume of bolus makes swallowing difficult.
The purpose of this study was to evaluate clear processes in the development of eye-hand-mouth coordination in infants from the pre-self feeding stage. We filmed 2 healthy female infants sucking objects (big and small wooden sticks, small plastic cubes, medium and large wooden cubes) with a digital video camera every 2 to 4 weeks from 2 to 11 months (child A) and from 4 to 11 months (child B).
The following activities were observed： 1) manner of reaching for objects，2) grasping，3) change in line of sight，4) manner of putting objects into the mouth, and 5) compensatory neck movement.
Our conclusions were：
1. Hand-mouth coordination seemed to develop before reaching movement, and to be induced visually from the age of 5 to 6 months.
Object sucking in the pre-self feeding stage starts before the initiation of ablactation and ends by late ablactation.
2. The 2 subjects grasped stick-type objects and put them in their mouths earlier than cube-type objects. lt appears that stick-type objects are easier for infants to manipulate than cube-type objects during the developmental process.