Suncus murinus belongs to insectivora and has been developed as a laboratory animal in Japan. It is relatively small in size (male: 50-70g, female: 30-50g), and there are no problems in the handling, housing and breeding of the animal. We have found that administration of emetogenic drugs, X-ray irradiation and oscillation easily causes emesis in this animal. Since simple reciprocal shaking (frequency: 1 Hz, amplitude: 4cm) is enough to induce vomiting within as short as 2 min, Suncus murinus is currently the most sensitive animal to motion sickness. Information conserning the purchase and special animal chow is available at the Central Institute for Experimental Animals. Our knowledge of emesis and motion sickness is still very poor. The presence of a "vomiting center" and a "CTZ: chemoreceptor trigger zone" were proposed about a half century ago but substantiating evidence is still lacking. Antiemetic dugs have been developed to reduce the number of vomiting episodes; however, in terms of quality of life, complete blockade of nausea rather than vomiting is desirable. We believe that Suncus murinus will be a useful experimental animal for research on emesis and the development of new antiemetic drugs.
"Dizziness" includes dizziness, vertigo, ataxia and psychogenic unsteadiness and is the second most common symptom next to pain. The diagnosis and treatment of dizziness is discussed, together with a discussion to differentiate life-threatening dizziness from non-life-threatening dizziness. A complaint of dizziness may be more serious than a complaint of vertigo, and danger signs include markedly dilated pupils. Dizziness with abnormal vital signs and with neurological and/or neuro-ophthalmological symptoms may indicate that the patient is in a very serious condition. Neurological therapy for dizziness includes tPA, Heparin, anticoagulants for CVA related dizziness, anti-Parkinsonism therapy for Parkinsonism related dizziness. In this report therapy for migraine without Ergotamine alkaloid for dizziness of brainstem migraine is discussed, together with therapy for cervical dizziness.
We encountered two patients with paraneoplastic neurologic syndrome who visited our ENT clinic complaining of vertigo. The first patient was a 73-year-old woman who was admitted to our hospital because of dysequilibrium and dysarthria of subacute onset. Chest CT showed swelling of the mediastinal and right hilar lymphnodes. Pathological examination of the hilar lymphnodes taken by thoracotomy revealed small cell carcinoma of the lung. Brain CT and brain MRI were normal. Cytological study of the cerebrospinal fluid was class I. Paraneoplastic cerebellar degeneration was diagnosed. Neuro-otological examinations revealed: 1) gaze nystagmus on both right and left lateral gaze, 2) saccadic pursuit, 3) hypometric saccades, 4) diminished caloric nystagmus and 5) decreased visual suppression of caloric nystagmus. Treatment with plasmapheresis was successful to improve limb/truncal ataxia, dysarthria, and neuro-otological findings. The second patient was a 54-year-old woman who had had surgical treatment 3 years before for ovarian cancer. She visited our ENT clinic because of vigorous vertigo and diplopia of sudden onset. Neurological examinations revealed reduced deep tendon reflexes and neuro-otological examinations revealed: 1) bilateral abducens nerve palsy, 2) gaze nystagmus on both right and left lateral gaze, 3) saccadic pursuit, and 4) markedly diminished caloric nystagmus. Gynecological examinations revealed recurrent ovarian cancer. Brain CT and brain MRI were normal. Cytological study of the cerebrospinal fluid was class I. Paraneoplastic brainstem encephalitis was diagnosed. Steroid pulse therapy improved her subjective symptoms and neuro-otological findings. We emphasize that the early induction of plasmapheresis or steroid pulse therapy should be used to treat patients with paraneoplastic neurologic syndrome and that neuro-oto-logical examinations are indispensable for quantitatively assessing the effectiveness of these treatments.
Positional vertigo of peripheral origin usually resolves by itself or by conservative treatments. However, some cases resist conventional treatments and show disabling vertigo. The case presented herein is a 57-year-old woman who developed positional vertigo following head injury. She showed direction-changing vertical-rotatory nystagmus upon positional nystagmus test. Drug therapy and physical maneuver failed to control her symptoms and nystagmus. Canal plugging procedure to the right posterior semicircular canal successfully eliminated the vertigo and the nystagmus. The hearing remained unchanged. Close analysis of nystagmus is necessary for the precise diagnosis of the affected organ and selection of the appropriate treatment.
Many researchers have reported the usefullness of repositioning manuevers for BPPV, such as Epley's procedure and Lempert's method, since canalolithiasis was recently found to be an etiologic factor of BPPV. The affected side should be determined before performing repositioning manuevers, because the therapy is directed to the posterior or horizontal semicircular canal on the affected side. However, in many cases the affected side cannot be determined because symptoms and signs are not found at the time of their visit. On this study, we investigated data taken at first visit from patient with suspected BPPV to determine the affected side. We also investigated the ther-apeutic effects of habituation training therapy which we used for BPPV. BPPV was suspected in 203 of 737 outpatients complaining of vertigo on their first visit. A previous history of positioning vertigo was reported in 199 of the 203 patients with suspected BPPV. However, a difference in vertigo between right-ear-down and left-ear-down position was clear only in 47 patients (23.2%), and it was not clear in 156 (76.8%). Decreasing and alternative positional nystagmus was observed in 92 patients (45.3%), and not observed in 111 (54.7%). Thus, the affected side was determined in only 95 patients (46.8%), and not determined in 108 (53.2%). Habituation training therapy was performed in 190 patients with BPPV and suspected BPPV. As a result, positional vertigo and/or nystagmus disappeared after therapy in 183 patients. The habituation training therapy was found to be effective to treat BPPV not only when the affected side was determined, but also suspected BPPV when the affected side was undetermined.
The effects of sports training on equilibrium function were evaluated with Equi-TestTM. Posture control of athletes was evaluated by sensory organization test (SOT) and movement coordination test (MCT). The SOT evaluates postural stability under 6 conditions such as a reduction in visual and/or somatosensory information. The MCT evaluates the strength of postural response to the acute translations of force plates. The protocols and results were as follows: (1) Two groups were tested. Group 1 included 14 ski runners from the ski club at our university. Group 2 was a 12-subject control group with no sports training. Both groups were tested in October before the ski season and in April of the next year, after the ski season. In both examinations, the postural stability in SOT of the ski group was better than that of the control group in conditions 4 to 6. Furthermore, in conditions 3 to 6, the stability of ski group in April had improved compared to that in October, suggesting that ski training contributed to the improvement of equilibrium function. The response strength in backward translation had significantly decreased in April in both groups, but that in forward translation significantly decreased only in the ski group, suggesting that the skilled skiers might become able to utilize minimal appropriate response strength to perturbations. (2) Thirteen female high school gymnasts were tested. In SOT, correlation between postural stability and the number of training years was analyzed. The findings showed that postural stability tended to become worse as the number of training years increased, which may due to the specificity of training for this sport. The findings in these two studies suggest that equilibrium function varies among sports.
In previous studies, many evaluation parameters for the center of foot pressure (CFP) in a static standing posture have been proposed, but their reliability and inter-relationships have not been sufficiently examined. The purposes of this study were to examine trial-to-trial reliability and the inter-relationships of various evaluation parameters and to propose useful ones. Thirty healthy young adults were selected as subjects. The measurement of CFP for 1 minute was carried out 10 times with 1 minute rest for each subject. The measurement device was an Anima's stabilometer G5500. The data was recorded every 20 msec. Seventy-six evaluation parameters, excepting composite parameters from 114 parameters proposed in previous studies, were selected from the following domains: distance, center of pres-sure, distribution of amplitude, area, velocity, power spectrum, and vector for body sway. The intraclass correlation coefficients (ICC) for 10 trials were 0.7 or over for all parameters excepting for the X-axis and the Y-axis distribution for body sway, and skewness and kurtosis for body sway speed, but a significant difference between the first trial and the other trials was found in many parameters. Therefore, the ICC was recal-culated by excluding the first trial. As a result, no significant difference was found other than that of the distance of the root of the mean square and the area of the root of the mean square. The ICC was 0.7 or over, excepting for the following parameters: the X-axis and the Y-axis distribution for body sway and skewness and kurtosis for body sway speed, the cross correlations for body sway and body sway speed, the C ratio of the power spectrum area on the X-axis, the A ratio of the power spectrum area on the Y-axis and the root of the mean square-axis. Inter-correlation coefficients between parameters in each domain of distance, center of pressure, distribution of amplitude, area, velocity, power spectrum, and vector for body sway were mostly high values of 0.9 or over. Thus, it was considered that there is a close relationship between theoretically similar parameters and any of them could be selected as useful parameters. Based on the above-stated examination, 60 evaluation parameters shown in Table 5 were finally selected.
The case of a 57-year-old woman who manifested long lasting imbalance and jumbling of objects after meningitis is reported from the point of view of neurotology. She had been healthy until she underwent surgery for the right patellar joint fixation under spinal anesthesia in June 5, 1987. Lumbar puncture examination showed an increase in cell counts, protein and glucose levels in spinal fluid. In June 21st 1987, she has repeatedly experienced episodes of balance disorder, vertigo and jumbling of objects. No neurological signs were observed, except for the balance disorders. Audiological exami-nation showed normal hearing and normal ABR. Vestibular examination revealed loss of caloric reaction, decrease in visual acuity by 0.2 during exercise task, abnormal balance board test and abnormal eye head coordination. A test of oculomotor system of saccade, smooth pursuit and OKN was normal. However, visual fixation test was abnormal. In conclusion the findings in this case of imbalance and jumbling of objects resulted from the bilateral loss of semicircular canal function due to meningitis.