This paper deals with our analysis and examination of the standing posture. 1. Romberg, Mann, and one-leg tests were useful not only to demonstrate the degree of equilibrium disturbance but also to differentiate labyrinthine equilibrium disturbance from cerebellar ataxia. 2. Stabilometry with computer analysis of the sway of the body's center of gravity was useful to record sway in the standing posture and to demonstrate peculiarities of equilibrium disturbances due to disorders of the labyrinth, cerebellum, basal ganglia, and cervical spinal cord. 3. Analysis with a feedback model of interactions between sway of the head and the nuchal muscle activity (labyrinthine righting system) and between sway of the body's center of gravity and activity of the soleus muscle (proprioceptive righting system) was useful to demonstrate characteristics of the labyrinthine and proprioceptive controls which act to maintain the standing posture. 4. Evoked electromyograms induced by the stimulation of the labyrinth appeared in the muscles of the gluteal and femoral regions and the legs. These muscle activities were varied with changes in head postition indicating that vestibulospinal reflexes are modulated by input from the neck proprioceptors. All kinds examinations related to standing posture are nesessary to clarify the mechanism of control of standing posture and to examine static equilibrium in clinical practice.
Horizontal positional nystagmus due to peripheral vestibular lesions might be caused by unilateral dysfunction of the utricular apparatus. To determine whether horizontal positional nystagmus is caused by utricular dysfunction alone, we examined the dynamic response of positional nystagmus in eleven patients with positional vertigo when the head was rotated from the supine position to the left and to the right. Positional nystagmus varied with the speed and the direction of the head rotation in all cases. Positional nystagmus was probably provoked not only by the head position but also by the acceleration or the velocity of head rotation. A recent study indicated that horizontal nystagmus induced by off-vertical axis rotation is due to utricular changes and is related to the velocity of head rotation. Therefore, it may be that horizontal positional nystagmus is not necessarily provoked by an interaction between the lateral canal and the utricle, but by utricular dysfunction alone.
The cerebellum functions as a central control for the bodily movements and equilibrium. One may be particularly conscious of a malfunctioning cerebellum when moving. For this study we recorded and analyzed the stability of the center of gravity in patients with known cerebellar disorders when attempting to stand erect and still. The analysis included the spatial extent of the movements as a parameter of the magnitude of sway and the different 8 directional sway velocities in order to determine the sway characteristics. The patients had tumors confined to the cerebellum. If the lesion was confined to a cerebellar hemisphere the spatial magnitude of the sway and the sway velocities were within the normal range, despite increased variability. When the velocities to the lateral and antero-posterior directions were compared, the former predominated. The Romberg value was somewhat smaller than that of normal controls. There were increasing spatial magnitude of sway and directional velocities in patients with paravermian and vermian lesions. The Romberg value was larger. The lateral sway velocity exceeded that of antero-posterior sway with eyes open or were closed ; the difference was more obvious when the eyes clsoed. There was no correlation between uni-hemispheric and hemisphericparavermian lesions as to lateral sway velocities and laterality of the lesion. Restricted cerebellar hemispheric lesions show no clearcut abnormalities in central gravitational movements. However, when the pathology begins to involve the median part of the cerebellum, the sway becomes abnormally large. Vermian lesions are associated with obviously larger sway. This study implies that the midline portion of the cerebellum plays important role in the control of body stability. The negative Romberg value may mean that the sway increases proportionally when the eyes are closed in both patients groups and normal controls.
A total of 21 vertigo patients were examined by vestibular tests and magnetic resonance imaging (MRI). All the patient were over 50 years old. Patients with known causes of vertigo, such as Meniere's disease, were excluded. Abnormal MRI findings were obtained in 15 patients : cerebral infarction, cerebral ischemia, cerebral atrophy, and subcortical high intensity area. The 12 patients with abnormal MRI findings without cerebral atrophy were compared with the 8 with normal MRI. Patients with abnormal MRI tend to have a long history of vertigo (more than 1-year), associated with headache and/or systemic disease such as hypertension, hyperlipidemia or diabetes. Vestibular examinations often show an abnormal stepping test or disturbances of optokinetic patterns.
A 12-year-old female had iritis, episcleritis, papilledema and vestibuloauditory dysfunction. The diagnosis was atypical Cogan's syndrome as described by Cody and Haynes. The initial symptoms were high fever and injected bulbar conjunctiva. Attack of vertigo, as in Ménière's disease, appeared 2 months after the onset. The results of equilibrium and glycerol tests, and electrocochleography suggested endolymphatic hydrops in the inner ear. Within 4 weeks after the initiation of steroid therapy, hearing improved and ocular symptoms disappeared without papilledema. At the time of discharge, she had no ataxia, but bilateral CP was present in the caloric test. We considered that the disorder of the inner ear in Cogan's syndrome is hydrops due to vascular insufficiency.
The cervico-vestibular interaction was investigated in 20 patients with unilateral labyrinthine dysfunction and 16 normal subjects using tonic stimulation of the neck and caloric stimulation. Caloric nystagmus was modulated by tonic neck stimution in the patients with unilateral labyrinthine dysfunction. Tonic stimulation of the neck enhanced caloric nystagmus induced by stimulation of the diseased ear and suppressed nystagmus induced by stimulation of the normol ear in these patients. However, this modulation was not observed in the normal subjects. These results were the same as in the previous investigation using neck vibration, suggesting that input from the neck proprioceptors is quite important in controlling eye movements in patients with unilateral labyrinthine dysfunction, and that in these patients the sensory input modulation from the neck proprioceptors may induce decompensation, even though compensation occurs following unilateral labyrinthine dysfunction. Moreover, in the patients with unilateral labyrinthine dysfuntion, the vestibulo-ocular reflex may be influenced by normal movements such as ventriflexion or torsion and decompensation may be induced by those movements.
Physiological reactions of the otolith neurons were investigated in the lateral vestibular nucleus (LVN) in the cat. The physiological differences between the ventral and dorsal part of the LVN were examined by tilting and rotating stimulation. 1) In the ventral part of the LVN, many neurons reacted to lateral tilting, and a close relation of this region to the utricles was suspected. 2) In the dorsal part of the LVN, neurons reacting to tilting and those reacting to rotating were found, and some reacted to both. This region was suspected to have indirect connections with otoliths and semicircular canals. 3) In the neurons of the LVN which reacted to lateral tilting, 67% (16/24) were excited by ipsilateral tilting.
A 20-year-old male had alternating nystagmus and no other abnormal neurological findings. The nystagmus was generally left-beating, and almost jerking. The mean velocity of the slow phase was 65°/second, with the mean frequency was 4.2 Hz. The optokinetic pattern was the inverted type. Caloric responses were brisk. The nystagmus sometimes turned spontaneously into the alternating type. Although the amplitude and frequency of alternating nystagmus was not “crescendo and decrescendo”, the alternating cycle was nearly stable and the average duration of nystagmus in either direction was typical (about 110second). Moreover alternating nystagmus was induced by smooth pursuit eye movement. We considered that alternating nystagmus in this patient was induced by a modification of the vestibulo-ocular reflex caused by smooth pursuit eye movement.
We report the results of questionnaires about daily balance functions in 57 patients with unilateral vestibular loss after surgery for acoustic neurinoma. In many cases, imbalance increased temporarily after operation, but soon returned to almost the preoperative state. Head or body imbalance was most often experienced during sudden head movements as looking back or bending down to pick things up. However, we found no significant correlation between the results of gaze function tests (passive rotation test, high frequency head oscillation test) and the results of questionnaires. We selected the following five factors as fundamental elements related to difficulty of daily actions, 1) modality of movement (active or passive), 2) presence of head movement, 3) vision, 4) transfer of the center of gravity, 5) supporting area of the sole. Theoretically, it is possible to evaluate daily balance functions by examining several representative movements the difficulties of which are decided mostly by one of these factors.
Five patients with vertigo were examined radiologically and neurotologically. Generally a posterior inferior cerebellar artery (PI-CA) branching from the vertebral artery (VA) below the foramen magnum is seldom seen in normal persons. But if a PICA or bypass branches from the VA below the foramen magnum, vertebro-basilar insufficiency may occur due to pressure on the bloodstream from the edge of the foramen magnum, especially during tests in the hanging head position. The diagnosis of vertebro-basilar insufficiency induced by pressure by the edge of foramen magnum was made by vertebral angiography in five cases. Electronystagmography results also presented.
In the majority of cases Wallenberg's syndrome is due to infarction in the are supplied by the posterior inferior cerebellar artery, but rarely other causes can also produce it. We describe a patient with the syndrome caused by glioma of the lateral medulla oblongata, and review the literature of Wallenberg's syndrome associated with neoplastic disease. A 46-year-old man admitted because of progressive dysphagia and vertigo. Neurological examination revealed atypical symptoms and signs of Wallenberg's syndrome on the right side ; hypalgesia of the second and third divisions of the left trigeminal verve, paresis of the right palate and uvula, and ataxia of the right extremities. Although CT showed no abnormality in the posterior fossa, MRI demonstrated a mass with abnormal signal intensities in the right dorsolateral portion of the medulla. Biopsy specimens showed astrocytoma (grade III). From the present case and a review of 10 previously reported cases of Wallenberg's syndrome caused by neoplastic diseases, clinical features are characterized by gradual development and steady progression of symptoms, non-classical or atypical symptomatology, numerous additional symptoms and signs depending on the site and size of the tumor, and a poor prognosis.
Ingestion of alcohol reduces cerbellar control of the vestibulo-ocular reflex (VOR). To investigate compensatory processes after labyrinthine loss, we examined VOR and gaze function before and after alcohol ingestion in 10 patients. A control study was done on 17 normal adults. The subjects were rotated sinusoidally in an electorically driven chair under two conditions : mental arithmatic in the dark and gaze fixation on a target on the wall. Normal adults did not show any significant change in gain after alcohol ingestion in either case. The patients with unilateral labyrinthine loss presented larger differences in the gains between rotation to the intact side and to the affected side after alcohol ingestion. These changes were found in both the alert-in-the dark condition and the spatially-fixed target condition. The present study suggests significant cerebellar control of VOR and gaze function during recovery from unilateral labyrinthine loss.
The course of Meniere's disease was followed in 195 patients (137 with unilateral disease and 58 with bilateral fluctuating hearing loss). (1) In unilateral cases, hearing levels fell in 3 years to an average of 30 dB, followed by annual increases of 10 dB for the next 10 years. Deterioration then usually ceased. In the first involved ear in bilateral cases, hearing levels increased during the first year to an average of 50 dB, followed by a total 20 dB increase over the next 10 years. After this time another rapid deterioration occurred. Second involved ears showed hearing level increases averaging a total of 20 dB over the first 4 years, after which hearing rapidly deteriorated to the level of the first involved ear by the 10th year. (2) Vertigo attacks were most frequent during the first year, then decreased rapidly the second year, followed by more gradual decreases. Unilateral and bilateral cases showed an almost equal incidence of attacks. (3) In unilateral cases, caloric responses of the affected ears decreased steadily to approximately 60% of those of unaffected ears by the end of the second decade. Caloric responses in bilateral cases fell to approximately 50% of normal levels. The rate of reduction in both 1st and 2nd ears was almost the same. (4) The general course of bilateral cases differed from that of unilateral cases, suggesting the possibility of different etiologies and/or pathophysiologies. Accurate early diagnosis is thus of great importance. During our long term study it was found that : (5) Most suspected cases receiving definitive diagnoses showed recurrent vertigo attacks and cochlear symptoms such as hearing difficulty and/or tinnitus at the time of the first examination, though fluctuation was not evident. (6) Positive glycerol tests were generally predictive of later definite Meniere's disease. (7) Repetitive audiometry was useful for the confirmation of definite disease.