Four patients with a cerebrovascular disease characterized by palato-ocular myoclonus (POM) were compared with two patients with dentatorubropalli-doluysian atrophy (DRPLA) exhibiting dysfunction of the dentate nucleus of the cerebellum and the cerebellofugal pathway, a part of Guillain-Mollaret's Triangle. A clinical comparison revealed significant imformation. 1) PMO was noted in patients with lesions probably involving the tractus tegmentaris centralis and nucleus olivaris inferior. 2) In these four patients, the frequency of POM was 2.0 to 4.0Hz. 3) Intention or action myoclonus was pronounced in patients with lesions of the cerebellofugal pathway (tractus dentatorubralis), but typical POM was not noted. 4) In lateralized disease, palatal myoclonus (PM) was directed to the most affected hemisphere. In patients with a symmetric disturbance, a vertically directed upward traction was noted. 5) In those patients with a right-left difference in PM, horizontal nystagmus mixed with ROM was directed to the side ipsilateral to the pronounced traction of the palate. 6) In one patient with vertical pendular oscillation due to pontine disturbance (accompanied by a bilateral PPRF disturbance), PM was noted only if there was concomitant presence of disease of the tractus tegmentaris centralis. 7) When other myoclonus was also noted with pendular oscillation, the term ROM is recommended. When myoclonus dose not accompany this sign, the term of acquired pendular nystagmus (APN) or acquired pendular oscillation (APO) is recommended. 8) A vague statement has been made regarding the appearance of POM in the presence of a disturbance of Guillain-Mollaret's Triangle. However, although rhythmic myoclonus limited to the palate may appear with some lesions, myoclonus may be limited to the eyeballs (APN) in association with other lesions. In addition, both types of myoclonus may coexist. 9) The oral administration of Clonazepam was effective in the treatment of APN.
We report a case of divergence nystagmus recorded by ENG, review the literature and discuss the probable etiology. A 72-year-old male had had cardiac arrhythmia for several years. He complained of blurred vision and unsteady gait after an episode suggestive of cerebrovascular disorder. CT scan revealed a small low density area in his brain-stem. The neurological examination was normal except for eye movements. Neuro-otological examination showed divergence nystagmus on primary eye position, horizontal gaze nystagmus on both sides, direction changing positional nystagmus to the nasal side, no abnormality of saccadic or smooth pursuit eye movements, slightly reduced optokinetic response and normal caloric response with normal visual suppression. There were no abnormal findings on audiological examination. Divergence nystagmus is a very rate phenomenon in clinical practice. We could find only 6 case reports, some of which cannot be considered thorough by studied. There has been no general agreement on the responsible lesion or mechanism. In our case, CT of the brain revealed a small low density area in the pons, but we cannot immediatedly conclude that the focus of divergence nystagmus is in the pons. Recent studies, however, suggestthat not only a convergence but also a divergence center exists in the tegmental area of the mid-brain.
Congenital nystagmus in itself is not a disease which causes vertigo. However, 31 of 64 patients who visited our department with congenital nystagmus during the past 12 years had vertigo. The peculiarities of the vertigo in these patients were examined by neurological and neurootological examinations, and orthostatic dysregulation was evaluated in 15 patients with congenital nystagmus and vertigo. 1) Twelve patients had orthostatic dysregulation, which was evaluated by either criteria of O.D. or the Schellong test. 2) Basilar artery stenosis was found in one patient examined by cerebral angiography. 3) Irregular spike and wave complexes were recorded in one patient's electroencephalogram after megibal activation. 4) One patient had canal paresis. The diagnoses related to vertigo in the 15 patients with congenital nystagmus were : orthostatic dysregulation in nine, circulatory disturbance of the labyrinth in two, Meniere's disease in one, cerebrovascular insufficiency in one, sequelae of head injury in one, and autonomic seizures in one. Of the 15 patients, 13 had some autonomic disturbance. The results suggest that autonomic failure is associated with disturbance of the pursuit eye movement system in some cases of congenital nystagmus.
Stabilometry has recently become recognized as a useful way to evaluate human standing ability. However, the clinical evaluation of each parameter and its normal range in different age groups have not yet been determined. The test, which was recommended by the Japan Equilibrium Research Association in 1983, was applied to 300 normal subjects in this study. Each subject was asked to stand in Romberg's posture on a force plate for one minute with eyes open and for one minute with eyes closed. The mean values, their standard deviations and the upper limits of the normal ranges of total length of movement of the center of gravity, sway area and maximum width of lateral and antero-posterior body sway, were obtained in male and female subjects of different ages. It was statistically confirmed that the mean values in those over 60 years of age were larger than the values in younger groups. The frequency analysis of body sway showed a tendency towards increased amplitude in the frequency range less than 2Hz and decreased amplitude in the frequency range between 5 and 10Hz in the older group.
Fukuda's stepping test was modified and made more sensitive to detect latent imbalance of labyrinthine function. The subject was asked to shake his head 7 times at one hertz in about 90 degrees in a horizontal plane and to step in the same position with both arms stretched straight before him. This test was applied to 12 patients whose vestibular function as tested by Romberg, Mann and Fukuda's method had become normal after an attack of vertigo due to unilateral vestibular paralysis. All these patients showed deviation and a tendency to fall to the affected side.
A 67-year-old woman noticed tremor of her hand and jerking of her eyeballs on May 20, 1986, and then became unable to stand. The cerebrospinal changes and Magnetic Response Imaging (MRI) findings were compatible with encephalitis. She was treated with decadron, and the tremor and ocular oscillations gradually decreased. The abnormal ocular movements which were recorded by electro-oculography (EOG) on June 24, revealed frequent, irregular, rapid, multidirectional conjugate ocular oscillations (so-called opsoclonus) with the eye open or closed. These ocular oscillations were suppressed with Frenzel's spectacles. Gradually, the vertical components of the opsoclonus decreased. On June 26, in addition to the opsoclonus, pendullar oscillation consisting of approximately equal amplitude (so-called flutter-like oscillations) developed. The small ocular oscillations similar to flutter like oscillation were recorded by EOG and a fine intension tremor was still present after recovery. The latency of the saccade was prolonged by interruption of the abnormal ocular movements. It seems that the opsoclonus and flutter-like oscillation in this patient represented tremor of the eyeballs caused by a disorder of the burst cells in the brain stem saccadic control system in addition to a disturbance of the cerebellar dentate nuclear system.
Transient deviations of closed eyes during head turning were compared with those during head tilting, horizontal linear acceleration of the body and trunk rotation with the head fixed. During head tilting, no deviations occurred in 52.5%, but small deviations (11.1°±4.1°) could be seen in 30% which appeared to be different from those seen during head rotation. Horizontal linear acceleration did not show any deviations in 75%, and trunk rotation with head fixed could not elicit them in 54.2%. These results indicate that these ocular deviations with eyes closed during head turning are not elicited by otolith input and/or only by cervical torsion, but by the sensation of the direction of head rotation from specific cervical proprioceptors, which are considered to be most sensitive in head rotation.
We report here a rare case of vertical nystagmus, dysarthria and broad-based gait due to after-effects of lithium intoxication. A 65-year-old man was admitted with dysarthria and gait disturbance. About 14 years ago, he had begun treatment with lithium carbonate for manic psychosis. Ten years ago, he developed dysarthria and a broad-based gait due to lithium intoxication. Neuro-otological examination demonstrated, downbeat nystagmus in the primary position, rebound nystagmus and direction changingopposing vertical positioning nystagmus. Failure of fixation-suppression of caloric nystagmus was noted in both sides. Eye-tracking test revealed saccadic eye movements, and slow phase OKN velocity was limited billaterally. The equilibrium disturbances observed in this patient's neurological and ENG findings might be attributed to pathological conditions of cerebellar vermis, flocculus and partly brainstem. He was treated with thyroid stimulating hormone (2mg/day) for 18 days. Thereafter, gradually he recovered from some of his neurological symptoms : dysarthria, gait disturbance, rebound nystagmus and direction changing opposing vertical positioning nystagmus. His vertical nystagmus, however, remained unchanged.
Five patients with cerebellar infarction consulted one of us (Otolaryngologist) at an early stage of the disease. Dizziness or gait disturbance was the chief complaint in four of the five. Cerebellar signs were seen in three, but only for a short period. Muscular weakness and unequal tendon reflexes were noted in only two patients and hypesthesia in one. Thus, symptoms were similar to those of patients with inner ear lesions. Neuro-otologic examination revealed bilateral gaze nystagmus in all five patients for one to two weeks. Positional and paroxysmal nystagmus tests showed down beat nystagmus in two patients and apogeotropic direction changing positional nystagmus in two. No hearing disturbance occurred in any of them. Brain CT examination should be performed if any of the above-mentioned signs are present in dizzy patients.
The difference of velocity of the eyes on caloric nystagmus, during which the inward movement of each eye is faster than the outward movement (adducent preponderance), was investigated electronystagmographically. 1) Adducent preponderance was present in both eyes, open or closed. 2) The difference of velocity of each eye was reduced by shortening the distance between the electrode, and as a result, the tendency to adducent preponderance decreased. 3) This difference was not seen in optokinetic nystagmus. 4) In one-eyed patients, adducent preponderance could be seen in the healthy eye, but some potential was also recorded on the anophthalmic side, presumably due to the interfering potential from the healthy eye, and the adducent preponderance was strenghtened. 5) Adducent preponderance with caloric nystagmus could be recognized by photo-electronystagmography without electrodes. The mechanism of adducent preponderance is discussed from the points of view of neuroanatomy and physiology.
Vinpocetine 5mg (Calan® Tab., one tablet) was administered orally three times daily to 42 patients with vertigo or dizziness as their chief complaint for 4 to 8 weeks and the clinical efficacy of the drug was investigated. At the same time, the influence of the drug on vertebral arterial blood flow and common carotid arterial blood flow was tested by the ultrasonic doppler method. 1. The clinical efficacy based on subjective symptoms and objective findings was excellent in 28.6%, good in 31.0%, fair in 16.6%, and poor in 23.8%. The efficacy rate (fair to excellent) was as high as 76.2%. 2. Clinical efficacy tended to be higher in patients over 50 years old than in younger patients. 3. In patients showing a decrease or right-left difference in vertebral arterial blood flow before administration, the efficacy rate was low, i.e. 52.4%, as compared with 100% in the normal blood flow group. 4. In 19 patients in whom the vertebral arterial blood flow could be determined before and after administration, the drug caused a significant increase in blood flow. On the other hand, no change in blood flow was found in the common carotid arteries. 5. In patients with a vertebral arterial blood flow of 0.8ml/s or less prior to administration, the treatment was invariably ineffective. The efficacy rate was higher in those showing no laterality after administration than in those with laterality. 6. One patient who was followed for a long time showed progressive improvement in clinical symptoms as the vertebral arterial blood flow improved. 7. No adverse reaction was observed, nor was there any change in blood pressure or pulse rate.