Spinocerebellar degeneration (SCD) is a progressive ataxia disease that can affect the spine, the cerebellum, the nervous system and the muscles. Recently, many of the dominantly inherited ataxias have been renamed Spinocerebellar Ataxia or SCA. The SCAs are usually followed by a number which indicates that the ataxia is caused by a specific genetic defect. New subtypes are found each year based on ongoing genetic studies. We now distinguish more than 60 SCA subtypes. In general, the main features of the clinical presentation of the patient with SCA are family history suggestive of autosomal-dominant traits, adult onset, mostly between 30-50 years, cerebellar ataxia with signs and symptoms of extra-cerebellar involvement in the majorities of cases, slow progression resulting in progressive impairment and variable phenotypes within one family. The patients frequently reveal unsteadiness of gait associated with nystagmus. Brainstem and cerebellar lesions affect physiological eye movements, e.g., saccade, smooth pursuit and VOR suppression. For this, some of them visit the otolaryngologist at their first hospital visit. To distinguish the SCA diseases from other peripheral vestibular disorder, it is necessary for otolaryngologists to understand the characteristics of the SCA diseases.
I investigated the effectiveness of the immediate caloric test for acute vertigo cases. I was able to diagnose 21 (29.5%) cases of vestibular neuronitis immediately by performing a caloric test in 71 acute vertigo cases. I confirmed that as an effect of the steroid dosage on vestibular neuritis, the maximum slow phase velocity of the nystagmus significantly improved after the steroid dosage from the second week, and the obstacles to everyday life due to the vertigo using DHI (Dizziness Handicap Inventory) significantly improved from the fourth week. I made the first medical examination within 30 days from the onset and, for vestibular neuronitis cases in which treatment was started, the effect of the steroid treatment was significantly seen in all cases. I diagnosed vestibular neuronitis by performing a caloric test for the acute vertigo cases immediately, and starting treatment promptly was believed to be required.
To maintain an upright standing posture, voluntary control is indispensable together with regulation by the postural reflexes and cooperative movements controlled by the cerebellum and basal ganglia. We developed a new method for frequency analysis of the sway of the center of gravity in a standing posture (i.e. peak-area frequency spectrum analysis) and previously reported on the properties of the spectrum related to the posture regulation mechanism. In this study, we attempted to examine the characteristics of voluntary control using this method. The experimental conditions and the results are as follows. A Natural quiet standing. The subjects comprised 8 healthy adults ranging in age from 25 to 57. The spectrum showed power-law distribution of different slopes (value of scaling exponent) in the low frequency band (0.01～1Hz) and the high frequency band (1～5Hz). The difference in the slope shows that the system which acts on postural control is different in both bands. Based on previous studies, it is conceivable that sway in the low frequency depends on the regulation of the visual and vestibular system, and sway in the high frequency depends on regulation of the spinal proprioceptive system. B Standing straight while actively shaking the body. The subjects comprised 9 healthy adults ranging in age from 22 to 78. 1) The locus of center of gravity of the body (stabilogram) tended to show a circular pattern. 2) The area-frequency spectrum showed that distribution of the low frequency band indicated the same slope as distribution of the high frequency band. In voluntary body sway, regulation by the spinal proprioceptive system plays the leading role even in the low frequency band. 3) In the elderly, the spectrum showed an age-related abnormality. These findings suggest the failure of posture control by the basal ganglia precedes voluntary movement.
Introduction: In positional vertigo, spontaneous reversal of the initial positional nystagmus (the secondary phase nystagmus) is clinically rare without head position changes. We present herein a case of positional vertigo with the secondary phase nystagmus monitored and video-recorded using an infrared CCD camera. Patient: A 65-year-old woman visited our otorhinolaryngological clinic with rotatory positional vertigo. At the initial visit, upbeat-torsional (counterclockwise) nystagmus induced by the head positional test was observed for>70s, with a latency of 2s; furthermore, the reversal of nystagmus was not observed when the head was moved back to the sitting position. Three days later, downbeat-torsional (clockwise) nystagmus induced by the head positional test was observed for 19s with a latency of 3s, and it was followed by reversal of initial positional nystagmus for 75s without head position changes. Conclusion: The duration of positional nystagmus was>70s, and the reversal of nystagmus was not observed when the head was moved back to the sitting position. Therefore, we speculated that positional vertigo presumably involved canalolithiasis within the short-arm of the posterior canal. Further, we speculated that the secondary phase nystagmus was presumably due to the coexistence of long-arm type anterior canalolithiasis and short-arm type posterior canalolithiasis.
The healthy-ear-down 135°maneuver (H-135°M) was devised for the treatment of lateral semicircular canal benign paroxysmal positional vertigo (BPPV) exhibiting paroxysmal geotropic positional nystagmus (geotropic N) and the affected-ear-down 135°maneuver (A-135°M) was devised for the treatment of lateral semicircular canal BPPV exhibiting Persistent apogeotropic positional nystagmus (apogeotropic N). Keeping the head in the healthy-ear-down 135°position could easily force the debris into the utricle. Rolling the head from the affected-ear-down 135°position to the supine position could detach the debris from the canal side of cupula and move it further in the posterior direction. After undergoing one H-135°M, the patients were evaluated with the head roll test the next day. After undergoing one A-135°M, the patients were immediately evaluated with the head roll test. Ninety-five percent (55/58) of patients with geotropic N treated by H-135°M exhibited disappearance of geotropic N, and 5% (3/55) did not. Forty-five patients exhibited complete resolution of nystagmus and 4 patients converted to posterior semicircular canal BPPV. Seventy-one percent (15/21) of patients with apogeotropic N treated with A-135°M converted to geotropic N, and 29% (6/21) did not change. H-135°M and A-135°M had some advantages including easily changing the head and body positions, the treatment could be conducted successively after the head roll test, and treatment could even be performed for patients with cervical spondylosis and obesity. In particular, H-135°M had the advantage of confirming the affected side, as it would have been misdiagnosed if there was vertigo in the healthy-ear-down 135°position. To date, there has been no specific treatment established for apogeotropic N. However, A-135°M can elicit conversion to geotropic N in about 70% of apogeotropic N cases, and H-135°M can bring about good resolution of geotropic N in 95% of geotropic N cases.
Acute vertigo and dizziness are two of the most common symptoms that prompt patient visits to internal medicine practitioners and the emergency room. Most of these patients are diagnosed as having peripheral vertigo. However, central vertigo is identified in some cases that is sometimes life threatening and the diagnoses require careful attention. Although vertigo due to cerebrovascular disorders is usually associated with other neurologic symptoms or signs, small infarcts in the cerebellum or brainstem can present with vertigo without other localizing symptoms. Diagnosis of such isolated vertigo has been increasing with recent developments in clinical neuro-otology and neuroimaging. We recently encountered five patients with central vertigo who were referred to the otolaryngology department as having peripheral vertigo from an internal medicine department and an emergency room. We present on and discuss the clinical manifestations of nystagmus, localization of the lesion based on magnetic resonance imaging (MRI) findings of the brain, and risk factors (hypertension and diabetes, obesity, heart disorder) of these cases.
To evaluate the function of the phase on the vestibulo-ocular reflex (VOR) with sinusoidal rotation tests, we assessed young, healthy volunteers, patients with canal paresis (CP), benign paroxysmal positional vertigo (BPPV), and acoustic neurinomas (ATs). For the control condition, subjects, with their eyes open, were sinusoidally rotated in complete darkness at a frequency of 0.4 and 0.8Hz with a maximum angular velocity of 60°/s for 30 seconds. Sinusoidal tests were performed at earth vertical axis rotation (EVAR) and 30° nose-up, off-vertical axis rotation (OVAR). We observed a significant phase delay at 0.8Hz EVAR on the unilateral CP patients vs controls, and 0.4Hz OVAR on the AT patients vs controls. On BPPV patients, we found a significant phase lead at 0.8Hz OVAR compared to EVAR, which was not observed after recovery of the BPPV: these responses consisted in a reduction of the VOR gain on BPPV. We propose that evaluating the VOR phase is one useful way to understand the vestibular function.
Canalolithiasis and cupulolithiasis are known to be a primary etiology of benign paroxysmal positional vertigo (BPPV). In lateral canal type BPPV (L-BPPV), direction-changing geotropic or apogeotropic nystagmus is present. In many cases, the latency is long in canalolithiasis and short in cupulolithiasis. However, there are a few cases that do not fit in this general notion. Physiological factors, including volume, number, friction and viscosity of the otoconial debris, and velocity of the moving debris may well affect the latency of nystagmus. Horizontal nystagmus induced by an utricular disorder is another potential factor that may contribute to horizontal nystagmus of L-BPPV. The nystagmus pattern in L-BPPV is not simple, but sometimes complex, thus making its diagnosis difficult.
The horizontal canal type of benign paroxysmal positional vertigo (H-BPPV) is the most common cause of direction-changing positional nystagmus. H-BPPV with geotropic positional nystagmus is caused by canalolithiasis in the horizontal semicircular canal (HSCC). When a patient with HSCC canalolithiasis makes a lateral head turn toward the affected ear, the free-floating debris creates an ampullopetal endolymph flow. As a result, a geotropic nystagmus (fast phase toward the ground) is caused. When the patient turns away from the affected side, the free-floating debris creates an ampullofugal flow. The flow ends when the debris reaches its lowest position in the canal and the geotropic nystagmus disappears rapidly. On the other hand, some cases show geotropic positional nystagmus, which is not transient but persistent. Persistent geotropic positional nystagmus is induced by a light cupula. In this study, to classify these types of geotropic positional nystagmus as transient (transient geotropic positional nystagmus, TGPN) or persistent (persistent geotropic positional nystagmus, PGPN), the time constant (TC) of nystagmus was calculated. Geotropic positional nystagmus was recorded by video-oculography and analyzed three-dimensionally. The slow phase eye velocity of nystagmus against time was approximated exponentially and TC was calculated as the reciprocal of the coefficient of time. Instances of geotropic positional nystagmus in patients with H-BPPV were classified as TGPN with a TC of ≤35 sec or PGPN with a TC of >35 sec. In conclusion, we showed that the TC of positional nystagmus is an objective index of TGPN or PGPN and proposed that a TC of ≤35 sec indicates a TGPN while a TC of >35 sec indicates a PGPN.
Direction-changing positional nystagmus caused by a peripheral vestibular lesion (DCPN) can be classified into the geotropic and apogeotropic types, based upon the direction of horizontal nystagmus in the right ear down position and the left ear down position, and also paroxysmal and persistent types based upon the duration of horizontal nystagmus. The incidence of DCPNs was estimated and cases that converted from apogeotropic to geotropic DCPN were reported. During the course of 9 years and 5 months, 230 patients had DCPN. Among these, 90 patients had paroxysmal geotropic DCPN, 90 had persistent apogeotropic DCPN and 50 had persistent geotropic DCPN. In 90 cases with persistent apogeotropic DCPN, 59 cases (66%) converted to paroxysmal geotropic DCPN during the head roll test or after performing the barbecue rotation of 360° towards the healthy side. The pathophysiology was estimated that lateral semicircular canal benign paroxysmal positional vertigo (BPPV) (canalolithiasis, the debris being located in the anterior part of the canal) changed to lateral semicircular canal BPPV (canalolithiasis, the debris being located in the posterior part of the canal). Furthermore, 2 cases of persistent apogeotropic DCPN that converted to persistent geotropic DCPN naturally without physiotherapy were also reported. To compare persistent apogeotropic DCPN and persistent geotropic DCPN in these cases, the directions of nystagmus were completely reversed in the right side down position and in the left side down position, and also reversed in the supine position and in the prone position, changing in the nearly sitting position. It was shown that both types of DCPN were identical with respect to the affected side and pathogenesis, but small differences or changes in the pathophysiology might lead to both types of DCPN. The pathophysiological mechanism(s) underlying persistent apogeotropic DCPN and persistent geotropic DCPN remain unknown.
Lateral semicircular canal benign paroxysmal positional vertigo reveals atypically direction changing positional nystagmus (geotropic and apogeotropic). Furthermore, this condition used to be recognized as the clinical sign of posterior cranial fossa lesions, in particular, lesions of the brainstem and cerebellum. On the other hand, a good number of clinical reports indicate, nowadays, that such positional nystagmus is more likely to be caused by peripheral vestibular lesions and this has become widely well-known. For instance, geotropic direction changing positional nystagmus is caused by canalolithiasis and apogeotropic direction changing nystagmus is associated with cupulolithiasis. Some textbooks argue whether or not such positional nystagmus could represent central nervous system findings and signs, and this still remains controversial. We therefore tried to examine states of nystagmus based on a review of clinical papers and deliberate the clinical significance and diagnostic value of nystagmus. Base on the results of our literature research we were unable to determine whether or not nystagmus findings could suggest central nervous system lesions. We concluded that, notwithstanding direction changing positional nystagmus, the best approach would be to consider each situation again from the beginning, taking the patient's present history in greater detail and performing neurological and neuro-otological examinations on each patient, which could provide the most important information to doctors regarding dizzy patients.