Low-Frequency Sensorineural Hearing Loss Associated With Iron-Deficiency Anemia.

Past studies have found an association between cochlear hydrops or early Meniere's disease and acute low-frequency hearing loss (ALHL) without vertigo. However, its mechanism remains unclear in some ALHL cases. This report presents a case of ALHL associated with iron-deficiency anemia (IDA). The patient was a 49-year-old female who had previously been treated with betamethasone for sudden hearing loss in the right ear. Eight months later, the symptoms recurred and cochlear hydrops was diagnosed. Isosorbide and betamethasone were administered orally, and intravenous hydrocortisone tapering was added 1 week later, but these treatments were ineffective. At the same time and subsequently, iron sucrose was intravenously administered for IDA, and the patient's hearing loss gradually resolved within 2 months. In view of the increase in serum hemoglobin levels after iron therapy, this might have been the most effective treatment in this case. The hearing loss could therefore be associated with the patient's IDA.

Efficacy of Yokukansan, a traditional Japanese herbal medicine, in patients with dizziness and irritability.

OBJECTIVE: Irritability is an emotional stress symptom that causes or exacerbates dizziness. Antidepressants may be helpful for some conditions that are accompanied by irritability; however, they do not completely inhibit irritability. Yokukansan (YKS), a traditional Japanese herbal medicine, has been used for neurosis, insomnia, and children's irritability and night crying. The study investigated the efficacy of YKS in nystagmus in patients with chronic dizziness and irritability. METHODS: Twenty-two cases with chronic dizziness and irritability were reviewed retrospectively. The patients were divided into two groups: control patients (0-7 days of treatment) and YKS-treated patients (YKS cases; >7 days of treatment). Dizziness before and during (after, in the controls) YKS treatment was evaluated by scoring the nystagmus intensity on a 5-point scale. The average scores were calculated within a maximum of 6 months before and during or after treatment. The normalized scores were also calculated. The optimal treatment regimen was calculated via receiver operating characteristic (ROC) curve analysis. RESULTS: There were six control cases (1 male, 5 females; mean age: 59.5 years). There were 16 YKS cases (3 males, 13 females; mean age: 61.8 years). While the group mean nystagmus intensity scores significantly decreased from 1.18 to 0.73 in the YKS cases, it did not change in the control cases. The group mean of the normalized nystagmus intensity scores during treatment was 0.73 in the YKS cases. The results of the ROC curve analysis indicated the optimal cut-off period of the YKS treatment was 10 days. CONCLUSION: The oral administration of YKS for more than 10 days was optimal. The treatments with YKS could be a good option for the treatments of vertigo.

Model of optokinetic responses involving two different visual motion processing pathways.

To understand visual motion processing underlying the optokinetic response (OKR), we developed a biomimetic model that reproduces the findings from behavioral experiments. We recorded OKRs induced by drifting gratings with different spatiotemporal frequencies from humans and non-human primates. The characteristics of the initial open-loop responses and the closed-loop eye velocity gains were analyzed using a model developed in this study. The model consists of two pathways with different dynamics. One mediates the transient response (transient pathway) and the other the sustained response (sustained pathway). Each pathway has a different spatiotemporal frequency dependence. Assuming there are different visual sensitivities for these pathways, one tuned to lower spatial and higher temporal frequencies on the retina and the other tuned to stimulus velocity, we successfully reproduced the course of OKRs. Our results suggest that two different neural circuitries/populations contribute to visual processing in the different stages of OKRs.

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS).

Cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS) is a novel ataxic disorder consisting of the triad of cerebellar impairment, bilateral vestibular hypofunction, and a somatosensory deficit. We report the first Japanese case of CANVAS. The patient is a 68-year-old Japanese male. He was referred to our university for further evaluation of progressive gait disturbance and ataxia. He exhibited horizontal gaze-evoked nystagmus and sensory deficit. Nerve conduction studies showed sensory neuronopathy. Magnetic resonance imaging showed the atrophy of vermis but not of the brainstem. The caloric stimulation and video head impulse test (vHIT) showed bilateral vestibulopathy. The visually enhanced vestibulo-ocular reflex (VVOR) was also impaired. In addition to neurological and electrophysiological examinations, simple neuro-otological examinations (i.e., caloric stimulation, vHIT, and VVOR) may reveal more non-Caucasian cases.

End-tidal CO2 relates to seasickness susceptibility: A study in Antarctic voyages.

OBJECTIVE: To investigate the relationship between end-tidal CO2 (EtCO2) and seasickness (motion sickness at sea) during an Antarctic voyage. METHODS: In this study, we measured EtCO2 and severity of seasickness using the subjective symptoms of motion sickness (SSMS). We sampled EtCO2 and SSMS every 3-4h for 3 days from the date of sail in 16 healthy subjects. This experiment was performed on an icebreaker (standard displacement: 12,650t). RESULTS: Since 2 subjects dropped out because of severe motion sickness, available data were collected from 14 subjects. On analysis of all data of all subjects grouped together, there seemed to be a significant negative correlation between EtCO2 and SSMS (R=-0.27, P=0.0005). However, in individual subjects, this correlation was not obvious. During the voyage, EtCO2 level in the seasickness susceptible group was lower than that in the non-susceptible group (P=0.018). Both EtCO2 increasing in the non-susceptible group and decreasing in the susceptible group contribute to the difference in EtCO2 levels. We suggest that the cause of this increase in EtCO2 level in the non-susceptible group was unwitting slow and deep breathing to resist seasickness. CONCLUSION: We revealed that for seasickness during an Antarctic voyage, EtCO2 level relates to susceptibility, but not occurrence or severity. Measurement of EtCO2 levels may be useful to identify seasickness-susceptible persons and to efficiently prevent seasickness.

Opioid-Induced Nausea Involves a Vestibular Problem Preventable by Head-Rest.

BACKGROUND AND AIMS: Opioids are indispensable for pain treatment but may cause serious nausea and vomiting. The mechanism leading to these complications is not clear. We investigated whether an opioid effect on the vestibular system resulting in corrupt head motion sensation is causative and, consequently, whether head-rest prevents nausea. METHODS: Thirty-six healthy men (26.6 ± 4.3 years) received an opioid remifentanil infusion (45 min, 0.15 µg/kg/min). Outcome measures were the vestibulo-ocular reflex (VOR) gain determined by video-head-impulse-testing, and nausea. The first experiment (n = 10) assessed outcome measures at rest and after a series of five 1-Hz forward and backward head-trunk movements during one-time remifentanil administration. The second experiment (n = 10) determined outcome measures on two days in a controlled crossover design: (1) without movement and (2) with a series of five 1-Hz forward and backward head-trunk bends 30 min after remifentanil start. Nausea was psychophysically quantified (scale from 0 to 10). The third controlled crossover experiment (n = 16) assessed nausea (1) without movement and (2) with head movement; isolated head movements consisting of the three axes of rotation (pitch, roll, yaw) were imposed 20 times at a frequency of 1 Hz in a random, unpredictable order of each of the three axes. All movements were applied manually, passively with amplitudes of about ± 45 degrees. RESULTS: The VOR gain decreased during remifentanil administration (p<0.001), averaging 0.92 ± 0.05 (mean ± standard deviation) before, 0.60 ± 0.12 with, and 0.91 ± 0.05 after infusion. The average half-life of VOR recovery was 5.3 ± 2.4 min. 32/36 subjects had no nausea at rest (nausea scale 0.00/0.00 median/interquartile range). Head-trunk and isolated head movement triggered nausea in 64% (p<0.01) with no difference between head-trunk and isolated head movements (nausea scale 4.00/7.25 and 1.00/4.5, respectively). CONCLUSIONS: Remifentanil reversibly decreases VOR gain at a half-life reflecting the drug's pharmacokinetics. We suggest that the decrease in VOR gain leads to a perceptual mismatch of multisensory input with the applied head movement, which results in nausea, and that, consequently, vigorous head movements should be avoided to prevent opioid-induced nausea.

Periodic alternating nystagmus during caloric stimulation.

Periodic alternating nystagmus (PAN) is a form of horizontal jerk nystagmus characterized by periodic reversals in direction. We report a case who exhibited transient PAN induced by caloric stimulation. The patient was a 75-year-old male. He had experienced floating sensation in January 2010. Eight months later, he was referred to our university hospital. Gaze nystagmus and positional tests revealed no nystagmus. Only weak right-beating horizontal nystagmus was observed during left Dix-Hallpike maneuver. Electronystagmography showed normal saccadic and smooth pursuit eye movements. The optokinetic nystagmus pattern test was also bilaterally normal. However, during the caloric stimulation to the right ear, at 166 s from the start of irrigation, the direction of nystagmus alternated from leftward to rightward, and thereafter this reversal of direction repeated 15 times. Magnetic resonance imaging showed no significant lesion except for chronic ischemia in the brain. The patient probably had some kind of latent lesion of impaired velocity storage and exhibited transient PAN induced by caloric stimulation. Caloric stimulation is useful and simple examination to disclose latent eye movement disorders of which velocity storage mechanism is impaired.

Middle ear malformations in identical twins.

The majority of the congenital anomalies of middle ear are solitary and a non-hereditary. We report cases of identical twins with congenital incudo-stapedial disconnection. Case 1 was an 8-year-old girl. Hearing impairment was identified at the age of three. She was referred to our university hospital in April 2005. Pure-tone audiogram showed conductive hearing impairments. Computed tomography (CT) revealed the incudo-stapedial disconnections in both ears. The exploratory tympanotomies on the right and left ears were performed in May and July 2005, respectively. The surgical findings showed absence of the long process and presence of the lenticular process of the incus in both ears. After the reconstructions of ossicular chain, the hearing of both ears improved. Case 2 was an 11-year-old girl. The hearing impairment of the right ear was identified in May 2008. She was referred to our university hospital three months later. Pure-tone audiogram showed the conductive hearing impairment in the right ear. CT revealed the incudo-stapedial disconnection in the right ear. The surgery showed the same findings as those of case 1. Anomalies of both cases suggest that the lenticular process of the incus and the stapes originate from a common primordium.

A case report of HTLV-I associated myelopathy presenting with cerebellar ataxia and nystagmus.

HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) is characterized by spastic paraparesis in the lower extremities, and urinary disturbance. HAM/TSP has also been less frequently associated with cerebellar syndromes and nystagmus. We report a case of HAM/TSP presenting with cerebellar ataxia and nystagmus. The patient was a 73-year-old woman who was born in southern Japan. At age 41, she developed pain and spasticity in the bilateral lower limbs and gradually progressive gait disturbance. At age 57, she was diagnosed with HAM/TSP based on spastic paraparesis in the lower limbs, urinary disturbance and positive anti HTLV-I antibody in serum and cerebrospinal fluid. In June 2008, she was referred to our university and hospitalized for rehabilitation. Twenty days later, she experienced rotatory vertigo sensation. Magnetic resonance imaging revealed pontocerebellar atrophy. The patient presented with cerebellar signs in the upper limbs, gaze-evoked nystagmus in the sitting position and right-beating horizontal nystagmus in the supine and head-hanging positions. Electronystagmography (ENG) showed horizontal saccadic overshoot dysmetria and horizontal saccadic pursuit. Nystagmus is rare among the literature on HAM/TSP. ENG is helpful to evaluate and confirm the cerebellar syndromes of HAM/TSP.

[Congenital ossicular malformation: a study of 27 ears].

Despite otological surgical progress improving clinical congenital ossicular malformation management, some cases remain inadequately treated. We report 27 cases of congenital ossicular malformation, focusing on reasons for remaining or delayed postoperative hearing loss evaluated in 27 congenital ossicular malformation cases in Kyoto Prefecture from 2002 to 2008. Overall success was 93% (25/27) 6 months postoperatively. Two ears had no hearing improvement and three delayed hearing loss 8 to 48 months postoperatively. The first two ears underwent small fenestration stapedotomy with malleus attachment piston, and the other three tympanoplasty type III using an autologous ossicle or total ossicular replacement prosthesis (TORP) as a columella. We discuss problems and solutions using a malleus attachment piston or prosthesis, preoperative audio-and radiological findings, and operative findings including facial nerve anomaly and congenital cholesteatoma.

Angioedema: 6 years experience with fourteen cases.

OBJECTIVE: To study the difference in the findings between the causes of angioedema and the characteristics of angioedema induced by angiotensin receptor II blockers (ARBs), and to investigate whether laboratory examinations for acute phase inflammatory markers can aid in diagnosis and predict airway risk. METHODS: We retrospectively reviewed fourteen cases of patients with angioedema that were treated from 2000 to 2006. Data were collected regarding age, sex, location of the edema, cause, time course of resolution and laboratory examinations (leukocyte counts, serum C-reactive protein (CRP) level, complement function and the activity of C1 esterase inhibitor). RESULTS: The causes of angioedema were ACEIs in six patients (42.9%), candesartan (ARB) in three (21.4%), HAE (types 1 and 2) in two, and unknown in three. Of these patients, 71.4% exhibited edema in the floor of the mouth, irrespective of the cause. Two patients with edema induced by candesartan exhibited both lingual and laryngeal edemas. The remaining one with candesartan-induced edema exhibited edema in the neck and mediastinum and pleural effusion. The average time to resolution was 4.1 days, ranging from one to twelve days. The edema in eleven patients resolved with conservative therapy, while three patients underwent tracheotomy. In two patients with candesartan-induced edema, although the edemas resolved completely after cessation of candesartan administration, the edemas reappeared in the same locations, two and thirty days after the cessation of candesartan for each patient. None of the patients with angioedema induced by ACEIs exhibited elevation of serum CRP levels. No significant differences were found for leukocyte counts and serum CRP levels between patients with angioedemas induced by ACEIs, ARB and those of unknown cause. No significant differences were observed in the above findings between the patients who underwent tracheotomy and those who did not. Two patients exhibited low C4 levels, and one of the two exhibited no activity of C1 esterase inhibitor. CONCLUSION: Consistent with previous reports, angioedema in the floor of the mouth extending to the tongue should be considered as a possible risk factor for airway compromise. Laboratory examinations for acute phase inflammatory markers are not useful for diagnosis and are not predictive for airway intubation and tracheotomy. Angioedema induced by candesartan can present in anomalous sites and reappear following drug cessation even if the edema has resolved completely.

Low-grade cribriform cystadenocarcinoma of the parotid gland: a case report.

Low-grade cribriform cystadenocarcinoma is a rare tumor that is recognized as a variant of cystadenocarcinoma by the 2005 WHO classification. We report a case of low-grade cribriform cystadenocarcinoma. The patient was a 32-year-old woman who presented with a mass in the right parotid region. Computed tomography and magnetic resonance imaging revealed a polycystic mass in the right parotid gland. The preoperative fine needle aspiration biopsy showed no malignancy, however the frozen section during surgery showed carcinoma. The patient subsequently underwent total parotidectomy with preservation of the facial nerve. Microscopically, the tumor had a typical feature of intraductal proliferation. There was a golden brown pigment and PAS-positive/diastase-resistant cytoplasmic granules in the epithelium of the cysts. Immunohistochemically, smooth muscle actin highlighted the cells rimming the cystic spaces. The tumor cells were negative for S-100 protein. The patient has no recurrence and no facial palsy after the treatment.

The effects of prolonged viewing of motion on short-latency ocular following responses.

The adaptive effects of prolonged viewing of conditioning motion on ocular following responses (OFRs) elicited by brief test motion of a random-dot pattern were studied in humans. We found that the OFRs were significantly reduced when the directions of the conditioning and test motions were the same. The effect of conditioning motion was still observed when the speeds of the conditioning and test motions did not match. The effect was larger when the conditioning duration was longer, and decayed over time with increased temporal separation between the conditioning and test periods. These results are consistent with the characteristics of motion adaptation on the initial smooth pursuit responses. We also obtained data suggesting that the persistence of the effect depends on visual stimulation in the time between the conditioning and test periods, and that the presence of a stationary visual stimulus facilitates recovery from the motion adaptation.

Case report: two cases of hearing impairment due to intracranial hypotension.

We report two cases of spontaneous intracranial hypotension (SIH) that presented with orthostatic hearing impairment. Pure tone audiometry in case 1 and distortion-produced otoacoustic emissions (DPOAEs) in case 2 clearly revealed orthostatic low-frequency hearing impairment. The symptoms resolved with conservative therapy in case 1, but they did not resolve completely after three treatments with epidural blood patch in case 2. The orthostatic changes at low-frequency that were present in both examinations indicated a relative endolymphatic hydrops due to SIH. Both otological examinations were useful to infer the pathophysiology of hearing impairment associated with SIH.

Preparatory gain modulation of visuomotor transmission for smooth pursuit eye movements in monkeys.

It has been reported that the visuomotor processing underlying the initiation of smooth pursuit eye movement is modulated in relation to the recent experience of eye movements: the initial pursuit eye velocity is larger after experiencing repeated pursuits than saccades. To assess which parameters of the previously executed pursuits play an essential role in modulating the gain of visuomotor transmission, we recorded the ocular responses of monkeys to a brief perturbing motion of the tracking target injected before the start of the eye movements. First, we compared the perturbation responses among the blocks in which the duration of executing pursuit was varied. We found that the response amplitude increased with the increase of the pursuit duration and it reached a plateau level at 100-200 ms of the duration. Second, a comparison of the perturbation responses in the blocks in which target velocity was different showed a gradual increase of the response as a function of the required pursuit velocity. Third, when the animals repeatedly performed pursuits, the response amplitude gradually increased with increasing interval between the appearance of the target and the onset of perturbation. On the other hand, such an increase was not observed when the animals repeatedly performed saccades. These results suggest that before initiating eye movements, the pursuit system modulates the gain of visuomotor transmission so as to be closely related to the properties of the repeatedly experienced eye movements and this gain modulation is triggered by the target's appearance.

The effects of preceding moving stimuli on the initial part of smooth pursuit eye movement.

We examined whether there are any adaptive effects on the pursuit initiation after a prolonged exposure to moving visual stimuli. The eye movements of six human subjects were recorded with the scleral search-coil technique or a Dual Purkinje Image Eye-tracker system. A random-dot image appeared on a CRT monitor and moved coherently in one direction (rightward or leftward) at 10 deg/s for 4 s, while the subject fixated on a stationary target (conditioning stimulus). The screen was blanked for 0.2 s, and then the target stepped to the right or left of the center and moved 10 deg/s leftward or rightward. We measured change in the eye position over the open-loop period of the pursuit initiation. When the pursuit target moved in the same direction as the preceding visual stimulus, a significant reduction in the initial tracking responses (55.9% decrease on average) was found. We then studied in detail the properties of the motion adaptation in pursuit initiation by varying the visual conditions systematically and obtained the following findings. When the subjects tracked the target that moved at 10 deg/s, the pursuit initiation was affected not only by the conditioning stimulus of the same speed as the target, but also by those of different speeds. Further, the conditioning stimulus moving at 10 deg/s affected the pursuit initiation not only when the target moved with the same speed but also when it moved at different speeds (more remarkable for slower speeds). The effect of conditioning stimuli on the pursuit initiation was larger when the duration of the conditioning period was longer. The effect of conditioning stimuli decayed as the duration of the blank period became longer. The findings from the present study are consistent with the properties of neurons in the middle temporal area of monkeys.

The visual motion detectors underlying ocular following responses in monkeys.

Psychophysical evidence indicates that visual motion can be sensed by low-level (energy-based) and high-level (feature-based) mechanisms. The present experiments were undertaken to determine which of these mechanisms mediates the initial ocular following response (OFR) that can be elicited at ultra-short latencies by sudden motion of large-field images. We used the methodology of Sheliga, Chen, Fitzgibbon, and Miles (Initial ocular following in humans: A response to first-order motion energy. Vision Research, 2005a), who studied the initial OFRs of humans, to study the initial OFRs of monkeys. Accordingly, we applied horizontal motion to: (1) vertical square-wave gratings lacking the fundamental ("missing fundamental stimulus") and (2) vertical grating patterns consisting of the sum of two sinusoids of frequency 3f and 4f, which created a repeating pattern with beat frequency, f. Both visual stimuli share a critical property: when subject to 1/4-wavelength steps, their overall pattern (feature) shifts in the direction of the steps, whereas their major Fourier component shifts in the reverse direction (because of spatial aliasing). We found that the initial OFRs of monkeys to these stimuli, like those of humans, were always in the opposite direction to the 1/4-wavelength shifts, i.e., in the direction of the major Fourier component, consistent with detection by (low-level) oriented spatio-temporal filters as in the well-known energy model of motion analysis. Our data indicate that the motion detectors mediating the initial OFR have quantitatively similar properties in monkeys and humans, suggesting that monkeys provide a good animal model for the human OFR.