Vertical Nystagmus Research Articles

6572 Acute Adrenal Crisis Secondary To Undiagnosed Addison's Disease

Abstract Disclosure: J.M. Deirmenjian: None. H. Nickowitz: None. T. Kavafyan: None. Addison’s disease, also known as primary adrenal insufficiency, is when the adrenal gland has a defect in making cortisol. Signs and symptoms of Addison’s disease include nausea, vomiting, diarrhea, fatigue, dizziness, hyperpigmentation, and mood changes. Acute Adrenal Crisis can occur as a result of Addison’s disease when patients experience acute physiologic stress such as acute illness. Patient is a 35- year-old woman with a PMHx of iron deficiency anemia presenting with intractable nausea and vomiting for 10 days and a single witnessed syncopal episode two days prior to presentation. She was also had intermittent dizziness. Patient initially presented to urgent care where she was found to be hyponatremic and then was sent to the ED. She had no seizure like activity or rashes prior to admission. On initial physical exam, her skin was warm and dry with skin discoloration and hyperpigmentation. She was awake, alert, and oriented to person, place, time, and situation. Patient had no neurological deficits and no lateral or vertical nystagmus on initial assessment. On admission, patient was hyponatremic to 114 mEq/L, potassium was 5.0 mEq/L, and glucose level was 79 mg/dL. Despite receiving a 500 cc NS bolus, 1L NS bolus, 25 grams of albumin, and D5-0.45 NS at 50 cc/hr, the hyponatremia was difficult to correct. Her sodium initially corrected to 120 mEq/L but the sodium later decreased to 117 mEq/L. The morning after admission, patient became hypotensive and hypoglycemic. Random cortisol was measured and found to be 2.2 mcg/dL, raising concern for acute adrenal crisis as a result of undiagnosed Addison’s Disease. ACTH level was 17 pg/mL. Endocrinology was consulted and she was treated with IV 100 mg Hydrocortisone in addition to IV hydrocortisone 50 mg IV q6h. Patient was able to be transitioned to PO hydrocortisone 15 mg qAM and 5 mg qPM and was started on PO fludrocortisone 0.1 mg daily. On day of discharge, sodium improved to 127 mEq/L. CT Abdomen with contrast was completed to evaluate the adrenal glands and it showed a normal appearance of the adrenal glands. The etiology of the patient’s acute adrenal crisis was secondary to undiagnosed Addison’s Disease. It is interesting to note that patient was not hypoglycemic on admission but later became hypoglycemic during her hospital course. Adrenal crisis is a possible fatal complication of undiagnosed Addison’s disease. Therefore, a possible Addison’s Disease diagnosis is important to consider when patients are presenting with symptoms such as nausea, vomiting, dizziness, and electrolyte derangements including hyponatremia. If patient’s present with hyponatremia, ruling out possible adrenal insufficiency by checking a cortisol level may change the course of patient’s care. After discharge, she was able to establish care with Endocrinology and remain stable on treatment with PO hydrocortisone and PO fludrocortisone. Presentation: 6/3/2024

Retrospective analysis of nystagmus characteristics and clinical applications of positional testing in patients with cupulolithiasis of the posterior semicircular canal in benign paroxysmal positional vertigo.

This study aimed to investigate the characteristics of positional nystagmus in patients with cupulolithiasis of the posterior semicircular canal-benign paroxysmal positional vertigo (PC-BPPV-cu) to improve clinical diagnostic accuracy. This study retrospectively analyzed 128 cases of PC-BPPV-cu and 128 cases of canalolithiasis of BPPV (PC-BPPV-ca). General data, intensity, distribution, and the correlation of positional nystagmus were compared between the two groups. Compared to the PC-BPPV-ca group, more cases from the PC-BPPV-cu group initially presented in the emergency department (P < 0.05). The most frequent positional nystagmus induced by PC-BPPV-cu was torsional-upbeat nystagmus, characterized by the upper pole of the affected eye beating toward the lower ear and vertically upward (387 cases, 59.7%). It was followed by torsional-downbeat nystagmus, characterized by the upper pole of the unaffected eye beating toward the lower ear and vertically downward (164 cases, 25.3%). The former represented posterior canal excitatory nystagmus (PC-EN), while the latter represented posterior canal inhibitory nystagmus (PC-IN). In the PC-BPPV-cu group, PC-EN was most easily caused by the Half Dix-Hallpike (HH) maneuver on the affected side, while PC-IN was most easily induced by a face-down position (FDP) on the unaffected side at approximately 45° angle (45° FDP). The vertical slow phase velocity (v-SPV) of positional nystagmus was more potent in the affected HH than in other positions with PC-EN (all P < 0.05); the v-SPV of positional nystagmus was greater in the 45° FDP than in different positions with PC-IN (all P < 0.05); the v-SPV of the affected Dix-Hallpike (DH) maneuver in the PC-BPPV-ca group was significantly greater than that of the affected HH maneuver in the PC-BPPV-cu group (P < 0.05). The a priori analysis showed that the strongest correlation with HH positional nystagmus was observed in the affected side roll test, followed by the DH maneuver. In the PC-BPPV-cu group, the HH maneuver most easily induced PC-EN on the affected side, and PC-IN was most easily induced by the 45° FDP. In some cases of PC-BPPV-cu, significant nystagmus was not observed to be induced in the DH position on the affected side; however, vertical rotation nystagmus was induced in the roll-test position on the affected side. In such cases, PC-BPPV-cu diagnosis should be considered, and HH and 45° FDP tests should be conducted to support the diagnosis.

Oculopalatal Tremor: A Narrative Review of Pathophysiology, Clinical Presentation, and Management Strategy

Abstract Oculopalatal tremor (OPT) is a complex neurological disorder characterized by acquired oscillatory nystagmus synchronized with tremors of the soft palate and other muscles. The article discusses the pathology, clinical manifestations, and diagnostic methods of OPT. A comprehensive literature search was conducted in PubMed and Google Scholar using keywords and relevant articles were studied and analysis was done. Vertical pendular nystagmus is the hallmark, while other muscles such as the neck, head, larynx, and diaphragm may be affected. The pathophysiology is due to lesions of the Guillain–Mollaret triangle (GMT), which causes hypertrophy of the inferior olivary. Neuroimaging reveals hypertrophy of the inferior olivary medulla, which aids in diagnosis. Drug treatments such as gabapentin and memantine can reduce nystagmus, although the visual quality may not permanently improve. The study explores the complexity of the pathophysiology and clinical presentation of OPT. New treatments that target abnormal neuronal connections with drugs such as quinine or mefloquine are being investigated. The potential of deep brain stimulation (DBS) remains uncertain, with promising aspects but limited efficacy. A synergy of technology and treatment is proposed to advance OPT treatment. Future studies will aim to clarify the nuances of responses to OPT and may include a comparative study of medication and DBS. OPT is mainly caused by a disruption in GMT/dentato-rubro-olivary pathway, presenting with tremor, and nystagmus is diagnosed with magnetic resonance imaging. Gabapentin and memantine have proved to be effective in improving the condition except for visual changes.

A Novel Type of Autosomal Dominant Episodic Nystagmus Segregating with a Variant in the FRMD5 Gene

ABSTRACT To describe the phenotype of a novel form of autosomal dominant episodic nystagmus and to identify the potential genetic aetiology. We identified several individuals in a large Swedish family affected by episodic nystagmus. In total, 39 family members from five generations were invited to participate in the study, of which 17 were included (12 affected and 5 unaffected). The phenotype of the nystagmus was described based on data collected from family members through questionnaires, interviews, clinical examinations and from video recordings of ongoing episodes of nystagmus. Whole genome sequencing (WGS) and further Sanger sequencing for segregation of the identified candidate variants was performed in eight participants (six affected and two unaffected). The 12 affected participants showed a phenotype with episodic nystagmus of early onset. A vertical jerk nystagmus with variable amplitude and frequency was characterized in the analysed video material. No other eye pathology or other disease that could explain the episodic nystagmus was identified among the family participants. Genetic analysis identified a missense variant (p.Ser375Phe) in the gene FRMD5, which segregated with the disease in the eight individuals analysed, from three generations. We describe a novel autosomal dominant form of early onset episodic nystagmus and suggest the FRMD5 gene as a strong candidate gene for this disorder.

Artery Of Percheron Infarction: A Great Mimicker

The thalamus is a deep structure located in the diencephalon, whose arterial blood supply is mainly from four branches of posterior cerebral artery. The artery of percheron (AOP) is an infrequent variation of thalamic perfusion, occlusion of which presents with a heterogenous, atypical list of symptoms without focal signs. This is in contrast to the typical, easily recognizable focal neurology of other ischemic infarcts. Therefore, AOP infarctions may be misdiagnosed, delayed in diagnosis or missed altogether. It is a rare, but vital area of neurology that needs to be studied by clinicians to facilitate an overall care for patients.We report the case of a 59-year-old lady who presented to us with bilateral complete ptosis with bilateral vertical gaze palsy and nystagmus, whose initial NCCT brain was normal. Subsequent MRI showed bilateral thalamic and midbrain ischemic infarctions in the artery of Percheron distribution. Our case highlights the importance of high degree of suspicion, early diagnosis and role of MRI in the diagnosis when initial CT is normal.

CENTRAL VERTIGO DUE TO ISCHEMIC STROKE IN A YOUNG WOMAN: A CASE REPORT

Background: Vertigo is a symptom that patients often complain about. Vertigo is divided into peripheral and central. One of the causes of central vertigo is ischemic stroke. Ischemic stroke generally occurs in elderly people, but in recent years there has been an increase cases in young people. In addition, the prevalence of stroke is more common in men than women, but recently there has been an increase cases in women. Case summary: A 25-year-old woman presented with sudden vertigo. Physical examination revealed obesity, bidirectional horizontal and vertical nystagmus, left hemiparesis, and hemihypesthesia. Head CT scan showed lacunar infarction in the right basal ganglia and periventricular. The patient was given antiplatelet and vertigo management. Conclusion: Vertigo should be differentiated between peripheral or central vertigo at the emergency department, as it will determine further management. Stroke can occur in young women. Therefore, it is important for clinicians to think about the diagnosis of stroke in patients with vertigo that occur in young women.

Feasibility of video-based real-time nystagmus tracking: a lightweight deep learning model approach using ocular object segmentation.

Eye movement tests remain significantly underutilized in emergency departments and primary healthcare units, despite their superior diagnostic sensitivity compared to neuroimaging modalities for the differential diagnosis of acute vertigo. This underutilization may be attributed to a potential lack of awareness regarding these tests and the absence of appropriate tools for detecting nystagmus. This study aimed to develop a nystagmus measurement algorithm using a lightweight deep-learning model that recognizes the ocular regions. The deep learning model was used to segment the eye regions, detect blinking, and determine the pupil center. The model was trained using images extracted from video clips of a clinical battery of eye movement tests and synthesized images reproducing real eye movement scenarios using virtual reality. Each eye image was annotated with segmentation masks of the sclera, iris, and pupil, with gaze vectors of the pupil center for eye tracking. We conducted a comprehensive evaluation of model performance and its execution speeds in comparison to various alternative models using metrics that are suitable for the tasks. The mean Intersection over Union values of the segmentation model ranged from 0.90 to 0.97 for different classes (sclera, iris, and pupil) across types of images (synthetic vs. real-world images). Additionally, the mean absolute error for eye tracking was 0.595 for real-world data and the F1 score for blink detection was ≥ 0.95, which indicates our model is performing at a very high level of accuracy. Execution speed was also the most rapid for ocular object segmentation under the same hardware condition as compared to alternative models. The prediction for horizontal and vertical nystagmus in real eye movement video revealed high accuracy with a strong correlation between the observed and predicted values (r = 0.9949 for horizontal and r = 0.9950 for vertical; both p < 0.05). The potential of our model, which can automatically segment ocular regions and track nystagmus in real time from eye movement videos, holds significant promise for emergency settings or remote intervention within the field of neurotology.

Chiari I Malformation Presenting Vertical Gaze-Evoked Nystagmus : A Case Report

Abstract&#x0D; Introduction : Chiari malformation is characterized by herniation of posterior cerebellar vermis in which type 1 malformation has coexisting syringomyelia of cervicothoracic spinal cord. This malformation can be congenital or acquired, in which gaze-evoked nystagmus is the typical movement deficit. This case aimed to report a case of vertical gaze-evoked nystagmus as a primary symptom to detect Type I Chiari Malformation.&#x0D; Case Illustration : A 44-year-old woman presented with involuntary movements of both eyes in the last 5 months with vision problems in which objects appear to jump or vibrate. Visual acuity was 20/50 in both eyes with 12 prism diopters BI exotropia. We recognized vertical and torsional nystagmus in upgaze without any movement in primary gaze. While performing supraduction, the oscillation was detected and increased. Brain MRI revealed Type I Chiari Malformation.&#x0D; Discussion : Nystagmus was seen in many diseases of the central nervous system, in particular those affecting the brainstem and cerebellum. Vertical gaze evoked nystagmus was a disorder of the gaze holding function, purely vertical gaze-evoked nystagmus is observed in midbrain lesions involving the interstitial nucleus of Cajal (INC) as the neural integrator for vertical gaze-holding function. Based on this pathophysiology, the Brain MRI of this patient revealed some degrees of compression in midbrain, and cervico medullary junction due to her brain malformation.&#x0D; Conclusion : A sustained gaze-evoked nystagmus is an important ocular finding that may indicate serious neurologic pathology. It is important for an eye care provider to thoroughly examine additional tests to determine the underlying cause of the nystagmus.

Investigation on biomechanical responses in bilateral semicircular canals and nystagmus in vestibulo-ocular reflex experiments under different forward-leaning angles.

Different head positions affect the responses of the vestibular semicircular canals (SCCs) to angular movement. Specific head positions can relieve vestibular disorders caused by excessive stimulating SCCs. In this study, we quantitatively explored responses of human SCCs using numerical simulations of fluid-structure interaction and vestibulo-ocular reflex (VOR) experiments under different forward-leaning angles of the head, including 0°, 10°, 20°, 30°, 40°, 50°, and 60°. It was found that the horizontal nystagmus slow-phase velocity and corresponding biomechanical responses of the cupula in horizontal SCC increased with the forward-leaning angles of the head, reached a maximum when the head was tilted 30° forward, and then gradually decreased. However, no obvious vertical or torsional nystagmus was observed in the VOR experiments. In the numerical model of bilateral SCCs, the biomechanical responses of the cupula in the left anterior SCC and the right anterior SCC showed the same trends; they decreased with the forward-leaning angles, reached a minimum at a 40° forward tilt of the head, and then gradually increased. Similarly, the biomechanical responses of the cupula in the left posterior SCC and in the right posterior SCC followed a same trend, decreasing with the forward-leaning angles, reaching a minimum at a 30° forward tilt of the head, and then gradually increasing. Additionally, the biomechanical responses of the cupula in both the anterior and posterior SCCs consistently remained lower than those observed in the horizontal SCCs across all measured head positions. The occurrence of these numerical results was attributed to the consistent maintenance of mutual symmetry in the bilateral SCCs with respect to the mid-sagittal plane containing the axis of rotation. This symmetry affected the distribution of endolymph pressure, resulting in biomechanical responses of the cupula in each pair of symmetrical SCCs exhibiting same tendencies under different forward-leaning angles of the head. These results provided a reliable numerical basis for future research to relieve vestibular diseases induced by spatial orientation of SCCs.

The First 100 Children Treated in a Newly Established Pediatric Vertigo Center.

Correctly diagnosing dizziness in children is essential for appropriate management; nevertheless, healthcare professionals face challenges due to children's limited ability to describe their symptoms and their cooperation during physical examination. The objective of this study is to describe the first 100 patients seen at a newly established pediatric vertigo center. This is a retrospective review of a consecutive series of 100 patients seen at our pediatric vertigo clinic in a tertiary referral center from August 2019 until June 2022. Comprehensive clinical data were collected. The diagnoses were established by 2 pediatric otolaryngologists based on validated diagnostic criteria. Trends in diagnosis, investigation, and treatment of these patients were analyzed. A total of 100 children were included in the study. Vestibular migraine was the most common diagnosis (20%) followed by benign paroxysmal vertigo of childhood (14%). Eleven patients had combined pathologies. Fifteen out of 70 children (21%) had abnormal audiograms, 30 out of 48 children (62.5%) had abnormal vestibular testing, and 6 out of 31 (19%) patients had abnormal imaging. Fifty-one children received medical treatment, 23 received vestibular physiotherapy, and 9 patients had particle repositioning maneuvers; moreover, 17 of these patients received multimodal treatment. Our analysis suggests that imaging and audiology testing have relatively low yield in the assessment of pediatric vertigo. On the other hand, vestibular testing detected a high proportion of abnormalities, such as saccadic pursuit, vertical nystagmus, central positional nystagmus, and abnormal directional preponderance, particularly associated with vestibular migraine. Given the complexity of diagnosing vertigo in children, it is critical to establish multidisciplinary specialized centers capable of providing accurate diagnosis and treatment for these children.

Quantifying Induced Nystagmus Using a Smartphone Eye Tracking Application (EyePhone).

There are ≈5 million annual dizziness visits to US emergency departments, of which vestibular strokes account for over 250 000. The head impulse, nystagmus, and test of skew eye examination can accurately distinguish vestibular strokes from peripheral dizziness. However, the eye-movement signs are subtle, and lack of familiarity and difficulty with recognition of abnormal eye movements are significant barriers to widespread emergency department use. To break this barrier, we sought to assess the accuracy of EyePhone, our smartphone eye-tracking application, for quantifying nystagmus. We prospectively enrolled healthy volunteers and recorded the velocity of induced nystagmus using a smartphone eye-tracking application (EyePhone) and then compared the results with video oculography (VOG). Following a calibration protocol, the participants viewed optokinetic stimuli with incremental velocities (2-12 degrees/s) in 4 directions. We extracted slow phase velocities from EyePhone data in each direction and compared them with the corresponding slow phase velocities obtained by the VOG. Furthermore, we calculated the area under the receiver operating characteristic curve for nystagmus detection by EyePhone. We enrolled 10 volunteers (90% men) with an average age of 30.2±6 years. EyePhone-recorded slow phase velocities highly correlated with the VOG recordings (r=0.98 for horizontal and r=0.94 for vertical). The calibration significantly increased the slope of linear regression for horizontal and vertical slow phase velocities. Evaluating the EyePhone's performance using VOG data with a 2 degrees/s threshold showed an area under the receiver operating characteristic curve of 0.87 for horizontal and vertical nystagmus detection. We demonstrated that EyePhone could accurately detect and quantify optokinetic nystagmus, similar to the VOG goggles.

Bow and Lean Test for Rare Variants of Vertical Semicircular Canal BPPV.

The objective of this study was to assess the clinical significance of the Bow and Lean Test (BLT) for the diagnosis of different variants of vertical canal Benign Paroxysmal Positional Vertigo (BPPV). BLT is commonly used for diagnoses of lateral semicircular canal (LSC) BPPV. However, vertical nystagmus in the BLT may indicate the presence of other variants such as PSC-BPPV. 567 patients with vertical canal BPPV were recruited. Patients with anterior semicircular canal (ASC) or PSC-BPPV were weekly examined until the negativization of BPPV. Nystagmus characteristics during BLT were analyzed. Of 567 patients with vertical canal BPPV, 1.4% had ASC-BPPV. BLT was positive in 155 patients, showing patterns like down-beating nystagmus in bowing and no nystagmus in leaning (15.52% of patients), and down-beating in bowing and up-beating in leaning (6.17%), which was predominantly present in PSC-canalolithiasis. Statistically significant differences were observed in the direction of nystagmus provoked by BLT in PSC-BPPV subtypes. No significant differences were found in nystagmus latency or duration during BLT positions. Among BPPV subtypes, there was a significant difference in nystagmus duration and latency, especially between cupulolithiasis and other variants. BLT's sensitivity was 0.93 in bowing and 1 in a leaning position, while specificity was 0.93 and 0.82 respectively. Beyond the LSC, the BLT has expanded to other variants. However, study results differ likely due to variations in patient characteristics and test execution. Currently, no specific features for ASC have been found to differentiate it from PSC-BPPV limiting the test's use for this variant. 3, according to Oxford Center for Evidence-Based Medicine Laryngoscope, 134:2405-2410, 2024.

Acute isolated vertigo with vertical up-beating nystagmus: A rare case of nucleus intercalatus of Staderini ischemia

The role of intercalatus nucleus of Staderini (INS), the most caudal of the perihypoglossal nuclei, is much debated. Last research seems to suggest that this nucleus plays a role as a vertical eyes movements integrator. The few clinical reports present in the literature that describe isolated lesions of the INS have described patients presenting in acute with up-beating vertical spontaneous nystagmus. Isolated acute lesion of INS is, in fact, much rare, and, without other neurological signs, is exceptional. We present a case of acute isolated vertigo with no other neurological signs or symptoms, due to INS ischemia provoked by vertebral artery stenosis. The patient presented with spontaneous vertical up-beating nystagmus that showed at videonystagmographic recording, a clear exponential decay of angular slow-phase velocity, that is considered a typical sign of neural integrator impairment. This case seems to represent a further confirm that INS is part, as a vertical-to-position neural integrator, of the neural circuit controlling the vertical eyes movements.

Monoclonal Antibodies Targeting CGRP: A Novel Treatment in Vestibular Migraine.

Background. Monoclonal antibodies (mAbs) directed against the calcitonin gene-related peptide (CGRP) or its receptor represented the first targeted and specialized approach to migraine prophylaxis. Nevertheless, they have been rarely considered in the treatment of vestibular migraine (VM). Our aim was to evaluate the effectiveness of anti-CGRP mAbs in VM patients who did not respond to conventional migraine treatments. Methods. Consecutive VM patients treated with erenumab were considered. As a comparison, we considered the same VM patients during conventional migraine treatments (i.e., propranolol, flunarizine, or valproic acid), which were tried before mAbs therapy. Videonystagmography, the Italian version of the Dizziness Handicap Inventory (DHI) questionnaire, and migraine days over the last 3 months were evaluated in all patients before and after treatments. Results. In the present retrospective study, we included 21 female and 2 male VM patients, mean age 45.2 years. All patients underwent contrast-enhanced magnetic resonance imaging that ruled out other causes of vertigo. The DHI questionnaire significantly improved after mAb therapy (p < 0.0001). Mean migraine days over the last 3 months were significantly reduced after treatment (p = 0.001). Videonystagmography was altered in 11 (48%) patients prior to monoclonal antibodies. We found vertical positional nystagmus in 9 patients and horizontal positional nystagmus in 2 patients. After the treatment, we found vertical positional nystagmus only in 1 patient (p = 0.002). When patients were treated with conventional therapies, there was no significant reduction in DHI, and instrumental vestibular examinations remained altered. Conclusions. VM patients using anti-CGRP mAbs experienced a reduction in the dizziness-derived handicap, as reported in the DHI questionnaire. Furthermore, these treatments were significantly associated with a normalization of vestibular instrumental analysis. These findings were not seen with conventional treatments. Treatment with anti-CGRP mAbs may be effective in VM patients who did not respond to conventional migraine treatments. These findings should be tested in large, randomized clinical trials.

Nystagmus Based Screening System for Vestibular Schwannoma in Patients With Asymmetric Hearing Loss

Background and Objectives We conducted this study to propose a nystagmus based screening system (NBSS) for detecting vestibular schwannoma (VS) in patients with asymmetric sensorineural hearing loss (ASNHL).Subjects and Method Data of 90 patients diagnosed with VS were retrospectively analysed. For the 1:1 allocation, 90 ASNHL patients who were not diagnosed with VS were sequentially enrolled as the non-VS group and retrospectively analysed. Every participant received pure tone audiometry (PTA), a bedside vestibular function test, and magnetic resonance imaging. A total of 122 patients who passed the exclusion criteria were selected for the study.Results The sensitivity and specificity of the abnormal criteria of auditory brainstem response (ABR) for the detection of VS in patients (n=70) showing analyzable wave response were 80.0% and 52.0%, respectively. However, when we included all of the patients (n=122) who did not show analyzable wave response in ABR, the sensitivity and specificity of the abnormal criteria decreased to 34.8% and 68.4%, respectively. NBSS is composed of vertical spontaneous nystagmus, direction changing gaze evoked nystagmus, ipsilesional monophasic type head shaking nystagmus (HSN), and ipsilesional to contralesional biphasic type HSN. The sensitivity and specificity of the NBSS were 56.5% and 82.9%, respectively.Conclusion NBSS may be used as a supplementary test to ABR in detecting VS of ASNHL.

Unilateral Pendular Nystagmus in Multiple Sclerosis: A Case Series.

Acquired pendular nystagmus is most often seen in patients with demyelinating disease. Although it is often bilateral, rare cases may be monocular. There is paucity of data on the spectrum of clinical presentation, underlying mechanism, and response to treatment in patients with monocular pendular nystagmus. Retrospective case series of patients with monocular pendular nystagmus seen in 2 tertiary neuro-ophthalmology clinics between January 2019 and June 2022. All patients underwent a complete neuro-ophthalmological assessment and MRI. We describe 5 patients (3 women) aged 31-49 with monocular pendular nystagmus. All had a diagnosis of multiple sclerosis. Three patients had horizontal and 2 had vertical pendular nystagmus. The Snellen visual acuity in the eye with pendular nystagmus varied from 20/20 to 20/200. Two patients were asymptomatic and 3 suffered visually debilitating oscillopsia. Treatment response was available for 2 patients, both of which responded well to treatment with memantine. The pendular nystagmus was observed in the eye with worse visual acuity in 4 of 5 cases (80%). Three patients had bilateral pontine lesions, and 2 had unilateral pontine lesion ipsilateral to the side of nystagmus. Monocular pendular nystagmus in adults is seen most often in patients with multiple sclerosis. Asymmetry in brainstem lesions and afferent visual input may be the culprit. Treatment with memantine may result in significant improvement in symptomatic patients.

Analysis of spontaneous nystagmus and the frequency characteristics of affected semicircular canals in patients with vestibular neuritis

Objective: To investigate the spontaneous nystagmus (SN) and the frequency characteristics of affected semicircular canals in patients with vestibular neuritis (VN). Methods: This is a cross-sectional study. A total of 61 patients with VN admitted to the Department of Neurology of Shanxi Bethune Hospital from June 2020 to October 2021, 39 were male and 22 were female, with a mean age of (46±13) years old and male to female ratio of 1.77∶1. According to SN characteristics, 61 patients were divided into non-nystagmus group(nSN), horizontal nystagmus group(hSN) and horizontal-torsional nystagmus group (htSN). Clinical data were collected, and SN, unilateral weakness (UW), directional preponderance (DP), and video head impulse test (vHIT) gain were used as observation indicators. Statistical analysis by SPSS23.0 software. Normal distributed quantitative data (age, semicircular canal gain, SN intensity) were expressed by x¯±s, non-normal distributed quantitative data (disease course, UW, DP) were expressed by M(Q1,Q3), qualitative data were expressed by rate and composition ratio, difference analysis by one-way ANOVA, rank sum test, Chi-square test or Fisher's exact probability method, considered by P value<0.05. Results: (1)The disease course of nSN, hSN and htSN was 7.0 (4.0, 12.5), 6.0 (3.5, 11.5), and 3.0 (2.0, 6.5) days respectively, and there were statistical differences (χ2=7.31,P=0.026).(2)The horizontal nystagmus intensity of htSN was (16.8±8.6)°/s, which was significantly higher than that of (9.8±4.7)°/s in hSN (t=3.71, P<0.001). There was no significant difference in the positive rate of UW between the three groups (P=0.690), and there was a significant difference in the positive rate of DP in the three groups (χ2=12.23, P=0.002). The horizontal nystagmor intensity in the htSN was positively correlated with the vertical nystagmus intensity (r=0.59, P=0.001).(3)The gain of the affected horizontal canal of the three groups was statistically different (F=8.28, P=0.001), and the gain of the horizontal canal of hSN and htSN was significantly lower than that of nSN (t=2.74, P=0.008; t=4.05, P<0.001); The gain of the affected anterior canal in the three groups was statistically different (F=5.32, P=0.008). The gain of the anterior canal in both nSN and hSN was significantly higher than that in htSN (t=3.09, P=0.003; t=2.15, P=0.036). The horizontal canal gain of htSN is positively correlated with the anterior canal gain (r=0.74, P<0.001).(4)The affected semicircular canals in the two groups with no-vertical-component nystagmus (nSN and hSN) and the htSN were counted. The composition ratio of the affected semicircular canals in the two groups was different (χ2=8.34, P=0.015). Conclusion: The occurrence of SN in patients with VN is related to many factors, such as the disease course, low and high frequencies, and the severity of the condition in the affected semicircular canal.

Wernicke encephalopathy after sleeve gastrectomy

The article describes the case of a patient with Wernicke encephalopathy, which developed 3 months after the sleeve gastrectomy. An MRI of the brain was performed to verify the diagnosis, which revealed a symmetrical non-uniform increase in the MR signal on T2-WI and Tirm from the medial part of the thalamus, mastoid bodies and gray matter around the aqueduct of Sylvius. Thiamine infusion was promptly initiated as therapy. During treatment, acute neurological symptoms almost regressed, the patient was discharged in a satisfactory condition with preservation of vertical nystagmus under the supervision of specialists at the place of residence. Wernicke–Korsakoff syndrome more often occurs as a complication of alcoholism and arising from thiamine deficiency. However, the fact that this condition also occurs under the influence of other etiopathogenetic factors is often ignored by clinicians. In the management of patients after bariatric interventions, this condition is much more common in malabsorptive operations. However, a combination of certain factors can be described in patients after restrictive types of bariatric surgeries.

A neurodevelopmental disorder caused by a dysfunctional CACNA1A allele.

P/Q-type Ca2+ flux into nerve terminals via CaV2.1 channels is essential for neurotransmitter release at neuromuscular junctions and nearly all central synapses. Mutations in CACNA1A, the gene encoding CaV2.1, cause a spectrum of pediatric neurological disorders. We have identified a patient harboring an autosomal-dominant de novo frameshift-causing nucleotide duplication in CACNA1A (c.5018dupG). The duplicated guanine precipitated 43 residues of altered amino acid sequence beginning with a glutamine to serine substitution in CaV2.1 at position 1674 ending with a premature stop codon (CaV2.1 p.Gln1674Serfs*43). The patient presented with episodic downbeat vertical nystagmus, hypotonia, ataxia, developmental delay and febrile seizures. In patch-clamp experiments, no Ba2+ current was observed in tsA-201 cells expressing CaV2.1 p.Gln1674Serfs*43 with β4 and α2δ-1 auxiliary subunits. The ablation of divalent flux in response to depolarization was likely attributable to the inability of CaV2.1 p.Gln1674Serfs*43 to form a complete channel pore. Our results suggest that the pathology resulting from this frameshift-inducing nucleotide duplication is a consequence of an effective haploinsufficiency.

The Case Files

The Case Files