Multimodal Ophthalmic Imaging in Spinocerebellar Ataxia Type 7.

The aim of this case series and narrative literature review is to highlight the importance of multimodal imaging in the ophthalmological examination of patients with spinocerebellar ataxia type 7 and provide a summary of the most relevant imaging techniques. Three patients with SCA7 were included in this case series. A literature review revealed twenty-one publications regarding ocular manifestations of SCA7, and the most relevant aspects are summarized. The role of different imaging techniques in the follow-up of SCA7 patients is analyzed, including color vision testing, corneal endothelial topography, color fundus photography (CFP) and autofluorescence, near infrared reflectance imaging, spectral domain optical coherence tomography (SDOCT), visual field examination, and electrophysiological tests. SDOCT provides a rapid and non-invasive imaging evaluation of disease progression over time. Additional examination including NIR imaging can provide further information on photoreceptor alteration and subtle disruption of the RPE, which are not evident with CFP at an early stage. Electrophysiological tests provide essential results on the state of cone and rod dystrophy, which could be paramount in guiding future genetic therapies. Multimodal imaging is a valuable addition to comprehensive ophthalmological examination in the diagnosis and management of patients with SCA7.

Examination under anesthesia: Preferred Practice.

Pediatric ocular examinations are often a challenge in the outpatient setting due to limited cooperation of the child. Hence an evaluation under anesthesia (EUA) or sedation is important for a holistic ophthalmic examination. It can be combined with short procedures, such as suture removal and corneal scrappings, both for diagnosis and for the management of several ophthalmic disorders. It can also be performed before planning a surgical intervention to record the baseline characters and formulate or refine a surgical plan. Every EUA must be used as a chance to perform a complete ophthalmic examination rather than perform a single task such as recording the intraocular pressure. This article aims to provide a protocol that can be followed for a complete EUA.

Serum neurofilament light chain: a novel biomarker for early diabetic sensorimotor polyneuropathy.

AIMS/HYPOTHESIS: No established blood-based biomarker exists to monitor diabetic sensorimotor polyneuropathy (DSPN) and evaluate treatment response. The neurofilament light chain (NFL), a blood biomarker of neuroaxonal damage in several neurodegenerative diseases, represents a potential biomarker for DSPN. We hypothesised that higher serum NFL levels are associated with prevalent DSPN and nerve dysfunction in individuals recently diagnosed with diabetes. METHODS: This cross-sectional study included 423 adults with type 1 and type 2 diabetes and known diabetes duration of less than 1 year from the prospective observational German Diabetes Study cohort. NFL was measured in serum samples of fasting participants in a multiplex approach using proximity extension assay technology. DSPN was assessed by neurological examination, nerve conduction studies and quantitative sensory testing. Associations of serum NFL with DSPN (defined according to the Toronto Consensus criteria) were estimated using Poisson regression, while multivariable linear and quantile regression models were used to assess associations with nerve function measures. In exploratory analyses, other biomarkers in the multiplex panel were also analysed similarly to NFL. RESULTS: DSPN was found in 16% of the study sample. Serum NFL levels increased with age. After adjustment for age, sex, waist circumference, height, HbA1c, known diabetes duration, diabetes type, cholesterol, eGFR, hypertension, CVD, use of lipid-lowering drugs and use of non-steroidal anti-inflammatory drugs, higher serum NFL levels were associated with DSPN (RR [95% CI] per 1-normalised protein expression increase, 1.92 [1.50, 2.45], p<0.0001), slower motor (all p<0.0001) and sensory (all p≤0.03) nerve conduction velocities, lower sural sensory nerve action potential (p=0.0004) and higher thermal detection threshold to warm stimuli (p=0.023 and p=0.004 for hand and foot, respectively). There was no evidence for associations between other neurological biomarkers and DSPN or nerve function measures. CONCLUSIONS/INTERPRETATION: Our findings in individuals recently diagnosed with diabetes provide new evidence associating higher serum NFL levels with DSPN and peripheral nerve dysfunction. The present study advocates NFL as a potential biomarker for DSPN.

Current usage of electrophysiological tests in a secondary referral hospital in Korea.

PURPOSE: To investigate the current status of electrophysiological test use in ophthalmology. METHODS: We analyzed 1057 electrophysiological tests conducted at Kim's Eye Hospital from January 1 to December 31, 2018. The included tests were electroretinogram (full-field, multifocal, and pattern ERG), electrooculogram (EOG), and visual evoked potential (pattern and flash VEP). To investigate the distribution of use of subspecialties, it was divided by subspecialties (retina, glaucoma, oculoplastic surgery, pediatric ophthalmology, neuro-ophthalmology, cornea, and external diseases). RESULTS: The patients were aged 50.6 years on average and included 624 men and 433 women. Among the electrophysiological tests, VEP was the most common, with 567 cases (53.6%), followed by ERG with 311 cases (29.4%) and EOG with 98 cases (9.3%). Regarding the purpose of use, the objective of visual function evaluation was the highest at 56.3%, followed by the differential diagnosis of unknown causes (33.0%) and the confirmation of diagnoses (10.7%). Both VEP and ERG were used the most for visual function evaluation, and mfERG was most used for differential diagnosis of unknown etiology. Electrophysiological tests were most often used in the retina department, but VEPs were used in various fields such as neuro-ophthalmology, glaucoma, and oculoplastics. CONCLUSION: Electrophysiological tests are used to objectively evaluate visual function or discriminate diseases of unknown causes and are used in various departments. Electrophysiology testing is expected to be an additional test to assess visual function.

Electrophysiological and neuroimaging findings in a patient who developed visual loss after attempted suicide by hanging.

PURPOSE: To report the electrophysiological and neuroimaging findings in a patient who developed visual loss after attempted suicide by hanging. METHODS: A 45-year-old male presented with bilateral visual loss and difficulty in walking following a suicide attempt by hanging six months ago. He underwent a complete ophthalmologic examination, posterior segment optical coherence tomography (OCT), various electrophysiological tests and neuroimaging. RESULTS: His bilateral best-corrected visual acuity was logMAR 1.08. Intraocular pressures and ocular examination were normal except for bilateral temporal disk pallor. Macular OCT showed bilateral ganglion cell layer-inner plexiform layer complex thinning. Electroretinogram showed reduced b/a wave amplitude ratio in all the dark- and light-adapted International Society for Clinical Electrophysiology of Vision protocols in both the eyes. Pattern-reversal visually evoked potential (VEP) showed delayed latency of the P100 component in both the eyes. Electrooculography showed a normal light peak-to-dark trough ratio in both the eyes. Magnetic resonance imaging (MRI) brain showed chronic infarct and gliosis in both the occipital lobes. MR angiography showed pruning of P4 segments of both the posterior cerebral artery. Perfusion imaging showed reduction of perfusion in both the parieto-occipital lobes. CONCLUSION: Hanging survivors can develop visual loss after their recovery. The visual loss may be a result of simultaneous ischemic insult to the occipital lobe cortex, optic nerve and retina.

Retinal Ganglion Cells-Diversity of Cell Types and Clinical Relevance.

Retinal ganglion cells (RGCs) are the bridging neurons that connect the retinal input to the visual processing centres within the central nervous system. There is a remarkable diversity of RGCs and the various subtypes have unique morphological features, distinct functions, and characteristic pathways linking the inner retina to the relevant brain areas. A number of psychophysical and electrophysiological tests have been refined to investigate this large and varied population of RGCs. Technological advances, such as high-resolution optical coherence tomography imaging, have provided additional tools to define the pattern of RGC involvement and the chronological sequence of events in both inherited and acquired optic neuropathies. The mechanistic insights gained from these studies, in particular the selective vulnerability and relative resilience of particular RGC subtypes, are of fundamental importance as they are directly relevant to the development of targeted therapies for these invariably progressive blinding diseases. This review provides a comprehensive description of the various types of RGCs, the developments in proposed methods of classification, and the current gaps in our knowledge of how these RGCs are differentially affected depending on the underlying aetiology. The synthesis of the current body of knowledge on the diversity of RGCs and the pathways that are potentially amenable to therapeutic modulation will hopefully lead to much needed effective treatments for patients with optic neuropathies.

Electrophysiological Testing for the Investigation of Bradycardias.

In this article we review the role of electrophysiological testing in patients presenting with bradycardia due to sinus node or atrioventricular node disease. In sinus bradycardia the role of electrophysiology studies is not established. In AV conduction disturbances, an electrophysiology study may be necessary both for the establishment of atrioventricular block as the main cause of symptoms, and for identification of the anatomic site of block that may dictate the potential need of permanent pacing.

Impact of Educational Level on Performance on Auditory Processing Tests.

Research has demonstrated that a higher level of education is associated with better performance on cognitive tests among middle-aged and elderly people. However, the effects of education on auditory processing skills have not yet been evaluated. Previous demonstrations of sensory-cognitive interactions in the aging process indicate the potential importance of this topic. Therefore, the primary purpose of this study was to investigate the performance of middle-aged and elderly people with different levels of formal education on auditory processing tests. A total of 177 adults with no evidence of cognitive, psychological or neurological conditions took part in the research. The participants completed a series of auditory assessments, including dichotic digit, frequency pattern and speech-in-noise tests. A working memory test was also performed to investigate the extent to which auditory processing and cognitive performance were associated. The results demonstrated positive but weak correlations between years of schooling and performance on all of the tests applied. The factor "years of schooling" was also one of the best predictors of frequency pattern and speech-in-noise test performance. Additionally, performance on the working memory, frequency pattern and dichotic digit tests was also correlated, suggesting that the influence of educational level on auditory processing performance might be associated with the cognitive demand of the auditory processing tests rather than auditory sensory aspects itself. Longitudinal research is required to investigate the causal relationship between educational level and auditory processing skills.

Comparison of static wrist splint with static wrist and metacarpophalangeal splint in carpal tunnel syndrome.

BACKGROUND: The position of metacarpophalangeal (MCP) joints may be an important factor affecting the efficacy of splinting in patients with carpal tunnel syndrome (CTS). OBJECTIVE: The aim of the present study was to compare the efficacy of a neutral volar static wrist splint with a neutral volar static wrist and MCP splint in patients with CTS. METHODS: Fifty-four hands were included into the study. A neutral volar static wrist splint was given to the symptomatic hands of the patients in group 1 while a neutral volar static wrist and MCP splint was given to the symptomatic hands of the patients in group 2. Evaluation parameters were Visual Analog Scale for pain severity (VASp), grip strength, pinch strength, electrophysiologic tests and CTS Questionnaire (CTSQ) at baseline and four weeks later. RESULTS: At baseline there was no difference between groups. The intergroup comparison of the improvement showed significant differences in VASp at rest, grip strength, pinch strength and CTSQ functional capacity scores between groups in favor of wrist MCP splint. Although there were significant improvements with regard to sensory amplitude and motor latency in both groups after therapy, the differences between groups were not at the level of significance. CONCLUSIONS: The position of MCP joints seems to be an important factor for the treatment of CTS and should be considered while prescribing a splint to the patients with CTS.

Utilidad de ePEAT en determinar candidatura para implante coclear en pacientes pediátricos con malformaciones de oído interno: comunicación preliminar / Use of ePEAT to determine candidacy for cochlear implant in pediatric patients with inner ear malformations: preliminary communication

En candidatos a implante coclear con malformaciones del oído interno donde se encuentra un nervio coclear anormal, los estudios tradicionales y las imágenes muchas veces no pueden dar respuesta definitiva acerca de la funcionalidad y presencia del nervio coclear. Para esto ayudarían los estudios de electrofisiología. Se presentan tres casos clínicos de pacientes con malformaciones del oído interno que fueron evaluados con ePEAT para ayudar a determinar su candidatura a implante coclear. Los estudios electrofisiológicos no reemplazan a los estudios tradicionales de evaluación auditiva ni a los estudios por imágenes, sino que los complementan. Los casos presentados, demuestran que en casos de malformaciones de oído interno o CAI muy estrecho, en que se cuestiona seriamente la existencia de un nervio coclear funcional, y en casos de neuropatía auditiva, se hace necesario evaluar la función de la cóclea separadamente de la del nervio auditivo y la función del tronco. Para esto se utilizamos los ePEAT. Los ePEAT entregan información valiosísima ya que nos permite conocer las reales capacidades de los pacientes para transmitir un estímulo auditivo hacia el sistema nervioso central, definiendo mejor las expectativas con el uso implante, asistiéndonos en nuestra toma de decisiones.

In cochlear implant candidates with inner ear malformations, where there is an abnormal cochlear nerve, traditional studies and images cannot often provide definitive answers about the functionality and presence of the cochlear nerve. In these cases, electrophysiology studies can be used. We present 3 cases of patients with inner ear malformations who were evaluated with ePEAT to determine their candidacy for a cochlear implant. Electrophysiological studies do not replace traditional hearing screening studies or imaging studies, but complement them. The cases presented in this study demonstrate that in patients with inner ear malformations or very narrow internal auditory canal, where we question the existence of a functional cochlear nerve, and in cases of auditory neuropathy, it is necessary to evaluate the cochlear function separately from the auditory nerve and from the brainstem. In these cases we use ePEAT. ePEAT give us valuable information about the real abilities of patients to transmit an auditory stimulus to the central nervous system, which help us to define expectations with cochlear implant use, assisting us in our decision-making.

Electrophysiologic evaluation of psychogenic movement disorders.

Psychogenic movement disorders (PMD) are a group of disorders which are in the border zone between neurology and psychiatry. All necessary laboratory investigations should be done to rule out an underlying organic disorder. While clinical acumen of a trained movement disorder specialist may be sufficient to diagnose most PMD, there are clinical situations where electrophysiological tests are required either to rule out an organic movement disorder or even diagnose a PMD. Current electrophysiological test are most useful for tremor, followed by jerks and least for spasms or dystonia. Commonly used electrophysiologic tests include multichannel surface electromyography (EMG), accelerometry, electroencephalography time locked with EMG, premovement potential (Bereitschaftspotential), and somatosensory evoked potentials. Psychogenic tremor is a low frequency tremor with variable frequency and duration of EMG bursts, entrainable, has a high coherence with voluntary movements, and presence of coactivation sign. Patients with psychogenic jerks have well organized triphasic pattern of activation of agonist and antagonist muscles. The jerks are associated with EMG bursts of long duration (usually > 70 ms), long and variable latencies in stimulus induced jerks, absence of craniocaudal pattern of muscle recruitment in apparent startle response, and often a Breitschaftspotential (premovement potential) precedes the jerk. Electrophysiological characterization of psychogenic dystonia is difficult and the tests are usually performed to rule out organic dystonia with characteristic findings. Finally, caution should be exerted in interpreting the electrophysiological tests as both false positive and false negative diagnosis of PMD may still occur.