The latest medical research on Neuro Ophthalmology

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about neuro ophthalmology gathered by our medical AI research bot.

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Preoperative and postoperative memory in epilepsy patients with 'gliosis only' versus hippocampal sclerosis: a matched case-control study.

Neurology, Neurosurgery and Psychiatry

Gliosis only (GO) and hippocampal sclerosis (HS) are distinct histopathological entities in mesial temporal lobe epilepsy. This study explores whether this distinction also exists on a functional level when evaluating pre- and postoperative memory.

Using a retrospective matched case-control study design, we analysed verbal and visual memory performance in 49 patients with GO and 49 patients with HS before and one year after elective surgery.

Clinical differences were evident with a later age at seizure onset (18±12 vs 12±9 years) and fewer postoperative seizure-free patients in the GO group (63% vs 82%). Preoperatively, group and individual-level data demonstrated that memory impairments were less frequent, less severe and relatively non-specific in patients with GO compared with HS. Postoperatively, verbal memory declined in both groups, particularly after left-sided resections, with more significant losses in patients with GO. Factoring in floor effects, GO was also associated with more significant visual memory loss, particularly after left resections.

Compared with HS, GO is characterised by (1) a later onset of epilepsy, (2) less pronounced and more non-specific memory impairments before surgery, (3) a less successful surgical outcome and (4) a more significant memory decline after surgery. Overall, our results regarding cognition provide further evidence that GO and HS are distinct clinical entities. Functional integrity of the hippocampus appears higher in GO, as indicated by a better preoperative memory performance and worse memory outcome after surgery. The different risk-benefit ratios should be considered during presurgical patient counselling.

Somatic symptom disorder in patients with post-COVID-19 neurological symptoms: a preliminary report from the somatic study (Somatic Symptom Disorder Triggered by COVID-19).

Neurology, Neurosurgery and Psychiatry

To assess the diagnosis of somatic symptom disorder (SSD) in patients with unexplained neurological symptoms occurring after SARS-CoV-2 infection, also referred to as long COVID.

Patients were contacted for a standardised psychometric evaluation by phone, followed by a self-survey.

Although the patients did not meet the DSM-5 criteria for a functional neurological symptom disorder specifically, SSD diagnosis based on DSM-5 criteria was positive in 32 (64%) patients. In the remaining 18 patients, SSD was considered possible given the high score on diagnostic scales. Physical examination were normal for all. Brain MRI showed unspecific minor white matter hyperintensities in 8/46 patients. Neuropsychological assessment showed exclusively mild impairment of attention in 14 out of 15 tested patients, in discrepancy with their major subjective complaint. Forty-five (90%) patients met criteria for Chronic Fatigue Syndrome. Seventeen (32%) patients were screened positive for mood-anxiety disorders, 19 (38%) had a history of prior SSD and 27 (54%) reported past trauma. Additional self-survey highlighted post-traumatic stress disorder in 12/43 (28%), high levels of alexithymia traits and perfectionism. Long-lasting symptoms had a major impact with a high rate of insomnia (29/43, 67%), psychiatric follow-up (28/50, 56%) and work or pay loss (25/50, 50%).

A majority of patients with unexplained long-lasting neurological symptoms after mild COVID met diagnostic criteria for SSD and may require specific management.


Exploring the phenotype of Italian patients with ALS with intermediate ATXN2 polyQ repeats.

Neurology, Neurosurgery and Psychiatry

To detect the clinical characteristics of patients with amyotrophic lateral sclerosis (ALS) carrying an intermediate ATXN2 polyQ number of repeats in a large population-based series of Italian patients with ALS.

The study population includes 1330 patients with ALS identified through the Piemonte and Valle d'Aosta Register for ALS, diagnosed between 2007 and 2019 and not carrying C9orf72, SOD1, TARDBP and FUS mutations. Controls were 1274 age, sex and geographically matched Italian subjects, identified through patients' general practitioners.

We found 42 cases and 4 controls with≥31 polyQ repeats, corresponding to an estimated OR of 10.4 (95% CI 3.3 to 29.0). Patients with≥31 polyQ repeats (ATXN2+) compared with those without repeat expansion (ATXN2-) had more frequently a spinal onset (p=0.05), a shorter diagnostic delay (p=0.004), a faster rate of ALSFRS-R progression (p=0.004) and King's progression (p=0.004), and comorbid frontotemporal dementia (7 (28.0%) vs 121 (13.4%), p=0.037). ATXN2+ patients had a 1-year shorter survival (ATXN2+ patients 1.82 years, 95% CI 1.08 to 2.51; ATXN2- 2.84 years, 95% CI 1.67 to 5.58, p=0.0001). ATXN2 polyQ intermediate repeats was independently related to a worse outcome in Cox multivariable analysis (p=0.006).

In our population-based cohort, ATXN2+ patients with ALS have a distinctive phenotype, characterised by a more rapid disease course and a shorter survival. In addition, ATXN2+ patients have a more severe impairment of cognitive functions. These findings have relevant implications on clinical practice, including the possibility of refining the individual prognostic prediction and improving the design of ALS clinical trials, in particular as regards as those targeted explicitly to ATXN2.

Risk of stroke in multiple sclerosis and neuromyelitis optic spectrum disorder: a Nationwide cohort study in South Korea.

Neurology, Neurosurgery and Psychiatry

People with multiple sclerosis (MS) are more likely to develop stroke than those without. However, little is known about the association between neuromyelitis optica spectrum disorder (NMOSD) and the risk of stroke. We aimed to estimate the risk of stroke in patients with MS and NMOSD in South Korea.

Data from the Korean National Health Insurance between January 2010 and December 2017 were analysed. A total of 1541/1687 adult patients with MS/NMOSD, who were free of stroke were included. Matched controls were selected based on age, sex and the presence of hypertension, diabetes mellitus and dyslipidaemia.

The risk of developing stroke was 2.78 times higher (adjusted HR (aHR), 95% CI 1.91 to 4.05) in patients with MS compared with controls matched by age, sex, hypertension, diabetes mellitus and dyslipidaemia. The risk of stroke in NMOSD was also higher than that in matched controls (aHR=1.69, 95% CI 1.10 to 2.61) and not statistically different from that of MS (p=0.216). The patients with MS had a higher risk for either of ischaemic or haemorrhagic stroke (HR=2.63 and 2.93, respectively), whereas those with NMOSD had a higher risk for ischaemic stroke (HR=1.60) with marginal statistical significance.

The risk of stroke is increased in patients with MS and NMOSD and seemed comparable between the two conditions. This is the first study that estimates the risk of stroke in patients with MS and NMOSD within the same population.

Prevalence of young-onset dementia: nationwide analysis of routinely collected data.

Neurology, Neurosurgery and Psychiatry

Young-onset dementia prevalence is understudied internationally. Previous studies have been limited by low case numbers, reliance on single sources of routinely collected health data for case identification and inclusion of a limited age range. Our objective was to determine the 1-year period prevalence of diagnosed dementia in people aged 0-64 in the entire New Zealand population using routinely collected health data.

A population-based descriptive study was carried out in New Zealand (population 4.8 million) using routinely collected deidentified health data from 2016 to 2020. Dementia cases in seven linked health datasets in the New Zealand Integrated Data Infrastructure were identified using diagnostic codes and/or use of antidementia medication. Prevalence for each of the four study years was calculated by age, sex and ethnicity.

From a total population of 4 027 332-4 169 754 individuals aged 0-64, we identified 3396-3474 cases of 'all-cause' dementia in each of the study years (prevalence crude range: 83-84/100 000 people aged 0-64; 139-141/100 000 people aged 30-64 years; 204-207/100 000 people aged 45-64 years). Age-standardised prevalence was higher in males than females. Age-standardised and sex-standardised prevalence was higher in Māori and Pacific People than European and Asian.

By using a large study population and multiple national health datasets, we have minimised selection bias and estimated the national prevalence of diagnosed young-onset dementia with precision. Young-onset dementia prevalence for the total New Zealand population was similar to reported global prevalence, validating previous estimates. Prevalence differed by ethnicity, which has important implications for service planning.

Ipsilateral and axial tremor response to focused ultrasound thalamotomy for essential tremor: clinical outcomes and probabilistic mapping.

Neurology, Neurosurgery and Psychiatry

NCT01932463, NCT01827904, and NCT02252380.

To investigate the effects of MRgFUS in patients with ET with an emphasis on ipsilateral-hand and axial tremor subscores.

Tremor scores and adverse effects of 100 patients treated between 2012 and 2018 were assessed at 1 week, 3, 12, and 24 months. A subgroup analysis of ipsilateral-hand tremor responders (defined as patients with ≥30% improvement at any time point) and non-responders was performed. Correlations and predictive factors for improvement were analysed. Weighted probabilistic maps of improvement were generated.

Significant improvement in axial, contralateral-hand and total tremor scores was observed at all study visits from baseline (p<0.0001). There was no significant improvement in ipsilateral subscores. A subset of patients (n=20) exhibited group-level ipsilateral-hand improvement that remained significant through all follow-ups (p<0.001). Multivariate regression analysis revealed that higher baseline scores predict better improvement in ipsilateral-hand and axial tremor. Probabilistic maps demonstrated that the lesion hotspot for axial improvement was situated more medially than that for contralateral improvement.

MRgFUS significantly improved axial, contralateral-hand and total tremor scores. In a subset of patients, a consistent group-level treatment effect was observed for ipsilateral-hand tremor. While ipsilateral improvement seemed to be less directly related to lesion location, a spatial relationship between lesion location and axial and contralateral improvement was observed that proved consistent with the somatotopic organisation of the ventral intermediate nucleus.

Relationship between motor cortical and peripheral axonal hyperexcitability in amyotrophic lateral sclerosis.

Neurology, Neurosurgery and Psychiatry

Previous studies have shown that patients with amyotrophic lateral sclerosis (ALS) have hyperexcitability in both the motor cortex and peripheral motor axons, but the relationship between central and peripheral excitability has not been fully disclosed.

Threshold tracking transcranial magnetic stimulation (TMS) and motor nerve excitability testing were prospectively performed in 53 patients with ALS and 50 healthy subjects, and their relations to compound muscle action potential (CMAP) amplitude and revised ALS Functional Rating Scale were cross-sectionally analysed.

Compared with controls, patients with ALS showed both cortical and peripheral hyperexcitability; TMS showed reduced short-interval intracortical inhibition (interstimulus interval 1-7 ms) (p<0.001) and shortened silent period (p<0.05), and median nerve excitability testing revealed greater changes in depolarising threshold electrotonus (TEd) and greater superexcitability (p<0.0001, both), suggesting reduced axonal potassium currents. Significant correlations between cortical and peripheral excitability indices were not found. Greater changes in TEd (90-100 ms) (R=-0.33, p=0.03) and superexcitability (R=0.36, p=0.01) were associated with smaller amplitude of CMAP, whereas cortical excitability indices had no correlation with CMAP amplitude. More rapid motor functional decline was associated with only greater TEd (90-100 ms) (β=0.46, p=0.001).

Our results suggest that in ALS, cortical excitability is continuously high regardless of the extent of the peripheral burden, but peripheral hyperexcitability is associated with the extent of the peripheral burden and disease evolution speed. Alterations of ion channel function may play an important role in ALS pathophysiology.

CSF levels of SNAP-25 are increased early in Creutzfeldt-Jakob and Alzheimer's disease.

Neurology, Neurosurgery and Psychiatry

Synaptosomal-associated protein 25 (SNAP-25) in cerebrospinal fluid (CSF) is an emerging synaptic biomarker for the early diagnosis of Alzheimer's disease (AD). However, comprehensive studies investigating the marker in Creutzfeldt-Jakob disease (CJD) and in the differential diagnosis of neurodegenerative diseases are still lacking.

We developed a novel, sensitive ELISA for the measurement of SNAP-25 in CSF. In total, we analysed 316 patients from 6 diagnostic groups comprising patients with AD (n=96), CJD (n=55), Parkinson's disease spectrum (n=41), frontotemporal lobar degeneration (n=25) and amyotrophic lateral sclerosis (n=24) and non-neurodegenerative control patients (n=75). Using receiver operating characteristic curve analysis, we analysed the differential diagnostic potential and compared the results with core AD biomarkers.

SNAP-25 CSF concentrations were elevated in AD and CJD (p<0.0001) but not in the other neurodegenerative diseases. Increased levels were observed already at early AD and CJD stages (p<0.0001). In CJD, SNAP-25 levels correlated negatively with survival time (r=-0.33 (95% CI -0.57 to -0.04, p=0.02). For the discrimination of AD from all other diseases except CJD, we observed a good diagnostic performance for CSF SNAP-25 (area under the curve (AUC) 0.85) which was further improved by applying the ratio with CSF amyloid-β 1-42 (AUC 0.95). For CJD, we could demonstrate a strong differential diagnostic potential against all other groups including AD (AUC 0.97).

Using the novel established CSF SNAP-25 ELISA, we here demonstrate the applicability of SNAP-25 as an early synaptic biomarker for both AD and CJD with a possible prognostic value in patients with CJD.

Comorbidity of long COVID and psychiatric disorders after a hospitalisation for COVID-19: a cross-sectional study.

Neurology, Neurosurgery and Psychiatry

Long COVID is a major public health issue. Whether long COVID is comorbid with psychiatric disorders remains unclear. Here, we investigate the association between long COVID, psychiatric symptoms and psychiatric disorders.

Eight long COVID complaints were investigated: fatigue, respiratory and cognitive complaints, muscle weakness, pain, headache, paraesthesia and anosmia. The number of complaints, the presence/absence of each COVID-19 complaint as well as lung CT scan abnormalities and objective cognitive impairment) were considered. Self-reported psychiatric symptoms were assessed with questionnaires. Experienced psychiatrists assessed Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition-based diagnoses of psychiatric disorders.

One hundred and fifteen (65%) patients had at least one long COVID complaint. The number of long COVID complaints was associated with psychiatric symptoms. The number of long COVID complaints was higher in patients with psychiatric disorders (mean (m) (SD)=2.47 (1.30), p<0.05), new-onset psychiatric disorders (m (SD)=2.41 (1.32), p<0.05) and significant suicide risk (m (SD)=2.67 (1.32), p<0.05) than in patients without any psychiatric disorder (m (SD)=1.43 (1.48)). Respiratory complaints were associated with a higher risk of psychiatric disorder and new-onset psychiatric disorder, and cognitive complaints were associated with a higher risk of psychiatric disorder.

Long COVID is associated with psychiatric disorders, new-onset psychiatric disorders and suicide risk. Psychiatric disorders and suicide risk should be systematically assessed in patients with long COVID.

Younger age at multiple sclerosis onset is associated with worse outcomes at age 50.

Neurology, Neurosurgery and Psychiatry

Older age at multiple sclerosis (MS) onset has been associated with worse 10-year outcomes. However, disease duration often exceeds 10 years and age-related comorbidities may also contribute to disability. We investigated patients with>10 years disease duration to determine how age at MS onset is associated with clinical, MRI and occupational outcomes at age 50.

We included patients enrolled in the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women's Hospital with disease duration>10 years. Outcomes at age 50 included the Expanded Disability Status Scale (EDSS), development of secondary-progressive multiple sclerosis (SPMS), brain T2-lesion volume (T2LV) and brain parenchymal fraction (BPF), and occupational status. We assessed how onset age was independently associated with each outcome when adjusting for the date of visit closest to age 50, sex, time to first treatment, number of treatments by age 50 and exposure to high-efficacy treatments by age 50.

We included 661 patients with median onset at 31.4 years. The outcomes at age 50 were worse the younger first symptoms developed: for every 5 years earlier, the EDSS was 0.22 points worse (95% CI: 0.04 to 0.40; p=0.015), odds of SPMS 1.33 times higher (95% CI: 1.08 to 1.64; p=0.008), T2LV 1.86 mL higher (95% CI: 1.02 to 2.70; p<0.001), BPF 0.97% worse (95% CI: 0.52 to 1.42; p<0.001) and odds of unemployment from MS 1.24 times higher (95% CI: 1.01 to 1.53; p=0.037).

All outcomes at age 50 were worse in patients with younger age at onset. Decisions to provide high-efficacy treatments should consider younger age at onset, equating to a longer expected disease duration, as a poor prognostic factor.

Three-Year Outcomes of Under-flap Stromal Bed CXL for Early Post-LASIK Ectasia.

Refractive Surgery

To investigate the 36-month clinical outcomes of under-flap stromal bed CXL (ufCXL) and report on its ability to stabilize post-laser in situ keratomileusis (LASIK) ectasia.

This case series included 20 eyes with diagnosed early post-LASIK ectasia treated with ufCXL. Inclusion criteria were early, mild post-LASIK ectasia, defined as new-onset postoperative manifest refraction cylinder of 1.50 diopters (D) or less, with new topographic inferior steepening consistent with ectasia, uncorrected distance visual acuity of 20/40 or better, and corrected distance visual acuity of 20/25 or better. The existing LASIK flap was lifted, 0.25% isotonic riboflavin was applied directly to the stromal bed, the flap was repositioned, and 18 mW/cm2 ultraviolet light was applied for 5 minutes to the corneal flap surface. Post-ufCXL ophthalmic data were compared to pre-ufCXL baseline measurements.

Visual outcomes were maintained pre-ufCXL to 36 months post-ufCXL, with preserved safety index (P = .6545), efficacy index (P = .4980), spherical equivalent accuracy (P = .1536), defocus equivalent accuracy (P = .1032), central corneal thickness (P = .5196), and corneal irregularity indices at 3 mm (P = .8548) and 5 mm (P = .3399). Refractive astigmatism significantly decreased from 0.83 to 0.55 D pre-ufCXL to post-ufCXL (P = .0439), as did maximum keratometry from 42.40 to 42.00 D pre-ufCXL to post-ufCXL (P = .0420). The ufCXL demarcation line depth was 336 ± 21 µm post-ufCXL, with normal endothelial cell density (2,574 ± 203 cells/mm2). Only 1 of 20 eyes showed evidence of progression of 1.00 D in maximum keratometry.

The ufCXL procedure shows promise in stabilizing early post-LASIK ectasia. Visual function, refractive astigmatism, maximum keratometry, and corneal irregularity indices were statistically maintained at 36 months postoperatively. [J Refract Surg. 2022;38(8):511-519.].

Detection of Corneal Ectasia Using OCT Maps of Pachymetry and Posterior Surface Mean Curvature.

Refractive Surgery

To quantify the abnormal corneal thinning and posterior surface steepening that is observed in keratoconus with an Ectasia Index.

Optical coherence tomography (OCT) was used to image the corneas of normal individuals and patients with varying stages of keratoconus (manifest, subclinical, and forme fruste). Maps of corneal pachymetry and posterior surface mean curvature were generated, and an Ectasia Index was calculated by multiplying Gaussian fits obtained from the two types of maps. Repeated five-fold cross-validation was used to evaluate the ability of the Ectasia Index to differentiate between normal and keratoconic eyes. The classification performance of the Ectasia Index was compared to minimum pachymetry and maximum posterior mean curvature.

Thirty-two eyes from 16 normal individuals, 89 eyes from 63 patients with manifest keratoconus, 16 eyes from 15 patients with subclinical keratoconus, and 26 eyes from 26 patients with forme fruste keratoconus were included in the study. During cross-validation, 100% of the eyes with manifest (89 of 89) and subclinical (16 of 16) keratoconus were correctly classified by the Ectasia Index. The average classification accuracy for the forme fruste keratoconus group was 63 ± 21% (16.4 of 26). The specificity for the normal group was 91 ± 10% (29.1 of 32). The Ectasia Index had a higher sensitivity for keratoconus detection and similar specificity in comparison to minimum pachymetry and maximum posterior mean curvature.

The Ectasia Index could be a valuable additional metric for clinicians to consider when screening for keratoconus. [J Refract Surg. 2022;38(8):502-510.].