Electrophysiological Findings Research Articles

Predictive coding in neuropsychiatric disorders: A systematic transdiagnostic review.

The predictive coding framework postulates that the human brain continuously generates predictions about the environment, maximizing successes and minimizing failures based on prior experiences and beliefs. This PRISMA-compliant systematic review aims to comprehensively and transdiagnostically examine the differences in predictive coding between individuals with neuropsychiatric disorders and healthy controls. We included 72 articles including case-control studies investigating predictive coding as the primary outcome and reporting behavioral, neuroimaging, or electrophysiological findings. Thirty-three studies investigated predictive coding in the schizophrenia spectrum, 33 in neurodevelopmental disorders, 5 in mood disorders, 4 in neurocognitive disorders, 1 in post-traumatic stress disorder, and 1 in substance use disorders. Oddball and oddball-like paradigms were most frequently used to quantify predictive coding performance. Evidence showed heterogeneous impairments in the predictive coding abilities of the brain across neuropsychiatric disorders, particularly in schizophrenia and autism. Patients within the schizophrenia spectrum showed a consistent pattern of impaired non-social predictive coding. Conversely, predictive coding deficits were more selective for social cues in the autism spectrum. Predictive coding impairments were correlated with clinical symptom severity. These findings underscore the potential utility of predictive coding as a framework for understanding cognitive dysfunctions in the neuropsychiatric population, even though more evidence is needed on underexplored conditions, also considering potential confounders such as medication use and sex/gender. The potential role of predictive coding as a determinant of treatment response may also be considered to tailor personalized interventions.

Electrophysiological Abnormalities in Finger Extension Weakness and DOwnbeat Nystagmus Motor Neuron Disease: Three New Patients and Review of the Literature.

Finger Extension Weakness and DOwnbeat Nystagmus Motor Neuron Disease (FEWDON-MND) is characterized by motor weakness predominantly affecting finger extension, accompanied by downbeat nystagmus. To date, only 11 patients have been reported. The present study adds a further three and aims to provide a more detailed description of the electrodiagnostic features of these patients. We present the clinical and electrophysiological features of three French patients from specialized motor neuron centers and review the electrophysiological findings of previously reported patients. These three patients presented with pure motor weakness affecting finger extension and downbeat nystagmus. They exhibited a slowly progressive disease course without respiratory involvement. Nerve conduction studies showed decreased compound muscle action potential amplitudes in the extensor indicis muscles. Abnormal spontaneous activity on needle electromyography (EMG) was rare in two patients, absent in one, and otherwise limited to weak muscles. Additionally, chronic motor axon loss features suggestive of motor neuronopathy were seen in our patients. Importantly, they were also detected in distant asymptomatic muscles. The three patients reported here confirm the typical phenotype of FEWDON-MND, characterized by slowly progressive distal motor weakness initially affecting finger extension, associated with downbeat nystagmus. Although chronic motor axon loss features have been found in all reported patients, our three patients show that active denervation can be absent or rare. Thus, finger drop and diffuse chronic neurogenic changes on EMG should lead clinicians to look for downbeat nystagmus and to consider FEWDON-MND.

Repeat Procedures After Pulsed Field Ablation for Atrial Fibrillation: MANIFEST-REDO Study.

Initial clinical studies of pulsed field ablation (PFA) to treat atrial fibrillation (AF) indicated a >90% durability rate of pulmonary vein isolation (PVI). However, these studies were largely conducted in single centers and involved a limited number of operators. The electrophysiological findings and outcomes in patients undergoing repeat ablation after an initial PF ablation for AF are incompletely understood. In the MANIFEST-REDO study, we investigated patients who underwent repeat ablation due to clinical recurrence - AF or atrial tachycardia (AT) - following first-ever PVI with a pentaspline PFA catheter (Farawave; Boston Scientific Inc). At 22 centers, 427 patients (age 64±11 years; 37% female) were included. Of note, the recurrent arrhythmia leading to the repeat ablation was paroxysmal AF (51%), persistent AF (30%), or AT (19%). At the repeat procedure, the PV reconnection rates were: 30% (LSPV), 28% (LIPV), 33% (RSPV) and 32% (RIPV). In 45% of patients all PVs were durably isolated at the beginning of the repeat procedure, with the previous use of any imaging or mapping modality being univariately associated with durable PVI. After a post-redo follow-up period of 284 [90-366] days, the primary effectiveness endpoint (freedom from documented AF/AT lasting ≥30s after 3-month blanking without class I/III antiarrhythmic drugs or symptoms) was achieved in 65% of patients, with significant differences between groups (PAF 65% vs. PersAF 56% vs. AT 76%; p=0.04). Persistent AF as recurrent arrhythmia after the initial PFA ablation predicted AT/AF recurrence after repeat ablation (HR 1.241 (95% CI 1.534-1.005 CI); p=0.045). The procedural complication rate was 2.8%. In repeat procedures for AF/AT performed after an index procedure with PFA for AF, PV reconnections are not uncommon. Repeat procedures can be performed safely and with an acceptable subsequent success rate.

Associations Between Stages of Diabetic Polyneuropathy and Quality of Life, Neuropathic Pain, and Well-Being: A Multicenter, Cross-Sectional Analysis Based on Electroneuromyographic Findings

This study aimed to investigate the relationship between electrophysiological findings of diabetic neuropathy (DN) and patients' quality of life, neuropathic pain levels, and well-being. A cross-sectional study was conducted in 12 centers in Turkey. DN patients were categorized into four stages based on electrophysiological findings using the Baba classification. Scales such as Short Form-36 (SF-36), Douleur Neuropathique 4-Questions (DN4), Brief Pain Inventory (BPI), and WHO-5 Well-Being (WHO-5 WB) were used to assess quality of life, pain, and well-being. Additional factors like HbA1c levels and diabetes duration were analyzed. Among 323 DN patients, 90 were in stage 1, 84 in stage 2, 72 in stage 3, and 77 in stage 4. There were no significant differences in age or gender between the stages. Diabetes duration and HbA1c levels were significantly lower in stage 1 compared to later stages. SF-36 and WHO-5 WB scores declined, while DN4 and BPI pain interference scores increased in the later stages. These findings persisted after adjusting for confounders such as age, BMI, comorbidities, and diabetes duration. Patients with advanced-stage DN experienced a poorer quality of life, greater pain, and more frequent comorbidities compared to early-stage patients. Electrophysiological findings should be considered in the clinical management of DN.

Electrophysiological findings of brainstem auditory evoked potentials in infants with down syndrome: A systematic review and meta-analysis.

to summarize the evidence on the electrophysiological findings in the auditory brainstem response (ABR) in infants with DS. This is a systematic review study, whose protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42023424139) and conducted in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Observational studies were included: cross-sectional and cohort studies that performed ABR evaluation in infants with DS up to two years of age, which had their results compared with normal infants, of the same age group. The search for studies was performed in the following databases: PubMed, LILACS, Scopus, CINHAL, Web of Science, Scielo, Embase and LIVIVO, and in the gray literature: Google Scholar and Proquest. There were no restrictions on language or publication date. The methodological quality of the included studies was assessed using the JBI (Joanna Briggs Institute) checklist. Phases 1 (reading of titles and abstracts) and 2 (reading in full), data extraction, assessment of methodological quality and certainty of evidence were performed independently by the reviewers. Existing disagreements were resolved in a consensus meeting. A total of 494 articles were obtained, which after removal of duplicates and independent analysis by the reviewers, ten studies were selected for qualitative synthesis and four studies were selected for meta-analysis. There was heterogeneity between the effects observed in the ABR parameters (I2=78%) with an overall pooled effect size of -0.05 (95% confidence interval of -0.13-0.03; p=0.22) indicating no significant difference in ABR responses between groups. The certainty of the evidence assessed by GRADE was considered very low due to inconsistency and imprecision. The results of the meta-analysis indicate that there are no significant diferences in ABR parameters, including waves I, III, and V and the I - V interpeak interval, between infants with and without DS up to two years of age. However, the limitations found, such as methodological heterogeneity, small sample sizes and variability in the age range of the participants, generated uncertainty in the results. Therefore, the certainty of the evidence was classified as very low, according to the GRADE methodology.

Age-Related Ventricular Tachycardia Substrate Characteristics for Repaired Tetralogy of Fallot Before Transcatheter Pulmonary Valve Placement.

Ventricular tachycardia (VT) substrate characteristics before transcatheter pulmonary valve replacement (TPVR) in repaired tetralogy of Fallot (rTOF) are unknown. In this study, the authors sought to evaluate substrates for sustained monomorphic VT before TPVR in rTOF. Retrospective (2017 to 2021) and prospective (commencing 2021) rTOF patients with native right ventricular outflow tract referred for electrophysiology study (EPS) before TPVR were included. Electrophysiologic findings and outcomes of VT ablation were determined. One-hundred eighty patients (mean age 39 ± 14 years, 54% male, 71 retrospective, 109 prospective) were identified. At EPS, monomorphic VT was induced in 45 (25%), and a slowly conducting anatomic isthmus alone was observed in 40 (22%). VT isthmus conduction velocity decreased (-0.08m/s per decade; P=0.008) and VT inducibility (P< 0.001 for trend) and cycle length (CL) (+15ms per decade, P=0.005) increased with age. Multivariable factors associated with shorter VT CL included preserved isthmus conduction velocity (-50ms per m/s; P=0.02), absence of atrial flutter (-18ms; P=0.007), and improved RV ejection fraction (-16ms per 10% increase; P=0.007). Catheter ablation was acutely successful in 80/83 (96%). At repeated EPS after a median of 5months, previously ablated substrates were evident in 3/24 (13%) and new VT substrates in 3/33 (9%). Pre-TPVR VT substrates in rTOF demonstrate age-related degeneration that was associated with VT inducibility and VT CL. Both recovery of VT isthmus conduction and new VT substrates were observed after TPVR despite successful catheter ablation.

Can rewards enhance creativity? Exploring the effects of real and hypothetical rewards on creative problem solving and neural mechanisms

Reward cues have long been considered to enhance creative performance; however, little is known about whether rewards can affect creative problem solving by manipulating states of flexibility and persistence. This study sought to elucidate the differential impacts of real versus hypothetical rewards on the creative process utilizing the Chinese compound remote association task. Behavioral analysis revealed a significantly enhanced solution rate and response times in scenarios involving real rewards, in contrast to those observed with hypothetical rewards. Electrophysiological findings indicated that hypothetical rewards led to more positive P200-600 amplitudes, in stark contrast to the amplitudes observed in the context of real rewards. These findings indicate a positive impact of real rewards on creative remote associations and contribute new insights into the relationship between rewards and creative problem solving, highlighting the crucial role of persistence/flexibility in the formation of creativity.

Neuronal ceroid lipofuscinoses type 7 (CLN7): a case series reporting cross sectional and retrospective clinical data to evaluate validity of standardized tools to assess disease progression, quality of life, and adaptive skills

BackgroundThis study evaluated the clinical characteristics of neuronal ceroid lipofuscinosis type 7 or CLN7 disease spectrum to characterize the clinical, electrophysiologic and neuroimaging phenotypes.MethodsWe performed a single-center cross sectional data collection along with retrospective medical chart review in patients with a genetic diagnosis of CLN7. This study received ethical approval by the University of Texas Southwestern Medical Center Institutional Review Board. A total of 8 patients were included between the ages of 4 to 6 years. All patients had a genetic diagnosis of CLN7 with homozygous or compound heterozygous mutations in the MFSD8 gene. The information collected includes patient demographics, developmental history, neurological events including seizures and neurodevelopmental regression along with further evaluation of brain magnetic resonance imaging and electrophysiological findings. The clinical phenotype is described through cross sectional and retrospective data collection and standardized tools assessing quality of life and functional skills.ResultsOur findings in this cohort of CLN7 patients indicated that development is initially normal with onset of clinical symptoms as early as two years of age. Language problems were noted prior to or at the onset of seizures in all cases. Gait problems were noted prior to seizure onset in 3 of 8 patients, and at or within 6 months after the onset of seizures in 5 of 8 patients. All patients followed a progressive course of language, motor, and neurocognitive deterioration. Congruent with the medical history, our patients had significantly low scores on adaptive abilities. Natural history data such as this can be used to support future clinical trial designs.ConclusionsThis study provides a comprehensive description of CLN7 disease, highlighting clinical data alongside standardized neuropsychological assessments, neuroimaging, and electrophysiologic data. It emphasizes the value of importance of standardized tools for understanding disease phenotype and their potential use as endpoints in future clinical trials. The findings established can provide a baseline for developing future prospective natural history studies and potential therapeutic clinical trials.

Effects of chronic empathic stress on synaptic efficacy, as well as short-term and long-term plasticity at the Schaffer collateral/commissural- CA1 synapses in the dorsal hippocampus of rats.

Empathy, the ability to comprehend and share others' emotional states, impacts brain functions. This invivo electrophysiological study explored the influence of chronic empathic stress on synaptic efficacy, as well as short-term and long-term plasticity at the Schaffer collateral/Commissural - CA1 synapses in the dorsal hippocampus of rats, in situations of social equality and inequality. Forty-eight male rats were randomized into six groups: control, pseudo-observer, pseudo-demonstrator, observer, demonstrator, and co-demonstrator(Co, Pse-Ob, Pse-De, Ob, De, Co-De) groups. Stress induction(2h/day, 21 days) was performed in situations of equality and inequality. Serum corticosterone levels, slope, amplitude, and area under the curve(AUC) of field excitatory postsynaptic potentials(fEPSPs) were assessed in the hippocampal CA1 area using input-output(I/O) functions, paired-pulse(PP) responses with different interpulse intervals(IPIs), and long-term potentiation (LTP) after high-frequency stimulation (HFS). The fEPSP slope, amplitude, and AUC significantly decreased in all stress groups, especially in the De and Pse-De groups. These parameters were significantly increased in the Co-De and Ob groups compared to theDe group. Notably, the corticosterone levels strongly confirmed the electrophysiological findings. Chronic empathic stress could disrupt synaptic efficacy and plasticity in the CA1 area. Empathic stress, involving the presence of cagemates in situations of social equality and inequality, can modify long-term plasticity and serum corticosterone levels in demonstrators and co-demonstrators. Under empathic stress related to situations of inequality, freely moving observers may influence the demonstrators' stress experience. Therefore, the presence of a conspecific in the social inequality conditions had significant suppressive effects on long-term plasticity, while conversely, under equality conditions, long-term plasticity was favorably improved through social buffering.

Behavioral decline in Shank3Δex4–22 mice during early adulthood parallels cerebellar granule cell glutamatergic synaptic changes

BackgroundSHANK3, a gene encoding a synaptic scaffolding protein, is implicated in autism spectrum disorder (ASD) and is disrupted in Phelan-McDermid syndrome (PMS). Despite evidence of regression or worsening of ASD-like symptoms in individuals with PMS, the underlying mechanisms remain unclear. Although Shank3 is highly expressed in the cerebellar cortical granule cells, its role in cerebellar function and contribution to behavioral deficits in ASD models are unknown. This study investigates behavioral changes and cerebellar synaptic alterations in Shank3Δex4–22 mice at two developmental stages.MethodsShank3Δex4–22 wildtype, heterozygous, and homozygous knockout mice lacking exons 4–22 (all functional isoforms) were subjected to a behavioral battery in both juvenile (5–7 weeks old) and adult (3–5 months old) mouse cohorts of both sexes. Immunostaining was used to show the expression of Shank3 in the cerebellar cortex. Spontaneous excitatory postsynaptic currents (sEPSCs) from cerebellar granule cells (CGCs) were recorded by whole-cell patch-clamp electrophysiology.ResultsDeletion of Shank3 caused deficits in motor function, heightened anxiety, and repetitive behaviors. These genotype-dependent behavioral alterations were more prominent in adult mice than in juveniles. Reduced social preference was only identified in adult Shank3Δex4–22 knockout male mice, while self-grooming was uniquely elevated in males across both age groups. Heterozygous mice showed little to no changes in behavioral phenotypes in most behavioral tests. Immunofluorescence staining indicated the presence of Shank3 predominantly in the dendrite-containing rosette-like structures in CGCs, colocalizing with presynaptic markers of glutamatergic mossy fiber. Electrophysiological findings identified a parallel relationship between the age-related exacerbation of behavioral impairments and the enhancement of sEPSC amplitude in CGCs.LimitationsOther behavioral tests of muscle strength (grip strength test), memory (Barnes/water maze), and communication (ultrasonic vocalization), were not performed. Further study is necessary to elucidate how Shank3 modulates synaptic function at the mossy fiber-granule cell synapse in the cerebellum and whether these changes shape the behavioral phenotype.ConclusionsOur findings reveal an age-related exacerbation of behavioral impairments in Shank3Δex4–22 mutant mice. These results suggest that Shank3 may alter the function of glutamatergic receptors at the mossy fiber-cerebellar granule cell synapse as a potential mechanism causing cerebellar disruption in ASD.

Genetically confirmed Charcot–Marie–Tooth disease type 2A manifesting with postural tremor: a case report

BackgroundCharcot–Marie–Tooth disease is a spectrum of inherited disorders characterized by both motor and sensory manifestations, which include prominent distal muscle weakness, foot deformities (pes cavus and hammer toes), and sensory deficits. Postural tremor as a manifestation of Charcot–Marie–Tooth is seldom present, except in a variant of Charcot–Marie–Tooth subtype 1 (Roussy–Levy syndrome), and its presence often results in a diagnostic dilemma.Case presentationWe present a 34-year-old Eritrean man who came to our hospital with a complaint of tremors of the hands of 6 months duration. Associated with this, he had difficulty walking and weakness of the distal extremities bilaterally, prominently involving the lower limbs. The patient denied a family history of such illness. Physical examination revealed distal muscle weakness (4+/5 on upper limbs, while 3/5 on lower limbs bilaterally), pes cavus deformity, absent ankle reflexes, and mild vibratory sensory loss. We noted a postural tremor that attenuated when the patient assumed an anatomic position. The tremor was limited to the hands. Nerve conduction study of upper and lower limbs showed moderate to severe motor axonal and demyelinating polyneuropathy (axonal > demyelinating), suggestive of mixed axonal and demyelinating hereditary polyneuropathy. Subsequently, genetic testing revealed copy number changes (heterozygous deletion) on the MPZ and MFN2, while the PMP22 gene showed ambiguous copy number changes (decrease) on exons 2 and 3. Tying the clinical, electrophysiologic, and genetic findings, consideration of Charcot–Marie–Tooth subtype 2A with postural tremor was made. Subsequently, the patient was managed with regular physiotherapy and an anxiolytic resulting in minimal symptom improvement.ConclusionThe present case describes a 34-year-old male patient with Charcot–Marie–Tooth subtype 2A presenting with neuropathic postural tremor, which is a rare presentation of a common hereditary polyneuropathy. This case highlights the fact that tremors can be associated with peripheral neuropathy syndromes, and a high index of suspicion is needed to rightly diagnose our patients.

A rare kind of Guillain-Barre syndrome triggered by acute hepatitis A infection in a pediatric patient: a case report and review of literature.

Guillain-Barre Syndrome (GBS) is a rare but serious neurological disorder characterized by acute flaccid paralysis and areflexia, usually after an infectious disease. This case report describes a previously healthy 9-year-old boy who developed GBS following an acute hepatitis A infection. The patient presented with rapidly progressive weakness, ascending paralysis, and areflexia, confirmed by clinical and electrophysiological findings. Results were consistent with the GBS subgroup of Acute Motor Axonal Neuropathy. Treatment with intravenous immunoglobulin (IVIG) led to gradual improvement, highlighting the importance of early recognition and intervention. This report reviews the current literature on the association between GBS and hepatitis A, emphasizing the rarity of such cases in pediatric populations. The report aims to raise awareness among clinicians about this potential complication of hepatitis A, underscoring the need for prompt diagnosis and treatment to improve outcomes in similar cases. The report emphasizes the need for prompt diagnosis and treatment to improve outcomes in similar cases.

The Effects of Memantine on Cisplatin-Induced Ototoxicity

Introduction: We aimed to investigate electrophysiologically and histopathologically, the protective effects of intratympanic memantine, an N-methyl-D-aspartate receptor antagonist, on ototoxicity caused by cisplatin, an anti-neoplastic agent used in many types of cancer. Methods: Thirty-seven guinea pigs with a normal auditory function were randomly allocated to group 1 (cisplatin; n = 8), group 2 (memantine; n = 8), group 3 (cisplatin + memantine; n = 8), group 4 (cisplatin + physiological serum [PS]; n = 8), and group 5 (control; n = 5). Auditory assessments were conducted using distortion product otoacoustic emissions (DPOAE) within a frequency range of 1–32 kHz and auditory brainstem responses (ABRs) within 8–32 kHz. A single dose of cisplatin (12 mg/kg) was administered intraperitoneally, followed by intratympanic administration of 0.2 mL of either memantine or PS to both ears at least half an hour before cisplatin administration. Subsequent auditory evaluations were conducted 72 h after cisplatin administration. Histopathological analyses were performed using light microscopy of the right ear and scanning electron microscopy (SEM) of the left ear. Results: Auditory evaluations conducted before and after treatment revealed significant findings. Specifically, within groups 3 and 4, ABR thresholds were elevated at all frequencies (p = 0.00), whereas the DPOAE signal-to-noise ratios were reduced at frequencies of 8, 12, 16, and 24 kHz (p = 0.001, p = 0.01, p = 0.01, and p = 0.00, respectively). Histopathologically, both light microscopy and SEM revealed that the cisplatin + memantine group exhibited fewer hair cells and nuclear degeneration in the spiral ganglion than the cisplatin and cisplatin + PS groups. Additionally, the stria vascularis thickness was greater in the cisplatin + memantine group than in cisplatin and cisplatin + PS groups. Conclusion: Despite the negative electrophysiological findings, the histopathological outcomes suggest that intratympanic memantine may have a potential protective effect against cisplatin-induced ototoxicity. However, further investigations are warranted to corroborate these findings and elucidate the underlying mechanisms of action of memantine.

Fasciculation potentials are related to the prognosis of amyotrophic lateral sclerosis.

Some prognostic biomarkers of amyotrophic lateral sclerosis (ALS) have been described; however, they are inadequate for satisfactorily predicting individual patient outcomes. Fasciculation potentials (FPs) on electromyography (EMG) are useful for the early diagnosis of ALS, and complex FPs are associated with shorter survival in ALS. In this study, we investigated the relationship between the proportion of muscles with FPs, biochemical markers, and the prognosis of ALS. 89 Patients with ALS were retrospectively classified into three groups based on the interval from onset to death or tracheostomy (less than 1 year: fast progression; from 1 year to less than 3 years: average progression; 3 years or more: slow progression). We performed statistical analysis of the electrophysiological findings, including the percentage of examined muscles with FPs, and biochemical markers evaluated on admission. Patients with fast ALS progression had a higher percentage of muscles with FPs (93.1% vs. 37.9%, P<0.001) and lower uric acid (UA) levels (male: 4.19 mg/dl vs 5.55 mg/dl, P<0.001; female: 3.71 mg/dl vs 5.41 mg/dl, P<0.001) than patients with slow progression. Survival curves demonstrated a relationship between these factors and the survival time in patients with ALS. Furthermore, UA levels were correlated with the percentage of muscles with FPs. Our electrophysiological findings suggest that ALS presents with multisystem neurological manifestations, and these manifestations differed among the groups classified by disease progression. The percentage of muscles with FPs on EMG and serum UA levels were especially associated with the prognosis of ALS.

Fusion Free Median Corpectomy - Long-Term Consequence of Foregoing Fusion and Fixation: A Serendipitous Observation.

Anterior cervical corpectomy and fusion (ACCF) involves placement of a graft/implant to ensure fusion and stabilization along with neural decompression. We share our experience with a subset of ACCF patients in whom graft/implant could not be placed post decompression for varying reasons but had a favorable long-term outcome. The necessity for routine fusion after corpectomy is critically analyzed, and the feasibility of an alternative surgical option without graft/implant is discussed. A retrospective observational study of long-term outcomes of five patients with cervical compressive myelopathy who underwent neural decompression alone without an in situ graft/implant was done. All the patients underwent the modified cervical corpectomy technique, involving a smaller wedge size (12 × 15 mm) corpectomy. Pre- and postoperative clinical, radiological, electrophysiological, and operative findings were meticulously evaluated and analyzed. This retrospective observational study reviewed records of 124 patients who underwent ACCF between 1998 and 2012. The surgical procedure involved a wedge median cervical corpectomy. In seven patients, graft/implant could not be placed or had to be removed for various reasons. Long-term follow-up was available for five of these patients who were included in the study. In two patients, the graft could not be placed intraoperatively due to hemodynamic complications. In one patient, the graft had to be removed due to postoperative infection, and in two patients, the graft had to be removed due to graft extrusion. Four patients showed marked improvement, and one patient showed minimal improvement on long-term follow-up in clinical, radiological, and electrophysiological parameters. This small case series suggests that a modified cervical corpectomy technique, involving a smaller wedge size (12 × 15 mm), may be considered in selected cases without radicular symptoms. This approach helps to provide neural decompression without compromising stability and avoids graft-related complications. While promising, further research, including prospective randomized-controlled trials, is essential to validate the biomechanical properties and clinical outcomes of this modified technique compared to traditional ACCF.

Remodeling of adult rat heart subjected to pressure overload from the neonatal period is dependent on the sex

Abstract Background Congenital heart diseases (CHD) represents the most common birth defect. Despite progress in their treatment improving acute survival, there is a paucity of data concerning the long-term consequences of CHD in adults. Purpose Here, we investigate the remodeling in adult rat hearts subjected to pressure overload from the early postnatal period. Methods We used the neonatal abdominal aortic constriction (AAC) model to analyze morphological, functional (by echocardiography), and electrophysiological long-term outcomes. Given the known differences in cardiac pathologies between males (M) and females (F), we focused on the role of sex in cardiac remodeling. Results Our data showed that both sexes exhibited a similar left ventricular weight/body weight ratio at the age of 12 weeks, indicating comparable left ventricle (LV) enlargement as a response to AAC (increase by 103 ± 9 % in M AAC and 99 ± 10 % in F AAC vs. sham-operated animals). However, the right ventricular weight/body weight and lung/ body weight ratios, indicative of LV failing, differed significantly between sexes with better values in F AAC. The favorable cardiac remodeling in F AAC was corroborated by significantly smaller LV systolic and diastolic diameters, along with a lower amount of myocardial fibrosis. Using optical mapping, we revealed preserved longitudinal and transversal conduction velocities (CVL; CVT) in females (CVL 104 ± 8 vs. 109 ± 8 cm/s and CVT 66 ± 7 vs. 59 ± 6 cm/s in F AAC and F Sham, respectively). However, compared to M Sham, the conduction velocities in M AAC showed a significant decrease (CVL 80 ± 3 vs. 92 ± 3 cm/s and CVT 35 ± 2 vs. 54 ± 3 cm/s). Similarly, the amount of connexion 43 (Cx43) and its phosphorylated state (Cx43Ser368) was preserved in F AAC while exhibiting a decrease in M AAC compared to the sham-operated controls. Thus, electrophysiological findings implicate that while the adult M AAC underwent pro-arrhythmogenic remodeling due to the elevated workload, the adult F AAC preserved physiological conduction properties. Conclusion Our data showed different consequences of the increased pressure load exposed from early after birth to the adult M and F heart. These findings highlighted the involvement of both sexes in cardiac studies.

Relationship between fatigue and quantitative electromyography findings in patients with myasthenia gravis

BackgroundFatigue is a common complaint among patients with myasthenia gravis (MG). In this study, we investigated the alterations in muscle morphology in patients with MG experiencing fatigue using quantitative electromyography (QEMG), and explored the relationship between electrophysiological findings and the severity of both fatigue and disease. MethodsWe performed QEMG of the biceps brachii muscle using the peak ratio method and multi-motor unit potential (MUP) analysis across three groups: 18 MG patients with fatigue, 34 MG patients without fatigue, and 33 healthy subjects. Stimulated single-fiber EMG was performed on the frontalis muscle. The severity of perceived fatigue and disease was subsequently assessed using the quantitative myasthenia gravis (QMG) score, the MG-activities of daily living (MG-ADL) profile, self-reported fatigue questionnaires, and handgrip strength measurements. ResultsThe QEMG study revealed a reduced mean MUP duration and size index (SI), in addition to an increased peak ratio in patients with MG (p < 0.05), which tended to be more pronounced in those experiencing fatigue. Compared to healthy subjects, MG patients with fatigue displayed a myopathic pattern characterised by a high peak ratio, short duration, and small-amplitude MUPs, without any increase in the number of phases or small time intervals. The mean peak ratio was positively correlated with the QMG, MG-ADL, and Fatigue Impact Scale total and physical subscores (p < 0.05). Further, MG patients with fatigue exhibited reduced maximum grip strength, which was positively correlated with the mean MUP duration, amplitude, SI, and thickness, and negatively correlated with the mean peak ratio (p < 0.05). No significant differences were observed in the jitter or block measurements (p > 0.05). ConclusionsThe present study investigated electrophysiological findings that were not considered or theorised in prior studies on patients with MG experiencing fatigue. The results of this study suggest that myopathic changes may be a critical pathophysiological component underlying the fatigue associated with MG.

A cortical field theory – dynamics and symmetries

We characterise cortical dynamics using partial differential equations (PDEs), analysing various connectivity patterns within the cortical sheet. This exploration yields diverse dynamics, encompassing wave equations and limit cycle activity. We presume balanced equations between excitatory and inhibitory neuronal units, reflecting the ubiquitous oscillatory patterns observed in electrophysiological measurements. Our derived dynamics comprise lowest-order wave equations (i.e., the Klein-Gordon model), limit cycle waves, higher-order PDE formulations, and transitions between limit cycles and near-zero states. Furthermore, we delve into the symmetries of the models using the Lagrangian formalism, distinguishing between continuous and discontinuous symmetries. These symmetries allow for mathematical expediency in the analysis of the model and could also be useful in studying the effect of symmetrical input from distributed cortical regions. Overall, our ability to derive multiple constraints on the fields — and predictions of the model — stems largely from the underlying assumption that the brain operates at a critical state. This assumption, in turn, drives the dynamics towards oscillatory or semi-conservative behaviour. Within this critical state, we can leverage results from the physics literature, which serve as analogues for neural fields, and implicit construct validity. Comparisons between our model predictions and electrophysiological findings from the literature — such as spectral power distribution across frequencies, wave propagation speed, epileptic seizure generation, and pattern formation over the cortical surface — demonstrate a close match. This study underscores the importance of utilizing symmetry preserving PDE formulations for further mechanistic insights into cortical activity.

Single simple question in axonal polyneuropathy.

The single simple question (SSQ), "What percentage of normal (0%-100%) do you feel regarding your disease?" has proven feasible and valid in assessing myasthenia gravis and a heterogeneous spectrum of neuropathies. This study explores the utility of the SSQ in axonal polyneuropathies (PNPs), encompassing diabetic neuropathy, and evaluates its responsiveness to scale changes. A retrospective chart review of 150 patients with axonal PNP responding to the SSQ was performed. Patients underwent clinical and electrophysiological evaluations, and were evaluated by clinical and disability scales, including the Medical Research Council sum score, modified Toronto Clinical Neuropathy score (mTCNS), Overall Neuropathy Limitation Scale, and Rasch-built Overall Disability Scale (RODS). The SSQ total scores correlated moderately with both the RODS score (r = .59, p < .001) and the mTCNS symptom score (r = -.43, p < .001), maintaining significance after adjustment for multiple comparisons. Longitudinally, after adjusting for multiple comparisons, the change in mTCNS symptom score retained statistical significance (adjusted p = .048). The SSQ did not show any association with electrophysiological parameters or sensory symptoms, other than a lower score in those with pain (100% with SSQ <40%, 85% with SSQ 40%-70%, and 34% with SSQ >70%). The SSQ is a feasible, valid scale that may be utilized to assess and follow patients with length-dependent axonal PNPs. Given that the SSQ is not strongly associated with clinical and disability scales or electrophysiological findings, additional investigations are required for a comprehensive assessment of PNP.

Absolute beta power in exercisers and nonexercisers in preparation for the oddball task.

High levels of physical conditioning are associated with improvements in cognitive performance. In this sense, electroencephalographic (ECG) correlates are used to investigate the enhancing role of physical exercise on executive functions. Oscillations in the β frequency range are proposed to be evident during sensorimotor activity. To investigate the ECG changes influenced by aerobic and resistance exercises performed in an attention task by analyzing the differences in absolute β power in the prefrontal and frontal regions before, during, and after the oddball paradigm in practitioners and nonpractitioners of physical exercise. There were 15 physical activity practitioners (aged 27 ± 4.71) and 15 nonpractitioners (age 28 ± 1.50) recruited. A two-way analysis of variance (ANOVA) was implemented to observe the main effect and the interaction between groups and moments (rest 1, pre-stimulus, and rest 2). An interaction between group and moment factors was observed for Fp1 (p < 0.001); Fp2 (p = 0.001); F7 (p < 0.001); F8 (p < 0.001); F3 (p < 0.001); Fz (p < 0.001); and F4 (p < 0.001). Electrophysiological findings clarified exercisers' specificity and neural efficiency in each prefrontal and frontal subarea. Our findings lend support to the current understanding of the cognitive processes underlying physical exercise and provide new evidence on the relationship between exercise and cortical activity.