Brachial Plexus Injury Associated with Median Sternotomy during Cardiac Surgery: Three Cases of C8 Radiculopathy Due to the Fracture of the First Rib

In cardiac surgery, median sternotomy is often necessary during certain surgical processes and it can cause the rare complication of brachial plexus injury. Retraction of the rib cage during median sternotomy may produce a fracture of the first thoracic rib at the costovertebral junction which might penetrate or irritate the lower root of the brachial plexus. Because the C8 ventral root is located immediately superior to the first thoracic rib, the extraforaminal C8 root is thought to be the key location of brachial plexus injury by the first rib fracture. This report describes three cases of brachial plexus injury after median sternotomy in a single center. In our cases, fracture of the first rib and consequent brachial plexus injury is confirmed with imaging and electrophysiologic studies. The fracture of the first rib is not detected with standard plain images and it is confirmed only with CT or MRI studies. Advanced imaging tools are recommended to assess the first rib fracture when brachial plexus injury is suspected after median sternotomy.

Swiss National Registry on Catheter Ablation Procedures: Changing Trends over the Last 20 Years

The Swiss Ablation Registry provides a national database for electrophysiologic studies and catheter ablations. We analyzed the database to provide an in-depth look at changing trends over the last 20 years. During the study period a total of 78622 catheter ablations (age 61.0 ± 1.2 years; 63.7% male) were performed in 29 centers. The number of ablations increased by approximately ten-fold in 20 years. Ablation for atrial fibrillation (AF) was the main driver behind this increase, with more than hundred-fold (39.7% of all ablations in 2019). Atrioventricular-nodal-reentrant-tachycardia (AVNRT) and accessory pathways, being the main indications for ablation in 2000 (44.1%/25.1%, respectively), made up of only a small proportion (15.2%/3.5%,) respectively in 2019. Fluoroscopy, ablation, and procedure durations were reduced for all ablations over time. The highest repeat ablations were performed for ventricular tachycardia and AF (24.4%/24.3%). The majority of ablations (63.0%) are currently performed in private hospitals and non-university public hospitals whereas university hospitals had dominated (82.4%) at the turn of the century. A pronounced increase in the number of catheter ablations in Switzerland was accompanied by a marked decrease in fluoroscopy, ablation, and procedure durations. We observed a shift toward more complex procedures in older patients with comorbidities.

Genetic Inhibition of Serum Glucocorticoid Kinase 1 Prevents Obesity-related Atrial Fibrillation

Rationale: Given its rising prevalence in both the adult and pediatric populations, obesity has become an increasingly important risk factor in the development of atrial fibrillation. However, a better mechanistic understanding of obesity-related atrial fibrillation is required. Serum glucocorticoid kinase 1 (SGK1) is a kinase positioned downstream of multiple obesity-related pathways, and prior work has shown a pathologic role for SGK1 signaling in ventricular remodeling and arrhythmias. Objective: To determine the mechanistic basis of obesity associated atrial fibrillation and explore the therapeutic potential of targeting SGK1 in this context. Methods and Results: We utilized a mouse model of diet induced obesity to determine the atrial electrophysiologic effects of obesity using electrophysiologic studies, optical mapping, and biochemical analyses. In C57BL/6J mice fed a high fat diet, there was upregulation of SGK1 signaling along with an increase in AF inducibility determined at electrophysiology (EP) study. These changes were associated with an increase in fibrotic and inflammatory signaling. Transgenic mice expressing a cardiac specific dominant negative SGK1 (SGK1 DN) were protected from obesity-related AF as well as the fibrotic and inflammatory consequences of AF. Finally, optical mapping demonstrated a shorter action potential duration and patch clamp revealed effects on INa, with a decreased peak current as well as a depolarizing shift in activation/inactivation properties in atrial myocytes. Conclusions: Diet induced obesity leads to increased cardiac SGK1 signaling as well as an increase in AF inducibility in obese mice. Genetic SGK1 inhibition reduced AF inducibility, and this effect may be mediated by effects on inflammation, fibrosis, and cellular electrophysiology.

Case Report: Neurogenic Thoracic Outlet Syndrome Without Electrophysiologic Abnormality

Neurogenic thoracic outlet syndrome (N-TOS) is a chronic compressive brachial plexopathy that involves the C8, T1 roots, and/or lower trunk. Medial antebrachial cutaneous (MABC) nerve conduction study (NCS) abnormality is reportedly one of the most sensitive findings among the features of N-TOS. The aim of the present study was to report clinical features, imaging findings, treatment, and prognoses of two N-TOS patients with no abnormalities in electrophysiological studies. Both patients presented with paresthesia of unilateral arm, and examination revealed no neurologic deficits. Electrophysiologic studies including MABC NCS were normal. Computed tomography (CT) angiography and brachial plexus magnetic resonance imaging (MRI) of the patients showed compression and displacement of the neurovascular bundle in the thoracic outlet by causative structures. Due to their sensory symptoms and CT angiography and brachial plexus MRI findings, after excluding other diseases, we diagnosed them with N-TOS. With the development of imaging techniques, more patients presenting with clinical features of lower trunk brachial plexopathy and anomalous structures compressing the neurovascular bundle on imaging studies can be diagnosed with N-TOS, even if electrophysiologic studies including MABC NCS do not show abnormalities.

Prosody in Children with Atypical Development

Atypicalities of communication development are among the most common developmental disabilities. As an aspect of communication, prosody is frequently affected in children with atypical development, sometimes as one concomitant of a primary disorder and, in rarer cases, as a prominent feature of the communication profile. This chapter reviews four developmental disorders in which prosody is frequently impaired: autism spectrum disorder, developmental language disorder, cerebral palsy, and hearing loss. Brief descriptions of the impact of each of these disorders on communicative function will be presented. Effects on prosody, including prevalence of prosodic dysfunction within each disorder and the perceptual and acoustic characteristics of the associated prosodic deficits, will be explored. Strategies for assessing and treating prosodic deficits in current clinical use will be outlined. Discussion will focus on potential a etiologies for the observed prosodic deficits, using data from behavioural, genetic, neuroimaging, and electrophysiologic studies, as well as the interpretation of findings on prosodic atypicalities in light of current linguistic, psycholinguistic, and neurolinguistic understanding of language function. Recommendations for further research on the characteristics, assessment, and treatment of prosodic disorders in developmental disabilities will be provided.

Progressive Limb Weakness and Sensory Loss in a Young Woman

Patients with neuromuscular disease often present with a combination of symptoms that suggest a wide differential diagnosis. Traditionally, electrophysiologic studies and microscopy have aided the clinician in making a diagnosis. More recently, genetic testing for specific diseases has helped to ensure correct diagnosis. The following is a case that emphasizes the importance of combining clinical, electrophysiologic, microscopic and finally, genetic findings.

Neurobiology of Psychotic Disorders

Efforts to prevent or lessen the functional impact of psychosis can be informed by a better understanding of the neurobiological underpinnings at the earliest stages of the disorder. Understanding these processes early in the psychosis spectrum will in turn allow more targeted efforts to prevent or minimize functional limitations among patients with psychosis. Advances in technology have enabled the study of a host of biomarkers implicated in the neurobiology of psychosis offering unique avenues to investigate mechanisms of disease while at the same time shedding some light on more patient-tailored treatments and setting the foundation for personalized medicine in psychosis. Insights into the neurobiology of psychosis are reviewed, including findings from neuroimaging, neurocognitive, and electrophysiologic studies and findings related to the role of hypothalamic-pituitary axis activity and neuroinflammation in the emergence of psychosis. Biomarker-informed treatments are discussed, and potential promising biomarkers and related treatments are proposed. This review contains 5 figures, 13 tables, and 85 references. Key words: attenuated risk syndrome, biomarkers, prodrome, psychosis, schizophrenia, treatment

Neurobiology of Psychotic Disorders

Efforts to prevent or lessen the functional impact of psychosis can be informed by a better understanding of the neurobiological underpinnings at the earliest stages of the disorder. Understanding these processes early in the psychosis spectrum will in turn allow more targeted efforts to prevent or minimize functional limitations among patients with psychosis. Advances in technology have enabled the study of a host of biomarkers implicated in the neurobiology of psychosis offering unique avenues to investigate mechanisms of disease while at the same time shedding some light on more patient-tailored treatments and setting the foundation for personalized medicine in psychosis. Insights into the neurobiology of psychosis are reviewed, including findings from neuroimaging, neurocognitive, and electrophysiologic studies and findings related to the role of hypothalamic-pituitary axis activity and neuroinflammation in the emergence of psychosis. Biomarker-informed treatments are discussed, and potential promising biomarkers and related treatments are proposed. This review contains 5 figures, 13 tables, and 85 references. Key words: attenuated risk syndrome, biomarkers, prodrome, psychosis, schizophrenia, treatment

Identification of GGC repeat expansion in the NOTCH2NLC gene in amyotrophic lateral sclerosis

ObjectiveTo determine whether the GGC repeats in the NOTCH2NLC gene contribute to amyotrophic lateral sclerosis (ALS).MethodsIn this study, 545 patients with ALS and 1,305 healthy controls from mainland China were recruited. Several pathogenic mutations in known ALS-causative genes (including C9ORF72 and ATXN2) and polynucleotide repeat expansions in NOP56 and AR genes were excluded. Repeat-primed PCR and GC-rich PCR were performed to determine the GGC repeat size in NOTCH2NLC. Systematic and targeted clinical evaluations and investigations, including skin biopsy and dynamic electrophysiologic studies, were conducted in the genetically affected patients.ResultsGGC repeat expansion was observed in 4 patients (numbers of repeats 44, 54, 96, and 143), accounting for ≈0.73% (4 of 545) of all patients with ALS. A comparison with 1,305 healthy controls revealed that GGC repeat expansion in NOTCH2NLC was associated with ALS (Fisher exact test, 4 of 545 vs 0 of 1,305, p = 0.007). Compared to patients with the neuronal intranuclear inclusion disease (NIID) muscle weakness–dominant subtype, patients with ALS phenotype carrying the abnormal repeat expansion tended to have a severe phenotype and rapid deterioration.ConclusionOur results suggest that ALS is a specific phenotype of NIID or that GGC expansion in NOTCH2NLC is a factor that modifies ALS. These findings may help clarify the pathogenic mechanism of ALS and may expand the known clinical spectrum of NIID.

Diabetic Distal Symmetrical Polyneuropathy: Correlation of Clinical, Laboratory, and Electrophysiologic Studies in Patients with Type 2 Diabetes Mellitus

This cross-sectional study is aimed at determining the prevalence of distal symmetrical polyneuropathy (DSPN) and diabetic peripheral neuropathic pain (DPNP) in participants with type 2 diabetes mellitus (T2DM); finding the risk factors for DSPN and DPNP via biochemical tests; and correlating DSPN and DPNP with the results of electrophysiologic studies, quantitative sensory tests, and neurologic examination. The 145 participants with T2DM enrolled were divided into the DSPN (abnormal nerve conduction studies (NCS) with signs of polyneuropathy), subclinical DSPN (abnormal NCS without signs of polyneuropathy), minimal DSPN (normal NCS with signs of polyneuropathy), and no DSPN groups. The biochemical risk factors of diabetic peripheral neuropathy were investigated. Neurologic examinations, laboratory tests, NCS, vibration threshold tests, and thermal threshold tests were conducted. The modified Michigan Neuropathy Screening Instrument (mMNSI) and Douleur Neuropathique 4 were used to evaluate the severity of DSPN and DPNP, respectively. In all, 30% of participants had DSPN and 11% had DPNP. DSPN correlated strongly with male gender and higher glycohaemoglobin levels; NCS abnormality correlated with higher glycohaemoglobin levels; DSPN severity correlated with NCS of each stimulating nerve. DPNP commonly occurred with clinical and electrophysiologic evidence of DSPN. Symptomatic diabetic polyneuropathy significantly correlated with longer disease duration, higher glycohaemoglobin levels, and abnormal vibration tests. The thermal threshold test combined with nerve conduction tests could detect most of the patients with DSPN, subclinical DSPN, and minimal DSPN. Poor diabetic control was independently associated with the development of DSPN. DPNP was associated with DSPN. The combination of thermal threshold tests with NCS can potentially provide the diagnosis of DSPN.