The clinical and genetic spectrum of inherited glycosylphosphatidylinositol deficiency disorders

Inherited glycosylphosphatidylinositol deficiency disorders (IGDs) are a group of rare multisystem disorders arising from pathogenic variants in glycosylphosphatidylinositol anchor pathway (GPI-AP) genes. Despite associating 24 of at least 31 GPI-AP genes with human neurogenetic disease, prior reports are limited to single genes without consideration of the GPI-AP as a whole and with limited natural history data. In this multinational retrospective observational study, we systematically analyse the molecular spectrum, phenotypic characteristics, and natural history of 83 individuals from 75 unique families with IGDs, including 70 newly reported individuals: the largest single cohort to date. Core clinical features were developmental delay or intellectual disability (DD/ID, 90%), seizures (83%), hypotonia (72%), and motor symptoms (64%). Prognostic and biologically significant neuroimaging features included cerebral atrophy (75%), cerebellar atrophy (60%), callosal anomalies (57%), and symmetric restricted diffusion of the central tegmental tracts (60%). Sixty-one individuals had multisystem involvement including gastrointestinal (66%), cardiac (19%), and renal (14%) anomalies. Though dysmorphic features were appreciated in 82%, no single dysmorphic feature had a prevalence >30%, indicating substantial phenotypic heterogeneity. Follow-up data were available for all individuals, 15 of whom were deceased at the time of writing. Median age at seizure onset was 6 months. Individuals with variants in synthesis stage genes of the GPI-AP exhibited a significantly shorter time to seizure onset than individuals with variants in transamidase and remodelling stage genes of the GPI-AP (P=0.046). Forty individuals had intractable epilepsy. The majority of individuals experienced delayed or absent speech (95%); motor delay with non-ambulance (64%); and severe-to-profound DD/ID (59%). Individuals with a developmental epileptic encephalopathy (51%) were at greater risk of intractable epilepsy (P=0.003), non-ambulance (P=0.035), ongoing enteral feeds (P<0.001), and cortical visual impairment (P=0.007). Serial neuroimaging showed progressive cerebral volume loss in 87.5% and progressive cerebellar atrophy in 70.8%, indicating a neurodegenerative process. Genetic analyses identified 93 unique variants (106 total), including 22 novel variants. Exploratory analyses of genotype-phenotype correlations using unsupervised hierarchical clustering identified novel genotypic predictors of clinical phenotype and long-term outcome with meaningful implications for management. In summary, we expand both the mild and severe phenotypic extremities of the IGDs; provide insights into their neurological basis; and, vitally, enable meaningful genetic counselling for affected individuals and their families.

Directional electrodes in deep brain stimulation: Results of a survey by the European Association of Neurosurgical Societies (EANS)

Introduction

Directional Leads (dLeads) represent a new technical tool in Deep Brain Stimulation (DBS), and a rapidly growing population of patients receive dLeads.

Research question

The European Association of Neurosurgical Societies(EANS) functional neurosurgery Task Force on dLeads conducted a survey of DBS specialists in Europe to evaluate their use, applications, advantages, and disadvantages.

Material and methods

EANS functional neurosurgery and European Society for Stereotactic and Functional Neurosurgery (ESSFN) members were asked to complete an online survey with 50 multiple-choice and open questions on their use of dLeads in clinical practice.

Results

Forty-nine respondents from 16 countries participated in the survey (n = 38 neurosurgeons, n = 8 neurologists, n = 3 DBS nurses). Five had not used dLeads. All users reported that dLeads provided an advantage (n = 23 minor, n = 21 major). Most surgeons (n = 35) stated that trajectory planning does not differ when implanting dLeads or conventional leads. Most respondents selected dLeads for the ability to optimize stimulation parameters (n = 41). However, the majority (n = 24), regarded time-consuming programming as the main disadvantage of this technology. Innovations that were highly valued by most participants included full 3T MRI compatibility, remote programming, and closed loop technology.

Discussion and conclusion

Directional leads are widely used by European DBS specialists. Despite challenges with programming time, users report that dLeads have had a positive impact and maintain an optimistic view of future technological advances.

Putative autoimmune mechanisms for Acute Disseminated Encephalomyelitis (ADEM) and Guillain-Barré Syndrome (GBS) associated with SARS-CoV-2 infection

The novel coronavirus severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, responsible for the ongoing COVID-19 pandemic, is associated with a broad manifestation of neurological disease, including Acute Disseminated Encephalomyelitis (ADEM) and Guillain-Barré Syndrome (GBS), amongst other forms of autoimmune encephalitis, stroke, encephalopathy, delirium, and cranial neuropathies. These phenomena are not limited to human coronaviruses but are also seen in a minority of patients in response to other viral infection. There is good evidence that an autoimmune mechanism hypothesis is likely. The final pathology is probably the culmination of mixed mechanisms such as vascular and immune dysregulation as well as direct viral invasion of neurons – though there is little if any evidence of viral invasion in the literature to date. The aim of this review is to elucidate the emerging evidence about this subset of COVID-19-associated neurological disease. This unique opportunity to study the interactions between virus and host immune and central nervous system (CNS) to gain novel insights applicable to other probable autoimmune neurological disease. I have conducted a literature search as well as drawn on my own observations from the COVID-19 and encephalitis multidisciplinary meetings at Queen Square National Hospital for Neurology and Neurosurgery, London, UK.

Emerging potential mechanisms and predispositions to the neurological manifestations of COVID-19

A spectrum of neurological disease associated with COVID-19 is becoming increasingly apparent. However, the mechanisms behind these manifestations remain poorly understood, significantly hindering their management. The present review subsequently attempts to address the evolving molecular, cellular and systemic mechanisms of NeuroCOVID, which we have classified as the acute and long-term neurological effects of COVID-19. We place particular emphasis on cerebrovascular, demyelinating and encephalitic presentations, which have been reported. Several mechanisms are presented, especially the involvement of a "cytokine storm". We explore the genetic and demographic factors that may predispose individuals to NeuroCOVID. The increasingly evident long-term neurological effects are also presented, including the impact of the virus on cognition, autonomic function and mental wellbeing, which represent an impending burden on already stretched healthcare services. We subsequently reinforce the need for cautious surveillance, especially for those with predisposing factors, with effective clinical phenotyping, appropriate investigation and, if possible, prompt treatment. This will be imperative to prevent downstream neurological sequelae, including those related to the long COVID phenotypes that are being increasingly recognised.

Sacrohysteropexy with synthetic mesh in Aba, South-Eastern Nigeria: a report of three cases and review of the literature

The surgical treatment of uterovaginal prolapse in women who wish to preserve their uteri for fertility presents a challenge to a gynecologist. This is particularly more challenging in Nigeria and the rest of Africa where there is not only a strong cultural aversion to hysterectomy but women also prefer large family size and male babies. This underscores the need for fertility friendly, uterus-preserving procedures. Three young women under the age of 40 presented with uterovaginal prolapse. They were of low parity and wanted to preserve their uteri for future reproductive function. They had open abdominal suspension of their uteri to the sacrum using a synthetic polypropylene mesh. A pus-string suture was also used to obliterate their pouch of Douglas to prevent future enterocele. Pelvic anatomy was restored and normal vaginal axis was achieved. They had uneventful post-operative period. In resource-limited settings, open abdominal (rather than laparoscopic) sacrohysteropexy with synthetic mesh is an effective and safe alternative to Manchester operation and other vaginal procedures in women who desire to preserve the uterus for future reproductive function.