Limbic encephalitis associated with elevated antithyroid antibodies

Immune-mediated limbic encephalitis affects both adults and children. Patients typically present with seizures, memory problems, and imaging changes in the medial temporal lobes. Both paraneoplastic and nonparaneoplastic forms have been described in which the antibody to the voltage-gated potassium channel-complex associated protein, leucine-rich glioma-inactivated 1, is most commonly reported. Elevated antithyroid antibodies have also been reported in a range of neurological syndromes with encephalopathy, such as limbic encephalitis, often collectively termed Hashimoto encephalopathy, a condition whereby corticosteroids responsiveness with a complete recovery is commonly observed. Here we describe 3 children presenting with limbic encephalitis with elevated thyroid antibodies that did not respond to corticosteroids alone and required more aggressive immunotherapy, mirroring the slower treatment response that is more frequently seen in other immune-mediated forms of limbic encephalitis.

PLA2G6-associated neurodegeneration (PLAN): further expansion of the clinical, radiological and mutation spectrum associated with infantile and atypical childhood-onset disease

Phospholipase A2 associated neurodegeneration (PLAN) is a major phenotype of autosomal recessive Neurodegeneration with Brain Iron Accumulation (NBIA). We describe the clinical phenotypes, neuroimaging features and PLA2G6 mutations in 5 children, of whom 4 presented with infantile neuroaxonal dystrophy (INAD). One other patient was diagnosed with the onset of PLAN in childhood, and our report highlights the diagnostic challenges associated with this atypical PLAN subtype. In this series, the neuroradiological relevance of classical PLAN features as well as apparent claval hypertrophy' is explored. Novel PLA2G6 mutations were identified in all patients. PLAN should be considered not only in patients presenting with a classic INAD phenotype but also in older patients presenting later in childhood with non-specific progressive neurological features including social communication difficulties, gait disturbance, dyspraxia, neuropsychiatric symptoms and extrapyramidal motor features.

Autoantibody biomarkers in childhood-acquired demyelinating syndromes: results from a national surveillance cohort

BACKGROUND

Autoantibodies to glial, myelin and neuronal antigens have been reported in a range of central demyelination syndromes and autoimmune encephalopathies in children, but there has not been a systematic evaluation across the range of central nervous system (CNS) autoantibodies in childhood-acquired demyelinating syndromes (ADS).

METHODS

Children under the age of 16 years with first-episode ADS were identified from a national prospective surveillance study; serum from 65 patients had been sent for a variety of diagnostic tests. Antibodies to astrocyte, myelin and neuronal antigens were tested or retested in all samples.

RESULTS

Fifteen patients (23%) were positive for at least one antibody (Ab): AQ4-Ab was detected in three; two presenting with neuromyelitis optica (NMO) and one with isolated optic neuritis (ON). Myelin oligodendrocyte glycoprotein (MOG)-Ab was detected in seven; two with acute disseminated encephalomyelitis (ADEM), two with ON, one with transverse myelitis (TM) and two with clinically isolated syndrome (CIS). N-Methyl-D-Aspartate receptor (NMDAR)-Ab was found in two; one presenting with ADEM and one with ON. Voltage-gated potassium channel (VGKC)-complex antibodies were positive in three; one presenting with ADEM, one with ON and one with CIS. GlyR-Ab was detected in one patient with TM. All patients were negative for the VGKC-complex-associated proteins LGI1, CASPR2 and contactin-2.

CONCLUSIONS

A range of CNS-directed autoantibodies were found in association with childhood ADS. Although these antibodies are clinically relevant when associated with the specific neurological syndromes that have been described, further studies are required to evaluate their roles and clinical relevance in demyelinating diseases.

Neurological manifestations of influenza infection in children and adults: results of a National British Surveillance Study

BACKGROUND

The emergence of influenza A(H1N1) 2009 was met with increased reports of associated neurological manifestations. We aimed to describe neurological manifestations of influenza in adults and children in the United Kingdom that presented at this time.

METHODS

A 2-year surveillance study was undertaken through the British adult and pediatric neurological surveillance units from February 2011. Patients were included if they met clinical case definitions within 1 month of proven influenza infection.

RESULTS

Twenty-five cases were identified: 21 (84%) in children and 4 (16%) in adults. Six (29%) children had preexisting neurological disorders. Polymerase chain reaction of respiratory secretions identified influenza A in 21 (81%; 20 of which [95%] were H1N1) and influenza B in 4 (15%). Twelve children had encephalopathy (1 with movement disorder), 8 had encephalitis, and 1 had meningoencephalitis. Two adults had encephalopathy with movement disorder, 1 had encephalitis, and 1 had Guillain-Barré syndrome. Seven individuals (6 children) had specific acute encephalopathy syndromes (4 acute necrotizing encephalopathy, 1 acute infantile encephalopathy predominantly affecting the frontal lobes, 1 hemorrhagic shock and encephalopathy, 1 acute hemorrhagic leukoencephalopathy). Twenty (80%) required intensive care, 17 (68%) had poor outcome, and 4 (16%) died.

CONCLUSIONS

This surveillance study described a cohort of adults and children with neurological manifestations of influenza. The majority were due to H1N1. More children than adults were identified; many children had specific encephalopathy syndromes with poor outcomes. None had been vaccinated, although 8 (32%) had indications for this. A modified classification system is proposed based on our data and the increasing spectrum of recognized acute encephalopathy syndromes.

The functional, social and economic impact of acute encephalitis syndrome in Nepal--a longitudinal follow-up study

BACKGROUND

Over 133,000 children present to hospitals with Acute Encephalitis Syndrome (AES) annually in Asia. Japanese encephalitis (JE) accounts for approximately one-quarter of cases; in most cases no pathogen is identified and management is supportive. Although JE is known to result in neurological impairment, few studies have examined the wider impact of JE and AES on patients and their families.

METHODOLOGY/PRINCIPAL FINDINGS

Children (aged 1 month-14 years) with AES were assessed 5-12 months after discharge from two Nepali hospitals. Assessment included clinical examination, the Liverpool Outcome Score (LOS) - a validated assessment of function following encephalitis, questionnaires about the child's social participation since discharge, and out-of-pocket costs to the family. Children were classified as JE or 'other AES' based on anti-JE virus antibody titres during acute illness. Contact was made with the families of 76% (73/96) of AES children. Six children had died and one declined participation. 48% (32/66) reported functional impairment at follow-up, most frequently affecting behaviour, language or limb use. Impairment was more frequent in JE compared to 'other AES' cases (68% [13/19] versus 40% [19/47]; p = 0.06). 49% (26/53) had improvement in LOS between discharge and follow-up. The median out-of-pocket cost to families, including medical bills, medication and lost earnings was US$ 1151 (10 times their median monthly income) for children with severe/moderate impairment and $524 (4.6 times their income) for those with mild/no impairment (P = 0.007). Acute admission accounted for 74% of costs. Social participation was limited in 21% of children (n = 14).

CONCLUSIONS/SIGNIFICANCE

Prolonged functional impairment was common following AES. Economic impact to families was substantial. Encouragingly, almost half the children improved after discharge and most reported sustained social participation. This study highlights a need for long-term medical support following AES. Rationalisation of initial expensive hospital treatments may be warranted, especially since only supportive treatment is available.

An investigation into the relationship between vigabatrin, movement disorders, and brain magnetic resonance imaging abnormalities in children with infantile spasms

AIM

We aimed to investigate the relationship between movement disorders, changes on brain magnetic resonance imaging (MRI), and vigabatrin therapy in children with infantile spasms.

METHOD

Retrospective review and brain MRI analysis of children enrolled in the International Collaborative Infantile Spasms Study (ICISS) who developed a movement disorder on vigabatrin therapy. Comparisons were made with controls within ICISS who had no movement disorder.

RESULTS

Ten of 124 infants had a movement disorder and in eight it had developed on vigabatrin therapy. Two had a movement disorder that resolved on dose-reduction of vigabatrin, one had improvement on withdrawing vigabatrin, two had resolution without any dose change, and in three it persisted despite vigabatrin withdrawal. The typical brain MRI changes associated with vigabatrin therapy were noted in two infants. Ten control infants were identified. Typical MRI changes noted with vigabatrin were noted in three controls.

INTERPRETATION

It is possible that in two out of eight cases, vigabatrin was associated with the development of a movement disorder. In six out of eight cases a causal relationship was less plausible. The majority of infants treated with vigabatrin did not develop a movement disorder. MRI changes associated with vigabatrin do not appear to be specifically related to the movement disorder.

The prevalence of neurodevelopmental disorders in children prenatally exposed to antiepileptic drugs

The aim of this study was to compare the prevalence of diagnosed neurodevelopmental disorders in children exposed, in utero, to different antiepileptic drug treatments. A prospective cohort of women with epilepsy and a control group of women without epilepsy were recruited from antenatal clinics. The children of this cohort were followed longitudinally until 6 years of age (n=415). Diagnosis of a neurodevelopmental disorder was made independently of the research team. Multiple logistic regression analysis revealed an increase in risk of neurodevelopmental disorders in children exposed to monotherapy sodium valproate (VPA) (6/50, 12.0%; aOR 6.05, 95%CI 1.65 to 24.53, p=0.007) and in those exposed to polytherapy with sodium VPA (3/20, 15.0%; aOR 9.97, 95% CI 1.82 to 49.40, p=0.005) compared with control children (4/214; 1.87%). Autistic spectrum disorder was the most frequent diagnosis. No significant increase was found among children exposed to carbamazepine (1/50) or lamotrigine (2/30). An accumulation of evidence demonstrates that the risks associated with prenatal sodium VPA exposure include an increased prevalence of neurodevelopmental disorders. Whether such disorders are discrete or represent the severe end of a continuum of altered neurodevelopmental functioning requires further investigation. Replication and extension of this research is required to investigate the mechanism(s) underpinning the relationship. Finally, the increased likelihood of neurodevelopmental disorders should be communicated to women for whom sodium VPA is a treatment option.

Migrating partial seizures of infancy: expansion of the electroclinical, radiological and pathological disease spectrum

Migrating partial seizures of infancy, also known as epilepsy of infancy with migrating focal seizures, is a rare early infantile epileptic encephalopathy with poor prognosis, presenting with focal seizures in the first year of life. A national surveillance study was undertaken in conjunction with the British Paediatric Neurology Surveillance Unit to further define the clinical, pathological and molecular genetic features of this disorder. Fourteen children with migrating partial seizures of infancy were reported during the 2 year study period (estimated prevalence 0.11 per 100,000 children). The study has revealed that migrating partial seizures of infancy is associated with an expanded spectrum of clinical features (including severe gut dysmotility and a movement disorder) and electrographic features including hypsarrhythmia (associated with infantile spasms) and burst suppression. We also report novel brain imaging findings including delayed myelination with white matter hyperintensity on brain magnetic resonance imaging in one-third of the cohort, and decreased N-acetyl aspartate on magnetic resonance spectroscopy. Putaminal atrophy (on both magnetic resonance imaging and at post-mortem) was evident in one patient. Additional neuropathological findings included bilateral hippocampal gliosis and neuronal loss in two patients who had post-mortem examinations. Within this cohort, we identified two patients with mutations in the newly discovered KCNT1 gene. Comparative genomic hybridization array, SCN1A testing and genetic testing for other currently known early infantile epileptic encephalopathy genes (including PLCB1 and SLC25A22) was non-informative for the rest of the cohort.

Suboptimal management of central nervous system infections in children: a multi-centre retrospective study

OBJECTIVE

We aimed to audit the regional management of central nervous system (CNS) infection in children.

METHODS

The study was undertaken in five district general hospitals and one tertiary paediatric hospital in the Mersey region of the UK. Children admitted to hospital with a suspected CNS infection over a three month period were identified. Children were aged between 4 weeks and 16 years old. Details were recorded from the case notes and electronic records. We measured the appropriateness of management pathways as outlined by national and local guidelines.

RESULTS

Sixty-five children were identified with a median age of 6 months (range 1 month to 15 years). Ten had a CNS infection: 4 aseptic meningitis, 3 purulent meningitis, 3 encephalitis [2 with herpes simplex virus (HSV) type 1]. A lumbar puncture (LP) was attempted in 50 (77%) cases but only 43 had cerebrospinal fluid (CSF) available for analysis. Of these 24 (57%) had a complete standard set of tests performed. Fifty eight (89%) received a third generation cephalosporin. Seventeen (26%) also received aciclovir with no obvious indication in 9 (53%). Only 11 (65%) of those receiving aciclovir had CSF herpes virus PCR. Seventeen had cranial imaging and it was the first management step in 14. Treatment lengths of both antibiotics and aciclovir were highly variable: one child with HSV encephalitis was only treated with aciclovir for 7 days.

CONCLUSIONS

The clinical management of children with suspected CNS infections across the Mersey region is heterogeneous and often sub-optimal, particularly for the investigation and treatment of viral encephalitis. National guidelines for the management of viral encephalitis are needed.

Congenital trigeminal anaesthesia: a rare preventable cause of visual loss in children

Congenital trigeminal anaesthesia (CTA) is a rare condition characterised by a congenital deficit involving all or part of the sensory component of the trigeminal nerve in children. It is a heterogeneous condition that can present in isolation or is associated with congenital abnormalities affecting the mesoderm, ectoderm and/or brainstem. The authors report a case of a 4-year-old girl who presented with reduced visual acuity, painless bilateral keratitis and painless non-healing lesions on the face, who was confirmed to have CTA on detailed neurophysiological investigations. She also had associated unilateral renal dysplasia and Duane syndrome. The authors also discuss an up-to-date review of the published cases of CTA in literature, the first of which was reported as early as 1984.

Childhood presentation of COL4A1 mutations

AIM

To describe the clinical and radiological features of four new families with a childhood presentation of COL4A1 mutation.

METHOD

We retrospectively reviewed the clinical presentation. Investigations included radiological findings and COL4A1 mutation analysis of the four cases. Affected family members were identified. COL4A1 mutation analysis was performed in all index cases and, where possible, in affected family members.

RESULTS

The three male and one female index cases presented with recurrent childhood-onset stroke, infantile hemiplegia/spastic quadriplegia, and infantile spasms. Additional features such as congenital cataracts and anterior segment dysgenesis were present. Microcephaly and developmental delay/learning difficulties were present in three cases. Three cases had one or more family member affected in multiple generations, with a total of 11 such individuals identified. The clinical features showed a wide intrafamilial variation. Magnetic resonance imaging (MRI) showed bilateral white matter change in all cases, except in one mutation-positive family member. Unilateral or bilateral porencephaly was present in cases with infantile hemiplegia, and a diagnosis of clinical stroke was supported by the presence of intracerebral haemorrhage. The age at diagnosis was between 1 year and 6 years for the children with presentation in infancy and 12 months after stroke in a 14-year-old male. Three new pathogenic mutations were identified in the COL4A1 gene.

INTERPRETATION

COL4A1 mutations can present in children with infantile hemiplegia/quadriplegia, stroke or epilepsy, and a motor disorder. The presence of eye features and white matter change on MRI in childhood can help point towards the diagnosis. Once the diagnosis is made, a careful search can identify affected family members.

Paediatric acquired demyelinating syndromes: incidence, clinical and magnetic resonance imaging features

Objective:

Changing trends in multiple sclerosis (MS) epidemiology may first be apparent in the childhood population affected with first onset acquired demyelinating syndromes (ADSs). We aimed to determine the incidence, clinical, investigative and magnetic resonance imaging (MRI) features of childhood central nervous system ADSs in the British Isles for the first time.

Methods:

We conducted a population active surveillance study. All paediatricians, and ophthalmologists (n = 4095) were sent monthly reporting cards (September 2009–September 2010). International Paediatric MS Study Group 2007 definitions and McDonald 2010 MS imaging criteria were used for acute disseminated encephalomyelitis (ADEM), clinically isolated syndrome (CIS) and neuromyelitis optica (NMO). Clinicians completed a standard questionnaire and provided an MRI copy for review.

Results:

Card return rates were 90%, with information available for 200/222 positive notifications (90%). After exclusion of cases, 125 remained (age range 1.3–15.9), with CIS in 66.4%, ADEM in 32.0% and NMO in 1.6%. The female-to-male ratio in children older than 10 years (n = 63) was 1.52:1 (p = 0.045). The incidence of first onset ADS in children aged 1–15 years old was 9.83 per million children per year (95% confidence interval [CI] 8.18–11.71). A trend towards higher incidence rates of ADS in children of South Asian and Black ethnicity was observed compared with White children. Importantly, a number of MRI characteristics distinguished ADEM from CIS cases. Of CIS cases with contrast imaging, 26% fulfilled McDonald 2010 MS diagnostic criteria.

Conclusions:

We report the highest surveillance incidence rates of childhood ADS. Paediatric MS diagnosis at first ADS presentation has implications for clinical practice and clinical trial design.

Management of suspected viral encephalitis in adults--Association of British Neurologists and British Infection Association National Guidelines

In the 1980s the outcome of patients with herpes simplex encephalitis was shown to be dramatically improved with aciclovir treatment. Delays in starting treatment, particularly beyond 48 h after hospital admission, are associated with a worse prognosis. Several comprehensive reviews of the investigation and management of encephalitis have been published. However, their impact on day-to day clinical practice appears to be limited. The emergency management of meningitis in children and adults was revolutionised by the introduction of a simple algorithm as part of management guidelines. In February 2008 a group of clinicians met in Liverpool to begin the development process for clinical care guidelines based around a similar simple algorithm, supported by an evidence base, whose implementation is hoped would improve the management of patients with suspected encephalitis.

Encephalitis in children

Encephalitis is an uncommon but potentially devastating neurological syndrome with different aetiologies including direct central nervous system infection with different agents (most commonly viral) and those mediated by the immune system. Whilst there have been several recent publications and guidelines on the management of bacterial central nervous system infections in adults and children, viral infections have been relatively neglected. Guidelines have been published for adults with encephalitis (www.liv.ac.uk/braininfections) but none exist for children. For these reasons, we have reviewed the literature on encephalitis and have formulated a suggested management strategy for children with suspected, clinically diagnosed and proven encephalitis. We have excluded neonates, as encephalitis in this age group has different clinical features and is beyond the scope of this review.

COL4A1 mutations associated with a characteristic pattern of intracranial calcification

Intracranial calcification (ICC) is a relatively common radiological finding in children undergoing investigation for neurological disorders. Many causes are recognised, and ICC is often regarded as a non-specific sign.From an ongoing study of ICC, we identified 5 patients with characteristic radiological features, in whom a mutation in the COL4A1 gene was found.All patients had CT and MR imaging. MR images demonstrated features of periventricular leukomalacia with irregular dilatation of the lateral ventricles with or without porencephaly, loss of hemispheric white matter volume, and high signal on T2 and FLAIR sequences within periventricular and deep white matter. Calcification was apparent on MR in 4 patients. CT scans demonstrated spot and linear calcification in the subependymal region and around areas of porencephaly. Calcification was also visible in the deep cerebral white matter and basal ganglia. 1 patient showed calcification in the central pons.ICC occurs in COL4A1-related disease. The radiological features are distinct from other conditions demonstrating recognisable patterns of ICC, such as congenital cytomegalovirus infection and Aicardi-Goutiéres syndrome. In the absence of a known risk factor for periventricular leukomalacia, the presence of these radio-logical findings should suggest the possibility of COL4A1-related disease.

Management of suspected viral encephalitis in children - Association of British Neurologists and British Paediatric Allergy, Immunology and Infection Group national guidelines

In the 1980s the outcome of patients with herpes simplex encephalitis was shown to be dramatically improved with aciclovir treatment. Delays in starting treatment, particularly beyond 48 h after hospital admission, are associated with a worse prognosis. Several comprehensive reviews of the investigation and management of encephalitis have been published. However, their impact on day-to-day clinical practice appears to be limited. The emergency management of meningitis in children and adults was revolutionised by the introduction of a simple algorithm as part of management guidelines. In February 2008 a group of clinicians met in Liverpool to begin the development process for clinical care guidelines based around a similar simple algorithm, supported by an evidence base, whose implementation is hoped would improve the management of patients with suspected encephalitis.

Paediatric UK demyelinating disease longitudinal study (PUDDLS)

Background

There is evidence that at least 5% of Multiple sclerosis (MS) cases manifest in childhood. Children with MS present with a demyelinating episode involving single or multiple symptoms prior to developing a second event (usually within two years) to then meet criteria for diagnosis. There is evidence from adult cohorts that the incidence and sex ratios of MS are changing and that children of immigrants have a higher risk for developing MS. A paediatric population should reflect the vanguard of such changes and may reflect trends yet to be observed in adult cohorts. Studying a paediatric population from the first demyelinating event will allow us to test these hypotheses, and may offer further valuable insights into the genetic and environmental interactions in the pathogenesis of MS.

Methods/Design

The Paediatric UK Demyelinating Disease Longitudinal Study (PUDDLS) is a prospective longitudinal observational study which aims to determine the natural history, predictors and outcomes of childhood CNS inflammatory demyelinating diseases. PUDDLS will involve centres in the UK, and will establish a cohort of children affected with a first CNS inflammatory demyelinating event for long-term follow up by recruiting for approximately 5 years. PUDDLS will also establish a biological sample archive (CSF, serum, and DNA), allowing future hypothesis driven research. For example, the future discovery of a biomarker will allow validation within this dataset for the evaluation of novel biomarkers. Patients will also be requested to consent to be contacted in the future. A secondary aim is to collaborate internationally with the International Paediatric Multiple Sclerosis Study Group when future collaborative studies are proposed, whilst sharing a minimal anonymised dataset. PUDDLS is the second of two jointly funded studies. The first (UCID-SS) is an epidemiological surveillance study that already received ethical approvals, and started on the 1st September 2009. There is no direct patient involvement, and UCID-SS aims to determine the UK and Ireland incidence of CNS inflammatory demyelinating disorders in children under 16 years.

Discussion

A paediatric population should reflect the vanguard of MS epidemiological changes and may reflect trends yet to be observed in adult MS cohorts. The restricted window between clinical expression of disease and exposure to environmental factors in children offers a unique research opportunity. Studying a paediatric population from the first demyelinating event will allow us to investigate the changing epidemiology of MS, and may offer further valuable insights into the genetic and environmental interactions in the pathogenesis of MS.

Acute central nervous system infections in adults--a retrospective cohort study in the NHS North West region

BACKGROUND

Over the last 15 years, bacterial meningitis has received considerable attention, including national guidelines, whilst viral central nervous system (CNS) infections have been relatively neglected. A recent pilot study suggested that management of patients with suspected viral encephalitis was often suboptimal.

AIM

To examine the relative incidence, clinical features and management of suspected acute CNS infections in adults across the NHS North West Region.

DESIGN

A multicentre cross-sectional retrospective cohort study at 10 hospitals across the region over 3 months (from September to December 2007). Following a screen of all patients who had cerebrospinal fluid (CSF) analysis or received intravenous aciclovir and/or third-generation cephalosporin, those with clinical features suspicious of a CNS infection were included. Management was compared with the national meningitis and regional encephalitis guidelines.

RESULTS

Three hundred and eighty-five patients were screened; 217 patients had a suspected CNS infection and 44 (20%) had a CNS infection: 18 aseptic meningitis (one herpes simplex virus [HSV]-2), 13 purulent meningitis (four Streptococcus pneumoniae) and 13 encephalitis (three HSV-1). The median (range) time from admission to suspicion of CNS infection and to LP was longer for patients with encephalitis than meningitis [4 (0.3-312) vs. 0.3 (0.1-12) h, P<0.001, and 23 (4-360) vs. 12 (2-48) h, P=0.042, respectively]; and the median time to treatment was longer for aciclovir than cephalosporin [7 (0.5-312) vs. 3 (0.3-312) h, P=0.002].

DISCUSSION

Encephalitis was as common as purulent meningitis, and HSV as common as Streptococcus pneumoniae. However, the management of patients with encephalitis was worse than meningitis. National encephalitis guidelines are needed.