Persistent brain metabolic impairment in long COVID patients with persistent clinical symptoms: a nine-month follow-up [18F]FDG-PET study.

PURPOSE: A hypometabolic profile involving the limbic areas, brainstem and cerebellum has been identified in long COVID patients using [18F]fluorodeoxyglucose (FDG)-PET. This study was conducted to evaluate possible recovery of brain metabolism during the follow-up of patients with prolonged symptoms. METHODS: Fifty-six adults with long COVID who underwent two brain [18F]FDG-PET scans in our department between May 2020 and October 2022 were retrospectively analysed, and compared to 51 healthy subjects. On average, PET1 was performed 7 months (range 3-17) after acute COVID-19 infection, and PET2 was performed 16 months (range 8-32) after acute infection, because of persistent severe or disabling symptoms, without significant clinical recovery. Whole-brain voxel-based analysis compared PET1 and PET2 from long COVID patients to scans from healthy subjects (p-voxel < 0.001 uncorrected, p-cluster < 0.05 FWE-corrected) and PET1 to PET2 (with the same threshold, and secondarily with a less constrained threshold of p-voxel < 0.005 uncorrected, p-cluster < 0.05 uncorrected). Additionally, a region-of-interest (ROI) semiquantitative anatomical approach was performed for the same comparisons (p < 0.05, corrected). RESULTS: PET1 and PET2 revealed voxel-based hypometabolisms consistent with the previously reported profile in the literature. This between-group analysis comparing PET1 and PET2 showed minor improvements in the pons and cerebellum (8.4 and 5.2%, respectively, only significant under the less constrained uncorrected p-threshold); for the pons, this improvement was correlated with the PET1-PET2 interval (r = 0.21, p < 0.05). Of the 14,068 hypometabolic voxels identified on PET1, 6,503 were also hypometabolic on PET2 (46%). Of the 7,732 hypometabolic voxels identified on PET2, 6,094 were also hypometabolic on PET1 (78%). The anatomical ROI analysis confirmed the brain hypometabolism involving limbic region, the pons and cerebellum at PET1 and PET2, without significant changes between PET1 and PET2. CONCLUSION: Subjects with persistent symptoms of long COVID exhibit durable deficits in brain metabolism, without progressive worsening.

Yellow fever vaccine-associated neurologic and viscerotropic disease: a 10-year case series of the French National Reference Center for Arboviruses with clinical and immunological insights.

BACKGROUND: Immunization against the Yellow fever virus (YFV) with the 17D live-attenuated vaccine is the most effective way to prevent the disease. However, unexpected severe adverse events can occur. They consist in a neurological impairment - neurological disease (YEL-AND), a YF-like illness - viscerotropic disease (YEL-AVD) or anaphylaxis. In this article, we describe the epidemiology, clinical and biological features of YEL-AND and YEL-AVD cases reported to the French National Reference Center for Arboviruses (NRCA) in the past 10 years. METHODS: We conducted a national, retrospective study using the database of the NRCA from June 2012 to June 2022. All patients whose biological samples were sent to the NRCA for detection of YFV by serology and/or RT-qPCR for a suspected vaccine-associated adverse event were included. We collected data by reading medical records and conducted complementary neuro-immunological analysis, followed by a search for autoimmunity against type-1-interferon when samples were available at the NRCA. RESULTS: There were 10 cases of YEL-AND and 2 cases of YEL-AVD reported to the NRCA in the past 10 years, which represented an overall incidence of 0.6 for 100 000 doses. A total of 6/12 cases were previously healthy patients (50%, mean age 31 years), and 4/12 cases had cardiovascular co-morbidities (42%, mean age 56 years). The majority of YEL-AND had a favourable outcome at 6 months of follow up. One YEL-AVD patient passed. In secondary analyses, we evidenced a significant blood cerebrospinal fluid (CSF) barrier dysfunction, without intrathecal synthesis of immunoglobulin and without argument for a neuron damage. We further detected a significant rate of anti-type-1alpha interferon antibodies in 3/10 tested patients (2 YEL-AND and 1 YEL-AVD). CONCLUSION: YEL-AND and YEL-AVD are rare events that can underlie defect in the innate immunity of apparently healthy or mild co-morbid subjects. Outcome was generally favourable in the YEL-AND cases of our series, but still life-threatening or even fatal in the YEL-AVD cases.

Splicing variants in NARS2 are associated with milder phenotypes and intra-familial variability.

Biallelic rare variants in NARS2 that encode the mitochondrial asparaginyl-tRNA synthetase are associated with a wide spectrum of clinical phenotypes ranging from severe neurodegenerative disorders to isolated mitochondrial myopathy or deafness. To date, only a small number of patients with NARS2 variants have been reported, and possible genotype-phenotype correlations are still lacking. Here, we present three siblings who had an early-onset hearing loss, while one developed severe symptoms in adulthood associated with early intellectual impairment, refractory seizures, moderate axonal sensorimotor neuropathy, and atypical psychiatric symptoms. Biochemical analysis revealed impairment of the activity and assembly of the respiratory chain complexes in this patient's muscle and fibroblasts. Whole Exome Sequencing allowed identification of a heterozygous variant NM_024678.5(NARS2):c.822G > C (p.Gln274His) that is known to be pathogenic and to affect splicing of the NARS2 gene, but was unable to detect a second variant in this gene. Coverage analysis and Sanger sequencing led to identification of a novel intronic deletion NM_024678.5(NARS2):c.922-21_922-19del in the three siblings in trans with the c.822G > C. Functional analysis by RT-PCR showed that this deletion was causing aberrant splicing and led to exon 9 skipping in NARS2 mRNA in patient fibroblasts. Our work expands the phenotype and genotype spectrum of NARS2-related disorders. We provide evidence of the pathogenic effect of a novel intronic deletion in the NARS2 gene and report on additional adult patients with a large intrafamilial variability associated with splice variants in this gene. More specifically, we detail the phenotype of the oldest living patient to date with NARS2 variants and, for the first time, we report the psychiatric symptoms associated with this gene. Our work confirms the complexity of genotype-phenotype correlation in patients with pathogenic NARS2 variants.

Herpetic encephalitis: which treatment for which body weight?

BACKGROUND: Prognosis of herpetic encephalitis remains severe, with a high proportion of deaths and sequelae. Its treatment is based on acyclovir, but the precise and most effective modalities of this treatment are not established. The objective of this study was to determine them. METHODS: For this, we carried out a descriptive, retrospective, monocentric study, using the current coding database at Marseille University Hospitals. Cohort was intended to be exhaustive for the disease, from January 2000 to June 2019, including patients hospitalized in intensive care and conventional hospitalization sector. Patients (n = 76) included were at least 16 years of age and had a clinical presentation, cerebral Magnetic Resonance Imaging, and/or electroencephalogram abnormalities consistent with herpetic encephalitis confirmed by a positive HSV-PCR in the CSF. Clinical data and treatment, including the doses actually administered to the patient, were compared according to patient's outcome. RESULTS: The mortality rate was 12%, whereas 49% had complete recovery and 39% sequelae impeding independence. Poor outcome was statistically associated with persistence of confusion, aphasia, and impaired consciousness lasting more than 5 days, superinfection, status epilepticus, and length of stay in intensive care unit. A statistical decision tree, constructed using the Classification And Regression Tree model, to prioritize treatment management, showed two main factors that influence the outcome: the patient's weight, and the average daily acyclovir dose actually administered. CONCLUSION: These results suggest to modify acyclovir management in herpetic encephalitis, for low-weight patients (< 79 kg) with a minimum dosage of 2550 mg/day (850 mg/ 8 h), when possible.

Decrease in the cortex/striatum metabolic ratio on [18F]-FDG PET: a biomarker of autoimmune encephalitis.

PURPOSE: The aim of this [18F]-FDG PET study was to determine the diagnostic value of the cortex/striatum metabolic ratio in a large cohort of patients suffering from autoimmune encephalitis (AE) and to search for correlations with the course of the disease. METHODS: We retrospectively collected clinical and paraclinical data of patients with AE, including brain 18F-FDG PET/CT. Whole-brain statistical analysis was performed using SPM8 software after activity parametrization to the striatum in comparison to healthy subjects. The discriminative performance of this metabolic ratio was evaluated in patients with AE using receiver operating characteristic curves against 44 healthy subjects and a control group of 688 patients with MCI. Relationship between cortex/striatum metabolic ratios and clinical/paraclinical data was assessed using univariate and multivariate analysis in patients with AE. RESULTS: Fifty-six patients with AE were included. In comparison to healthy subjects, voxel-based statistical analysis identified one large cluster (p-cluster < 0.05, FWE corrected) of widespread decreased cortex/striatum ratio in patients with AE. The mean metabolic ratio was significantly lower for AE patients (1.16 ± 0.13) than that for healthy subjects (1.39 ± 0.08; p < 0.001) and than that for MCI patients (1.32 ± 0.11; p < 0.001). A ratio threshold of 1.23 allowed to detect AE patients with a sensitivity of 71% and a specificity of 82% against MCI patients, and 98% against healthy subjects. A lower cortex/striatum metabolic ratio had a trend towards shorter delay before 18F-FDG PET/CT (p = 0.07) in multivariate analysis. CONCLUSION: The decrease in the cortex/striatal metabolic ratio has a good early diagnostic performance for the differentiation of AE patients from controls.

Persistent IgG anticardiolipin autoantibodies are associated with post-COVID syndrome.

Persistence of various symptoms in patients who have recovered from coronavirus disease 2019 (COVID-19) was recently defined as 'long COVID' or 'post-COVID syndrome' (PCS). This article reports a case of a 58-year-old woman who, although recovering from COVID-19, had novel and persistent symptoms including neurological complications that could not be explained by any cause other than PCS. In addition to a low inflammatory response, persistence of immunoglobulin G anticardiolipin autoantibody positivity and eosinopenia were found 1 year after acute COVID-19 infection, both of which have been defined previously as independent factors associated with the severity of COVID-19. The pathophysiological mechanism of PCS is unknown, but the possibility of persistence of the virus, especially in the nervous system, could be suggested with a post-infectious inflammatory or autoimmune reaction.

Adult-onset diagnosis of urea cycle disorders: Results of a French cohort of 71 patients.

Urea cycle disorders (UCD) are rare diseases that usually affect neonates or young children. During decompensations, hyperammonemia is neurotoxic, leading to severe symptoms and even coma and death if not treated rapidly. The aim was to describe a cohort of patients with adult onset of UCDs in a multicentric, retrospective and descriptive study of French adult patients with a diagnosis after 16 years of age of UCDs due to a deficiency in one of the 6 enzymes (arginase, ASL, ASS, CPS1, NAGS, OTC) or the two transporters (ORNT1 or citrin). Seventy-one patients were included (68% female, 32% male). The diagnosis was made in the context of (a) a metabolic decompensation (42%), (b) family history (55%), or (c) chronic symptoms (3%). The median age at diagnosis was 33 years (range 16-86). Eighty-nine percent of patients were diagnosed with OTC deficiency, 7% CPS1 deficiency, 3% HHH syndrome and 1% argininosuccinic aciduria. For those diagnosed during decompensations (including 23 OTC cases, mostly female), 89% required an admission in intensive care units. Seven deaths were attributed to UCD-6 decompensations and 1 epilepsy secondary to inaugural decompensation. This is the largest cohort of UCDs diagnosed in adulthood, which confirms the triad of neurological, gastrointestinal and psychiatric symptoms during hyperammonemic decompensations. We stress that females with OTC deficiency can be symptomatic. With 10% of deaths in this cohort, UCDs in adults remain a life-threatening condition. Physicians working in adult care must be aware of late-onset presentations given the implications for patients and their families.

Hemophagocytic Lymphohistiocytosis Gene Mutations in Adult Patients Presenting With CLIPPERS-Like Syndrome.

OBJECTIVE: To determine whether adult cases of Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS) may be related to familial hemophagocytic lymphohistiocytosis (HLH) causes, we have screened patients with adult-onset CLIPPERS for mutations in primary HLH-associated genes. METHODS: In our cohort of 36 patients fulfilling the criteria for probable or definite CLIPPERS according to the CLIPPERS-2017 criteria, we conducted a first study on 12 patients who consented to genetic testing. In these 12 patients, systemic HLH criteria were searched, and genetic analysis of 8 genes involved in primary HLH was performed. RESULTS: Four definite and 8 probable CLIPPERS were enrolled (n = 12). Mutations involved in HLH were identified in 2 definite and 2 probable CLIPPERS (4/12). Three of them had biallelic PRF1 mutations with reduced perforin expression in natural killer cells. The remaining patient had biallelic UNC13D mutations with cytotoxic lymphocyte impaired degranulation. None of the mutated patients reached the criteria for systemic HLH. During follow-up, 3 of them displayed atypical findings for CLIPPERS, including emergence of systemic non-Hodgkin lymphoma (1/3) and confluent gadolinium-enhancing lesions on brain MRI (3/3). CONCLUSIONS: In our patients presenting with adult-onset CLIPPERS, one-third have HLH gene mutations. This genetic treatable condition should be searched in patients with CLIPPERS, especially in those presenting with atypical findings.

High 18F-FDOPA PET Uptake in Primary Central Nervous System Lymphoma.

We present a 42-year-old woman with primary central nervous system lymphoma (PCNSL) and strong F-FDOPA PET uptake. F-FDOPA PET has high diagnostic accuracy in gliomas and brain metastases. The L-type amino acid transporter 1, targeted by F-FDOPA and C-MET PET, is a cell-type transporter usually upregulated in malignant tumors, including PCNSL. In this line, strong uptake was already shown with C-MET in PCNSL. We report the same findings with F-FDOPA. Consequently, PCNSL is a possible differential neoplastic diagnosis of F-FDOPA uptake among neoplastic lesions.

Contribution of Otoacoustic Emissions for Diagnosis of Atypical or Recurrent Intracranial Hypotension. A Cases Series.

BACKGROUND: The diagnosis of spontaneous or post-traumatic intracranial hypotension mainly rely on clinical features and neuroimaging. In atypical presentations, other non-invasive tests are missing to support the diagnosis of intracranial hypotension. The assessment of otoacoustic emissions (OAE) shown interest to monitor intracranial pressure mainly in cases of intracranial hypertension. This non-invasive method was also assessed in response to pressure change after lumbar puncture. A few reports showed abnormal results of distortion product otoacoustic emissions (DPOAE) in cases of spontaneous or post-traumatic intracranial hypotension. We describe additional results in a series of intracranial hypotension cases. We discuss the interest of DPOAE assessment in atypical presentations of intracranial hypotension. We review the other non-invasive tests reported in literature. METHODS: We studied 4 atypical or recurrent cases of spontaneous or post-traumatic intracranial hypotension by recording OAE in sitting then supine position. RESULTS: Unilateral or bilateral abnormal changes of DPOAE were recorded in all cases, in response to postural test. These changes were present even in the absence of vestibular symptoms. CONCLUSION: The study of OAE may be a non-invasive tool for the diagnosis of spontaneous intracranial hypotension.

Clinical presentation, treatment and outcome of IgG4-related pachymeningitis: From a national case registry and literature review.

Pachymeningitis is rare, either idiopathic or secondary to inflammatory disorders, after tumoral, surgical or infectious causes have been excluded. The fibroinflammatory IgG4-related disease is one of the etiologies of pachymeningitis with only few cases reported yet. From a single referral regional center, we evaluated the frequency of IgG4-related disease as the cause of inflammatory pachymeningitis in 10% of cases. From a National case registry of IgG4-related disease the pachymeningitis frequency was 4.1%. We report eight new cases with cranial, spinal or both involvements and a literature review of 46 pathological proven cases. We observed that IgG4-related pachymeningitis is in most cases not associated to extra-neurological manifestations of the disease. Only 27% of spinal and 40% of cranial IgG4-related pachymeningitis are associated with other disease localizations. First line treatment strategies included surgery and steroids. The use of immunosuppressants or rituximab was necessary in 18% of spinal and 54% of cranial localizations. Some patients remained with sequellae and clinical and/or radiological improvement can be difficult to obtain.

Post-malaria neurological syndrome: Imported case series and literature review to unscramble the auto-immune hypothesis.

Post-malaria neurological syndrome (PMNS) is a complication that occurs after recovery from a severe Plasmodium falciparum attack. Over the past two decades, the description of several imported cases has confirmed that this syndrome is a clearly distinct entity, different from other post malarial neurological disorders. However, the underlying mechanisms are not yet elucidated. Herein, we present five imported PMNS cases managed in Marseille, France. The detection of neuronal surface antibodies to an encephalitic syndrome of unknown origin allowed us to reveal positivity of anti Voltage-Gated-Potassium Channel antibodies (anti VGKC) in one of them. Using treatment options from other autoimmune encephalitis has to be explored in patients with PMNS.

Adult Niemann-Pick disease type C in France: clinical phenotypes and long-term miglustat treatment effect.

BACKGROUND: Niemann-Pick disease type C (NP-C) is a neurodegenerative lysosomal lipid storage disease caused by autosomal recessive mutations in the NPC1 or NPC2 genes. The clinical presentation and evolution of NP-C and the effect of miglustat treatment are described in the largest cohort of patients with adolescent/adult-onset NP-C studied to date. METHODS: Observational study based on clinical chart data from adult patients with NP-C (> 18 year old) diagnosed in France between 1990 and 2015. Retrospective data from patients at diagnosis, onset of miglustat therapy (if applicable), and last follow up were analysed. RESULTS: In France, patients with an adolescent-adult neurological form constituted approximately 25% of all NP-C cases diagnosed during the study period. Forty-seven patients (46 with NP-C1 and one with NP-C2; 53% female) were included. Mean ± SD (range) ages at neurological onset and diagnosis were 23.9 ± 12.5 (8-56) years and 34 ± 13.5 (15-65) years, respectively. At presentation, patients mainly had 1) impaired gait due to cerebellar ataxia and/or dystonia, 2) and/or cognitive/behavioural manifestations, 3) and/or psychotic signs. Initially, almost half of patients had only one of the above three neuro-psychiatric manifestations. Vertical supranuclear gaze palsy, usually occurring without patient complaint, was only detected on careful clinical examination and was recorded in most patients (93%) at the time of diagnosis, several years after neurological onset. Thirty-seven patients (79%) received miglustat, among whom seventeen (46%) continued beyond 2 years (at last follow up) to a maximum of 9.8 years. Eight patients (22%) discontinued treatment early due to side effects (n = 3) or perceived lack of efficacy (n = 5).Miglustat treatment duration correlated significantly with reduced neurological worsening (p < 0.001). Treatment for≥2 years was associated with improved patient survival (p = 0.029). Good responses to miglustat were associated with less severe neurological disability at the start of miglustat treatment (p = 0.02). CONCLUSION: The proportion of adolescent/adult-onset NP-C cases diagnosed in France increased 2.5-fold since 2009 compared with the 2000-2008 period due to improved awareness. Adolescent/adult-onset NP-C frequently presented initially with a non-specific isolated neuro-psychiatric manifestation (motor, cognitive or psychotic). Patients with less severe neurological disability responded better to miglustat therapy.

Psychiatric adult-onset of urea cycle disorders: A case-series.

Adult onset urea cycle disorders (UCD) may present with psychiatric symptoms, occasionally as the initial presentation. We aimed to describe the characteristics of patients presenting with a psychiatric adult-onset of UCDs, to discuss which signs could suggest this diagnosis in such a situation, and to determine which tests should be conducted. A survey of psychiatric symptoms occurring in teenagers or adults with UCD was conducted in 2010 among clinicians involved in the French society for the study of inborn errors of metabolism (SFEIM). Fourteen patients from 14 to 57 years old were reported. Agitation was reported in 10 cases, perseveration in 5, delirium in 4, and disinhibition in 3 cases. Three patients had pre-existing psychiatric symptoms. All patients had neurological symptoms associated with psychiatric symptoms, such as ataxia or dysmetria, psychomotor slowing, seizures, or hallucinations. Fluctuations of consciousness and coma were reported in 9 cases. Digestive symptoms were reported in 7 cases. 9 patients had a personal history suggestive of UCD. The differential diagnoses most frequently considered were exogenous intoxication, non-convulsive status epilepticus, and meningoencephalitis. Hyperammonemia (180-600 µmol/L) was found in all patients. The outcome was severe: mechanical ventilation was required in 10 patients, 5 patients died, and only 4 patients survived without sequelae. Adult onset UCDs can present with predominant psychiatric symptoms, associated with neurological involvement. These patients, as well as patients presenting with a suspicion of intoxication, must have UCD considered and ammonia measured without delay.