Magnetic resonance imaging and magnetic resonance spectroscopy in a young male patient with anti-N-methyl-D-aspartate receptor encephalitis and uncommon cerebellar involvement: A case report with review of the literature

Anti-N-methyl-D-aspartate receptor-associated encephalitis: A review of clinicopathologic hallmarks and multimodal imaging manifestations

Anti-N-methyl-D-aspartate receptor-associated encephalitis (NMDARE) is a rare immune-mediated neuroinflammatory condition characterized by the rapid onset of neuropsychiatric symptoms and autonomic dysfunction. The mechanism of pathogenesis remains incompletely understood, but is thought to be related to antibodies targeting the GluN1 subunit of the NMDA receptor with resultant downstream dysregulation of dopaminergic pathways. Young adults are most frequently affected; the median age at diagnosis is 21 years. There is a strong female predilection with a female sex predominance of 4:1. NMDARE often develops as a paraneoplastic process and is most commonly associated with ovarian teratoma. However, NMDARE has also been described in patients with small cell lung cancer, clear cell renal carcinoma, and other benign and malignant neoplasms. Diagnosis is based on correlation of the clinical presentation, electroencephalography, laboratory studies, and imaging. Computed tomography, positron emission tomography, and magnetic resonance imaging are essential to identify an underlying tumor, exclude clinicopathologic mimics, and predict the likelihood of long-term functional impairment. Nuclear imaging may be of value for prognostication and to assess the response to therapy. Treatment may involve high-dose corticosteroids, intravenous immunoglobulin, and plasma exchange. Herein, we review the hallmark clinicopathologic features and imaging findings of this rare but potentially devastating condition and summarize diagnostic criteria, treatment regimens, and proposed pathogenetic mechanisms.

Neurologic Presentation of Probable Seronegative Paraneoplastic Encephalitis in a Woman With an Ovarian Teratoma

We describe a case of probable autoimmune encephalitis developed as a result of paraneoplastic syndrome in a woman with an ovarian teratoma. Patients may present with psychiatric and neurological symptoms, which are caused by anti-N-methyl-D-aspartate (anti-NMDA) receptor antibodies produced in response to a teratoma that crosses the blood-brain barrier and damages brain tissue in the limbic area, causing encephalitis. Our patient presented with seizures, myoclonus, and memory problems. This is a relatively newly discovered and rare problem; however, it can be quite debilitating if left untreated. This diagnosis may be often missed due to the absence of highly sensitive tests. Autoimmune encephalitis has to be on the list of differential diagnoses for patients with new-onset psychiatric or neurological symptoms.

Clinical and Electroencephalographic Features of the Seizures in Neuronal Surface Antibody-Associated Autoimmune Encephalitis

Objectives: To investigate clinical and electroencephalographic features of the seizures in different types of neuronal surface antibody (NSAb)-associated autoimmune encephalitis (AE).

Methods: The clinical data of the seizures were analyzed in 18 patients with NSAb-associated AEs diagnosed in the First Affiliated Hospital of Dalian Medical University.

Results: From May 2013 to April 2019, a total of 18 cases of NSAb-associated AE were diagnosed, including 9 cases of leucine-rich glioma-inactivated 1 protein (LGI1) antibody-associated encephalitis, 7 cases of anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis, and 2 cases of anti-γ-aminobutyric acid B receptor (GABA_BR) encephalitis. All nine cases (100%) with LGI1 AE had seizures manifesting in three types: faciobranchial dystonia seizure (FBDS) (44.4%), mesial temporal lobe epilepsy (MTLE)-like seizure (66.7%), and focal to bilateral tonic–clonic seizure (FBTCS) (77.8%). Six of nine (66.7%) showed abnormal signal on hippocampus or basal ganglia in brain MRI. Five of seven cases (71%) with anti-NMDAR encephalitis had seizures manifesting in three types: focal aware seizure (40%), focal-impaired awareness seizure (20%), generalized tonic–clonic seizure (GTCS) (100%), and status epilepticus (SE) (40%). Three of seven (42.8%) showed abnormalities in brain MRI. Both patients with anti-GABA_BR encephalitis had seizures manifesting in two types: GTCS and MTLE-like seizure, one with SE. One showed abnormal signal on left hippocampus in brain MRI. All patients (100%) with three types of AE had abnormalities in electroencephalogram (EEG), showing diffuse (4/18) or focal slow waves (14/18) in background, interictal (10/18), or ictal (6/18) epileptic discharges in the temporal or other regions; two patients with anti-NMDAR encephalitis showed delta activity or rhythm in frontotemporal region. All patients with seizures showed good response to immunotherapy except one with LGI1 AE.

Conclusions: Most patients with NSAb-associated AE had seizures; seizure types varied between different types of AE. In LGI1 AE, the hippocampus and basal ganglia were two main targets; the corresponding seizure type was MTLE-like seizure and FBDS, respectively. Anti-NMDAR encephalitis had more generalized than focal seizures. Delta activity or rhythm in the frontotemporal region in EEG was helpful for diagnosis. Anti-GABA_BR encephalitis was characterized by refractory seizures as initial symptom, mainly GTCS or MTLE-like seizure. Most seizures in NSAb-associated AE showed good response to immunotherapy, and antiepileptic drugs should be considered as an add-on symptomatic treatment.

Catatonia in N-methyl-d-aspartate receptor antibody encephalitis: Phenomenological characteristics from a systematic review of case reports

OBJECTIVE

To ascertain the phenomenological characterisation of catatonia in N-methyl-d-aspartate receptor antibody encephalitis (NMDAr-AbE).

METHODS

A systematic review of case reports was undertaken in accordance with PRISMA guidelines. Case reports of NMDAr-AbE containing sufficient information on the cases' clinical presentation and meeting the study's inclusion criteria were selected. Cases were searched for clinical data in keeping with core catatonic signs by applying the screening instrument of the Bush-Francis Catatonia Rating Scale. When two or more core signs were ascertained catatonia was considered to be present.

RESULTS

2645 records were identified through the database search. Following screening and application of eligibility/inclusion criteria 139 articles were selected reporting on 189 individual subjects. Catatonia was present in 60% of these cases. The most prevalent signs were immobility/stupor (70%), mutism (67%), excitement (50%), posturing/catalepsy (34%), stereotypies (31%), and rigidity (30%). Immobility/stupor and excitement co-occurred in the same patient in 33% of cases.

CONCLUSION

The phenomenological profile of catatonia in this sample of cases of NMDAr-AbE was characterised by a preponderance of signs in the hypokinetic spectrum. However, excitement often co-occurred in these patients suggesting that fluctuations in catatonic semiology may be frequent.

Changes in metabolites in the brain of patients with fibromyalgia after treatment with an NMDA receptor antagonist

The aims of this work were to evaluate whether the treatment of patients with fibromyalgia with memantine is associated with significant changes in metabolite concentrations in the brain, and to explore any changes in clinical outcome measures. Magnetic resonance spectroscopy was performed of the right anterior and posterior insula, both hippocampi and the posterior cingulate cortex. Questionnaires on pain, anxiety, depression, global function, quality of life and cognitive impairment were used. Ten patients were studied at baseline and after three months of treatment with memantine. Significant increases were observed in the following areas: N-acetylaspartate (4.47 at baseline vs. 4.71 at three months, p = 0.02) and N-acetylaspartate+N-acetylaspartate glutamate in the left hippocampus (5.89 vs. 5.98; p = 0.007); N-acetylaspartate+N-acetylaspartate glutamate in the right hippocampus (5.31 vs 5.79; p = 0.01) and the anterior insula (7.56 vs. 7.70; p = 0.033); glutamate+glutamine/creatine ratio in the anterior insula (2.03 vs. 2.17; p = 0.022) and the posterior insula (1.77 vs. 2.00; p = 0.004); choline/creatine ratio in the posterior cingulate (0.18 vs. 0.19; p = 0.023); and creatine in the right hippocampus (3.60 vs. 3.85; p = 0.007). At the three-month follow-up, memantine improved cognitive function assessed by the Cognition Mini-Exam (31.50, SD = 2.95 vs. 34.40, SD = 0.6; p = 0.005), depression measured by the Hamilton Depression Scale (7.70, SD = 0.81 vs. 7.56, SD = 0.68; p = 0.042) and severity of illness measured by the Clinical Global Impression severity scale (5.79, SD = 0.96 vs. 5.31, SD = 1.12; p = 0.007). Depression, clinical global impression and cognitive function showed improvement with memantine. Magnetic resonance spectroscopy could be useful in monitoring response to the pharmacological treatment of fibromyalgia.

Phylogenetic Analysis to Explore the Association Between Anti-NMDA Receptor Encephalitis and Tumors Based on microRNA Biomarkers

MicroRNA (miRNA) is a small non-coding RNA that functions in the epigenetics control of gene expression, which can be used as a useful biomarker for diseases. Anti-NMDA receptor (anti-NMDAR) encephalitis is an acute autoimmune disorder. Some patients have been found to have tumors, specifically teratomas. This disease occurs more often in females than in males. Most of them have a significant recovery after tumor resection, which shows that the tumor may induce anti-NMDAR encephalitis. In this study, I review microRNA (miRNA) biomarkers that are associated with anti-NMDAR encephalitis and related tumors, respectively. To the best of my knowledge, there has not been any research in the literature investigating the relationship between anti-NMDAR encephalitis and tumors through their miRNA biomarkers. I adopt a phylogenetic analysis to plot the phylogenetic trees of their miRNA biomarkers. From the analyzed results, it may be concluded that (i) there is a relationship between these tumors and anti-NMDAR encephalitis, and (ii) this disease occurs more often in females than in males. This sheds light on this issue through miRNA intervention.

Pattern Recognition of the Multiple Sclerosis Syndrome

During recent decades, the autoimmune disease neuromyelitis optica spectrum disorder (NMOSD), once broadly classified under the umbrella of multiple sclerosis (MS), has been extended to include autoimmune inflammatory conditions of the central nervous system (CNS), which are now diagnosable with serum serological tests. These antibody-mediated inflammatory diseases of the CNS share a clinical presentation to MS. A number of practical learning points emerge in this review, which is geared toward the pattern recognition of optic neuritis, transverse myelitis, brainstem/cerebellar and hemispheric tumefactive demyelinating lesion (TDL)-associated MS, aquaporin-4-antibody and myelin oligodendrocyte glycoprotein (MOG)-antibody NMOSD, overlap syndrome, and some yet-to-be-defined/classified demyelinating disease, all unspecifically labeled under MS syndrome. The goal of this review is to increase clinicians’ awareness of the clinical nuances of the autoimmune conditions for MS and NMSOD, and to highlight highly suggestive patterns of clinical, paraclinical or imaging presentations in order to improve differentiation. With overlay in clinical manifestations between MS and NMOSD, magnetic resonance imaging (MRI) of the brain, orbits and spinal cord, serology, and most importantly, high index of suspicion based on pattern recognition, will help lead to the final diagnosis.

Effects of serial macrocyclic-based contrast materials gadoterate meglumine and gadobutrol administrations on gadolinium-related dentate nuclei signal increases in unenhanced T1-weighted brain: a retrospective study in 158 multiple sclerosis (MS) patients

PURPOSE

To perform T1 signal intensity (SI) measurements in the dentate nuclei of adult patients with confirmed multiple sclerosis (MS) after serial administrations of the macrocyclic gadolinium-based contrast agents (GBCAs), gadoterate meglumine and gadobutrol.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board and informed consent was waived. A review of our PACS database for the period from March 1, 2007 to July 31, 2016 revealed 158 confirmed MS patients who received exclusively either gadoterate meglumine (n = 81) or gadobutrol (n = 77) for diagnosis and follow-up. SI measurements on unenhanced T1-weighted images were performed on all scans of all patients and at regions of interest (ROIs) positioned on the dentate nucleus (DN) and pons. The dentate nucleus-to-pons (DNP) T1-SI ratio was subsequently calculated. Unpaired T test and regression analysis were used to evaluate statistical differences.

RESULTS

An increase in DNP was noted between the first and last MR examinations for both gadoterate meglumine (0.0032 ± 0.0216) and gadobutrol (0.0019 ± 0.0346). Although the differences were not statistically significant based across the entire patient population, visible T1 hyperintensity in the DN was noted in approximately one-third of all patients in each group that received at least five administrations of either GBCA.

CONCLUSIONS

SI increases on unenhanced T1-weighted images possibly indicative of gadolinium retention occur after serial administrations of the macrocyclic GBCAs, gadoterate meglumine and gadobutrol.

Neuroleptic malignant syndrome: an easily overlooked neurologic emergency

Neuroleptic malignant syndrome is an unpredictable iatrogenic neurologic emergency condition, mainly arising as an idiosyncratic reaction to antipsychotic agent use. It is characterized by distinctive clinical features including a change in mental status, generalized rigidity, hyperpyrexia, and dysautonomia. It can be lethal if not diagnosed and treated properly. Mortality and morbidity attributed to this syndrome have recently declined markedly due to greater awareness, earlier diagnosis, and intensive care intervention. In most cases, the syndrome occurs as a result of a rapid increase in a dose of neuroleptic, especially one of the long-acting ones. Pathophysiology behind this syndrome is attributed to a dopamine receptor blockade inside the neurons rendered by the offending drug and excessive calcium release from the sarcoplasmic reticulum of skeletal myocytes. Laboratory tests, although not diagnostic, may assist in assessing the severity of the syndrome and also the consequent complications. The syndrome has been described in all age groups and occurs more in males than in females. Genetics appears to be central regarding the etiology of the syndrome. Stopping the use of the offending agent, cold intravenous fluids, and removal of the causative agent and its possible active metabolites is the cornerstone of treatment. Periodic observation of psychotic patients recently started on antipsychotic medications, especially those being treated with depot preparations, may aid to an early diagnosis of the syndrome and lead to early treatment.

Is size an essential criterion to define tumefactive plaque? MR features and clinical correlation in multiple sclerosis

Tumefactive multiple sclerosis is an inflammatory demyelinating disease of the central nervous system. It has recently been described as a rare subtype of multiple sclerosis (MS) characterised by the appearance of solitary or multiple space-occupying lesions associated with imaging characteristics mimicking neoplasm. Atypical features include plaque size >2 cm with mass effect, oedema, and/or ring enhancement on magnetic resonance (MR) images.This study is a retrospective review designed to evaluate the prevalence of tumefactive plaques in a selected population of 440 MS patients referred to our MS centre in Southern Italy between 2005 and 2014. We analysed the radiographic features of lesions ranging in size from 0.5 to 2 cm to establish whether smaller plaques with MR characteristics similar to tumefactive plaques present different symptoms, disease evolution and prognosis. We also aimed to ascertain if MR features suggestive of biological aggressiveness could be useful prognostic criteria for a correct diagnosis of the disease and subsequent treatment. Our data suggest that lesions 0.5-2 cm and >2 cm have similar MR features and clinical evolution.