The importance of recognizing faciobrachial dystonic seizures in rapidly progressive dementias

Cortical metabolic characteristics of anti-leucine-rich glioma-inactivated 1 antibody encephalitis based on 18F-FDG PET

Purpose

A general glucose metabolism pattern is observed in patients with anti-leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis; however, it is unclear whether further subregional metabolic differences exist. Therefore, the present study aimed to conduct an in-depth exploration of the features of glucose metabolism within specific brain areas using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET).

Materials and methods

This retrospective study enrolled thirteen patients confirmed with LGI1 antibody encephalitis who were admitted to Beijing Tiantan Hospital from June 2021 to September 2022. All patients underwent 18F-FDG PET before initiating clinical treatment. Changes in glucose metabolism in specific brain areas were analyzed using Cortex ID software. The laterality of 18F-FDG uptake was assessed, and differences in specific brain areas were compared using paired t-tests.

Results

Significant metabolic changes in at least one brain region in 11 out of 13 patients (84.6%) were revealed by semi-quantitative analysis (z-score > 2). A bilateral decrease in the 18F-FDG metabolic pattern was revealed in almost all brain regions of interest; in contrast, a hypermetabolic pattern was observed in the medial temporal region, with mean z-scores of 1.75 ± 3.27 and 2.36 ± 5.90 on the left and right sides, respectively (p = 0.497). In the prefrontal and temporal lobes, 18F-FDG metabolism was significantly lower in the lateral region than in the medial region on both sides. For the cingulate cortex, significant hypometabolism was also observed in the posterior part compared to the anterior counterpart on both the left (z-score: −1.20 ± 1.93 vs. −0.42 ± 1.18, respectively; p = 0.047) and right (z-score: −1.56 ± 1.96 vs. −0.33 ± 1.63, respectively; p = 0.001) sides. However, a significant difference in regional metabolism was observed only on the left side (p = 0.041).

Conclusion

An asymmetric 18F-FDG metabolic pattern exists in patients with anti-LGI1 encephalitis. Meanwhile, varied regional metabolic differences were revealed bilaterally in specific cerebral areas, which could be associated with the clinical manifestations.

Confusion and Hallucination in a Geriatric Patient. Pitfalls of a Rare Differential: Case Report of an Anti-LGI1-Encephalitis

Background

Confusion and hallucinations in geriatric patients are frequent symptoms and typically associated with delirium, late-life psychosis or dementia syndromes. A far rarer but well-established differential in patients with rapid cognitive deterioration, acute psychosis, abnormal movements and seizures is autoimmune encephalitis. Exemplified by our case we highlight clinical and economic problems arising in management of geriatric patients with cognitive decline and psychotic symptoms.

Case Presentation

A 77-year-old female caucasian patient with an unremarkable medical history was hospitalized after a fall in association with diarrhea and hyponatremia. Upon adequate therapy, disorientation and troubled short-term memory persisted. Within a week the patient developed visual hallucinations. Basic blood and urine samples and imaging (cranial computed tomography and magnetic resonance imaging) were unremarkable. With progressive cognitive decline, amnestic impairment, word finding difficulty and general apathy, psychiatric and neurologic expertise was introduced. Advanced diagnostics did not resolve a final diagnosis; an electroencephalogram showed unspecific generalized slowing. Extended clinical observation revealed visual hallucinations and faciobrachial dystonic seizures. A treatment with anticonvulsants was initiated. Cerebrospinal fluid ultimately tested positive for voltage-gated potassium channel LGl1 (leucine-rich-inactivated-1) antibodies confirming diagnosis of autoimmune anti-LGI1 encephalitis. Immediate immunotherapy (high-dose glucocorticoids and administration of intravenous immunoglobulin G) led to a rapid improvement of the patient’s condition. After immunotherapy was tapered, the patient had one relapse and completely recovered with reintroduction of glucocorticoids and initiation of therapy with rituximab.

Conclusion

Rapidly progressive dementia in geriatric patients demands a structured and multidisciplinary diagnostic approach. Accurate management and financially supportable care is a major issue in rare diseases such as anti-LGI1-encephalitis. Education and awareness about autoimmune encephalitis of all physicians treating a geriatric population is important in order to involve expertise and establish treatment within reasonable time.

Drug-resistant epilepsy at the age extremes: Disentangling the underlying etiology

The incidence of epilepsy is highest at the extreme age ranges: childhood and elderly age. The most common syndromes in these demographics - self-limited epilepsies of childhood and idiopathic generalized epilepsies in pediatric age, focal epilepsy with structural etiology in older people - are expected to be drug responsive. In this work, we focus on such epilepsy types, overviewing the complex clinical background of unexpected drug-resistance. For self-limited epilepsies of childhood and idiopathic generalized epilepsies, we illustrate drug-resistance resulting from syndrome misinterpretation, reason on possible unexpected courses of epilepsy, and explicate the influence of inappropriate treatments. For elderly-onset epilepsy, we show the challenges in differential diagnosis possibly leading to pseudoresistance and analyze how drug-resistant epilepsy can arise in stroke, neurocognitive disorders, brain tumors, and autoimmune encephalitis. In children and senior people, drug-resistance can be regarded as a hint to review the diagnosis or explore alternative therapeutic strategies. Refractory seizures are not only a therapeutic challenge, but also a cardinal sign not to be overlooked in syndromes commonly deemed to be drug-responsive.

Faciobrachial motor seizures: A more apt description?

Autoimmune encephalitis associated with antibodies against leucine-rich glioma inactivated protein (LGI1) is classically associated with brief, recurrent, contractions of facial and upper limb muscles, typically on the same side. Commonly described as 'faciobrachial dystonic seizures' (FBDS), these seizures have become the semiological hallmark of anti-LGI1 encephalitis. However, the facial and upper limb contractions observed in patients with anti-LGI1 encephalitis associated seizures are not always dystonic in nature. Here, we briefly highlight the case of a patient who was admitted to our institution with faciobrachial tonic-myoclonic seizures to emphasize the fact that faciobrachial seizures in anti-LGI1 encephalitis are not always dystonic. We also review the literature on the semiology of these seizures in patients diagnosed with anti-LGI1 encephalitis and propose a more apt description for this phenomenon. Our case as well as the literature highlights that in anti-LGI1 encephalitis the typical seizure semiology of faciobrachial distribution includes tonic, clonic, dystonic, and myoclonic activity in isolation or combination with or without plus features. Given that accurate labelling of clinical phenomenology enables a better understanding of the underlying epileptic networks and precise diagnosis, we would suggest a more inclusive term 'faciobrachial motor seizures' instead of 'faciobrachial dystonic seizures' to describe the typical seizure semiology of anti-LGI1 encephalitis. Based on the presence or absence of specific clinical features, these seizures can be further sub-classified as focal aware faciobrachial motor seizures, focal impaired awareness faciobrachial motor seizures or focal faciobrachial motor plus seizures (aware or impaired awareness).

Case Report/Case Series: Rare case of anti-LGI1 limbic encephalitis with rapidly progressive dementia, psychiatric symptoms, and frequently seizures: A case report

RATIONALE

Anti leucine-rich glioma inactivated 1 (LGI1) limbic encephalitis (LE) is rare autoimmune encephalitis, characterized by acute or subacute cognitive impairment, faciobrachial dystonic seizures, mental disorders, and refractory hyponatremia. As a type of treatable rapidly progressive dementia with a good prognosis, early, and accurate diagnosis is essential. We present a case of anti-LGI1 LE who was initially misdiagnosed with Alzheimer disease because his clinical manifestations were similar to Alzheimer disease.

PATIENT CONCERNS

A male patient presenting with rapidly progressive dementia, faciobrachial dystonic seizures, psychiatric disturbance, and refractory hyponatremia was admitted. The scores of Mini-Mental State Examination, Montreal Cognitive Assessment, and Neuropsychiatric Inventory were 19/30, 16/30, and 91/144, respectively. Brain magnetic resonance images indicated moderate atrophy of the hippocampus and abnormally hyperintensities in the left medial temporal and hippocampus.

DIAGNOSIS

The patient was diagnosed with anti-LGI1 LE based on the presence of LGI-1 antibodies in the cerebrospinal fluid and serum and clinical manifestations.

INTERVENTIONS

Patient was treated with glucocorticoid against LGI1, antiepileptic drug, cholinesterase inhibitors, and other adjuvant therapy.

OUTCOMES

The patient showed marked improvement on immunotherapy. Clinical symptoms were disappeared and the LGI-1 antibodies in cerebrospinal fluid and serum were both negative at the time of discharge.

CONCLUSIONS

Recognition of the specific symptoms and LGI-1 antibody test will be helpful for the early diagnosis, prompt immunotherapy, and good prognosis. This case raises the awareness that rapidly progressive dementia with frequent seizures could be caused by immunoreactions.

Faciobrachial Myoclonus as the Presenting Manifestation of Diabetic Keto-Acidosis

Background:

Chorea and ballism are well-recognized acute potentially reversible movement disorders as the presenting manifestation of non-ketotic hyperglycemic states among older type-2 diabetics. Myoclonus as the form of presentation of diabetic keto-acidosis (DKA) in previously undiagnosed type-1 diabetic has never been reported before.

Case report:

We herein report the case of a 36-year-old previously healthy patient who presented with acute onset incessant faciobrachial myoclonus for 10 days. The patient was found to be suffering from DKA and eventually diagnosed as type-1 diabetes mellitus. Myoclonus disappeared with achieving euglycemia and did not recur.

Discussion:

Apart from expanding the spectrum of acute movement disorder among diabetics, this case reiterates the importance of rapid bedside measurement of capillary blood glucose in all patients presenting with acute onset abnormal movements irrespective of their past glycemic status. This simple yet life-saving approach can clinch the diagnosis at the earliest and thus will avoid costly investigations and mismanagement.

Autoimmune Encephalitis in Latin America: A Critical Review

Autoimmune encephalitis is an increasingly recognized cause of encephalitis. The majority of case series report patients residing in developed countries in the northern hemisphere. The epidemiologic features of autoimmune encephalitis in Latin America are still unclear. The aim of the study was to perform a review of the clinical presentation of autoimmune encephalitis in Latin America and compare to world literature. References were identified by an in-depth literature search and selected on the basis of relevance to the topic and authors' judgment. We selected clinical studies and case reports published from 2007 to July, 2020 including patients from Latin American countries. Of the 379 patients included, the majority were cases of anti-NMDA receptor encephalitis (93.14%), followed by anti-VGKC-complex encephalitis (N = 17; 4.48%), anti-GAD encephalitis (N = 9; 2.37%), anti-AMPA receptor encephalitis (N = 1; 0.26%), anti-GABA receptor encephalitis (N = 1; 0. 26%), anti-mGluR5 encephalitis (N = 1; 0. 26%), and anti-mGluR1 encephalitis (N = 1; 0. 26%). Reported cases of Anti-NMDA encephalitis in Latin-America had a very slight female predominance, lower prevalence of associated tumors and a lower incidence of extreme delta brush on electroencephalogram. Autoimmune encephalitis is possibly underdiagnosed in underdeveloped countries. Its outcome after treatment, however, appears to be similarly favorable in Latin American patients as has been reported in developed countries based on available case reports and case series. Regional specificities in the manifestation of autoimmune encephalitis could be related to epidemiologic factors, such as the presence of different triggers and different genetic and immunologic background, that need to be studied by future research.

Brain Magnetic Resonance Imaging Characteristics of Anti-Leucine-Rich Glioma-Inactivated 1 Encephalitis and Their Clinical Relevance: A Single-Center Study in China

Objective: To characterize the magnetic resonance imaging (MRI) features of anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis and explore their clinical relevance.

Methods: Patients with anti-LGI1 encephalitis who underwent MRI at our center were included in this study. Baseline and follow-up MRI characteristics were evaluated, and relationships between lesion location and clinical symptoms were analyzed. The extent of signal abnormalities within the lesion overlap region was measured and correlated with modified Rankin Scale scores and serum antibody titer.

Results: Seventy-six patients were enrolled, of which 57 (75%) were classified as MR positive. Brain lesions were located in medial temporal lobe (MTL) (89%) and basal ganglia (BG) (28%). Hippocampus and amygdala were lesion hubs with more than 50% lesion overlap. BG lesions were found in 30% of patients with faciobrachial dystonic seizure (FBDS) and only 7% of patients without FBDS (p = 0.013). Meanwhile, MTL lesions were more commonly observed in patients with memory impairment (70 vs. 0%, p = 0.017). MRI features included hyperintensity and edema at baseline, as well as hypointensity and atrophy at follow-up. Correlations between signal intensity of lesion hubs (including hippocampus and amygdala) and modified Rankin Scale scores were found on T2 (r = 0.414, p < 0.001) and diffusion-weighted imaging (r = 0.456, p < 0.001).

Conclusion: MTL and BG are two important structures affected by anti-LGI1 encephalitis, and they are associated with distinctive symptoms. Our study provided evidence from Chinese patients that BG lesions are more commonly observed in patients with FBDS, potentially suggesting BG localization. Furthermore, in addition to supporting diagnosis, MRI has the potential to quantify disease severity.

Electroencephalographic findings in antileucine-rich glioma-inactivated 1 (LGI1) autoimmune encephalitis: A systematic review

BACKGROUND

Antileucine-rich glioma-inactivated 1 (LGI1) autoimmune encephalitis is a distinct syndrome of early onset faciobrachial dystonic seizures (FBDS) and other focal seizures followed by neuropsychiatric symptoms. The electroclinical syndrome of this condition is yet to be fully understood. The main objective of this study was to determine the frequencies of electroencephalogram (EEG) findings in patients diagnosed with anti-LGI1 autoimmune encephalitis through a systematic review of published relevant articles.

METHODS

Major electronic healthcare databases were searched for relevant published articles until July 2020.

RESULTS

From 327 articles, 23 case reports and 14 case series were included in the review after satisfying the eligibility criteria. Data from a total of 151 cases of definite anti-LGI1 encephalitis were analyzed in this systematic review. Epileptiform discharges were the most frequent finding at 57.3%. Focal electroencephalographic abnormalities including slow wave (59.3%) and epileptiform activities (53.5%) most commonly arise from the temporal region. Faciobrachial dystonic seizures often have no ictal electroencephalographic correlate but would show electrodecremental events when seizure duration is prolonged.

CONCLUSION

Electroencephalogram abnormalities are seen in anti-LGI1 autoimmune encephalitis with epileptiform discharges as the most common finding followed by focal slowing. These findings were most frequently seen arising in the temporal region. Further studies using a standardized protocol focusing on electroencephalographic findings in anti-LGI1 encephalitis with clinical correlation to disease stage and treatment outcomes in terms of seizure control and memory and cognitive function are needed. Particular attention on ictal electrodecremental activity during FBDS should be done in studies with a larger sample size.

The Clinical Value of 18 F-FDG-PET in Autoimmune Encephalitis Associated With LGI1 Antibody

Purpose: The metabolic patterns of ¹⁸F-fluoro-2-deoxy-d-glucose positron emission tomography (¹⁸F-FDG-PET) in autoimmune encephalitis associated with leucine-rich glioma-inactivated 1 antibody (LGI1 AE) are still unclear. We performed a cohort study to investigate the clinical metabolic characteristics and diagnostic value based on ¹⁸F-FDG-PET in patients with LGI1 AE.

Materials and Methods: A total of 34 patients including 18 patients (53%) in the acute phase and 16 patients (47%) in the chronic phase who were diagnosed with LGI1 AE were retrospectively analyzed from October 2014 to June 2018 at the Department of Neurology in Beijing Tiantan Hospital, the Capital Medical University. The clinical data were collected by searching through electronic medical records.

Results: The initial ¹⁸F-FDG-PET scan indicated a significant abnormal metabolic pattern in 31 LGI1 AE patients (91%), whereas only 20 patients (59%) showed an abnormal MRI signal (P < 0.05). The ¹⁸F-FDG-PET metabolic pattern was reversible after treatment; most of the patients showed an almost normal uptake of ¹⁸F-FDG-PET after discharge. Regarding the spatial distribution, the abnormal metabolic pattern in LGI1 AE subjects exhibiting hypermetabolism was specifically located in the basal ganglia (BG) and medial temporal lobe (MTL). BG hypermetabolism was observed in 28 subjects (82%), and 68% of patients showed MTL hypermetabolism. A total of 17 patients (50%) exhibited faciobrachial dystonic seizures (FBDS), and the remaining subjects showed non-FBDS symptoms (50 and 50%). BG-only hypermetabolism was detected in seven subjects in the FBDS subgroup (7/16) but in only one subject in the non-FBDS subgroup (1/15) (44 vs. 7%, P < 0.05).

Conclusion:¹⁸F-FDG-PET imaging was more sensitive than MRI in the diagnosis of LGI1 AE. Isolated BG hypermetabolism was more frequently observed in subjects with FBDS, suggesting the potential involvement of the BG.