Post-streptococcal autoimmune dystonia with isolated bilateral striatal necrosis

De Novo Movement Disorders and COVID-19: Exploring the Interface

Background

Neurological manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are being widely documented. However, movement disorders in the setting of 2019 coronavirus infectious disease (COVID-19) have been a strikingly less discussed topic.

Objectives

To summarize available pieces of evidence documenting de novo movement disorders in COVID-19.

Methods

We used the existing PRISMA consensus statement. Data were collected from PubMed, EMBASE, Web of Science, and Scopus databases up to the 29th January, 2021, using pre-specified searching strategies.

Results

Twenty-two articles were selected for the qualitative synthesis. Among these, a total of 52 patients with de novo movement disorders were reported. Most of these had myoclonus, ataxia, tremor or a combination of these, while three had parkinsonism and one a functional disorder. In general, they were managed successfully by intravenous immunoglobulin or steroids. Some cases, primarily with myoclonus, could be ascribed to medication exposures, metabolic disturbances or severe hypoxia, meanwhile others to a post-or para-infectious immune-mediated mechanism. SARS-CoV-2 could also invade the central nervous system, through vascular or retrograde axonal pathways, and cause movement disorders by two primary mechanisms. Firstly, through the downregulation of angiotensin-converting enzyme 2 receptors, resulting in the imbalance of dopamine and norepinephrine; and secondly, the virus could cause cellular vacuolation, demyelination and gliosis, leading to encephalitis and associated movement disorders.

Conclusion

De novo movement disorders are scantly reported in COVID-19. The links between SARS-CoV-2 and movement disorders are not yet established. However, we should closely monitor COVID-19 survivors for the possibility of post-COVID movement disorders.

Acute Movement Disorders in Childhood

Acute-onset movement disorders (MDs) are an increasingly recognized neurological emergency in both adults and children. The spectrum of possible causes is wide, and diagnostic work-up is challenging. In their acute presentation, MDs may represent the prominent symptom or an important diagnostic clue in a broader constellation of neurological and extraneurological signs. The diagnostic approach relies on the definition of the overall clinical syndrome and on the recognition of the prominent MD phenomenology. The recognition of the underlying disorder is crucial since many causes are treatable. In this review, we summarize common and uncommon causes of acute-onset movement disorders, focusing on clinical presentation and appropriate diagnostic investigations. Both acquired (immune-mediated, infectious, vascular, toxic, metabolic) and genetic disorders causing acute MDs are reviewed, in order to provide a useful clinician’s guide to this expanding field of pediatric neurology.

Cytokine Production by Mononuclear Cells from Patients with Familial Infantile Bilateral Striatal Necrosis

Prompted by findings suggesting immune instability in infantile bilateral striatal necrosis (IBSN), we evaluated levels of proinflammatory (tumor necrosis factor α, interleukin [IL]-1β, IL-6, interferon [IFN]γ) and anti-inflammatory (IL-10 and IL-1ra) cytokines produced by peripheral blood mononuclear cells (PBMC) from 6 children with IBSN and 11 age-matched controls. Compared to controls, non-stimulated PBMC from the IBSN group produced a significantly lower level of IL-1ra (by 38%; p < 0.001) and significantly lower levels of TNFα, IL-1β, and IFNγ (by 36% [p < 0.001], 25% [p = 0.06], and 32% [p < 0.02]) under PBMC stimulation. The severe cachexia manifesting shortly after IBSN onset may impair the immunological state, placing patients at risk of death from hyperpyrexia and sepsis.

Neurological Disorders Associated with Striatal Lesions: Classification and Diagnostic Approach

Neostriatal abnormalities can be observed in a very large number of neurological conditions clinically dominated by the presence of movement disorders. The neuroradiological picture in some cases has been described as "bilateral striatal necrosis" (BSN). BSN represents a condition histo-pathologically defined by the involvement of the neostriata and characterized by initial swelling of putamina and caudates followed by degeneration and cellular necrosis. After the first description in 1975, numerous acquired and hereditary conditions have been associated with the presence of BSN. At the same time, a large number of disorders involving neostriata have been described as BSN, in some cases irrespective of the presence of signs of cavitation on MRI. As a consequence, the etiological spectrum and the nosographic boundaries of the syndrome have progressively become less clear. In this study, we review the clinical and radiological features of the conditions associated with MRI evidence of bilateral striatal lesions. Based on MRI findings, we have distinguished two groups of disorders: BSN and other neostriatal lesions (SL). This distinction is extremely helpful in narrowing the differential diagnosis to a small group of known conditions. The clinical picture and complementary exams will finally lead to the diagnosis. We provide an update on the etiological spectrum of BSN and propose a diagnostic flowchart for clinicians.

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS): An Evolving Concept

Pediatric autoimmune neuropsychiatric disorders associated with streptococcus infections (PANDAS) originated from the observational work of Swedo and collaborators, who formalized their definition in 1998 in a set of operational criteria. The application of these criteria, which focuses on tics and obsessive-compulsive symptoms as core symptoms, has encountered difficulties, eventually leading to a high rate of misdiagnosis. In particular, the core feature represented by the association between newly diagnosed infections and neuropsychiatric symptom relapses in youths with this diagnosis could not be demonstrated by longitudinal studies. Exploratory studies aiming to identify clinical or cognitive features that could discriminate PANDAS from other pediatric obsessive-compulsive and tic disorders present methodological limitations, and therefore are not conclusive. Other behavioral features, in addition to obsessive-compulsive symptoms and tics, have been included in pediatric acute-onset neuropsychiatric syndromes (PANS) and childhood acute neuropsychiatric syndromes (CANS), two new concepts recently proposed in order to define a much broader clinical spectrum encompassing etiologically diverse entities. Given the uncertainties on the clinical definition of PANDAS, it is not surprising that evidence in support of a post-infectious, immune-mediated pathophysiology is also insufficient. Anti-dopamine receptor antibodies might be relevant to both Sydenham's chorea (SC)-the prototypical post-streptococcal neuropsychiatric disorder-and some rare forms of encephalitis targeting the basal ganglia specifically, but studies exploring their association with children fulfilling Swedo's criteria for PANDAS have been inconclusive. Moreover, we lack evidence in favor of the efficacy of antibiotic prophylaxis or tonsillectomy in patients fulfilling Swedo's criteria for PANDAS, whereas a response to immune-mediated treatments like intravenous immunoglobulins has been documented by one study, but needs replication in larger trials. Overall, the available evidence does not convincingly support the concept that PANDAS are a well-defined, isolated clinical entity subdued by definite pathophysiological mechanisms; larger, prospective studies are necessary to reshape the nosography and disease mechanisms of post-streptococcal acute neuropsychiatric disorders other than SC. Research is also under way to shed further light on a possible relationship between streptococcal infections, other biological and psychosocial stressors, and the complex pathobiology of chronic tic disorders.

Progressive striatal necrosis associated with anti-NMDA receptor antibodies

Background

We report a case of childhood onset, generalized dystonia due to slowly progressive bilateral striatal necrosis associated with anti-N-methyl-D-aspartate receptor (NMDAR) antibodies. This clinical phenotype has not been previously associated with NMDA receptor autoimmunity.

Case presentation

An eighteen year old man presented with a history of childhood-onset, progressive generalized dystonia. Clinical examination revealed a pure generalized dystonia with no cognitive or other neurological findings. Magnetic resonance imaging showed bilateral high T2 signal striatal lesions, which were slowly progressive over a period of nine years. New parts of the lesion showed restricted water diffusion suggesting cytotoxic oedema. Positron emission tomography of the brain showed frontal hypermetabolism and cerebellar hypometabolism. Antibodies against the NR1 subunit of the NMDA receptor were detected in the patient’s serum and cerebrospinal fluid. There was no neoplasia or preceding infection or vaccination.

Conclusion

This is the first report of chronic progressive bilateral striatal necrosis associated with anti-NMDAR antibodies. Our findings expand the clinical spectrum of disease associated with anti-NMDAR antibodies and suggest that these should be included in the work-up of dystonia with striatal necrosis.

Update on pediatric dystonias: etiology, epidemiology, and management

Dystonia is a movement disorder characterized by sustained muscle contractions producing twisting, repetitive, and patterned movements or abnormal postures. Dystonia is among the most commonly observed movement disorders in clinical practice both in adults and children. It is classified on the basis of etiology, age at onset of symptoms, and distribution of affected body regions.

Etiology

The etiology of pediatric dystonia is quite heterogeneous. There are many different genetic syndromes and several causes of symptomatic syndromes. Dystonia can be secondary to virtually any pathological process that affects the motor system, and particularly the basal ganglia.

Classification

The etiological classification distinguishes primary dystonia with no identifiable exogenous cause or evidence of neurodegeneration and secondary syndromes.

Treatment

Treatment for most forms of dystonia is symptomatic and includes drugs (systemic or focal treatments, such as botulinum toxin) and surgical procedures. There are several medications including anticholinergic, dopamine-blocking and depleting agents, baclofen, and benzodiazepines. In patients with dopamine synthesis defects L-dopa treatment may be very useful. Botulinum toxin treatment may be helpful in controlling the most disabling symptoms of segmental or focal dystonia. Long-term electrical stimulation of the globus pallidum internum appears to be especially successful in children suffering from generalized dystonia.

Poststreptococcal dystonia with bilateral striatal enlargement: MR imaging and spectroscopic findings

Isolated bilateral striatal necrosis is an abnormality of the basal ganglia associated with acute dystonia in children. This report describes the development of dystonic movements in a 7-year-old male patient 2 weeks after streptococcal pharyngitis.

Annotation: PANDAS: a model for human autoimmune disease

BACKGROUND

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus infections (PANDAS) is a recently recognized syndrome in which pre-adolescent children have abrupt onsets of tics and/or obsessive-compulsive symptoms, a recurring and remitting course of illness temporally related to streptococcal infections, and associated neurologic findings including adventitious movements, hyperactivity and emotional lability.

METHODS

Inspired by observations of similar symptoms in children with Sydenham's chorea, a search was undertaken for clinical and laboratory evidence in support of the new syndrome.

RESULTS

Consistent and predictable clinical findings have been described in a large case series. Magnetic resonance imaging has supported the postulated pathobiology of the syndrome with evidence of inflammatory changes in basal ganglia. Antibasal ganglia antibodies have been found in some acute cases, mimicking streptococcal antigen epitopes.

CONCLUSIONS

While PANDAS remains a controversial diagnostic concept, it has stimulated new research endeavors into the possible links between bacterial pathogens, autoimmune reactions, and neuropsychiatric symptoms.

Anti-basal ganglia antibodies: a possible diagnostic utility in idiopathic movement disorders?

BACKGROUND

The spectrum of post-streptococcal brain disorders includes chorea, tics, and dystonia. The proposed mediators of disease are anti-basal ganglia (neuronal) antibodies (ABGA).

AIM

To evaluate ABGA as a potential diagnostic marker in a cohort of UK post-streptococcal movement disorders.

METHODS

Forty UK children presenting with movement disorders associated with streptococcal infection were recruited. ABGA was measured using ELISA and Western immunoblotting. To determine ABGA specificity and sensitivity, children with neurological diseases (n = 100), children with uncomplicated streptococcal infection (n = 40), and children with autoimmune disease (n = 50) were enrolled as controls.

RESULTS

The mean ELISA result was increased in the post-streptococcal movement disorder group compared to all controls and derived a sensitivity of 82.4% and specificity of 79%. The Western immunoblotting method to detect ABGA derived a sensitivity and specificity of 92.5% and 94.7% respectively. There was common binding to basal ganglia antigens of 40, 45, and 60 kDa. Immunofluorescence localised the antibody binding to basal ganglia neurones.

CONCLUSION

ABGA appears to be a potentially useful diagnostic marker in post-streptococcal neurological disorders. Western immunoblotting appears to be the preferred method due to good sensitivity and specificity and the ability to test several samples at once.

Dyskinesias and associated psychiatric disorders following streptococcal infections

BACKGROUND

The classical extrapyramidal movement disorder following beta haemolytic streptococcus (BHS) infection is Sydenham's chorea (SC). Recently, other post-streptococcal movement disorders have been described, including motor tics and dystonia. Associated emotional and behavioural alteration is characteristic.

AIMS

To describe experience of post-streptococcal dyskinesias and associated co-morbid psychiatric features presenting to a tertiary referral centre 1999-2002.

METHODS

In all patients, dyskinetic movement disorders followed BHS pharyngeal infection. BHS infection was defined by pharyngeal culture of the organism, or paired streptococcal serology. Movement disorders were classified according to international criteria, and validated by experienced child neurologists. Psychiatric complications were defined using ICD-10 criteria using a validated psychiatric interview.

RESULTS

In the 40 patients, the following dyskinetic movement disorders were present: chorea (n = 20), motor tics (n = 16), dystonia (n = 5), tremor (n = 3), stereotypies (n = 2), opsoclonus (n = 2), and myoclonus (n = 1). Sixty five per cent of the chorea patients were female, whereas 69% of the tic patients were male. ICD-10 psychiatric diagnoses were made in 62.5%. Using the same psychiatric instrument, only 8.9% of UK children would be expected to have an ICD-10 psychiatric diagnosis. Emotional disorders occurred in 47.5%, including obsessive-compulsive disorder (27.5%), generalised anxiety (25%), and depressive episode (17.5%). Additional psychiatric morbidity included conduct disorders (27.5%) and hyperkinetic disorders (15%). Psychiatric, movement, and post-streptococcal autoimmune disorders were commonly observed in family members. At a mean follow up of 2.7 years, 72.5% had continuing movement and psychiatric disorders.

CONCLUSION

Post-streptococcal dyskinesias occur with significant and disabling psychiatric co-morbidity and are potential autoimmune models of common "idiopathic" movement and psychiatric disorders in children. Multiple factors may be involved in disease expression including genetic predisposition, developmental status, and the patient's sex.