Long term survival in subacute sclerosing panencephalitis: an enigma

Patients With Subacute Sclerosing Panencephalitis in Japan: A 2022 Nationwide Survey

BACKGROUND

In Japan, the incidence of subacute sclerosing panencephalitis (SSPE) has reduced; however, the medical conditions and factors associated with disease progression remain unclear.

METHODS

A nationwide survey of SSPE was conducted using a questionnaire in 2022. We conducted a descriptive analysis of the patients with SSPE in 2022 and Cox proportional hazards analyses for disease progression. We compared the patients with SSPE with those in a 2007 survey.

RESULTS

A total of 37 surviving patients with SSPE were enrolled [median age: 32 years (range: 16-52 years)]. No new cases have been identified since 2017 in the survey. Jabbour stage IV was the most common stage (66.7%). The hazard ratios (95% confidence intervals) of male sex and age at the time of measles infection (years) were 2.56 (1.13-5.76) and 0.57 (0.34-0.93), respectively. Compared with those in 2007, the proportion of patients in hospitals decreased from 13.7% to 2.7%, whereas that of patients in nursing facilities increased from 17.6% to 29.7%. The proportions of patients prescribed inosine pranobex, interferon and ribavirin at the time of the survey decreased from 96.1% to 79.4%, 74.8% to 14.3% and 25.3% to 0%, respectively. The proportions of patients with gastrostomy, tracheostomy and ventilator use increased from 5.9% to 69.7%, 23.3% to 60.0% and 10.8% to 32.4%, respectively.

CONCLUSIONS

Decreased measles cases in Japan reduced new SSPE cases. However, surviving patients in 2022 had advanced disease stages and needed medical care. Male sex and early measles infection were significantly associated with disease progression.

Infectious leukoencephalopathies

Leukoencephalopathy from infectious agents may have a rapid course, such as human simplex virus encephalitis; however, in many diseases, it may take months or years before diagnosis, such as in subacute sclerosing panencephalitis or Whipple disease. There are wide geographic distributions and susceptible populations, including both immunocompetent and immunodeficient patients. Many infections have high mortality rates, such as John Cunningham virus and subacute sclerosing panencephalitis, although others have effective treatments if suspected and treated early, such as herpes simplex encephalitis. This chapter will describe viral, bacterial, and protozoal infections, which predominantly cause leukoencephalopathy. We focus on the clinical presentation of these infectious agents briefly covering epidemiology and subtypes of infections. Next, we detail current pathophysiologic mechanisms causing white matter injury. Diagnostic and confirmatory tests are discussed. We cover predominantly MRI imaging features of leukoencephalopathies, and in addition, summarize the common imaging features. Additionally, we detail how imaging features may be used to narrow the differential of a leukoencephalopathy clinical presentation. Lastly, we present an outline of common treatment approaches where available.

A recent surge of fulminant and early onset subacute sclerosing panencephalitis (SSPE) in the United Kingdom: An emergence in a time of measles

BACKGROUND

Subacute Sclerosing Panencephalitis (SSPE) is a fatal progressive neurological disorder following measles infection.

METHODS

Cases were collated from Paediatric Neurology centres in the UK over 24 months from 2017 to 2019 and represent all cases referred to the National Viral Reference Department (VRD). Diagnosis was established with detection of a raised measles index, demonstrating intrathecal measles antibody production.

FINDINGS

Six children presented with SSPE over two years, with median age five years (range 2-7 years) and median latency period three years (range 2-6 years). The majority were exposed to measles during infancy. Atypical features were common, including visual impairment, focal and generalised tonic-clonic seizures, headache, vomiting and movement disorders. EEG demonstrated typical features in five cases, though not always at presentation. Initial MRI was normal in four cases, with two showing focal and widespread white matter changes. Antiviral and immunomodulatory treatment led to minimal or no improvement. All progressed to cognitive regression, seizures and neurological decline within six months.

INTERPRETATION

These cases demonstrate the highest incidence of SSPE in the UK since 2000, all progressing to acute fulminant disease, following younger age of onset, short latency period and atypical presentations. Recent global surges in measles cases raise the importance of clinician awareness of SSPE as a potential diagnosis in children with neurological regression. Herd immunity remains the key protective mechanism for infants and groups that cannot be vaccinated. Health care providers, educators and governments must ensure resources continue to target effective education and access to immunisation programmes, the only means to combat this devastating and fatal condition.

Video Anthology of Movement Disorders Due to Infections in South Asia

South Asia, encompassing many populous countries including India, Pakistan, and Bangladesh, is home to a wide variety of infectious diseases several of which are disproportionately prevalent, endemic or distinctive to the region. These result in considerable morbidity and mortality, which can be greatly reduced through public-health measures, timely diagnosis and treatment. Some of these infectious diseases have neurological manifestations including movement disorders either due to the pathogen being neuroinvasive or via an immune-mediated response. For diseases such as Japanese encephalitis, movement disorders are the primary manifestation while for others, they can be a presenting feature. Thus, recognizing these movement disorders is often crucial to the diagnosis of the particular infection, and/or to exclude infection as a cause and arrive at the correct alternate diagnosis. Once diagnosed, the infection-related movement disorders are treated by targeting the infectious agent, or symptomatically. In this article, we describe and illustrate a variety of movement disorders that are seen in patients infected by viruses, bacteria and parasites in South Asia. This would be of value to neurologists practicing in the region and, with the increasing ease in movement of people and pathogens, those practicing elsewhere.

Clinical and magnetic resonance study of a case of subacute sclerosing panencephalitis treated with ketogenic diet

Background

Subacute sclerosing panencephalitis is a progressive neurodegenerative disorder caused by a latent and mutant measles virus which is extremely rare in developed countries. The lack of effective treatments leads to the research of other anti-inflammatory and neuroprotective treatments.

Case

Here we present a case of a 17-year-old patient affected by subacute sclerosing panencephalitis who manifest a dramatic improvement in neurological and general clinical conditions, as well as an arrest in the progression of demyelinating process in the central nervous system, after the beginning of a high ratio ketogenic diet.

Conclusions

Given its anti-inflammatory, antioxidant and metabolic effects, we believe that ketogenic diet utilisation could be a rational approach, can be considered a safe add-on therapy, carrying on with only a minimal risk of adverse effects or interactions.

Advances in Antiviral Therapy for Subacute Sclerosing Panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a late-onset, intractable, and fatal viral disease caused by persistent infection of the central nervous system by a mutant strain of the measles virus. Ribavirin intracerebroventricular therapy has already been administered to several SSPE patients in Japan based on fundamental and clinical research findings from our group, with positive therapeutic effects reported in some patients. However, the efficacy of this treatment approach has not been unequivocally established. Hence, development of more effective therapeutic methods using new antiviral agents is urgently needed. This review describes the current status of SSPE treatment and research, highlighting promising approaches to the development of more effective therapeutic methods.

Atypical adult-onset subacute sclerosing panencephalitis

Although subacute sclerosing panencephalitis is almost exclusively a childhood disease, it can occur in adults as well. We present an atypical case of adult-onset subacute sclerosing panencephalitis. The disease was characterized by prolonged insidious course followed by accelerated and aggressive phase, atypical EEG findings, and absence of myoclonic jerks. The diagnostic and treatment-related pitfalls are discussed.

Measles Encephalitis: Towards New Therapeutics

Measles remains a major cause of morbidity and mortality worldwide among vaccine preventable diseases. Recent decline in vaccination coverage resulted in re-emergence of measles outbreaks. Measles virus (MeV) infection causes an acute systemic disease, associated in certain cases with central nervous system (CNS) infection leading to lethal neurological disease. Early following MeV infection some patients develop acute post-infectious measles encephalitis (APME), which is not associated with direct infection of the brain. MeV can also infect the CNS and cause sub-acute sclerosing panencephalitis (SSPE) in immunocompetent people or measles inclusion-body encephalitis (MIBE) in immunocompromised patients. To date, cellular and molecular mechanisms governing CNS invasion are still poorly understood. Moreover, the known MeV entry receptors are not expressed in the CNS and how MeV enters and spreads in the brain is not fully understood. Different antiviral treatments have been tested and validated in vitro, ex vivo and in vivo, mainly in small animal models. Most treatments have high efficacy at preventing infection but their effectiveness after CNS manifestations remains to be evaluated. This review describes MeV neural infection and current most advanced therapeutic approaches potentially applicable to treat MeV CNS infection.

Subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a slowly progressive brain disorder caused by mutant measles virus. SSPE affects younger age groups. SSPE incidence is proportional to that of measles. High-income countries have seen substantial decline in SSPE incidence following universal vaccination against measles. SSPE virus differs from wild measles virus. Measles virus genome recovered from the autopsied brain tissues demonstrates clustered mutations in virus genome particularly in the M gene. These mutations destroy the structure and functioning of the encoded proteins. Complete infectious virus particle has rarely been recovered from the brain. Human neurons lack required receptor for entry of measles virus inside the neurons. Recent in vitro studies suggest that mutations in F protein confer hyperfusogenic properties to measles virus facilitating transneuronal viral spread. The inflammatory response in the brain leads to extensive tissue damage. Clinically, SSPE is characterized by florid panencephalitis. Clinically, SSPE is characterized by cognitive decline, periodic myoclonus, gait abnormalities, vision loss, and ultimately to a vegetative state. Chorioretinitis is a common ocular abnormality. Electroencephalography (EEG) shows characteristic periodic discharges. Neuroimaging demonstrates periventricular white matter signal abnormalities. In advanced stages, there is marked cerebral atrophy. Definitive diagnosis requires demonstration of elevated measles antibody titers in cerebrospinal fluid (CSF). Many drugs have been used to stabilize the course of the disease but without evidence from randomized clinical trials. Six percent of patients may experience prolonged spontaneous remission. Fusion inhibitor peptide may, in the future, be exploited to treat SSPE. A universal vaccination against measles is the only proven way to tackle this menace currently.

A long-term subacute sclerosing panencephalitis survivor treated with intraventricular interferon-alpha for 13 years

Subacute sclerosing panencephalitis (SSPE) is a rare, progressive, and fatal central nervous system disorder resulting from persistent measles virus infection. Long-term data are scarce, with a maximum follow-up period of 10 years. Interferon-alpha (IFN-α) is a protein that exerts its antiviral activity via enhancement of cellular immune response and is reported to be an effective drug for the treatment of SSPE. However, there is currently no consensus regarding the optimal duration of IFN-α therapy. Here, we present a case report of a patient with SSPE treated with long-term intraventricular IFN-α therapy, which facilitated clinical improvement and neurological stabilization without causing serious adverse effects. To the best of our knowledge, this is one of the longest follow-up studies investigating a patient with SSPE receiving intraventricular INF-α treatment. Further studies are necessary to validate the benefits and safety of long-term intraventricular IFN-α treatment in patients with SSPE.

Neuroleptic malignant syndrome as a presenting feature of subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a slowly progressive degenerative disorder caused by measles virus. It is characterised by typical clinical and electrophysiological features in the form of slow myoclonic jerks, with progressive cognitive impairment, visual symptoms, and periodic complexes on EEG, with raised titres of anti-measles antibodies in CSF and serum. Atypical presentations of SSPE have been reported including brainstem involvement, ADEM-like presentation, acute encephalitis, and cerebellar ataxia. Presentation with predominant extrapyramidal features is uncommon. We describe a case of SSPE presenting with extensive rigidity with highly elevated CPK values, mimicking neuroleptic malignant syndrome (NMS) which was most probably due to central dopaminergic blockade induced by the disease process. To our knowledge, this is the first case of SSPE presenting with a NMS-like syndrome.

Environmental, dietary and case-control study of Nodding Syndrome in Uganda: A post-measles brain disorder triggered by malnutrition?

Nodding Syndrome (NS) is an epileptic encephalopathy characterized by involuntary vertical head nodding, other types of seizures, and progressive neurological deficits. The etiology of the east African NS epidemic is unknown. In March 2014, we conducted a case-control study of medical, nutritional and other risk factors associated with NS among children (aged 5-18years) of Kitgum District, northern Uganda (Acholiland). Data on food availability, rainfall, and prevalent disease temporally related to the NS epidemic were also analyzed. In NS Cases, the mean age of reported head nodding onset was 7.6years (range 1-17years). The epidemiologic curve of NS incidence spanned 2000-2013, with peaks in 2003 and 2008. Month of onset of head nodding was non-uniform, with all-year-aggregated peaks in April and June when food availability was low. Families with one or more NS Cases had been significantly more dependent on emergency food and, immediately prior to head nodding onset in the child, subsistence on moldy plant materials, specifically moldy maize. Medical history revealed a single significant association with NS, namely prior measles infection. NS is compared with the post-measles disorder subacute sclerosing panencephalitis, with clinical expression triggered by factors associated with poor nutrition.

Prognosis and demographic characteristics of SSPE patients in Istanbul, Turkey

AIM

SSPE is a rare progressive, invariably fatal long-term complication of measles infection. In this study, we assessed the demographic and prognostic characteristics of 64 consecutive SSPE patients diagnosed at a tertiary center.

METHODS

The study had a retrospective design; data were obtained from patient records.

RESULTS

The study includes 64 patients diagnosed with SSPE. There was history of consanguineous marriage in 27 (42.2%) patients. The average patient lifespan was 3.8years (45days-12years). The average patient age at diagnosis was 12.3 (range, 5-17)years. A statistically significant correlation was found between the age at diagnosis and lifespan (p=0.002). A statistically significant correlation was found between the incubation period and patient lifespan (p<0.001). No significant correlation was found between duration in the intensive care unit and lifespan (p=0.122). Routine physical therapy had no significant impact on the average lifespan (p=0.619). No significant difference was found between the vaccination dose and lifespan (p=0.651).

CONCLUSIONS

High frequency of parental consanguinity in SSPE patients need to be evaluated as there might a genetic influence. Physical therapy and supportive treatments seems to have no affect on lifespan in SSPE patients. The age at diagnosis and incubation period might have an affect on prognosis and lifespan.

Fulminant subacute sclerosing panencephalitis presenting with acute ataxia and hemiparesis in a 15-year-old boy

Background

Subacute sclerosing panencephalitis (SSPE) is a delayed and fatal manifestation of measles infection. Fulminant SSPE is a rare presentation in which the disease progresses to death over a period of 6 months. The clinical features are atypical and can be misleading.

Case Report

We report herein a teenage boy who presented with acute-onset gait ataxia followed by right hemiparesis that evolved over 1 month, with left-hemispheric, delta-range slowing on the electroencephalogram (EEG). Magnetic resonance imaging disclosed multiple white-matter hyperintensities, suggesting a diagnosis of acute disseminated encephalomyelitis. He received intravenous steroids, and within 4 days of hospital admission he developed unilateral slow myoclonic jerks. Repeat EEG revealed Rademecker complexes, pathognomonic of SSPE, and an elevated titer of IgG antimeasles antibodies was detected in his cerebrospinal fluid. The disease progressed rapidly and the patient succumbed within 15 days of hospitalization. The diagnosis of SSPE was confirmed by autopsy.

Conclusions

This case illustrates the difficulty of recognizing fulminant SSPE when it manifests with asymmetric clinical and EEG abnormalities.

Subacute sclerosing panencephalitis in a toddler: changing epidemiological trends

Subacute sclerosing panencephalitis (SSPE) is a devastating “slow virus” brain disease resulting from persistent measles virus infection of neurons. The age at presentation is usually 8 to 11 years with onset usually occurring 2–10 years after measles infection. We report a 2-and-half-year-old boy who presented with progressively increasing myoclonic jerks and subtle cognitive decline. He was diagnosed as a case of SSPE based on clinical features, typical electroencephalographic finding, and elevated cerebrospinal fluid/serum measles antibody titers. He had measles 4 months prior to onset of symptoms. This case along with review of recently published reports suggests progressively decreasing latency period between measles infection and onset of symptoms observed in cases with SSPE. Clinical implication would mean investigating for SSPE even in infants or toddlers with compatible clinical features and recent history of measles infection.

Subacute sclerosing panencephalitis: A clinical appraisal

Introduction:

Subacute sclerosing panencephalitis (SSPE) is a rare chronic, progressive encephalitis affecting primarily children and young adults, caused by a persistent infection of immune resistant measles virus. The aim of the present study is to describe the clinical profile and natural history of patients with SSPE.

Methods:

We collected data of patients with SSPE during 2004-2010 who fulfilled Dyken's criteria. We analyzed demographical, clinical, electrophysiological, and imaging features.

Results:

Study included 34 patients, 26 (76.5%) males with age of onset from 3 to 31 years. Twenty one patients were below 15 years of age formed childhood SSPE and 13 above 15 years of age constituted adult onset group. 85.3% had low-socioeconomic status. Eleven received measles vaccination and seven were unvaccinated. 59.9% patients had measles history. Most common presenting symptom was scholastic backwardness (52.5%) followed by seizures (23.5%). Three patients each had cortical blindness, macular degeneration, decreased visual acuity, and optic atrophy. Electroencephalographic (EEG) showed long interval periodic complexes and cerebrospinal fluid anti-measles antibody was positive in all. Magnetic resonance imaging was done in 70.5% with was abnormal in 52.5%. Mean incubation period of SSPE after measles was 9.6 years. The follow-up duration was 1-10 years, (average of 2 years). Only one patient died from available data of follow-up, 9 were stable and 10 deteriorated in the form of progression of staging.

Conclusion:

SSPE is common in low-socioeconomic status. The profile of adult onset did not differ from childhood onset SSPE, except for a longer interval between measles infection and presence of the ophthalmic symptom as presenting feature in adult onset group.

The first genetic characterization of a D4 measles virus strain derived from a patient with subacute sclerosing panencephalitis

Measles virus (MV) strains derived from patients with subacute sclerosing panencephalitis (SSPE), SSPE strains, possess numerous mutations when compared to viruses belonging to the same genotype and circulating in similar time period. Although many SSPE strains have been extensively characterized, none of them belongs to D4 genotype which currently predominates in Europe where it has caused a number of recent outbreaks/epidemics. We sequenced an MV derived from a patient with long-term SSPE; the virus was named MVs/Zagreb.CRO/30.06[D4] (SSPE). Initial genetic analysis showed that it belongs to D4 genotype. The sequences of genes encoding matrix and fusion proteins indicate premature protein terminations. Putative hemagglutin (H) protein is lengthened for 20 amino acids, which is the longest H protein elongation so far found in SSPE viruses. Nucleotides 1421 A, 1422 G, 1507 C and 1542 C in nucleoprotein gene open reading frame seem to be specific for this D4 strain, differentiating it from other D4 non-SSPE strains. Besides, a unique mutation at position 543 of H protein was found, histidine instead of tyrosine. As persistent MV infections are initially established by "normal" wild-type MV strains, the presented comparative analyses describe alterations that could be involved in the maintenance of persistent infection, disease development and progression.

Subacute sclerosing panencephalitis: an update

Subacute sclerosing panencephalitis (SSPE) is a chronic encephalitis occurring after infection with measles virus. The prevalence of the disease varies depending on uptake of measles vaccination, with the virus disproportionally affecting regions with low vaccination rates. The physiopathology of the disease is not fully understood; however, there is evidence that it involves factors that favour humoral over cellular immune response against the virus. As a result, the virus is able to infect the neurons and to survive in a latent form for years. The clinical manifestations occur, on average, 6 years after measles virus infection. The onset of SSPE is insidious, and psychiatric manifestations are prominent. Subsequently, myoclonic seizures usually lead to a final stage of akinetic mutism. The diagnosis is clinical, supported by periodic complexes on electroencephalography, brain imaging suggestive of demyelination, and immunological evidence of measles infection. Management of the disease includes seizure control and avoidance of secondary complications associated with the progressive disability. Trials of treatment with interferon, ribavirin, and isoprinosine using different methodologies have reported beneficial results. However, the disease shows relentless progression; only 5% of individuals with SSPE undergo spontaneous remission, with the remaining 95% dying within 5 years of diagnosis.

Subacute sclerosing panencephalitis (SSPE) presenting as acute disseminated encephalomyelitis in a child

Subacute sclerosing panencephalitis (SSPE) typically presents with progressive mental deterioration, behavioral changes, and myoclonic jerks. Atypical presentations are not unknown and may result in diagnostic delays. A 9-year-old girl presented with poor balance and ataxia following an episode of upper respiratory tract infection. Neurological examination revealed mild hemiparesis and ataxia. Brain magnetic resonance imaging revealed scattered areas of T2 and fluid-attenuated inversion recovery hyperintensities in the white matter consistent with acute disseminated encephalomyelitis. Despite treatment with intravenous methylprednisolone, intravenous immunoglobulins, and plasmapheresis, progressive neurological worsening occurred. Later during the course of her illness, subacute sclerosing panencephalitis was suspected from the appearance of burst-suppression pattern on electroencephalogram, and the diagnosis confirmed by elevated titers of measles antibodies in cerebrospinal fluid. Physicians taking care of children need to be aware of atypical presentations of subacute sclerosing panencephalitis and must have a high index of suspicion to prevent diagnostic delays and avoid unnecessary diagnostic and therapeutic interventions.

Serial diffusion-weighted imaging in subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis may be associated with clinical features of frontal lobe dysfunction. We previously reported that frontal lobe volume falls significantly as clinical stage progresses, using three-dimensional magnetic resonance imaging-based brain volumetry. The hypothesis that frontal volume increases correlate with clinical improvement, however, was not tested in our previous study. Therefore, we reevaluated our patient with subacute sclerosing panencephalitis, to determine whether apparent diffusion coefficient maps can characterize the clinical course of subacute sclerosing panencephalitis. We studied an 8-year-old boy with subacute sclerosing panencephalitis, using serial diffusion-weighted imaging magnetic resonance imaging, and measured the regional apparent diffusion coefficient. The regional apparent diffusion coefficient of the frontal lobe decreased significantly with clinical progression, whereas it increased to within normal range during clinical improvements. The apparent diffusion coefficient of the other regions did not change. These results suggest that the clinical signs of patients with subacute sclerosing panencephalitis are attributable to frontal lobe dysfunction, and that apparent diffusion coefficient measurements may be useful in predicting the clinical course of subacute sclerosing panencephalitis.

Atypical subacute sclerosing panencephalitis: case report

Subacute sclerosing panencephalitis (SSPE) is a progressive inflammatory disorder of the central nervous system with both poor prognosis and high mortality. The disease has been related to a persistent and aberrant measles virus infection and no effective treatment has been available. We report a case of SSPE with atypical features including seizures at onset and a fulminant course in a 8 years-old boy who had been previously immunized against measles.

Subacute sclerosing panencephalitis (SSPE): an insight into the diagnostic errors from a tertiary care university hospital

Subacute sclerosing panencephalitis (SSPE) is a progressive disease caused by wild-type measles virus leading to premature death. Early diagnosis may help in medical interventions and counseling. The aim of this study was to ascertain diagnostic errors and their possible causes. Retrospective case record analysis of patients with subacute sclerosing panencephalitis, evaluated over a 10-year period, was performed. The following data were analyzed: initial symptoms and diagnosis, interval between onset of symptoms to diagnosis, and implications of delayed diagnosis. Among the 307 patients evaluated, initial diagnosis by various health care professionals was other than subacute sclerosing panencephalitis in 242 patients (78.8%). These included seizures, absence seizures, metachromatic leukodystrophy, Schilder's disease, cerebral palsy, hemiparkinsonism, Wilson's disease, vasculitis, spinocerebellar ataxia, motor neuron disease, nutritional amblyopia, tapetoretinal degeneration, catatonic schizophrenia, and malingering, among others. The interval between precise diagnosis and first reported symptom was 6.2 +/- 11.3 months (range, 0.2-96 months; median, 3 months). Forty-four patients (14.3%) who had symptoms for more than 1 year before the precise diagnosis had a protracted course as compared to the rest of the cohort ( P = .0001). Early and accurate diagnosis of subacute sclerosing panencephalitis needs a high index of suspicion.