A Multinational Survey on Actual Diagnostics and Treatment of Subacute Sclerosing Panencephalitis

Subacute sclerosing panencephalitis presenting as severe depression in an adult

Subacute sclerosing panencephalitis (SSPE) is a fatal disorder that occurs as a rare complication of childhood measles. Symptoms typically manifest between the ages of 5 and 15. While the incidence of SSPE is declining globally, it is still prevalent in regions where measles remains common and vaccination rates are low due to poverty and lack of health education. Diagnosing SSPE can be challenging, particularly when patients exhibit unusual symptoms. A thorough clinical evaluation, including vaccination history, physical examination, electroencephalogram (EEG) and Cerebrospinal fluid (CSF) analysis, can help in making a diagnosis. We present the case of a young woman in her early 20s who initially experienced depressive symptoms, followed by myoclonus, dementia and visual impairment. The patient was ultimately diagnosed with SSPE based on characteristic EEG findings, neuroimaging results, CSF analysis and elevated serum measles antibody levels.

Diagnostic reference value of antibody levels measured using enzyme immunoassay for subacute sclerosing panencephalitis

High measles-specific antibody titers in the cerebrospinal fluid (CSF) have important diagnostic significance for subacute sclerosing panencephalitis (SSPE), a progressive neurological disorder caused by measles virus variants. However, the diagnostic reference value of antibody levels and the usefulness of the CSF/serum ratio measured using enzyme immunoassays (EIAs) for SSPE diagnosis remain unclear. To facilitate SSPE diagnosis using EIAs, measles immunoglobulin G (IgG) titers in the CSF and serum of patients with and without SSPE were measured and their CSF/serum antibody ratios evaluated. Serum and CSF antibody levels were compared among three patients with SSPE (59 paired samples), 37 non-SSPE patients, and 2618 patients of unknown backgrounds. Of the 59 paired samples from three patients with SSPE, 56 paired samples (94.9%) showed CSF measles IgG levels ≥0.5 IU/mL and a CSF/serum ratio ≥0.05, whereas non-SSPE cases showed CSF measles IgG levels <0.1 IU/mL and a CSF/serum ratio <0.03. Of the 2618 CSF samples with unknown backgrounds, 951 showed measurable IgG levels with EIA, with a CSF/serum ratio peak of 0.005-0.02, with a 90th percentile of 0.05. Assuming the SSPE criteria as CSF measles IgG ≥0.5 IU/mL and a CSF/serum ratio ≥0.05, only 20 samples (0.8%) with unknown backgrounds were categorized as having SSPE. Conversely, assuming the non-SSPE criteria as CSF measles IgG <0.1 IU/mL and a CSF/serum ratio <0.03, 2403 samples (92%) with unknown backgrounds were categorized as not having SSPE. In conclusion, high CSF/serum ratios (≥0.05) and high measles CSF IgG levels (≥0.5 IU/mL) may be useful for diagnosing SSPE.

La panencéphalite sclérosante subaiguë de la rougeole

La panencéphalite sclérosante subaiguë (PESS), une complication tardive de la rougeole, est encore présente lors d’épidémies de cette maladie dues aux insuffisances de la vaccination. Après un rappel historique, nous aborderons la physiopathologie de la PESS et l’importance des critères diagnostiques. De nombreux travaux portant sur les paramètres de l’immunité innée et sur ceux des réponses interféron tendent à montrer une baisse de l’activité de l’immunité cellulaire au cours de cette maladie. Nous formulons ici plusieurs hypothèses s’appuyant sur des publications concernant différentes formes de la maladie : congénitales, périnatales, formes à incubation courte, semblables à l’encéphalite aiguë à inclusions (EAI), formes d’évolution rapide, formes retrouvées chez les immunodéprimés ou chez l’adulte. Des formes familiales ont également été identifiées, suggérant une origine génétique. Selon la durée de la période de latence entre rougeole et la PESS, deux groupes de patients ont été individualisés, incitant à des analyses rétrospective et prospective des exomes de ces malades. La connaissance des gènes participant à la maladie devrait être utile pour la compréhension de la physiopathologie de la PESS mais aussi d’autres infections neurologiques tardives dues à des virus à ARN.

Options in the Treatment of Subacute Sclerosing Panencephalitis: Implications for Low Resource Areas

Purpose of the review

Subacute sclerosing panencephalitis (SSPE) is a rare, slowly progressive, and frequently fatal neurodegenerative disorder caused by measles virus. The risk of SSPE remains significant globally, with fluctuating incidence noted in in tandem with measles vaccine uptake. This review aims to explore the current global status of SSPE, its treatment, and preventive measures.

Recent findings

An increase in measles cases have been reported in various parts of the world for different reasons related to the regional context of the outbreak. With reduction in measles vaccine doses since the onset of the COVID-19 pandemic, the future risk of SSPE can only accelerate. In recent years, subsequent cases of SSPE have been reported in the period following documented measles outbreaks in different settings. Concomitantly, there have been efforts to evaluate the efficacy of immunomodulatory, antiviral, and anti-seizure therapies that could ameliorate the devastating effects of this disease. This review elucidates on these approaches and their limitations, reasons for poor vaccine coverage in low- and middle-income countries, as well as the possible solutions to the prevention of measles and eventual avoidance of SSPE.

Summary

Prevention of measles virus infection with the resultant sequelae would be the most effective strategy for the management of SSPE. This approach would be particularly important in low resource setting that currently bears the double burden of widespread communicable diseases and malnutrition.

Trends and Treatment of Sub-Acute Sclerosing Panencephalitis: An Updated Review

Measles infection, caused by the “Rubeola” virus is a highly contagious disease with outrageously fatal consequences. Initiating with a variety of symptoms including fever, cough, conjunctivitis, and runny nose, it can lead to more severe sequelae including sub-acute sclerosing pan-encephalitis which is a potentially fatal and serious complication of measles. The lackluster vaccination processes in underdeveloped areas of the world due to suboptimal immunization programs, scarce resources, and insufficient political constancy still leads to increased cases of measles and its complications. A variety of management programs including the use of several medications have been introduced according to the literature in order to counter this dreadful disease. In this review article, we focus on assessment of the previous literature and discussing the possible treatment modalities of this currently irremediable disease.

Measles Sclerosing Subacute PanEncephalitis (SSPE), an intriguing and ever-present disease: Data, assumptions and new perspectives

BACKGROUND

Subacute sclerosing panencephalitis (SSPE) is a rare, non-treatable and fatal neurological complication of measles, still present due to the return of the epidemic linked to the loosening of vaccination policies. Its mechanism remains unexplained.

OBJECTIVE

The main objective was to investigate explanatory variables relating to the risk of developing SSPE and its pathophysiology.

METHODS

Literature analysis was focused on different varieties of SSPE: perinatal forms, short-incubation forms similar to acute measles inclusion body encephalitis (MIBE), rapidly evolving forms, forms occurring in the immunosuppressed, adult forms, and family forms. In addition, several studies on the parameters of innate immunity and interferon responses of patients were analyzed.

RESULTS

Two main data were highlighted: a relationship between the so-called fulminant forms and the prescription of corticosteroids was established. In familial SSPE, two groups were individualized according to the duration of the latency period, prompting an analysis of patient exomes.

CONCLUSION

Treatment with corticosteroids should be banned. Knowledge of the genes involved and epigenetics should be useful for understanding the pathophysiology of SSPE and other late-onset neurological infections with RNA viruses.

Utility of enzyme immunoassays for diagnosis of subacute sclerosing panencephalitis

BACKGROUND

Subacute sclerosing panencephalitis (SSPE) is a progressive neurologic disorder caused by the measles virus (MV) and is identified by positive MV-specific antibody titers, detected mainly by hemagglutination inhibition (HI) tests in the cerebrospinal fluid (CSF). However, an alternative method, the enzyme immunoassay (EIA), has increasingly become a preferred method for detecting MV antibodies. To establish the index for SSPE diagnosis using EIA, we investigated the correlation between HI and EIA titers of MV antibodies in SSPE patients.

METHODS

Data on MV antibody titers and measurement methods at the time of diagnosis in 89 Japanese SSPE cases diagnosed between 1979 and 2006 were obtained by a survey. We also assessed the serum and CSF MV antibody titers in three patients with SSPE and serum MV antibody titers in 38 healthy adults using immunoglobulin G (IgG)-EIA and HI.

RESULTS

In all cases diagnosed as SSPE, IgG-EIA titers in the CSF were ≥0.49 IU/mL. There was a positive correlation between serum antibody values in the controls measured by IgG-EIA and HI. In patients with SSPE, both serum and CSF antibody values, measured by IgG-EIA, and HI, were positively correlated, and a positive correlation was found between the serum and CSF MV antibody titers as measured by IgG-EIA. The serum/CSF MV antibody titer ratios determined by IgG-EIA were <20 in most SSPE patients.

CONCLUSIONS

Immunoglobulin G-EIA may be a suitable alternative method for SSPE diagnosis; however, its potential utility and the cut-off point of ≥0.49 IU/mL should be tested with additional patient cohorts.

Subacute sclerosing panencephalitis: clinical phenotype, epidemiology, and preventive interventions

Subacute sclerosing panencephalitis (SSPE) is a preventable condition reported in 6.5 to 11 per 100 000 cases of measles, and highest in children who contracted measles infection when they were less than 5 years of age. Children residing in areas with poor vaccination coverage and high prevalence of human immunodeficiency virus are at increased risk of developing SSPE. SSPE is life-threatening in most affected children. This report documents current data relating to the clinical phenotype, epidemiology, and understanding of SSPE, inclusive of preventive interventions. While improvements in disease progression with immunomodulation may occur, overall there is no cure. Most therapies focus on supportive needs. Seizures and abnormal movements may respond to carbamazepine. Many countries advocate policies to enhance vaccination coverage. Effective preventive health care programmes, assurance of parental perceptions, and crisis support for unprecedented events obstructing effective primary health care are needed. Until measles is eradicated worldwide, children in all regions remain at risk. WHAT THIS PAPER ADDS: Measles contracted under 5 years of age has highest risk of developing subacute sclerosing panencephalitis (SSPE). Children with, or exposed to, human immunodeficiency virus infection, who contract measles may be at increased risk of SSPE.

Inosine Pranobex: A Key Player in the Game Against a Wide Range of Viral Infections and Non-Infectious Diseases

Inosine pranobex (IP), commonly known as inosine acedoben dimepranol, isoprinosine and methisoprinol, has been proven to positively impact the host’s immune system, by enhancing T-cell lymphocyte proliferation and activity of natural killer cells, increasing levels of pro-inflammatory cytokines, and thereby restoring deficient responses in immunosuppressed patients. At the same time, it has been shown that it can affect viral RNA levels and hence inhibit growth of several viruses. Due to its immunomodulatory and antiviral properties, and its safety profile, it has been widely used since 1971 against viral infections and diseases, among which subacute sclerosis panencephalitis, herpes simplex virus, human papilloma virus, human immunodeficiency virus, influenza and acute respiratory infections, cytomegalovirus and Epstein–Barr virus infections. Following an analysis of almost five decades of scientific literature since its original approval, we here summarize in vivo and in vitro studies manifesting the means in which IP impacts the host’s immune system. We also provide a synopsis of therapeutic trials in the majority of which IP was found to have a beneficial effect. Lastly, positive results from limited studies, suggesting the putative future use of IP in new therapeutic indications are briefly described. In order to support use of IP against viral infections apart from those already approved, and to establish its use in clinical practice, further well-designed and executed trials are warranted.

Funding: Ewopharma International.

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.

Subacute sclerosing panencephalitis presenting as acute cerebellar ataxia and brain stem hyperintensities

BACKGROUND

Subacute sclerosing panencephalitis is a devastating neurodegenerative disease with a characteristic clinical course. Atypical presentations may be seen in 10% of the cases.

AIMS

To describe the atypical clinical and radiological features of SSPE in a child form endemic country.

METHODS

A 5-year-old boy presented with acute-onset cerebellar ataxia without associated encephalopathy, focal motor deficits, seizures or cognitive decline. He had varicella-like illness with vesicular, itchy truncal rash erupting one month prior to the onset of these symptoms. He underwent detailed neurological assessment, relevant laboratory and radiological investigations.

RESULTS

Neuroimaging revealed peculiar brain stem lesions involving the pons and cerebellum suggestive of demyelination. With a presumptive diagnosis of clinically isolated syndrome of demyelination, he was administered pulse methylprednisolone (30 mg/kg/day for 5 days). Four weeks later he developed myoclonic jerks. Electroencephalogram showed characteristic periodic complexes time-locked with myoclonus. CSF and serum anti-measles antibody titres were elevated (1:625).

CONCLUSION

Our report highlights that subacute sclerosing panencephalitis can present atypically as isolated acute cerebellar ataxia and peculiar involvement of longitudinal and sparing of transverse pontine fibres. The predominant brainstem abnormalities in the clinical setting may mimick acute demyelinating syndrome. Hence, it is important to recognize these features of subacute sclerosing panencephalitis in children, especially in the endemic countries.