Subacute sclerosing panencephalitis after intrauterine infection

Pediatric Subacute Sclerosing Panencephalitis: A Narrative Review on Measles and the Future of Vaccination

Subacute sclerosing panencephalitis is a rare complication due to persistent measles infection, characterized by cognitive and motor deterioration. Because subacute sclerosing panencephalitis is considered a potentially fatal complication of measles and usually presents in young populations, particularly those with measles infection under the age of 2 years, new approaches to implement vaccination programs must be devised to help avoid the worsening of patient outcome. Until the disease is eradicated globally, children in all regions of the world remain at risk of measles infection and its respective complications, and therefore, the vaccine is considered the optimal preventative measure. The legacy of measles virus goes beyond the immediate complications. Our study, therefore, aims to provide a comprehensive review on the updated insights into subacute sclerosing panencephalitis as a complication, as well as the extent and future considerations pertaining to vaccination programs in the pediatric population.

Subacute myoclonic measles encephalitis - An opportunistic HIV-associated infection

Introduction

An unusual cluster of myoclonic epilepsy was observed in a Romanian pediatric HIV cohort concurrent with measles outbreaks. We describe this particular form of subacute measles encephalitis (SME) in a group of HIV-infected children and adolescents with severe immunosuppression.

Methods

This is a single-center study, starting in 1997 and covering 4 measles outbreaks in Romania. The presumptive diagnosis of subacute myoclonic measles encephalitis (SMME) was based on: (1) epidemiological data, previous measles episode or presumed contact with measles virus (MV), (2) clinical presentation with initial localized myoclonic jerks with rapid extension and subsequent motor deficit with preserved mental status, and (3) neuroimaging studies revealing cortical gray matter lesions. Definitive diagnosis was based on a neuropathological exam and immunohistochemistry of brain tissues, and measles RNA detection in the cerebrospinal fluid (CSF).

Results

Thirty-six patients were diagnosed with a particular form of SME during consecutive measles outbreaks in Romania: 1996-1998 (22); 2005-2008 (12); 2010-2011 (1) and 2016-2018 (1). Most children were born in the late 80s and had parenterally acquired HIV infection in early childhood. Before the episode of SMME, 11 patients had confirmed measles, while the rest, without typical rash, had a respiratory tract infection and/or presumed previous measles contact. In all patients, the clinical onset was sudden, with unilateral myoclonus. MRI findings revealed mainly focal cortical gray matter lesions. Neurologic symptoms progressed rapidly to coma and death in most patients. Three patients survived SMME, they had higher CD4 count at onset, slower progression of neurological symptoms, and benefit of immune recovery with cART. Immunocytochemistry studies revealed MV in the brain with a pattern suggesting an ascending viral neural infection. MV was isolated from CSF in 7 out of 8 patients. Sequence analysis of MV RNA from both nasopharyngeal swabs and CSF was available for one patient with similar N-450 strain characteristics.

Conclusion

During an outbreak of measles, neurological manifestations, especially myoclonus in immunosuppressed patients, can be related to measles even in the absence of an acute episode. This particular form of subacute myoclonic measles encephalitis is an opportunistic fatal disease. Immune recovery due to effective antiretroviral treatment might increase survival.

Measles-Associated CNS Complications: A Review

Measles virus infection is a common infectious disease of childhood, incidence of which is still high in developing countries. Other than the morbidity associated with the acute systemic infection, the measles virus can cause serious fatal neural complications. It can either enter the brain leading to acute encephalitis like primary measles encephalitis and acute post infectious measles encephalomyelitis or it may persist in brain cells (as mutated virus) leading to long-term neurodegenerative diseases like measles inclusion body encephalitis and subacute sclerosing pan encephalitis. The patho-clinical features, treatment, and the outcomes of these complications are different and should be identified in time for early diagnosis and management.

Congenital Measles in a Premature 25-week Gestation Infant

We describe a premature infant with congenital measles. Laboratory testing confirmed measles in the mother (polymerase chain reaction- and IgM-positive) and congenital measles in the infant (polymerase chain reaction-positive, culture-positive and IgM-positive). The infant never developed a rash, pneumonia, or neurologic complications. This case supports using compatible laboratory findings to diagnose congenital measles in infants without clinical manifestations of measles.

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.

Atypical Subacute Sclerosing Panencephalitis in a Young Child: Implications for Change in Vaccination Strategy

Subacute sclerosing panencephalitis (SSPE) is a serious neurological complication of measles with no satisfactory treatment options. The prolonged incubation period makes it rare in young children. The occurrence of primary measles infection in infants before age of vaccination can be prevented only by ensuring adequate vaccination of all females in childbearing age. Here, we present a case of an atypical presentation of SSPE in a toddler who contracted measles at 6 months of age.

[Panencephalitis in children in modern conditions: clinical, etiological and mri-aspects]

AIM

To characterize the clinical picture, infectious etiology and MRI results of panencephalitis (PANE) in children, depending on the duration of the disease.

MATERIAL AND METHODS

Children (n=32) with PANE at the age from 3 months up to 17 years were examined for a group of actual viral and bacterial infections. The inclusion criterion was a diffuse lesion of white matter hemispheres on MRI. MRI of the brain and spinal cord, CSF study (pleocytosis, oligoclonal IgG, the main myelin protein (MBP) were performed. The follow-up was 5-10 years. The complex therapy included etiotropic (antiviral) and pathogenetic agents, with priority given to cytoflavin as a drug with a multimodal effect.

RESULTS

In 84.4% of cases, PANE in children are recorded under the age of 3 years and in 71.9% of cases, are associated with congenital infections with the prevalence of herpes viruses, especially cytomegalovirus (37,8%) and herpes type 6 (21.9%). In 78.3% of cases, PANE have chronic gradual development more often with a delay in the formation of motor and speech/prespeech skills, and manifested with pyramidal, cerebellar and other symptoms in the future. PANE is accompanied by a lesion of the white matter of the hemispheres in ¹/₂ cases with periventricular localization, less often in infratentorial structures (46.9%) and spinal cord (21.9%). With the duration of symptoms up to 3 months (n=22) PANE are characterized by inflammatory-demyelinating changes, signs of mass effect, contrast+, pleocytosis in CSF and the increase in MBP (average 4.2±0.8 ng/ml), and, with the duration of more than 3 months, by degenerative-sclerosing changes (n=10) and CSF oligoclonal IgG in 90% of cases.

CONCLUSION

In almost ²/₃ of cases, PANE are associated with congenital infections, accompanied by extensive symmetrical foci of demyelination in the CNS, and their clinical and laboratory parameters and outcomes depend on the start of treatment, with the positive dynamics in 75% of cases.

Eradication of measles: remaining challenges

Measles virus (MeV) is an aerosol-borne and one of the most contagious pathogenic viruses known. Almost every MeV infection becomes clinically manifest and can lead to serious and even fatal complications, especially under conditions of malnutrition in developing countries, where still 115,000 to 160,000 patients die from measles every year. There is no specific antiviral treatment. In addition, MeV infections cause long-lasting memory B and T cell impairment, predisposing people susceptible to opportunistic infections for years. A rare, but fatal long-term consequence of measles is subacute sclerosing panencephalitis. Fifteen years ago (2001), WHO has launched a programme to eliminate measles by a worldwide vaccination strategy. This is promising, because MeV is a human-specific morbillivirus (i.e. without relevant animal reservoir), safe and potent vaccine viruses are sufficiently produced since decades for common application, and millions of vaccine doses have been used globally without any indications of safety and efficacy issues. Though the prevalence of wild-type MeV infection has decreased by >90 % in Europe, measles is still not eliminated and has even re-emerged with recurrent outbreaks in developed countries, in which effective vaccination programmes had been installed for decades. Here, we discuss the crucial factors for a worldwide elimination of MeV: (1) efficacy of current vaccines, (2) the extremely high contagiosity of MeV demanding a >95 % vaccination rate based on two doses to avoid primary vaccine failure as well as the installation of catch-up vaccination programmes to fill immunity gaps and to achieve herd immunity, (3) the implications of sporadic cases of secondary vaccine failure, (4) organisation, acceptance and drawbacks of modern vaccination campaigns, (5) waning public attention to measles, but increasing concerns from vaccine-associated adverse reactions in societies with high socio-economic standards and (6) clinical, epidemiological and virological surveillance by the use of modern laboratory diagnostics and reporting systems. By consequent implementation of carefully designed epidemiologic and prophylactic measures, it should be possible to eradicate MeV globally out of mankind, as the closely related morbillivirus of rinderpest could be successfully eliminated out of the cattle on a global scale.

[Vaccination and pregnancy]

Vaccination against influenza is recommended during the vaccination period in pregnant women regardless of trimester. In contrast, administration of live vaccines, such as the vaccine against varicella, MMR (measles-mumps-rubella) is contraindicated in pregnant women. Vaccinations against hepatitis B, diphtheria, tetanus, poliomyelitis, hepatitis A can be made as indicated. Vaccination against yellow fever may be considered in pregnant women travelling to endemic countries. In post-partum period, live vaccines may be administered if necessary, especially vaccination against whooping cough for women not to date with their vaccinations. Vaccination against yellow fever is contraindicated in case of breast feeding. Prevention of pertussis in newborns is based in France on vaccination of the mothers in the post-partum period, and the close contacts of the newborn during the pregnancy ("cocooning").

Atypical subacute sclerosing panencephalitis with short onset latency

An 11-month-old boy presented with focal seizures, myoclonic jerks and altered sensorium of one month duration, with a history of measles at eight months of age. A diagnosis of Subacute sclerosing panencephalitis (SSPE) was made on the basis of typical EEG changes and presence of anti-measles antibody in cerebrospinal fluid. A differential diagnosis of SSPE should be considered in all forms of acute encephalopathy in infants for early diagnosis and management.

[Measles and pregnancy]

Because of insufficient vaccine coverage, there is an outbreak of measles since 2008 in France with an increasing incidence of cases, most of them among children less than 1 year old or young adults. When measles occurs during pregnancy, maternal and fetal morbidity is increased. Particularly pregnant women are exposed to a higher risk of severe respiratory distress that might cause death. Measles virus can be detected in the placenta. Placental infection appears to be involved in some cases of fetal death. The virus is not responsible for congenital defects but can induce histologic damages inside the placenta which may lead to fetal death. Major perinatal risks are also miscarriage and prematurity. When measles occurs in late pregnancy, congenital infection is possible with variable expression and a risk of subacute sclerosing panencephalitis. Non immune pregnant women or neonates exposed to measles should receive an immunoglobulin prophylaxis within 6 days after contact in order to reduce the risk of infection and severe morbidity. In case of declared measles infection, symptomatic treatment can be proposed and tocolysis can be used if preterm labor is associated. Daily fetal monitoring during the 14 days following the beginning of the eruption can be offered when the fetus is viable. Vaccination is recommended for the people born in France after 1980 with 2 doses of vaccine against measles, rubeola and mumps. Measles vaccine, an attenuated living vaccine, should not be administered during pregnancy but must be proposed before pregnancy or during the post-partum period.

The rationale for the use of measles post-exposure prophylaxis in pregnant women: a review

A review of published literature was undertaken to investigate the maternal and fetal effects of measles infection in pregnancy and to inform the need for post-exposure prophylaxis. There is no evidence to support an association between measles in pregnancy and congenital defects. However, the need for effective post-exposure protection is supported by studies suggesting a high risk of severe maternal morbidity, fetal loss and prematurity. Measles in late pregnancy can also lead to perinatal infection in the infant, which may be associated with a high mortality and the risk of subacute sclerosing panencephalitis. UK guidance recommends using human normal immunoglobulin for susceptible pregnant women exposed to measles. Although there is no direct evidence that this will reduce the complications of measles in pregnancy, it may attenuate disease and therefore reduce the rate of complications. Measures to identify women likely to be susceptible include assessment of age, vaccination history, and/or antibody testing.

[Measles, mumps and rubella virus infection in pregnancy. Possible adverse effects on pregnant women, pregnancy outcome and the fetus]

Measles, mumps and rubella are common childhood diseases. Therefore, frequent and intense contact with children of preschool age may be associated with a higher infection risk for childcare providers. This overview summarizes current knowledge on possible adverse effects of these infections on pregnant women, pregnancy outcome and the fetus. Acute rubella or mumps virus infections are apparently not more severe in pregnant than non-pregnant women. In contrast, measles virus infection in pregnancy is linked to a higher incidence of pneumonitis and hospitalization. Evidence of congenital defects due to fetal infection is only provided in case of rubella virus infection in early pregnancy. Following rubella virus infection in the first trimester an increased fetal loss rate was reported. In 1966, a prospective study showed also a significant association between maternal mumps in the first trimester and an increased risk of abortion. But other investigators could not confirm this association. Measles and rubella but not mumps virus infections are linked to an increased premature birth rate. Occurring in late pregnancy, all three infections can result in birth of an infected infant. But severe disease occurs rarely and is mostly reported for premature infants with early neonatal measles. Preventive measures, aimed to reduce the risk of infection or severe complications for pregnant childcare providers, should consider the individual history of the employee (e.g. previous immunizations or antibody test results), the current epidemiological situation and possible interventions like passive immunization in case of exposure to measles.