The measles that never really left: How SSPE silently attacks the brain years later

A child recovers from measles The fever disappears the rash fades and the family believes the illness is over Years later however the child may begin forgetting lessons losing previously acquired skills or behaving differently School performance deteriorates Falls become frequent Then come sudden jerking movements seizures and progressive loss of movement speech and visionIn severe cases the child can eventually lose the ability to walk swallow communicate or remain conscious This is subacute sclerosing panencephalitis SSPE a rare progressive and usually fatal neurological disease caused by persistent altered measles virus infection in the brainDr Fazal Nabi director of paediatrics at Jaslok Hospital in part seven of middayrsquos ninepart series on SSPE highlights how the disease is a stark reminder that measles is not simply a childhood infection that ends when the fever and rash disappearDr Fazal Nabi director of paediatrics at Jaslok Hospital Pic Special ArrangementldquoIn rare cases the virus can persist in the brain and years later lead to a devastating and progressive neurological illnessrdquo the expert saidSSPE generally appears several years after the original measles infection That long interval can make the connection difficult to recognise The disease usually begins insidiously with symptoms that may initially be mistaken for behavioural psychological or educational problemsldquoWhen a child develops unexplained behavioural or cognitive regression particularly when it is followed by myoclonic jerks or seizures SSPE should be considered especially if there is a history of measlesrdquo Dr Nabi saidldquoSubacute sclerosing panencephalitis or SSPE remains a rare but devastating consequence of natural measles infection Recent Indian research published in 2025 and a 2026 systematic review of neuroimaging underline the diseasersquos varied presentation severe outcomes and the urgent need for early recognition and preventionrdquo Dr Nabi saidEarly warning signsFalling school performanceForgetfulness and loss of learned skillsPersonality or behavioural changesIrritability and withdrawalSpeech deteriorationProgressive cognitive declineUnexplained falls or gait problemsLater development of myoclonic jerksSeizures and other movement abnormalitiesVisual impairmentFour stagesSSPE is commonly described clinically as a progressive fourstage disorder although the speed and exact pattern can vary between patientsStage I The hidden beginningThe child may still appear physically well but parents and teachers notice that something has changedPersonality and behavioural changesDeclining academic performanceMemory problemsIrritability or mood changesLoss of previously acquired abilitiesEarly speech or cognitive difficultiesThis is often the stage at which diagnosis is most easily missedStage II Jerks seizures and neurological declineNeurological abnormalities become unmistakableCharacteristic myoclonic jerksSeizuresWorsening intellectual impairmentSpeech deteriorationGait disturbancePoor coordinationAbnormal movementsStage III Severe neurological disabilityThe child progressively loses purposeful activityRigidity and dystoniaSevere motor impairmentLoss of independent movementVisual impairmentIncreasing difficulty communicatingProgressive loss of interaction with the environmentStage IV Profound neurological failureIn the final stage the patient may developAkinetic or vegetative stateSevere swallowing difficultyNutritional compromiseAutonomic dysfunctionRecurrent aspirationRespiratory complicationsLoss of meaningful communicationUltimately deathWhat happens inside the brainSSPE is not simply a second episode of ordinary measles Research indicates that the virus persists inside the central nervous system in an altered formMutations in viral proteins particularly those involved in viral assembly and release allow the virus to persist and spread from cell to cell while limiting the conventional release of infectious virusThe process can produce chronic inflammation neuronal injury demyelination gliosis and progressive cerebral atrophyThe important distinction is that SSPE is a delayed complication of a personrsquos earlier natural measles infection it is not an infection transmitted from a patient with SSPE to another personWhat a 2025 study revealedOne of the most important recent Indian datasets was published in 2025 by researchers from AIIMS New Delhi The study examined 144 patients with SSPE offering a contemporary hospitalbased picture of the disease in IndiaIt found substantial variation in clinical presentation and progression while confirming the severe functional and survival burden associated with the disease The study was hospitalbased and therefore should not be interpreted as a national incidence estimate for India Nevertheless it demonstrates that SSPE continues to impose a significant neurological burdenThe findings includedMean patient age of about 167 yearsMyoclonus among the most characteristic neurological manifestationsFrequent cognitive deteriorationCharacteristic periodic EEG abnormalities in many tested patientsAmong patients with available followup 48 per cent died233 per cent achieved a good functional outcome based on modified Rankin Scale criteriaCurrent therapeutic approachesIsoprinosineInterferonalphaRibavirinSymptomatic antiseizure treatmentRehabilitation and nutritional supportPalliative care in advanced disease2026 reviewA 2026 systematic review examining the neuroimaging spectrum of SSPE analysed 461 reported casesNeuroimaging was available in 456 cases with MRI performed in 394 The review found that935 per cent had whitematter abnormalitiesDiffuse bilateral whitematter changes were commonCortical abnormalities were also frequentCerebral atrophy was identified in a substantial proportionDeepgreymatter and brainstem abnormalities occurred less oftenImaging patterns could sometimes resemble other neurological diseasesThe findings are important because SSPE does not always produce one fixed MRI appearance Imaging abnormalities can change with disease progression and some patterns may mimic autoimmune metabolic inflammatory or other neurodegenerative disordersDiagnosis requires more than one clueDoctors generally combine the clinical history with EEG cerebrospinal fluid testing and brain imagingKey diagnostic toolsCSF measles antibodies Elevated measlesspecific IgG in CSF is a major diagnostic clue and can demonstrate intrathecal antibody productionEEG Periodic stereotyped highamplitude complexes are characteristic particularly when they correspond with myoclonic jerksMRI MRI may be normal early but can later reveal whitematter abnormalities and cerebral atrophyA normal early scan or nondiagnostic EEG should therefore not automatically exclude SSPE when the clinical picture is strongly suggestiveThe treatment challengeSSPE remains difficult to treat because the virus is persistently embedded within the brain and conventional antiviral strategies have limited evidence Some patients may receive combinations of antiviral and immunomodulatory therapy particularly during the earlier stagesHowever there is no proven cure Treatment responses are inconsistent evidence comes largely from small studies and observational experience large randomised controlled trials are lacking and advanced disease is particularly difficult to reverseSupportive treatment is therefore crucial and may include seizure control physiotherapy occupational therapy swallowing assessment nutritional support aspiration prevention respiratory care and palliative careMessage for parents doctorsThe disease is rare but its early symptoms can be deceptively ordinaryA previously healthy child who develops progressive loss of cognitive or behavioural abilities followed by myoclonic jerks seizures movement problems or visual deterioration warrants neurological evaluation particularly if there is a history of measlesThe key takeawaysThink SSPE when a child progressively regressesAsk about previous measles infectionLook for myoclonus and characteristic EEG abnormalitiesUse CSF measles antibodies to support diagnosisDo not dismiss SSPE because an early MRI is normalRecognise that MRI appearances can vary considerablyUnderstand that available treatments may slow disease but do not reliably cure itProvide multidisciplinary supportive careMost importantly prevent measles through recommended vaccinationPrevention is crucialldquoThere is currently no universally effective curative treatment for SSPE The objective is to slow progression where possible control seizures and other symptoms preserve function and provide comprehensive supportive care Ensuring that children receive their recommended measlescontaining vaccines is critical to reducing risk Prevention remains our strongest weapon By preventing measles infection in the first place we can prevent the devastating neurological legacy that SSPE can leave years laterrdquo Dr Nabi said