An eight-year-old boy presented with rhythmic myoclonic jerks that stretched back to the age of four years. He was diagnosed as having subacute sclerosing panencephalitis (SSPE). This is a progressive and almost uniformly fatal disease. His condition gradually deteriorated till he was unable to speak or walk. He also experienced incontinence and severe cognitive decline (stage 3a in the Risk and Haddad scale). An electroencephalogram (EEG) showed myoclonic jerks with periodic, generalised, high-amplitude and slow-wave complexes. Cerebrospinal fluid (CSF) findings also were supportive of the diagnosis of SSPE. The ketogenic diet (KD) therapy was started on the patient. His myoclonic jerks stopped after 11 months. After 36 months, his cognition and physical abilities vastly improved. His EEG showed no slow-wave complexes and background activity was almost normal.
SSPE is secondary to measles and causes inflammatory and neurodegenerative changes. KD has an anti-inflammatory effect and can halt and reverse neurodegenerative changes. Its neuroprotective effects could be due to the reduced oxidative stress, enhanced mitochondrial activity, and the suppression of pro-apoptotic factors. Thus, KD could control the myoclonic jerks and also reverse the cognitive and physical decline arising from SSPE.