Clues to new-onset epilepsy in young-onset dementia revealed


By Mardi Chapman

15 Apr 2021

Epilepsy is relatively common in people with younger-onset neurocognitive disorders (NCDs) especially those with an unspecified subtype of NCD, Australian research shows.

A retrospective study of 427 people, mostly diagnosed before 65 years of age with NCDs including Alzheimer’s, frontotemporal, vascular and movement disorder-associated dementia, found 9.4% also had epilepsy.

The study from the Royal Melbourne Hospital, published in Frontiers in Aging Neuroscience, found most people (82.5%) developed epilepsy after their cognitive decline – often within two to six years of its onset.

The most common types of seizures were focal to bilateral tonic-clonic seizure (35%), focal onset impaired awareness seizures (32.5%), and generalised tonic–clonic seizure (27.5%).

Of patients prescribed anti-seizure medication, 75% achieved seizure freedom for at least one year.

“Therefore, a high index of clinical suspicion for seizures may facilitate earlier diagnosis and treatment, and this might lead to better prognosis, and otherwise avoidable seizure-related injuries and hospitalisations,” the researchers said.

A multivariate analysis identified NCD subtype, age at onset of cognitive decline, and smoking status as risk factors for epilepsy.

The study found people with frontotemporal dementia and movement disorder-associated dementia showed a significantly lower risk of developing epilepsy compared to unspecified NCD (OR 0.23).

“People whose cognitive decline began at age 50 or less had a significantly higher risk of having epilepsy compared to those with cognitive decline starting after age 50 years (OR 2.29, 95% CI: 1.12–4.68, p = 0.023).”

And current smoking doubled the risk of epilepsy compared to non- or ex-smokers (OR 2.18).

Given smoking was a modifiable risk factor, the researchers said interventions to reduce or cease smoking should help reduce risk of new-onset epilepsy in those with NCDs.

They noted their results, from a tertiary neuropsychiatry service with expertise in young-onset NCDs, may not be generalisable to older people with more typical dementia.

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