Cognitive impairments in idiopathic generalised epilepsy ‘a shared family trait’

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Patients affected by a certain type of epilepsy are likely to experience cognitive impairments that are shared by other members of their family, a new study has revealed.

The King’s College London study has investigated the strong genetic component of idiopathic generalised epilepsy (IGE) in order to better understand why patients with this condition often show deficits in a range of frontal lobe functions.

IGE is the term used to describe forms of epilepsy that do not have any readily apparent causes and are not associated with structural brain abnormalities, meaning that a better understanding of their underlying genetic foundations is essential.

For this new study, 36 patients with IGE were examined using a series of neuropsychological tests sensitive to frontal lobe dysfunction, including assessments of executive function, nonverbal reasoning, verbal generativity, response inhibition, attention and working memory. 38 of their first-degree relatives and 40 healthy controls also underwent these tests.

Previous studies have hinted that unaffected siblings of people with IGE may share some of their cognitive deficits, suggesting these may be genetically determined endophenotypes – a discovery that would increase general understanding of the pathophysiology of these types of epilepsy.

Results published in the journal Epilepsia revealed not only that patients with IGE tended to experience deficits in nonverbal reasoning, verbal generativity, attention, and working memory, but also that their relatives exhibited a parallel profile, with significant impairments in these tasks.

Though the IGE patients tended to show greater deficits in these tasks than their relatives, this nevertheless indicates that these problems stem from the same underlying genetic cause.

The paper concluded: “This study shows that measures of nonverbal reasoning, verbal generativity, sustained attention and working memory are endophenotypes of IGE and offer the potential for aiding molecular genetic studies and elucidating the pathophysiology of IGE.

“Patients tended to demonstrate greater impairment in these tasks, possibly because of a greater genetic contribution and/or disease-related factors.”

Posted by Anne Brown