Factores de reserva asociados al deterioro cognitivo en epilepsia refractaria del lóbulo temporal

Laburpena

Epilepsy is a neurological disorder that often presents neuropsychological alterations. Particularly, in refractory temporal lobe epilepsy case there is cognitive impairment, specifically in episodic memory. Surgical intervention, which consist in the resection of the seizure focus, is an alternative when there isn't appropriate response to pharmacological treatment. Cognitive and cerebral reserve, are constructs that are applied when there is cognitive impairment and can act as protection factors. Brain reserve is focus on biological variables stable over the time, while cognitive reserve emphasizes in modifiable factors, related with cognitive activity throughout life. Neuropsychological alterations can befall in refractory epilepsy, both by the presence of seizures and by the surgical intervention itself, so it is proposed to apply the cognitive reserve concept in this patients group. Therefore, in this work, we suggest the possibility of appliying the brain and cognitive reserve in patients with refractory temporal lobe epilepsy that are going to have surgery. Neuropsychological performance of 238 patients (109 with right hemisphere localization and 129 with left hemisphere localization) both before and after the surgical intervention, is evaluated. After these evaluations, the different scores are analyzed according to their Brain Reserve and their Cognitive Reserve, distinguishing these according to the hemisphere of location of the epileptic focus. The results indicate that in the pre-surgical assessment, high Cognitive Reserve results in a better performance in different neuropsychological tests, with the exception of attentional function and resistance to interference. On the other hand, Brain Reserve, only improves the performance in general index of verbal intelligence and in working memory, in its phonological articulatory loop component, in the delayed verbal memory and in visual memory, regardless of the hemisphere in which the focus is located. In the case of patients with right hemisphere localization, Brain Reserve implies a better performance in general index of manipulative intelligence, in resistance to interference, attention, the central executive component of working memory and phonological verbal fluency. However, in left hemisphere patients, high Brain Reserve implies worst performance in resistance to interference, as well as in attention and in phonological verbal fluency. Regarding the post-surgical change, there is a decrease in verbal memory and an improvement of general index of verbal intelligence, as well as the articulatory phonological loop component of working memory. According to the Cognitive Reserve role in this change, we suggest that it is a protective factor to delayed verbal memory and working memory. In the right hemisphere, besides, it is a protective factor to phonological articultory loop and immediate memory, both verbal and visual. In left hemisphere case, Cognitive Reserve is a protective factor in sustained attention and in phonological verbal fluency. Brain Reserve, unlike Cognitive Reserve, is not shown as a protective factor on any neuropsychological tests. In conclusion, it can be assert that Cognitive Reserve is relevant for neuropsychological involvement in patients with TLE who will undergo surgery. This protective capacity take place specifically in areas that are not directly affected by the epileptic focus, resulting in improved capabilities when related to the extratemporal and contralateral areas