Épilepsie : pour une sémiologie neuropsychiatrique de la dépression

Abstract

The prevalence of psychiatric disorders is significantly higher among patients with epilepsy than the general population. Moreover, the profile of depressive disorder is often atypical in patients with epilepsy. Data from human and animal studies have tended to point towards a bidirectional link in the pathophysiological basis of both epilepsy and depressive syndrome. Depressive symptoms in epilepsy can be divided into those occurring in the peri-ictal period (pre-ictal, ictal and post-ictal), and those occurring in the inter-ictal period. Peri-ictal depressive disorders are particularly associated with temporal lobe epilepsies. These include: (i) peri-ictal dysphoria, (symptoms occur in the 24hour period preceding a seizure); (ii) ictal depression, (symptoms develop during the seizure); (iii) post-ictal depression, (symptoms occur in the 72hours following the seizure). The inter-ictal depressive disorders are not temporally related to seizures. The best characterized of these is “inter-ictal dysphoric disorder”. This includes labile depressive symptoms (depressed mood, anergia, pain, insomnia), labile affective symptoms (panic-like symptoms and anxiety), and supposedly “specific” symptoms (paroxysmal irritability and instable-euphoric moods). Standard psychiatric classification may be inadequate to describe some of the atypical profiles seen in this patient population. Depression in patients with epilepsy is therefore under-diagnosed, and yet contributes to poorer quality of life, epilepsy outcome and risk of suicide. It is recommended that an appropriate screening tool be used to detect signs of major depression, the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E). Clinicians should recognize the characteristics of peri-ictal and inter-ictal depressive syndromes.