Depression symptoms as a function of duration of intractable or controlled epilepsy

Identification of drug resistance in a validated cohort of incident epilepsy patients in the Danish National Patient Register

OBJECTIVE

The main purposes of this study were to validate the epilepsy diagnosis in incident epilepsy cases in the Danish National Patient Registry (DNPR), which contains information on nearly 9 000 000 individuals, and to identify persons in the validated cohort who fulfilled the International League Against Epilepsy (ILAE) criteria for drug-resistant epilepsy (DRE).

METHODS

We reviewed a random sample of medical records from all individuals registered with a first diagnosis of epilepsy (International Classification of Diseases, 10th Revision [ICD-10]: G40) or seizures (ICD-10: G41, R56, or F445) in the Central Denmark Region from 2010 to 2019. In persons with a validated incident epilepsy diagnosis, we determined the proportion with DRE at the latest contact. We performed logistic regression analyses to identify clinical factors that correlated with risk of DRE.

RESULTS

Of 20 723 persons with a first diagnosis of epilepsy (n = 11 812) or seizures (n = 8911), we reviewed the medical records of n = 1067 with incident epilepsy and n = 610 with incident seizures. Among those with a register diagnosis of epilepsy, the diagnosis was confirmed in 838 cases (45% females, mean age at onset = 42.4 years), providing a positive predictive value (PPV) of 79% (95% confidence interval [CI] = 76%-81%). The PPV of focal epilepsy was 86% (95% CI = 82%-89%), and the PPV of generalized epilepsy was 71% (95% CI = 61%-80%). Of 740 patients with confirmed incident epilepsy and ≥1 year of follow-up, 103 (14%) fulfilled the definition of DRE, 476 (64%) were drug responsive, and 161 (22%) had undefined responsiveness. In multivariable logistic regression analysis, early age at epilepsy onset, cognitive impairment, and a history of status epilepticus were associated with DRE.

SIGNIFICANCE

In the DNPR, we found a PPV of the epilepsy diagnosis of 79%. Among persons with confirmed epilepsy, 14% fulfilled ILAE criteria for DRE. Early age at epilepsy onset, cognitive impairment, and a history of status epilepticus were independently associated with drug resistance.

Which symptoms are indicative of depression in epilepsy settings? An analysis of the diagnostic significance of somatic and non-somatic symptoms

BACKGROUND

Depression is a common psychiatric co-morbidity in epilepsy. However, there have been no previous studies which have investigated the validity of individual symptoms for comorbid depression in epilepsy, in particular the diagnostic value of somatic and non-somatic symptoms.

METHODS

Patients with epilepsy diagnosed in a specialist epilepsy clinic were approached and completed several self-reported mood scales, prior to or immediately after their neurology outpatient consultations. Symptoms of depression were elicited using PHQ-9, BDI-II and HADS scales, comprising a total of 44 self report questions. 266 patients returned complete questionnaires of whom 18.0% met criteria for DSM-IV major depression according to the WHO Major Depression Inventory.

RESULTS

Against DSM-IV major depressive disorder (MDD), both somatic and non-somatic symptoms were valuable. The top five most useful questions relating to a diagnosis of MDD in epilepsy were "Moving or speaking so slowly that other people could have noticed" "Little interest or pleasure in doing things" "Feeling down depressed or hopeless" "Trouble concentrating on things such as reading" and "Feeling tired or having little energy." Four of these symptoms were rated as excellent initial screening questions for depression namely, "Moving or speaking so slowly that other people could have noticed" "Little interest or pleasure in doing things" "Feeling down depressed or hopeless" "Trouble concentrating on things such as reading." The item "Moving or speaking so slowly that other people could have noticed" from the PHQ9 was endorsed in about 90% of depressed patients with epilepsy but only about 6% of non-depressed patients.

CONCLUSION

These findings suggest that both somatic and non-somatic symptoms can be valuable when diagnosing depression in epilepsy and should be considered when designing scales for depression in epilepsy. Specific psychological symptoms and specific somatic symptoms are indicative of depression in epilepsy.