Validación de un cuestionario para el diagnóstico de la epilepsia en servicios de atención primaria

A Novel Parent Questionnaire for the Detection of Seizures in Children of Spanish-Speaking Families

BACKGROUND

We developed and validated a Spanish seizure screen for children based on a previously validated English seizure screen that could be administered by a trained research assistant in a 2-step process, approximating the clinical diagnostic process of a pediatric epilepsy specialist. This questionnaire was designed to study seizure prevalence in a research population of children at risk for epilepsy.

METHODS

Spanish-speaking parents of children 6 months to 17 years old were recruited from the pediatric neurology clinics at Boston Medical Center and interviewed using a computerized questionnaire. A computerized algorithm of parent responses rendered a seizure classification of positive or negative. Blinded to questionnaire results, pediatric neurologists served as the diagnostic gold standard, ranking each patient event using a 4-level scale based on clinical history and examination: (1) not likely, (2) indeterminate, (3) probable, and (4) almost certain where rankings of 3 or 4 lead to a diagnosis of seizure.

RESULTS

The questionnaire was completed by 163 enrolled parents. The seizure screen demonstrated a 94.2% sensitivity and 93.7% specificity for identifying seizures. The positive predictive value was 87.5%, and the negative predictive value was 97.2%.

CONCLUSIONS

This pediatric seizure questionnaire was both sensitive and specific for detecting clinically confirmed seizures. This tool may be useful to clinicians and researchers in screening large populations of children, decreasing the time and cost of added neurologic assessments.

Calibration of the Epilepsy Questionnaire for Use in a Low-Resource Setting

Background. Burden of epilepsy in sub-Saharan Africa is huge in the midst of shortage of human resource in its health sector. Using skilled staff to supervise and support lower level healthcare workers providing frontline primary healthcare is a pragmatic coping solution. But, lower level health providers face enormous challenges due to absent clinical algorithms or pragmatic rapid diagnostic tests. Objective. This study aimed to determine if the use of an epilepsy questionnaire in a traditional clinical setting would improve semiological details obtained and diagnostic accuracy. Methods. A prospective study was conducted involving patients diagnosed with epilepsy each with an eye witness who had regularly witnessed the seizures. Routine seizure history from clinical documentation and an interviewer-based questionnaire were compared. The data obtained were assessed for content, accuracy, intermethod and test-retest reliability. Results. Sixty-seven patients with a median age of 24 years were recruited. Routine seizure history had obtained less semiological details with inadequate description of nonmotor manifestations and lateralizing motor details. The questionnaire-obtained history showed higher accuracy for generalized onset seizure (0.83 vs. 0.56) and focal onset seizures (0.79 vs. 0.59). The questionnaire-obtained history also had good test-retest reliability for various semiological domains except automatisms. Conclusions. Routine seizure histories are not standardized. The use of a questionnaire goes a long way in improving semiology description in a low-resource setting and guides the health provider on what details to focus on. The use of epilepsy questionnaires should, therefore, be considered to improve semiology, especially in nonspecialist settings.

A pediatric epilepsy diagnostic tool for use in resource-limited settings: A pilot study

OBJECTIVE

It is estimated that nearly 80% of the 50 million people affected with epilepsy globally live in regions where specialist care and diagnostic tests are scarce and care is often delivered through a primary health provider with limited training. To improve diagnostic accuracy of the history and physical examination, we developed and piloted a questionnaire to discriminate between focal versus generalized epilepsy, with the future goal to guide medication choices.

METHODS

Through literature review and retrospective chart review of 75 children with epilepsy at Boston Children's Hospital, a 15-item questionnaire was developed. Simple motor seizures were excluded for the purposes of this questionnaire. The questionnaire was then translated in local dialects and prospectively validated at Muhimbili National Hospital in Dar Es Salaam, Tanzania, and University Teaching Hospital in Lusaka, Zambia. Children 6months-18years of age with suspected or active epilepsy were identified, and a nonphysician administered the questionnaire to the patient's caregiver. Next, each patient was evaluated by a pediatric neurologist blinded to the questionnaire results, and together with locally obtained but remotely interpreted EEG, an electroclinical diagnosis was made. The questionnaire data were compared with this clinical gold standard.

RESULTS

A total of 59 children participated: 28 from Tanzania and 31 from Zambia. Sixteen patients were excluded: 5 were excluded because of incomplete data, and 11 did not meet criteria for epilepsy based on initial screening questions. Of the remaining 43 patients, 28 had focal or multifocal epilepsy (65%), and 15 (35%) had generalized epilepsy. The questionnaire had a sensitivity of 78% and positive predictive value of 81.5%. Data were analyzed using a Rasch model, testing the questionnaire's internal consistency, reliability, and its discriminative validity in classifying focal versus generalized epilepsy against an electroclinical diagnosis. The mean epilepsy score for focal epilepsy was 0.084 logits compared with -1.147 logits for generalized epilepsy, demonstrating a large effect size [F (1, 41)=13.490, p<0.001].

CONCLUSIONS

Our questionnaire provides a straightforward method to improve diagnostic accuracy, and could assist in bridging the diagnostic gap in pediatric epilepsy in resource-limited settings. This tool was specifically designed to be easily implemented by any healthcare provider. This pilot study prompts broader prospective validation in additional settings for further refinement, and for performance assessment of impact on provider's practice, ability to guide medication choices, and ultimately improve treatment outcomes in resource-limited regions.

The validation of a three-stage screening methodology for detecting active convulsive epilepsy in population-based studies in health and demographic surveillance systems

Background

There are few studies on the epidemiology of epilepsy in large populations in Low and Middle Income Countries (LMIC). Most studies in these regions use two-stage population-based screening surveys, which are time-consuming and costly to implement in large populations required to generate accurate estimates. We examined the sensitivity and specificity of a three-stage cross-sectional screening methodology in detecting active convulsive epilepsy (ACE), which can be embedded within on-going census of demographic surveillance systems.

We validated a three-stage cross-sectional screening methodology on a randomly selected sample of participants of a three-stage prevalence survey of epilepsy. Diagnosis of ACE by an experienced clinician was used as ‘gold standard’. We further compared the expenditure of this method with the standard two-stage methodology.

Results

We screened 4442 subjects in the validation and identified 35 cases of ACE. Of these, 18 were identified as false negatives, most of whom (15/18) were missed in the first stage and a few (3/18) in the second stage of the three-stage screening. Overall, this methodology had a sensitivity of 48.6% and a specificity of 100%. It was 37% cheaper than a two-stage survey.

Conclusion

This was the first study to evaluate the performance of a multi-stage screening methodology used to detect epilepsy in demographic surveillance sites. This method had poor sensitivity attributed mainly to stigma-related non-response in the first stage. This method needs to take into consideration the poor sensitivity and the savings in expenditure and time as well as validation in target populations. Our findings suggest the need for continued efforts to develop and improve case-ascertainment methods in population-based epidemiological studies of epilepsy in LMIC.