Computed Tomography Abnormalities and Epidemiology of Adult Patients Presenting With First Seizure to the Emergency Department in Qatar

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1 ORIGINAL CONTRIBUTION Computed Tomography Abnormalities and Epidemiology of Adult Patients Presenting With First Seizure to the Emergency Department in Qatar Sameer A. Pathan, MCEM, Salem Abosalah, MD, Sana Nadeem, MBBS, Amjad Ali, MBBS, Asma A. Hameed, MBBS, Mandar Marathe, FCEM, and Peter A. Cameron, MD Abstract Objectives: There is little information available from the Middle Eastern region on adult patients presenting with first seizure. The objectives of this study were to describe epidemiological characteristics of patients presenting to the emergency department (ED) in Doha, Qatar, with first seizure and to determine the incidence of computed tomographic (CT) scan abnormalities. Methods: A retrospective cohort study was conducted on all adult patients with first seizure presenting to Hamad General Hospital ED over a 1-year period (June 2012 through May 2013). Electronic patient records were reviewed for demographics, neuroimaging, electroencephalography, laboratory test results, and medications administered. Results: There were 439 patients who satisfied inclusion criteria. Patients were aged a mean of 35.3 years (95% confidence interval [CI] = to years) with a male-to-female ratio of five to one. CT abnormalities were detected in 154 patients (35.3%; 95% CI = 30.81% to 39.82%). Out of reported abnormal scans, 14.7% patients had significant abnormalities such as neurocysticercosis (9.2%); brain metastasis and neoplasm (3.4%); and subarachnoid and subdural hemorrhage, cavernous sinus thrombosis, acute stroke, and brain edema (2.0%). None of the patients had any electrolyte abnormalities, and three patients had hypoglycemia. Patients with initial abnormal CT brain results were more likely to have recurrent seizures (OR = 1.65; 95% CI = 1.11 to 2.45) within 6 months. Conclusions: Adults who presented with first seizure to the ED in Qatar had a young male predominance, and a high proportion of brain CT scans were reported as abnormal. It is recommended that all such patients in this population should undergo prompt CT scanning in the ED, but the utility of routine electrolyte tests requires further investigation. ACADEMIC EMERGENCY MEDICINE 2014;21: by the Society for Academic Emergency Medicine Seizure is a common neurologic presentation to emergency department (EDs). 1 Lifetime risk of one seizure in prospective population-based studies is reported to be 8% to 10%, with a 3% chance of being diagnosed as epilepsy. 2,3 The incidence and prevalence of first seizure and epilepsy vary widely across the world. In 40% to 45% of cases, no cause is identified, and fewer than 10% have metabolic or From the Department of Emergency Medicine, Hamad General Hospital, Hamad Medical Corporation (SAP, SA, NS, AA, AAH, MM, PAC), Doha, Qatar; and the Department of Epidemiology and Preventive Medicine, The Alfred Hospital, Monash University (PAC), Melbourne, Victoria, Australia. Received April 20, 2014; revision received June 18, 2014; accepted July 4, Presented at the International Conference on Emergency Medicine, Hong Kong, June The study was funded by a grant from Medical Research Center (MRC#13378/13), Hamad Medical Corporation (HMC), Doha, Qatar. The authors have no potential conflicts to disclose. Supervising Editor: Clifton Callaway, MD, PhD. Address for correspondence and reprints: Sameer A. Pathan, MCEM; drsameer_pathan@live.com ISSN by the Society for Academic Emergency Medicine 1264 PII ISSN doi: /acem.12508

2 ACADEMIC EMERGENCY MEDICINE November 2014, Vol. 21, No toxicologic causes. 4,5 The incidence of computed tomography (CT) abnormalities in first seizure patients has a wide variability of 3% to 40%. 5 7 Among adult patients presenting to the ED with first seizure, the practice of performing neuroimaging in the ED varies widely. This decision is driven by various factors such as local epidemiology, presenting clinical symptoms and signs, availability of resources, and reliability of follow-up. Previous studies have shown that neuroimaging is beneficial in excluding or making emergency diagnoses. 5,8,9 The American College of Emergency Physicians (ACEP) Clinical Policy and Guidelines in Emergency Medicine Network (GEMNet) suggests that a brain CT should be performed in the ED if intracranial pathology is suspected or patients present with partial focal seizure; persistent altered mental status, persistent headache, new focal neurologic deficit, fever, or trauma; are immune compromised; or are at risk of bleeding. 10,11 In the absence of those, neuroimaging may be deferred to an early outpatient setting if reliable follow-up is available. 10 A low yield of extensive laboratory testing in first seizure patients, unless indicated by history or physical examination, has also been previously suggested. 12 ACEP and GEMNet guidelines also suggest that a blood glucose and sodium level should be determined in patients with first seizure with no comorbidities who have returned to their clinical baseline. 10,13 The value of these tests for first seizure in the Qatar population is unknown. So far there are no published data from Qatar on the epidemiology of adult patients presenting to the ED with first seizure. There is also a lack of reported data on the incidence of abnormalities detected on CT scans and the association of these abnormalities with repeat seizures in the near future. The aim of this study was to report the epidemiology, CT abnormalities, and role of routine electrolyte check in adult patients with first seizure presentation to the ED in Hamad General Hospital (HGH) in Qatar. METHODS Study Design A retrospective cohort study was conducted on all adult patients with first seizure presenting to the HGH ED over a 1-year period (June 2012 to May 2013). This study was reviewed by the hospital ethics board and approved for waiver of consent under Supreme Council of Health guidelines in Qatar. Study Setting and Population The HGH is a tertiary care health facility with approximately 420,000 annual patient visits to the ED. Based on published clinical guidelines and availability of resources, the ED practice guidelines recommend an urgent CT of the brain for all adult patients presenting with first seizure. 10,13 As a part of routine investigations, electrolyte and glucose testing are also recommended. Blood ethanol levels should be requested if clinically indicated. Patients who presented with a seizure following a history of injury to the head were excluded, as separate guidelines inform assessment of those patients. 14 Study Protocol Electronic patient records were reviewed retrospectively for the study period. Data collection was performed by a team of four members (NS, AA, AAH, MM) who were trained and audited by the principal investigator (SAP) for consistency in data recording. The variables extracted were demographic details (such as age, sex, nationality); reports of CT scan, magnetic resonance imaging (MRI), electroencephalography, and laboratory tests; medications prescribed; and final disposition. The medical records of each patient were screened for any further visit to the ED following seizure within 6 months from the index visit. An explicit chart review was conducted with relevant and available data recorded onto a standard electronic form with additional space to enter free-text comments. For patients admitted to the hospital, physical medical records were also reviewed. Information was recorded regarding the presentation and initial neurologic examination findings by the emergency physician and the neurologist. Neurologic examination findings extracted were the presenting Glasgow Coma Scale (GCS) score, pupil size and reactivity, signs of focal neurologic deficit, and signs of meningismus. All patients were investigated for any electrolyte imbalance, hypoglycemia, or other acute metabolic disturbance as the cause of seizure. For patients with abnormal values, physical medical records were also checked for treatment to correct those abnormalities. Data Analysis All data were extracted and stored in Microsoft Excel. Continuous variables are reported as mean with standard deviation (SD). Categorical variables were calculated as proportions and are presented with 95% confidence intervals (CIs). Odds ratios (ORs) to assess the association between variables were calculated and are presented with 95% CI. Statistical analyses were undertaken using Stata RESULTS During the 1-year study period 1,408 adult patients presented to the HGH ED with seizures. (Baseline characteristics are presented in Table 1.) There were 969 (68.8%) patients excluded because their age was under 14 years, a previous diagnosis of seizure disorder had been made, or there was associated trauma to the head. There were 439 (31.2%) first seizure patients included in the study; of these 20 were admitted to the hospital and 419 were discharged from the ED. The mean age was 35.3 years (95% CI = to years) and the maleto-female ratio was five to one (Figure 1). There were 436 patients (99.3%) investigated with CT scans of the brain during their ED visits. The CT scans were reported as being normal in 282 patients (64.6%; 95% CI = 60.0% to 69.1%), and CT abnormalities were detected in 154 patients (35.3%; 95% CI = 30.81% to 39.82%). Among patients with abnormal CT results, eight acute emergencies were identified, which included subarachnoid hemorrhage (SAH), cavernous sinus thrombosis, acute stroke, and brain edema. Other abnormalities reported on the CT were calcified or

3 1266 Pathan et al. CT FOR FIRST SEIZURE IN QATAR Table 1 Baseline Characteristics Variable Total (N =439) CT Normal (n =282) CT Abnormal (n =154) OR (95% CI) p-value Age (yr), mean (SD) (13.06) (16.69) 1.02 ( ) <0.01 Male sex 369 (84.0) 240 (85.1) 127 (82.5) 0.82 ( ) 0.47 Nationality Nepalese 101 (23) 53 (18.8) 48 (31.2) 1.37 ( ) 0.36 Indian 98 (22.3) 66 (23.4) 32 (20.8) 0.80 ( ) 0.52 Egyptian 29 (6.6) 18 (6.4) 10 (6.5) 0.87 ( ) 0.78 Sri Lankan 29 (6.6) 26 (9.2) 3 (1.9) 0.18 ( ) <0.01 Pakistani 17 (3.9) 12 (4.3) 5 (3.2) 0.65 ( ) 0.48 Bangladeshi 16 (3.6) 11 (3.9) 5 (3.2) 0.71 ( ) 0.58 Filipino 14 (3.2) 9 (3.2) 5 (3.2) 0.87 ( ) 0.78 Others 79 (18.0) 54 (19.1) 25 (16.2) 0.73 ( ) 0.39 Recurrence of seizures 217 (49.4) 125 (44.3) 92 (59.7) 1.65 ( ) 0.01 Data reported as n (%) unless otherwise noted Table 2 CT Abnormalities in First-time Seizure Patients Figure 1. Age distribution by sex. Bottom line is minimum age in the category, lower line of the box is 25th percentile, middle line in the box represents the median age, upper line of the box is 75th percentile, top line is maximum age, and dots are outliers. ill-defined hyper or hypodensities (10.8%), neurocysticercosis (9.2%), sequela of old stroke, old trauma or previous surgery (6.2%), and neoplasm (3.4%; Table 2). Of the three patients who did not have CT scans, all had MRI scans performed within 48 hours. Two patients had normal MRIs and one patient was found to have a meningioma. At 6 months following initial presentation, 217 patients (49.4%; 95% CI = 44.7% to 54.1%) re-presented with another seizure. Recurrent seizures within 6 months were higher among patients with CT abnormalities (OR = 1.65; 95% CI = 1.11 to 2.45). 15 None of the patients included in the study had any electrolyte abnormalities that required correction. Hypoglycemia was detected in three patients and was identified on presentation by bedside glucose check. Blood ethanol levels were high in two patients. Lumbar punctures were performed on two patients, indicated by fever. Both were found to be free of bacterial or viral infection on polymerase chain reaction microscopy, as well as on culture examination. Reported Findings n Percentage Normal CT Neurocysticercosis Calcified lesion and 26 6 ill-defined hyperdensities Ill-defined hypodensity Poststroke sequelae Neoplasm and metastasis Incidental finding Old surgery/old trauma sequelae Acute stroke Brain edema Subarachnoid hemorrhage Cavernous sinus thrombosis Cavernous angioma Chronic subdural hematoma Twenty cases were admitted into the hospital from the ED index visit and diagnosed as SAH (n =2), subdural hematoma (n =1), cavernous sinus thrombosis (n =1), acute stroke (n =3), primary neoplasm (n =7), metastasis (n =2), brain edema (n =2), and status epilepticus (n =2). We were able to trace 19 of the admitted patient chart records. On chart review 13 (65.0%) patients had normal neurologic examinations documented on their initial ED assessments and admitting neurologist notes, while four had detectable abnormalities on neurologic examination including focal deficits, unequal pupils, or a persistent low GCS score. Only two patients complained of persistent severe headache one had SAH and the other had a cavernous sinus thrombosis. DISCUSSION To the best of our knowledge this is the first reported study in Doha, Qatar, and probably in the Middle East, examining patients presenting with first seizure to an ED. We found that the majority of cases presenting with first seizure in Qatar were young male laborers, many of whom were from Nepal. Neurocysticercosis was the most common abnormality on CT in this Nepalese

4 ACADEMIC EMERGENCY MEDICINE November 2014, Vol. 21, No group. The initial CT scan in the overall cohort showed a substantial proportion of abnormalities. Guidelines also recommend routine testing of serum sodium in patients with first seizure. 10,13 In our study, no cases of hypo- or hypernatremia were detected, raising the question of the utility of routine testing in all patients with first seizure. However, this is a single-center retrospective cohort study and a prospective study that records all relevant variables using a larger sample size from multiple sites with a longer follow-up is required before changing recommendations. Neuroimaging in the ED Major guidelines suggest that in the absence of a history of trauma, malignancy, or immunocompromise, and if the patient recovers to a normal conscious level without any persistent headache or focal neurologic deficit, neuroimaging can be deferred to an outpatient clinic as long as follow-up is reliable. 10,13 The first seizure population in Qatar is different from that of many western countries. Most of the patients are young adults, migratory expatriates, and in this study, shown to have significant abnormalities on CT scan with normal clinical examination findings. This suggests that the generalizability of major guidelines in our population is limited. Neurocysticercosis The prevalence of CT diagnosed neurocysticercosis in this study was 9.2%, which is higher than the reported prevalence in other nonendemic areas. 16 Qatar is an oiland gas-rich country where 94% of working population is expatriates from different countries, including neurocysticercosis-endemic areas. The increase in frequency of international travelers and immigrants has made transfer of neurocysticercosis possible from endemic to nonendemic areas. There were four reported cases of neurocysticercosis in Qatari Muslim patients. 17 As pork meat ingestion is prohibited for Muslims, the most likely explanation is fecal oral chain of transmission among these patients. Possibly serologic screening of workers coming from the endemic areas should be considered in the future as part of preemployment health check-up, especially for those involved in food handling and domestic work. LIMITATIONS This study had a number of limitations that should be considered. It was a retrospective review of electronic records and best available physical file records, but included all consecutive presentations of patients with first seizure. Although HGH ED is the major emergency care provider, it is possible that some patients may have gone back to their home countries, as a majority of the population in Qatar is migratory. This study provides a population-based measure of the demographics of patients presenting to the ED with a first seizure only, and the true incidence of reported outcomes might be higher in the community. Selection bias may have been possible through the presenting complaint being documented as a secondary cause, such as tumor, postsurgery, or infection, rather than the first seizure. CONCLUSIONS Adult-onset first seizure presentations to a Qatar ED had a young male predominance, and a high proportion of brain scans were reported as abnormal. Routine testing of blood electrolytes in all adult patients with first seizure revealed no abnormalities. Acute emergencies with significant pathology on neuroimaging may present with completely normal neurologic examinations on ED presentation. Considering the higher incidence of CT abnormalities, seizure recurrence, coexistence of acute life-threatening diagnoses, and lack of appropriate follow-up, CT scanning of all patients presenting with first seizure in the ED is justified in our setting. The authors thank Mr. Jibin Moinudheen for his help in getting patients monthly ED visit registries. References 1. Huff JS, Morris DL, Kothari RU, Gibbs MA. Emergency department management of patients with seizures: a multicenter study. Acad Emerg Med 2001;8: Hauser WA, Annegers JF, Kurland LT. Incidence of epilepsy and unprovoked seizures in Rochester, Minnesota: Epilepsia 1993;34: Annegers JF, Hauser WA, Lee JR, Rocca WA. 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