Epilepsy is a disorder that causes recurring seizures, and various brain diseases are risk factors or causes of epilepsy (Shorvon, 2011). Epilepsy seizure occurs unpredictedly, which disables the doctor to observe the symptoms directly during the doctor’s appointment. Thus, a medical history through the patient or the guardian is highly important (Noachtar & R?mi, 2009). Electroencephalogram (EEG) is the most objective and useful test for epilepsy (Pillai & Sperling, 2006). Particularly, it is reported that the appearance of EEG wave during an EEG increases the risk of epilepsy more than 5 fold (Kim et al., 2013). This result can be confirmed in various studies (Annegers et al., 1986; Hauser et al., 1990; Shinnar et al., 1990, van Donselaar et al., 1992). However, there are cases where EEG waves were not found in EEG of epilepsy (Theodore et al., 1984) or where EEG waves were found in patients with no epilepsy seizure (Park, 2007). Thus, seizure in epilepsy patients is currently being treated based on each doctor’s personal experience (Pearce & Cock, 2006; Askamp & van putten, 2013). Therefore, the purpose of this study is to investigate the correlation between EEG results and complete blood cell count (CBC) test results in subjects who were diagnosed for epilepsy and to use the analyzed results for clinical baseline data.

1. Subjects

The subjects of this study were 244 patients who received an EEG at Seoul national university hospital in 2014 and who agreed to the research purposes of the study. Subjects were divided into normal and abnormal group of 122 patients according to the EEG results, regardless of their gender and age. It was approved by the institutional review board (IRB Approval Number: H-1504-094-666).

2. Anthropometric measurements and blood test

Anthropometric measurements were obtained using an automated anthropometric instrument by the nurses, and an automatic blood cell analyzer was used to test white blood cell (WBC), red blood cell (RBC), hemoglobin (Hb), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell volume distribution width (RDW), platelet (PLT), platelet crit (PCT), mean platelet volume (MPV), neutrophil segment, lymphocyte, monocyte, and eosinophil for CBC test at the Department of Laboratory Medicine.

3. EEG

EEG was conducted using Comet at a sample frequency of 200 Hz, frequency filter at maximum 70 Hz and minimum 1.0 Hz, sensitivity of 150 μV/pp, and AC resistance below 10 kΩ.

4. Statistical analysis

Statistical analysis was performed using the SPSS (PC, Version 21.0) program. A frequency analysis and mean (M) and standard deviation (SD) were calculated for the physical features, CBC results, and EEG test results of the subjects. An independent t-test was performed for analysis of differences, and a correlation analysis was performed for relational analysis. All statistical significance level was set as p<0.05.

1. General characteristics of EEG result group

This study investigated 244 patients who were diagnosed for epilepsy with 128 being males and 116 females. The average age of the 122 subjects in the normal group appointed by the EEG results was 57.84±15.08 and the average age of the abnormal group was 54.01±18.98. The average height of the normal group was 160.99±18.64 and 162.01±12.83 for the abnormal group, and the average weight of the normal group was 65.61±15.39 and 62.40±17.40 for the abnormal group. The average systolic blood pressure of the normal group was 117.06±23.58 and 116.79±20.50 for the abnormal group, and the average diastolic blood pressure was 72.46±13.86 in the normal group and 71.66±13.87 in the abnormal group. The two groups appeared as composing equal subjects as there was no significant difference in age, height, weight, systolic blood pressure, and diastolic blood pressure (Table 1).

Table 1

General characteristics of EEG result group

Character	Total N=244	Normal group N=122	Abnormal group N=122	F/t
	M±SD
Age	55.92±17.21	57.84±15.08	54.01±18.98	16.84†/1.74
Height (cm)	161.50±15.98	160.99±18.64	162.01±12.83	.12/−.50
Weight (kg)	64.00±16.47	65.61±15.39	62.40±17.40	.28/1.52
SBP (mmHg)	116.92±22.05	117.06±23.58	116.79±20.50	.86/.09
DBP (mmHg)	72.06±13.83	72.46±13.83	71.66±13.87	.12/.45

Abbreviation: SBP, systolic blood pressure; DBP, diastolic blood pressure.

^†p<0.01.

2. CBC results by EEG result group

The difference in CBC test results in the normal group and abnormal group according to the EEG results was shown by several variables. The average WBC in the normal group was 6.30±2.06 and 6.91±2.48 in the abnormal group, with the abnormal group showing a significantly higher value (p<0.05). The average RBC in the normal group was 4.42±0.50 and 4.25±0.59 in the abnormal group, with the normal group showing a significantly higher value (p<0.05). The average neutrophil level in the normal group and abnormal group was 54.36±12.50 and 59.68±12.97, respectively, with the abnormal group showing significantly higher value (p<0.01). The average lymphocyte level in the normal group and abnormal group was 34.63±11.53 and 29.25±11.64, respectively, with the abnormal group being significantly higher (p<0.01) (Table 2).

Table 2

Results of CBC by EEG Result group

Variable	Total N=244	Normal group N=122	Abnormal group N=122	F/t
		M±SD
WBC (mm3)	6.60±2.30	6.30±2.06	6.91±2.48	1.94/−2.09*
RBC (million/mm3)	4.33±0.55	4.42±0.50	4.25±0.59	3.88/2.39*
Hb (g/dL)	13.30±1.92	13.47±1.83	13.13±1.99	1.11/1.35
HCT (%)	39.84±5.08	40.42±4.79	39.26±5.31	1.44/1.79
MCV (fL)	92.12±6.25	91.68±7.02	92.56±5.35	1.75/−1.09
MCH (pg)	30.72±2.59	30.53±2.90	30.92±2.23	1.53/−1.18
MCHC (%)	33.32±1.32	33.25±1.37	33.39±1.27	.14/−.79
RDW (%)	13.29±1.52	13.29±1.57	13.29±1.47	.00/−.02
PLT (thousand/mm3)	220±72.92	224.52±72.60	215.53±73.26	.02/.96
PCT (%)	0.21±0.06	0.21±0.06	0.21±0.06	1.67/.76
PDW (%)	12.08±3.24	327.12±784.70	70.88±34.99	.06/.98
Neutrophil (%)	57.02±12.98	54.36±12.50	59.68±12.97	.12/−3.26†
Lymphocyte (%)	31.94±11.87	34.63±11.53	29.25±11.64	.08/3.62†
Monocyte (%)	7.59±2.23	7.37±2.03	7.80±2.41	2.32/−1.49
Eosinophil (%)	2.69±2.42	2.76±2.21	2.61±2.62	2.09/.46

Abbreviation: WBC, white blood cell; RBC, red blood cell; Hb, hemoglobin; HCT, hematocrit; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; RDW, red cell volume distribution width; PLT, platelet; PCT, platelet crit; MPV, mean platelet volume.

^*p<0.05,

^†p<0.01.

3. Correlation analysis of EEG results and CBC results

According to a correlation analysis of EEG results and CBC results of the subjects, WBC showed a positive correlation (p<0.05) to any problems in the EEG wave, while RBC showed a negative correlation (p<0.05). Neutrophil showed a positive correlation (p<0.05), while lymphocyte showed a negative correlation (p<0.01) (Table 3).

Table 3

Correlation of EEG result and CBC

	WBC	RBC	Neutrophil	Lymphocyte
EEG Result	.13*	−.15*	.21†	−.23†

Abbreviation: EEG, electroencephalogram.

^*p<0.05,

^†p<0.01.

4. Regression analysis of EEG results and CBC results

WBC values showed a positive correlation to EEG results with a t value of 2.09 (p<0.01), which is affected under a statistically significant level. The correlation to RBC was negative, with a t value of ?2.39 (p<0.05), which is affected at a statistically significant level, and the t value of neutrophil was 2.12 (p<0.01), showing a positive correlation to EEG results and being affected at a statistically significant level. The correlation to lymphocyte was negative, with a t value of ?3.62 (p<0.01), which is affected at a statistically significant level. The R² value of the variable with statistical significance in the WBC (0.02), RBC (0.02), neutrophil (0.04), lymphocyte (0.05) (Table 4).

Table 4

Relation of EEG result and CBC

	EEG Result
	β	SE	t	p	D-W	R/R2/F
WBC	.61	.29	2.09	.00†	2.00	.13/.02/4.39*
RBC	−.17	0.07	−2.39	.02*	1.98	.02/.02/5.74*
Neutrophil	5.32	1.63	3.26	.00†	2.12	.04/.04/10.65†
Lymphocyte	−5.37	1.48	−3.62	.00†	2.09	.05/.05/13.12†

Abbreviation are the same as those in Table 2, 3.

^*p<0.05,

^†p<0.01.

The purpose of this study was to investigate the correlation between EEG waves and the results from CBC tests in 244 patients who were diagnosed for epilepsy. The 4 categories that displayed a significant correlation between EEG results and CBC blood test results were WBC, RBC, neutrophil, and lymphocyte, where WBC (p<0.05) and neutrophil (p<0.01) showed a positive correlation, while RBC (p<0.05) and lymphocyte (p<0.01) showed a negative correlation. One of the limitations of this study is that it did not take in consideration of the medicine the patients would take for treatment of epilepsy, as anti-epilepsy treatments are known to induce hematological side effects, causing aplastic anemia, leukopenia, thrombopenia, megaloblastic anemia, etc. (Son et al., 2013). Epilepsy patients have fatigue is 44% (Ettinger et al., 1998). Antiepileptic of osteopenia and osteoporosis observed by measuring the marker that indicates the activity of osteoclasts and osteoblasts in the blood and urine to generate a result, the enzyme-induced antiepileptic reduces the blood calcium and vitamin D to increase the bone-specific Alkaline phosphatase (ALP) levels and, it promotes bone turnover (Yu, 2008). However, all of the subjects in this study are patients who were diagnosed for epilepsy and who were taking certain anti-epilepsy medicines. Patients who were taking anti-epilepsy medicines and had abnormal EEG waves showed a positive correlation to WBC (p<0.05) and neutrophil (p<0.01), but a negative correlation to RBC (p<0.05) and lymphocyte (p<0.01). These statistically significant results are highly meaningful, and suggest further studies for statistical analysis of larger amount of data.

This study was financially supported by Dongnam Health University.