MEG Waveform Analysis from Language Cortical Areas in Patients with Brain Tumor – A Preliminary Study

Abstract

Language plays an important part in human for expressing their thoughts and emotions, where the source of function originated from the brain. This study aims to estimate the early and long latency language-related magnetic fields (LRFs) in patients with brain tumor. The study hypothesized that the brain tumor would alter the patients LRFs as compared to healthy subjects. Three patients with brain tumor which invades the language region in the brain were selected as subjects while two normal healthy subjects were taken as a control group regardless of gender. All the subjects had to undergo a Magnetoencephalography (MEG) scanning while doing a task related to language function. The subjects were shown four characters Malay semantic word and had to do silent reading while asked to lessen their movement (such as blinking) during the whole scanning procedure. The waveform was taken between the latency fields of -150 to 850 ms, and then filters were applied before analyzing the signals. The areas of analysis were done at the Occipital, Temporal, and Frontal region of the brain while the components taken were N100, N200, N400 and N600 with respect to the location. The LRFs were taken from both left and right side of the brain. The results obtained show significant difference of LRFs between the patient and control groups in term of both latency and amplitude. The latency and amplitude readings were inconsistent for all patients while the consistency for the control group was constant. The dominance of brain activation was shown to be on the left side for both control and patient group. As conclusion, there is no difference between patient and control group LRFs due to limitation of study.