Abstract:

In brain gliomas infiltrate white matter, compressing or destroying axons en passant. Such tumors rarely invade cortex; they alter local blood flow and cellular metabolism and produce seizures by corticopedal disruption and deafferentiation. The case of a 15-yr-old girl who developed complex partial seizures (daze, mastication) at 13 yr is reported. EEG disclosed left anterior temporal and right mesial temporal foci. An unorthodox occipital approach removed a grade IV astrocytoma deep within the left temporal region, sparing auditory and visual functioning. The patient was tested with four sets of synthesized sounds [D. M. Daly et al., J. Neurophysiol. 44, 200--222 (1980)]. Pre-op auditory functioning was intact with vowels, BDG, and BW. Performance on GY was aberrant but better than chance with right ear (AD)/hand, right ear/left hand, and left ear (AS)/right hand, but nearly normal with left ear/hand; typically AD boundary increased >10 ms; AS decreased <15 ms. Post-operatively GY performance improved tenfold (LRCS). At one year, cumulative AD performance was diminished only by brief fixed-response episodes; at 2 yr performance was within normal limits. Results demonstrate distant electrographic foci resolved and performance improved over a considerable time once malignant irritative source was removed.