Contributed by: Fatai Akemokwe, MBBS, Patricia Bacus, MD, Divya Menghani, MBBS, Meriem Bensalem-Owen, MD, FACNS, Zahra Haghighat, MD, Gulam Khan, MD, Kimberly Jones, MD, Zabeen Mahuwala, MD, University of Kentucky College of Medicine, Lexington, KY, USA
A 9-year-old boy was transferred to our hospital after a spell described as an angry outburst followed by transient headache, abdominal pain, and unsteady gait. He had a history of in-utero drug exposure, autism spectrum disorder, and attention deficit hyperactivity disorder. His paternal uncle and grandmother had epilepsy. He was evaluated 2 years earlier for staring episodes, head and body movements and angry outbursts. His awake routine EEG at that time was normal, and those spells were deemed behavioral. During his current hospitalization, his neurological examination was unremarkable. Routine EEG showed a 11 Hz posterior dominant rhythm and runs of 5-Hz sharply contoured theta rhythm over the left temporal electrodes (F7/T7/P7) during drowsiness. These lasted up to 8 seconds without any evolution (Figure 1). There was no change in concomitant clinical behavior. Intravenous levetiracetam was administered due to the initial concern that this pattern was ictal. However, continuous video-EEG still showed runs of notched monomorphic 5Hz theta predominantly over F7/T7/P7 and independently over F8/T8/ P8 lasting up to 47 seconds during drowsiness and these did not persist into stage N2 of sleep (Figure 2). Similar rhythms were provoked by hyperventilation.
Figure 1. Scalp EEG tracing showing sharply contoured monomorphic theta over F7/T7/P7 electrodes. Sensitivity 7 µV/mm, time base 30 mm/sec, HFF 70 Hz, LFF 1 Hz, Notch filter 60 Hz
Figure 2. Scalp EEG tracing (average referential montage) showing notched monomorphic theta over F7/T7/P7 electrodes with onset of similar activity on F8/T8/P8 near the end of the tracing. Sensitivity 10 µV/mm, time base 30 mm/sec, HFF 70 Hz, LFF 1 Hz, Notch filter 60 Hz
Question 1: Given the patient’s history and EEG findings, what is the most likely diagnosis?
Question 2: Which of the following statements is incorrect regarding the above EEG findings?
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