Authors :
Presenting Author: Ryosuke Suzui, MD – Nagoya University Graduate School of Medicine
Takamasa Mitsumatsu, MD – Nagoya University Graduate School of Medicine
Ayano Yanagisawa, MD – Nagoya University Graduate School of Medicine
Misa Hashimoto, MD – Nagoya University Graduate School of Medicine
Misae Yamada, MD – Nagoya University Graduate School of Medicine
Anna Shiraki, PhD – Nagoya University Graduate School of Medicine
Masahiro Kawaguchi, PhD – Nagoya University Graduate School of Medicine
Yuji Ito, MD,PhD – Nagoya University Graduate School of Medicine
Tomohiko Nakata, MD,PhD – Nagoya University Graduate School of Medicine
Jun Natsume, Professor – Nagoya University Graduate School of Medicine
Koichi Fujiwara, Lecturer – Nagoya University Graduate School of Engineering, Nagoya
Kazuhiro Muramatsu, Professor – Jichi Medical University
Hiroyuki Kidokoro, Lecturer – Nagoya University Graduate School of Medicine
Rationale:
Beta-propeller protein-associated neurodegeneration (BPAN) is a neurodegeneration disorder with brain iron accumulation, caused by de novo mutations in the WDR45 gene. BPAN is initially characterized by global developmental delay and epilepsy in infancy and childhood. In young adulthood, patients experience rapid cognitive and motor declines with dyskinesia and parkinsonism. Brain MRI shows iron deposits in the globus pallidus and substantia nigra, but these features typically appear in childhood or adolescence. Early diagnosis is challenging because clinical features in infancy and early childhood are nonspecific and the lack of significant findings on imaging studies. We have previously reported that high amplitude fast activity (HAFA) on EEG may serve as a useful diagnostic marker. In the last AES annual meeting, we reported about temporal changes of quantitative characteristic of HAFA. In this study, we aimed to compare quantitative characteristics of fast activity in children with BPAN to those in normal EEG.
Methods:
We analyzed 21 data from 9 children with BPAN. As a control group, we used 40 data from age-matched female recorded at Nagoya University Hospital. In control group, none of the patients were diagnosed as epilepsy or receiving anti-seizure medications. The most common reason for undergoing EEG among these patients was pre- or post-treatment evaluation related to intensive therapy of hematological diseases such as hematopoietic stem cell transplantation. Sampling frequencies of EEG ranged from 200 to 500 Hz. To minimize contamination of motion artifacts, EEG records during sleep were used. We computed the average power across all channels, the power spectrum and the multiscale entropy (MSE) of EEG from 18Hz to 40Hz, which indicate the scale of amplitude, the distribution of frequency and complexity of waveform, respectively.
Results:
In BPAN group, multiple EEG recordings were obtained in seven of the nine children. Three patients were diagnosed as epilepsy for focal seizures, atonic seizures and epileptic spasms, respectively. None of the patients were receiving benzodiazepines or barbiturates. Figure 1 shows comparison of quantitative characteristics between both groups. The BPAN group exhibited significantly higher power and MSE, whereas the control group showed a higher power spectrum’s coefficient of variation, standard deviation normalized by the mean (p< 0.01). Figure 2 shows the trend of each quantitative characteristics. Across patients in BPAN group with multiple EEG recordings, the power in the initial recording was higher than that in the final recording(p=0.03). No clear age-related trends were observed for the power spectrum or MSE.