Electroencephalography findings to differentiate acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) from prolonged febrile seizures.
Abstract number :
2.034
Submission category :
3. Neurophysiology / 3C. Other Clinical EEG
Year :
2016
Submission ID :
195483
Source :
www.aesnet.org
Presentation date :
12/4/2016 12:00:00 AM
Published date :
Nov 21, 2016, 18:00 PM
Authors :
Atsuko Ohno, Nagoya University; Akihisa Okumura, Aichi Medical University; Tatsuya Fukasawa, Anjo Kosei Hospital; Takeshi Suzuki, Anjo Kosei Hospital; Yuji Nakamura, Toyohashi municipal hospital; Misa Miyake, Fujita Health University School of Medicine; T
Rationale: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is one of the common acute encephalopathies associated with infection in childhood in Japan. AESD is clinically characterized by a febrile status epilepticus as an initial neurological symptom followed by secondary seizures and white matter lesions on a diffusion-weighted image at day 4 to 6. It is important to differentiate AESD from a prolonged febrile seizure (PFS), because AESD has a high incidence of severe neurologic sequelae. The aim of this study was to clarify the usefulness of electroencephalogram (EEG) for early differentiation of AESD and PFS. Methods: We enrolled patients with AESD or PFS from 6 hospitals between 2009 and 2015. We reviewed EEGs that were performed before the secondary seizures in patients with AESD and those within 3 days of seizures in patients with PFS. EEGs were evaluated by 2 pediatric neurologists. We examined focal or generalized slowing, presence or absence of spindles, decrease of fast waves, and paroxysmal discharges. Results: We reviewed EEGs in 7 patients with AESD and 17 with PFS. Median age was 12 months (range 5-62 months) in AESD and 21 months (range 5-54 months) in PFS. Median date of EEG recording was 2nd from the onset of seizures in both groups. Focal or generalized slowing was observed in 4 of 7 (57%) patients with AESD, and 7 of 17 (41%) with PFS. Absence of spindles was observed in 7 (100%) patients with AESD and 1 (6%) with PFS. Decrease of fast waves was observed in 4 (57%) patients with AESD and none with PFS. Paroxysmal discharges were not observed in any patients. Fisher's exact test revealed that absence of spindles and decrease of fast waves were significantly more frequent in patients with AESD than those with PFS (p < 0.01). Conclusions: EEG within a few days from the onset of febrile status epilepticus is useful for the differentiation of AESD and PFS. Absence of spindles and decrease of fast waves are key findings to distinguish AESD from PFS. The absence of spindles suggests abnormality of thalamo-cortical networks in AESD. Funding: none
Neurophysiology