Pathomechanism of infantile traumatic brain injury with a biphasic clinical course and late reduced diffusion evaluated by MR spectroscopy

• Published in: Journal of the neurological sciences 2024-11, Vol.466, p.123228, Article 123228
• Main Authors: Yasukohchi, Madoka, Omata, Taku, Ochiai, Kenta, Sano, Kentaro, Murofushi, Yuka, Kimura, Sho, Takase, Nanako, Honda, Takafumi, Yasukawa, Kumi, Takanashi, Jun-ichi
• Format: Article
• Language: English
• Subjects: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD); Infantile traumatic brain injury with a biphasic clinical course and late reduced diffusion; Magnetic resonance spectroscopy; Subdural hematoma; Traumatic brain injury
• ISSN: 0022-510X; 1878-5883; 1878-5883
• DOI: 10.1016/j.jns.2024.123228

Infantile traumatic brain injury (TBI) with a biphasic clinical course and late reduced diffusion (TBIRD) has recently been reported as a distinct type of TBI in infancy. However, the pathological and prognostic factors of TBIRD remain unknown. We aimed to compare patients with and without TBIRD and evaluate the pathomechanism of TBIRD using magnetic resonance spectroscopy (MRS). Ten Japanese patients with TBI were admitted to our hospital and underwent MRS between September 2015 and September 2022 (age range, 3–15 months; median age, 8.5 months). TBIRD was diagnosed in six patients. MRS data were compared among patients with TBIRD, patients without TBIRD, and controls. Neurological prognosis was classified into grades 1 (normal) to 3 (severe). In patients with TBIRD, MRS revealed an increase in the glutamine (Gln) level on days 3–29, which subsequently became close to normal. The degree of Gln elevation in the non-TBIRD group was smaller (117–158 % of controls) than that in the TBIRD group (210–337 %) within 14 days. MRS in the TBIRD group showed decreased N-acetyl aspartate (NAA) concentrations. The degree of NAA decrease was more prominent in grade 3 than in grades 1 and 2. NAA levels in the non-TBIRD group were almost normal. Patients with TBI and markedly elevated Gln levels on MRS may develop TBIRD. Neuro-excitotoxicity is a possible pathological mechanism of TBIRD. Decreased NAA levels may be useful for predicting the prognosis of patients with TBIRD. •Patients with TBI with markedly elevated Gln levels on MRS may develop TBIRD.•Neuroexcitotoxicity is a possible underlying pathomechanism of TBIRD.•Decreased NAA levels may be useful in predicting prognosis.