Acute encephalopathy with biphasic seizures and late reduced diffusion with concurrent transverse myelitis

We describe a patient with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) with unique features, including concurrent transverse myelitis. A 2-year-old previously healthy girl had clinical findings consistent with AESD, occurring in association with influenza A infection. The posterior brain regions were most severely affected, resulting in cortical blindness. She also developed bilateral limb weakness, and spine MRI revealed transverse myelitis in the cervical region. She was treated acutely with intravenous methylprednisolone. Serum anti-myelin oligodendrocyte glycoprotein and anti-aquaporin-4 antibodies were negative, as was an anti-extractable nuclear antigen panel. Although her clinical presentation was severe, she improved dramatically over the following months, and 6 months following initial presentation, her parents felt she had returned to baseline. This is the first report of AESD occurring in combination with transverse myelitis. The co-occurrence of the two conditions is unlikely to be coincidental, suggesting that there may be a shared or overlapping immunological pathway involved. The patient's recovery was impressive, which could partially relate to the acute treatment with corticosteroids.

Restricted Diffusion in the Bilateral Subcortical Motor Areas Associated with Status Epilepticus in an Infant with Kawasaki Disease

Status epilepticus (SE) often causes neuronal death in the cerebrum and consequent long-term sequelae. Acute encephalopathy with biphasic seizures and late reduced diffusion is clinically characterized by SE associated with fever and seizure clusters that occur 3-9 days after symptom onset. MRI reveals reduced diffusion in the frontal or frontoparietal subcortical white matter, with sparing of the perirolandic region following seizure clusters. Kawasaki disease (KD) is an acute self-limited vasculitis secondary to activation of the immune system; KD is rarely complicated by acute encephalopathy. We report the case of a male infant who developed SE associated with KD and showed late reduced diffusion in the subcortical white matter beneath the bilateral motor cortices (primary motor, premotor and supplementary motor areas) and the right frontal cortex. The patient had characteristic neurological sequelae in the chronic phase, including clumsiness of fingers and forearms, impaired discrimination of tactile sensation and position sense on digits in his hands and feet, corresponding to the lesions with reduced diffusion at the acute phase.

Arterial spin labeling image findings in the acute phase in paediatric patients with acute encephalopathy with biphasic seizures and late reduced diffusion

Introduction

Diagnosing acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) after the first seizure (early seizure/seizures, ES/ESs) is challenging because a reduced apparent diffusion coefficient (ADC) in the cortical or subcortical white matter, often described as having a "bright-tree appearance (BTA)," is usually not observed until secondary seizures (late seizures, LSs) occur. Previous studies have reported hypoperfusion on arterial spin labeling (ASL) within 24 h after ES/ESs in patients with AESD and hyperperfusion within 24 h after LS onset. This study aimed to investigate cerebral blood flow in the hyperacute phase (between ES/ESs and LSs) using ASL in patients with AESD.

Methods

Eight ASL images were acquired in six patients with AESD admitted to our hospital from October 2021 to October 2022. ASL findings in the hyperacute phase were investigated and video-electroencephalogram findings obtained around ASL image acquisition in the hyperacute phase were evaluated.

Results

Four ASL images were obtained for three patients before LS onset, with three images showing hyperperfusion areas and one image showing hypoperfusion areas. These hyperperfuion regions coincided with BTA on subsequent images of these patients.In one patient, the first ASL image was obtained in the late hyperacute phase and revealed hyperperfusion areas with a slightly abnormal change on diffusion-weighted image (DWI), which were not accompanied by ADC abnormalities. The second ASL image obtained 51 h after the first ASL, and before LS onset revealed more prominent hyperperfusion areas than the first ASL image, which were accompanied by BTA. In another patient, the ASL image obtained 82 h after ES revealed hyperperfusion areas without abnormal change on DWI or ADC.

Conclusion

This study revealed that two patients exhibited hyperperfusion regions and another patient exhibited hypoperfusion regions among three patients who underwent ASL imaging during the period from 24 h after ES/ESs to LSs in patients with LSs or cooling initiation in patients without LSs due to early anaesthesia induction (late hyperacute phase). Further prospective studies on cerebral blood flow are required to explore the relationship among the timing of image acquisition, the presence of electrographic seizures, and ASL findings in patients with AESD.

Infantile Hypoxic Encephalopathy Mimicking Acute Encephalopathy with Biphasic Seizures and Late Reduced Diffusion (AESD) Identified as an Episode of Brief Resolved Unexplained Event (BRUE)

Acute encephalopathy with biphasic seizures and reduced diffusion (AESD) is characterized by biphasic seizures following febrile viral infections and delayed reduced diffusion of the cerebral white matter on magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) (bright tree appearance, BTA). However, hypoxic encephalopathy with biphasic seizures and AESD-mimicking imaging findings has not been reported. We report a case of hypoxic encephalopathy due to suffocation with concomitant biphasic seizures and BTA, mimicking AESD. On day 1, a healthy 5-month-old girl was found face down with decreased breathing and a deteriorating consciousness level, suggesting a brief resolved unexplained event (BRUE). Electroencephalography (EEG) revealed periodic epileptic discharges, suggesting possible nonconvulsive status epilepticus. Despite improvements in consciousness level and EEG abnormalities on day 2, her consciousness level deteriorated again with generalized tonic-clonic seizures on day 3, and a head MRI-DWI revealed restricted diffusion predominantly in the subcortical areas, suggesting BTA. Treatment for acute encephalopathy resolved the clinical seizures and EEG abnormalities. Persistence of abnormal EEG, reflecting abnormal excitation and accumulation of neurotoxic substances caused by hypoxia, may have contributed to the development of AESD-like findings. As hypoxic encephalopathy causes AESD-like biphasic seizures, monitoring consciousness level, seizure occurrence, and EEG abnormalities even after acute symptoms have temporarily improved following hypoxia is essential.

Neuroimaging in acute infection-triggered encephalopathy syndromes

Acute encephalopathy associated with infectious diseases occurs frequently in Japanese children (400-700 children/year) and is the most common in infants aged 0-3 years. Acute encephalopathy is classified into several clinicoradiological syndromes; acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common subtype, followed by clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) and acute necrotizing encephalopathy (ANE). Neuroimaging, especially magnetic resonance imaging (MRI), is useful for the diagnosis, assessment of treatment efficacy, and evaluation of the pathophysiology of encephalopathy syndromes. MRI findings essential for diagnosis include delayed subcortical reduced diffusion (bright tree appearance) for AESD, reversible splenial lesions with homogeneously reduced diffusion for MERS, and symmetric hemorrhagic thalamic lesions for ANE. We reviewed several MRI techniques that have been applied in recent years, including diffusion-weighted imaging for the characterization of cerebral edema, arterial spin labeling for evaluating cerebral perfusion, and magnetic resonance spectroscopy for evaluating metabolic abnormality.

Early Phase Increase in Serum TIMP-1 in Patients with Acute Encephalopathy with Biphasic Seizures and Late Reduced Diffusion

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most frequent subtype of acute encephalopathy syndrome among Japanese children. Exanthem subitum is the most common causative infectious disease of AESD. We herein retrospectively analyzed serum and cerebrospinal fluid (CSF) concentrations of matrix metalloproteinase-9 (MMP-9), tissue inhibitor matrix metalloproteinase-1 (TIMP-1), and seven cytokines in patients with AESD or prolonged febrile seizure (FS) to assess the pathophysiology of AESD and detect biomarkers for diagnosing AESD in the early phase.

METHODS

Serum and CSF samples were obtained from 17 patients with AESD (1st seizure phase group, n = 7; 2nd seizure phase group, n = 10) and 8 with FS. The concentrations of MMP-9, TIMP-1, and seven cytokines were measured by enzyme-linked immunosorbent assays or cytometric bead arrays.

RESULTS

Serum concentrations of TIMP-1 were significantly higher in the 1st seizure phase group than in the 2nd seizure phase group. No significant differences were observed in serum concentrations of MMP-9 or the MMP-9/TIMP-1 ratio.

CONCLUSIONS

The MMP-9-independent increase in circulating TIMP-1 concentrations observed in the present study may be associated with the pathophysiology of AESD in the 1st seizure phase.

Truncal Instability and Titubation in Patients With Acute Encephalopathy With Reduced Subcortical Diffusion

The present retrospective study aimed to investigate the presence of truncal instability or titubation after the first seizure and second phase in patients with acute encephalopathy with reduced subcortical diffusion (AED). Of the 15 patients with AED who were admitted to our hospital for 3 years and 2 months and had reached developmental milestones for sitting before disease onset, six experienced moderate-to-severe truncal instability while sitting after the first seizure. These patients had a significantly longer first seizure duration and significantly lower GCS scores 12-24 h after the first seizure, as well as significantly higher Tada score and Creatinine and blood glucose levels than those with mild or no truncal instability while in a seated position after the first seizure. Three 1-year-old children with bilateral frontal lobe lesions, particularly in the bilateral prefrontal lobe regions, demonstrated truncal titubation, which has not previously been reported as a clinical feature of AED. Tada score reported to be a predictor of AED prognosis and truncal instability in the sitting position after the first seizure may represent disease severity, but not the specific lesions. Conversely, truncal titubation might be suggestive of bilateral frontal lobe lesions, particularly in patients without severe instability. Further studies on the role of bilateral prefrontal lobe lesions to truncal titubation in patients with AED using more objective evaluation methods, such as stabilometry, are necessary.

Infant with right hemiplegia due to acute encephalopathy with biphasic seizures and late reduced diffusion (AESD): A case report

RATIONALE

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a condition characterized by biphasic convulsions and disturbance of consciousness. In Japan, the most common pediatric cases of acute encephalopathy are associated with infection. AESD usually occurs in early childhood, with the characteristic magnetic resonance imaging (MRI) appearance called "bright tree appearance." The disease often has neurological sequelae and interferes with the schooling of children and their activities of daily living; however, there are few clinical case reports of hemiplegia caused by AESD.

PATIENT CONCERNS

A case with right-sided hemiplegia due to AESD in an 11-month-old girl who was followed up to 30 mo of age.

DIAGNOSES

The patient was diagnosed with overlap AESD and hemiconvulsion-hemiplegia-epilepsy syndrome (HHE syndrome), based on the clinical course and imaging findings. DNA tests of her blood and cerebrospinal fluid revealed the presence of human herpesvirus 6.

INTERVENTIONS

Pharmacotherapy and rehabilitation therapy.

OUTCOME

Gross motor function has recovered considerably, but she had a mild developmental delay at 30 mo old.

LESSONS

Hemiplegia due to AESD was extremely rare, and appropriate rehabilitation treatment resulted in recovery of physical function. However, as mild developmental delay was observed, the patient was referred to a specialized facility before entering school.

Kawasaki disease presented with status epilepticus and diffusion MRI abnormalities in the subcortical white matter

BACKGROUND

Kawasaki disease (KD) is an acute, self-limited vasculitis of unknown etiology that occurs predominantly in infants and young children. Encephalitis/encephalopathy is an extremely rare complication of KD.

CASE

A previously healthy 8-month-old Japanese boy had a prolonged seizure after febrile illness for one day. On the fourth day, he had bilateral nonexudative conjunctivitis, changes in the extremities, rash and induration at the Bacillus Calmette-Guerin inoculation site. He was diagnosed with incomplete KD and treated with immunoglobulin. On the fifth day, he had cluster seizures. Brain magnetic resonance imaging (MRI) showed restricted diffusion in the left subcortical white matter, which was consistent with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD). He was treated with controlled normothermia, pulseddose methylprednisolone, continuous infusion of midazolam, and edaravone. On the tenth day, he had a recurrent fever and was treated with a second course of immunoglobulin. Subsequently, he had defervescence, and the abnormal signal detected in the MRI disappeared. At the age of 11 months, he had normal growth and development for his age by the Denver Developmental Screening Test.

CONCLUSION

It is necessary to consider AESD as the differential diagnosis of prolonged seizure in infants with KD. Brain MRI led to early diagnosis and intervention in our patient. The neurological prognosis of our patient was relatively good, but the prognosis of KD with AESD is unknown. To clarify this, further case accumulation is warranted.

Granzyme A Participates in the Pathogenesis of Infection-Associated Acute Encephalopathy

OBJECTIVE

The present study aimed to determine whether granzymes are implicated in the pathogenesis of infection-associated acute encephalopathy (AE).

METHODS

We investigated granzyme and cytokine levels in the cerebrospinal fluid of patients with acute encephalopathy or complex febrile seizures (cFS). A total of 24 acute encephalopathy patients and 22 complex febrile seizures patients were included in the present study. Levels of granzymes A and B were measured using enzyme-linked immunosorbent assay, and levels of tumor necrosis factor α (TNF-α), interferon-γ (IFN-γ), interleukin 1β (IL-1β), IL-1 receptor antagonist (IL-1RA), IL-4, IL-6, IL-8, and IL-10 were assessed using the Bio-Plex suspension array system.

RESULTS

Cerebrospinal fluid levels of granzyme A were significantly higher, and those of TNF-α and IL-1RA were significantly lower in the AE group than in the cFS group; however, no significant differences in the levels of granzyme B, IFN-γ, IL-1β, IL-4, IL-6, IL-8, and IL-10 were observed between the 2 groups. In addition, no significant differences in granzyme A, granzyme B, or cytokine levels were observed between acute encephalopathy patients with and those without neurologic sequelae.

CONCLUSIONS

Our findings indicate the involvement of granzyme A in the pathogenesis of acute encephalopathy.

Acute encephalopathy with biphasic seizures and late reduced diffusion in Kawasaki disease

Herein we describe the case of a 7-month-old girl with Kawasaki disease (KD) in whom status epilepticus with fever developed on day 3 and cluster of seizures on day 6 of illness, followed by severe disturbance of consciousness afterward. Diffusion-weighted magnetic resonance imaging on day 6 of illness showed diffuse high signals in the bilateral subcortical white matter, while electroencephalogram indicated low-voltage slow waves. This indicated acute encephalopathy with biphasic seizures and late reduced diffusion (AESD); severe neurological sequelae remained. This is the first report of AESD as a complication of KD.

Thalamic lesions in acute encephalopathy with biphasic seizures and late reduced diffusion

BACKGROUND

We aimed to assess the characteristics of thalamic lesions in children with acute encephalopathy with biphasic seizures and late reduced diffusion.

METHODS

Using the Tokai Pediatric Neurology Society database, we identified and enrolled 18 children with acute encephalopathy with biphasic seizures and late reduced diffusion from 2008 to 2010. Using diffusion-weighted images, we identified patients with thalamic lesions and compared their clinical factors with those of patients without thalamic lesions. We analyzed the time sequence of thalamic, sucortical, and cortical lesions. To study the topography of thalamic lesions, we divided the thalamus into five sections: anterior, medial, anterolateral, posterolateral, and posterior. Subsequently, we analyzed the relationship between the topography of thalamic lesions and the presence of central-sparing.

RESULTS

Seven children presented with symmetrical thalamic lesions associated with bilateral subcortical or cortical lesions. No statistical difference in the clinical features was observed between individuals with and without thalamic lesions. These lesions were observed only when subcortical or cortical lesions were present. In 5 children, thalamic lesions were present in bilateral anterior or anterolateral sections and were associated with subcortical or cortical lesions in bilateral frontal lobes with central-sparing. In the other two children, thalamic lesions were extensive and accompanied by diffuse subcortical and cortical lesions without central-sparing.

CONCLUSION

Thalamic lesions in patients with acute encephalopathy with biphasic seizures and late reduced diffusion involve the anterior sections. The thalamocortical network may play a role in development of thalamic lesions in patients with acute encephalopathy with biphasic seizures and late reduced diffusion.

Cyclosporine for acute encephalopathy with biphasic seizures and late reduced diffusion

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common syndrome among the acute encephalopathies, and is associated with a high incidence of neurologic sequelae. This study examined the efficacy of cyclosporine (CsA) for the treatment of AESD.

METHODS

Fourteen children with AESD were recruited and categorized as group A (not receiving CsA) and group B (receiving CsA). Clinical course, laboratory data, magnetic resonance imaging (MRI), and outcome were analyzed retrospectively. We divided the patients into three types according to the distribution of abnormalities on MRI: frontal lobe predominant type, unilateral cerebral hemisphere type, and diffuse type. We used the Pediatric Cerebral Performance Category scale (PCPC) and the Pediatric Overall Performance Category scale (POPC) as prognostic measures.

RESULTS

Of the 14 children, five were boys (age range, 9-32 months). PCPC score was: 1 for seven patients, 2 for three patients, and 3 for four patients. There was no significant difference in PCPC between groups A and B (P = 0.293). POPC score was: 1 for six patients, 2 for five patients, and 3 for three patients. There was a significant difference in POPC between groups A and B when patients with the frontal lobe predominant type were excluded (P = 0.020).

CONCLUSIONS

CsA could improve the neurological prognosis of patients with AESD, except for those with frontal lobe predominant type.

Postictal subcortical restricted diffusion in a child with focal symptomatic epilepsy

BACKGROUND

Diffusion abnormalities on MRI are well described after prolonged seizures. However, isolated, focal, subcortical restricted diffusion is uncommon.

PATIENT

A girl of Kurdish descent experienced focal-onset epilepsy secondary to a left thalamic infarction at age 3 years. At age 6 years, she developed status epilepticus in the context of a febrile illness.

RESULTS

Four days after the seizure, she had neurological deterioration including involuntary posturing movements and irritability. A brain MRI revealed left hemisphere subcortical restricted diffusion, predominantly in the frontal and occipital regions. She experienced persistent right hemiparesis for 2 months after the initial seizure.

CONCLUSIONS

This presentation is reminiscent of acute encephalopathy with biphasic seizures and late reduced diffusion, a syndrome thus far reported almost exclusively in Japan. This represents one of the few documented examples of acute encephalopathy with biphasic seizures and late reduced diffusion in an individual not of east Asian descent.

Cytokine and chemokine responses in the blood and cerebrospinal fluid of patients with human herpesvirus 6B-associated acute encephalopathy with biphasic seizures and late reduced diffusion

Acute encephalopathy with biphasic seizures and late reduced diffusion has become increasingly common among various types of human herpesvirus 6B (HHV-6B) encephalitis at the time of primary viral infection. The aim of the present study is to explore the pathophysiology of HHV-6B-associated acute encephalopathy with biphasic seizures and late reduced diffusion. Five cytokines and five chemokines were measured in serum and cerebrospinal fluid (CSF) obtained from 12 HHV-6B-associated acute encephalopathy with biphasic seizures and late reduced diffusion patients and 19 control exanthem subitum (without complications) patients. Serum interleukin (IL)-10 (P = 0.007) and IL-8 (P = 0.025) were significantly higher in the patients with the disease than controls. Serum IL-1β (P = 0.034) and monocyte chemoattractant protein (MCP)-1 (P = 0.002) were significantly higher in the controls than patients with the disease. In patients with the disease, IL-10 (P = 0.012), regulated on activation normal T cell expressed and secreted (RANTES; P = 0.001), and monokine induced by interferon γ (MIG; P = 0.001) were significantly higher in serum than CSF, meanwhile IL-6 (P = 0.034), IL-8 (P = 0.034), and MCP-1 (P = 0.001) were significantly higher in CSF than serum. Additionally, serum IL-10 was significantly higher in the disease patients with sequelae than those without sequelae (P = 0.016). Several cytokines and chemokines may be associated with the pathogenesis of acute encephalopathy with biphasic seizures and late reduced diffusion. Moreover, the regulation of cytokine networks appears to be different between peripheral blood (systemic) and central nervous system.