Concentric structure of thalamic lesions in acute necrotizing encephalopathy

Demyelination

Acute disseminated encephalomyelitis (ADEM) is a demyelinating disease that affects all ages, except children less than 2 years. It occurs during the course of various infections, particularly the acute exanthematous diseases of childhood (measles, rubella, chickenpox, and smallpox immunization), other common viral infections (i.e., Epstein-Barr virus, adenovirus, cytomegalovirus, influenza, rhinoviruses, coronaviruses), and following vaccination against smallpox, measles, and rabies. The clinical features are the same regardless of the inciting event. The symptoms develop days to weeks after the onset of the predisposing cause. The symptoms and signs of acute disseminated encephalomyelitis are related to the portion of the central nervous system (CNS) that is most severely damaged. Death occurs in 20%–30%. There are neurological deficits in survivors.

Acute necrotizing encephalopathy of childhood in non-Asian patients: report of three cases and literature review

Acute necrotizing encephalopathy of childhood is a novel type of parainfectious encephalopathy with a racial and geographic predilection, rarely reported from other than East Asian areas. The objective was to describe the clinical, imaging, and other laboratory findings of non-Asian patients with acute necrotizing encephalopathy. Data were collected from three patients diagnosed in Athens over a 4-year period plus 16 cases reported from other European and North American countries. One of the Greek children died, and the other two had a normal outcome. A neuropathologic examination in the fatal case showed edematous necrosis without inflammatory, reactive, or proliferative changes. Data from Greek and other non-Asian patients support the homogeneity of the disease worldwide.

Acute necrotizing encephalopathy: combined therapy and favorable outcome in a new case

BACKGROUND

Acute necrotizing encephalopathy (ANE) is a rare disease characterized by multiple, symmetrical brain lesions, affecting thalami, brainstem tegmentum, and cerebellar medulla; more inconstantly, other structures are involved, i.e., internal capsules, posterolateral putamen, and deep periventricular white matter.

FEATURES

The clinical picture consists of rapidly deteriorating acute monophasic encephalopathy preceded by prodromal febrile illness; the symptoms include hyperpyrexia, convulsions, recurrent vomiting, and coma within 24 h.

PROGNOSIS

The outcome is usually poor and approximately 70% of the patients die within a few days from the onset of fever. There is no specific therapy for ANE but, in some patients, the clinical status improved with steroid treatment.

Acute necrotizing encephalopathy associated with human herpesvirus-6 infection

An extremely rare case of acute necrotizing encephalopathy caused by human herpesvirus-6 variant type B infection is reported. The patient, a 14-month-old previously healthy female, presented with high fever and generalized tonic convulsion followed by rapid deterioration of consciousness. On the second day of the illness, the protein level of the cerebrospinal fluid increased without pleocytosis. On the third day, magnetic resonance images demonstrated symmetric, abnormal signal intensity lesions in the bilateral thalamus, cerebellum, and brainstem. On the fourth day, characteristic maculopapular rash of exanthema subitum appeared on the trunk. Human herpesvirus-6 deoxyribonucleic acid was detected by the polymerase chain reaction in the serum, and immunoglobulin G and immunoglobulin M of serum human herpesvirus-6 were positive. On the twelfth day of illness, the patient died as a result of severe brain damage. Acute necrotizing encephalopathy should be included in the differential diagnosis when examining infants and young children with fulminating consciousness disturbance and intractable convulsion. In addition, as a causative virus, human herpesvirus-6 has to be considered at the pre-eruptive stage of exanthema subitum. Magnetic resonance images are useful because they reveal the characteristic distribution of lesions specific to acute necrotizing encephalopathy.

Acute necrotizing encephalopathy in caucasian children: two cases and review of the literature

Acute necrotizing encephalopathy is a fulminant neurologic disease seen predominantly in Japan and Taiwan. We present two cases diagnosed at a Canadian center within the same year in Caucasian children. Both were previously well, developed an acute viral illness with fever and vomiting, and progressed to brain death within 2 to 4 days. Neuroimaging and postmortem examination demonstrated the unique features of bilateral and severe necrosis of deep gray- and subcortical white-matter structures. The first case was associated with extensive, but transient, hepatic involvement, recent varicella and rotavirus infections, and detailed metabolic studies, including mitochondrial functional analysis, were normal. The second case tested positive for influenza A infection, whereas evidence of liver damage was lacking. Both children demonstrated early lymphopenia and myocardial necrosis, two features not previously associated with acute necrotizing encephalopathy. These cases are unique in their occurrence in non-Japanese children and are among the first published reports in Canada.

Acute necrotizing encephalopathy in Korean infants and children: imaging findings and diverse clinical outcome

Objective

The purpose of our study was to describe acute necrotizing encephalopathy in Korean infants and children, and we sought to evaluate the prognostic factors.

Materials and Methods

Acute necrotizing encephalopathy was diagnosed in 14 Korean infants and children. We retrospectively analyzed the neuroimaging findings including the follow-up changes. The clinical course of the disease was graded, and we evaluated prognostic factors including age, serum level of the aminotransferase, hemorrhage, and localized atrophy of the brain.

Results

This encephalopathy predominantly affected the bilateral thalami (n=14), pons (n=12), and midbrain (n=10) in a symmetrical pattern. Hemorrhage was observed in eight patients (57%). On the follow-up images (n=12), the brain lesions were reduced in extent for all patients, and generalized atrophy was seen in six patients. Localized tissue loss was observed in five patients and a complete resolution occurred for one patient. All the patients survived and two recovered completely; mild (n=6) to severe (n=6) neurological deficits persisted in the remaining 12 patients. The significant prognostic factors identified in this study were the presence of hemorrhage (p = 0.009) and localized atrophy (p = 0.015).

Conclusion

Acute necrotizing encephalopathy in Korean patients showed the characteristic patterns of the post-infectious encephalopathy as described in the literature. The high survival rate and the relatively favorable clinical course observed for the present study suggest a more diverse spectrum of disease severity than was previously described. The presence of hemorrhage and localized tissue loss on MR images may suggest a poor prognosis.

A syndrome of bilateral hemorrhage of the thalamus and myocarditis with fatal course

We report the case of a 41-year-old patient with bilateral hemorrhage of the thalamus, leading to death. Post-mortem examination showed acute myocarditis. Neuropathological study showed perivascular infiltrates in affected thalamic regions. Laboratory investigation failed to find any causal agent. We hypothesize an infective agent, affecting the heart and thalamus, as the cause of this syndrome. Diaschisis due to the strategic anatomical position of the thalamus may have been responsible for coma state and death.

Molecular analysis of HLA class II-associated susceptibility to neuroinflammatory diseases in Korean children

The work was done to study immunogenetic peculiarities of neuroinflammatory diseases among Korean children. A total of 13 children with neuroinflammatory diseases (8 males and 5 females; mean age 4.6 +/-2.6 yr) were consecutively recruited. Geno-mic typing was performed on their HLA DRB/HLA DQB genes using PCR-SSOP/SSP techniques with gel immunoelectrophoresis. The frequencies of HLA-DR1 *15 in children with acute disseminated encephalomyelitis (ADEM) (31%) and DQB1 *06 in other neuroinflammatory diseases (38%) were significantly increased compared with control subjects. The frequencies of HLA-DRB3 * 0202 (100%), HLA-DRB1 * 1302 (67%), HLA-DRB3 * 0301 (67%), and HLA-DQB1 * 0301 (67%) were significantly increased in children with multiple sclerosis and the frequencies of HLA-DRB1 * 1501 (40%) and HLA-DRB5 * 0101 (40%) were significantly increased in children with ADEM. HLA-DRB1 * 1401, HLA- DRB3 * 0202, and HLA-DQB1 * 0502 were found in children with acute necrotizing encephalopathy. In conclusion, HLA-DR1 * 15 and DQB1 * 06 may be involved in susceptibility to inflammation in Korean children. The frequencies of HLA-DRB1 * 1501, HLA-DRB5 * 0101, HLA-DRB3 * 0301, and HLA-DQB1* 0602 were not as high in Korean children with multiple sclerosis as in western children. However, HLA-DRB3 * 0202 was seen in all children with multiple sclerosis. Our data may provide further evidence that the immunogenetic background of neuroinflammatory diseases in Korean is distinctly different from the ones in western countries. Further studies are necessary to confirm this finding.

Influenza A virus-associated acute necrotizing encephalopathy in the United States

During the past several years, influenza-associated acute necrotizing encephalopathy has been well-recognized in Asia but has not yet been reported in the United States. We describe a 28-month-old patient who displayed the classical clinical features of acute necrotizing encephalopathy in association with a documented influenza A infection. This disease is characterized by fever, a rapid alteration in consciousness and seizures, with radiologic involvement of the bilateral thalami and cerebellum.

Acute necrotizing encephalopathy associated with parainfluenza virus in a Caucasian child

Acute necrotizing encephalopathy is a severe parainfectious disorder with a clear racial predilection for Oriental children living in the Far East. The prognosis was originally reported as grave; however, a mild form of the disease has recently been described. A case of parainfluenza virus-associated acute necrotizing encephalopathy in a Caucasian child with a mild clinical course and excellent prognosis is presented. In this patient, the initial clinical picture was not very impressive, and the diagnosis was delayed until the third week of the illness, when neuroimaging was performed. Two months later, clinical and neuroimaging findings had almost completely resolved. Suggested criteria for a benign prognosis, such as normal liver function and cerebrospinal fluid protein levels, asymmetric thalamic lesions, and no brainstem involvement, were relevant in the present case. An extended diagnostic work-up for metabolic, vascular, coagulation, and infectious diseases was negative apart from a seroconversion for parainfluenza virus. To our knowledge, this is the first reported case of acute necrotizing encephalopathy associated with parainfluenza virus infection. Acute necrotizing encephalopathy, especially in the mild form, might not be fully recognized and could be underdiagnosed in Europe, where the reported incidence of the syndrome is very low.

Acute necrotizing encephalopathy: diffusion MR imaging and localized proton MR spectroscopic findings in two infants

In this report, we describe the findings of diffusion MR imaging and proton MR spectroscopy in two infants with acute necrotizing encephalopathy in which there was characteristic symmetrical involvement of the thalami. Diffusion MR images of the lesions showed that the observed apparent diffusion coefficient (ADC) decrease was more prominent in the first patient, who had more severe brain damage and a poorer clinical outcome, than in the second. Proton MR spectroscopy detected an increase in the glutamate/glutamine complex and mobile lipids in the first case but only a small increase of lactate in the second. Diffusion MR imaging and proton MR spectroscopy may provide useful information not only for diagnosis but also for estimating the severity and clinical outcome of acute necrotizing encephalopathy.