Infectious and autoantibody-associated encephalitis: clinical features and long-term outcome

BACKGROUND AND OBJECTIVES

Pediatric encephalitis has a wide range of etiologies, clinical presentations, and outcomes. This study seeks to classify and characterize infectious, immune-mediated/autoantibody-associated and unknown forms of encephalitis, including relative frequencies, clinical and radiologic phenotypes, and long-term outcome.

METHODS

By using consensus definitions and a retrospective single-center cohort of 164 Australian children, we performed clinical and radiologic phenotyping blinded to etiology and outcomes, and we tested archived acute sera for autoantibodies to N-methyl-D-aspartate receptor, voltage-gated potassium channel complex, and other neuronal antigens. Through telephone interviews, we defined outcomes by using the Liverpool Outcome Score (for encephalitis).

RESULTS

An infectious encephalitis occurred in 30%, infection-associated encephalopathy in 8%, immune-mediated/autoantibody-associated encephalitis in 34%, and unknown encephalitis in 28%. In descending order of frequency, the larger subgroups were acute disseminated encephalomyelitis (21%), enterovirus (12%), Mycoplasma pneumoniae (7%), N-methyl-D-aspartate receptor antibody (6%), herpes simplex virus (5%), and voltage-gated potassium channel complex antibody (4%). Movement disorders, psychiatric symptoms, agitation, speech dysfunction, cerebrospinal fluid oligoclonal bands, MRI limbic encephalitis, and clinical relapse were more common in patients with autoantibodies. An abnormal outcome occurred in 49% of patients after a median follow-up of 5.8 years. Herpes simplex virus and unknown forms had the worst outcomes. According to our multivariate analysis, an abnormal outcome was more common in patients with status epilepticus, magnetic resonance diffusion restriction, and ICU admission.

CONCLUSIONS

We have defined clinical and radiologic phenotypes of infectious and immune-mediated/autoantibody-associated encephalitis. In this resource-rich cohort, immune-mediated/autoantibody-associated etiologies are common, and the recognition and treatment of these entities should be a clinical priority.

Association between age and severity to leptospirosis in children

BACKGROUND

In endemic areas, leptospirosis is more common and more severe in adults compared with children. Reasons to explain this discrepancy remain unclear and limited data focusing on adolescents are available. The objective of the study was to describe disease spectrum and outcome differences in children and adolescents admitted for leptospirosis in a large at-risk population.

METHODS

Clinical and laboratory data were obtained on hospitalized cases in New Caledonia from 2006 to 2012.

RESULTS

Data of 60 patients <18 years of age (25 children under 14 and 35 adolescents aged 14 to 17) with confirmed leptospirosis were analyzed. Compared with children, adolescents presented more often with classic features of Weil disease (p = 0.02), combining hepatic and renal involvement with or without pulmonary participation. Jarisch-Herxheimer reactions were observed more often among adolescents (p<0.01). The overall case fatality rate was low (1 adolescent versus 0 children).

CONCLUSION

Severe leptospirosis in adolescents may be more likely to show adults' characteristics compared with children. Further studies are required to explore age-dependant host factors, including puberty-related physiological changes.

Treatment-responsive pandysautonomia in an adolescent with ganglionic α3-AChR antibodies

Autoimmune autonomic ganglionopathy (AAG) is a rare disorder that presents with pandysautonomia typically in middle age and elderly patients. AAG is typically associated with serum autoantibodies that bind to the alpha-3 subunit of the ganglionic acetylcholine receptor (α3-AChR Ab). We report a 13 year old girl who presented with gut pseudo-obstruction, bladder dysfunction and dilated pupils unresponsive to pilocarpine. She had positive α3-AChR Ab plus other autoantibodies suggesting an autoimmune diathesis. Our patient was initially resistant to steroid therapy but responded to the addition of azathioprine resulting in a near complete clinical remission. We conclude that pandysautonomia associated with α3-AChR Ab can occur in children and has multi-organ involvement.

[Leprosy with an unusual course]

In developed countries, Hansen disease, or leprosy, is a rare and little-known disease. Over the last few years, its prevalence in New Caledonia has remained stable (0.35 per 10,000 inhabitants). We report the case of an 11-year-old child who presented lepromatous leprosy complicated by a type 2 reaction. Despite appropriate treatment, the course was unusual with fever lasting a few weeks associated with asthenia, weight loss, and biological perturbations such as inflammatory syndrome, anemia, and hyperferritinemia. After a brief review of Hansen disease and its complications, we discuss the different hypotheses that can explain the clinical and biological progression of our patient (hemolytic anemia secondary to dapsone, type 2 reaction, and aspects of hemophagocytic syndrome) and describe therapeutic management, which led to a good outcome.