Acute disseminated encephalomyelitis presenting with bilateral transient amaurosis

Immediate relief of Mycoplasma pneumoniae encephalitis symptoms after intravenous immunoglobulin

Mycoplasma pneumoniae may cause acute encephalitis, resulting in severe neurologic complications despite antibiotic therapy. We report the case of a 12-year-old patient who presented with acute onset of orofacial tics, motor restlessness, compulsive behavior, and cerebellar symptoms. Cerebrospinal fluid examination demonstrated lymphocytic meningitis. Polymerase chain reaction for M. pneumoniae was strongly positive in the cerebrospinal fluid. Blood and cerebrospinal fluid were negative for M. pneumoniae antibodies (immunoglobulin M and immunoglobulin G). The child was administered intravenous gamma-globulin, which led to a dramatic improvement of her clinical condition and disappearance of the symptoms within 72 hours. This novel case points to the potential value of gamma-globulin in M. pneumoniae encephalitis confirmed with polymerase chain reaction and suggests that immediate administration of intravenous gamma-globulin in suspected mycoplasma encephalitis should be investigated in a larger patient cohort.

Acute disseminated encephalomyelitis following infectious mononucleosis

Two months following an Epstein-Barr virus infection, a 17-year-old white female presented with seizures, intermittent visual changes, and altered mental status. Magnetic resonance imaging showed white matter changes of acute disseminated encephalomyelitis with a predilection for posterior cerebral artery distributions but without radiological evidence of arteritis. Epstein-Barr virus titers and polymerase chain reaction analysis results for the virus were consistent with postinfectious acute disseminated encephalomyelitis. The symptoms and signs improved following treatment with high-dose corticosteroids and intravenous immunoglobulin. Although Epstein-Barr virus can cause acute viral encephalomyelitis, the authors report a case of acute disseminated encephalomyelitis months after acute Epstein-Barr virus infection.

Vasculitis and rheumatologic diseases may play role in the pathogenesis of acute disseminated encephalomyelitis (ADEM)

Acute disseminated encephalomyelitis (ADEM) is defined as a multifocal, monophasic, demyelinating, and inflammatory disease involving the central nervous system. It typically begins within 6 weeks of an antigenic challenge such as infection or immunization. Perivenous inflammation, edema and demyelination are the pathological hallmarks of ADEM. Reactivity of T-cells against myelin components such as myelin basic protein has been found in children with ADEM. The triggers for immune responses in ADEM are not known, but the two most widely accepted hypotheses are molecular mimicry and self-sensitization secondary to CNS infection. Inflammatory cytokines including tumor necrosis factor alpha (TNFalpha), interleukin 2 (IL2) and interferon gamma (INFgamma) are thought to be important in lesion formation in ADEM. Due to the active role of inflammatory cytokines in the pathogenesis of ADEM, any disease contributing to systemic formation of inflammatory cytokines can potentially be an etiologic factor for the initiation of ADEM. In vasculitis and rheumatologic diseases the number of T-cells, T helper type 1 cytokines and other inflammatory cytokines such as TNFalpha increase substantially. We present this hypothesis that in such setting of inflammation, adhesion molecules are up-regulated on the brain capillary endothelium by cytokines and other inflammatory mediators, altering the permeability of the brain blood barrier and so allowing for inflammatory cell migration. The migratory cells attack the basic myelin protein and the final result is the demyelination seen in ADEM. So we propose that vasculitis and rheumatologic diseases may play role in the pathogenesis of ADEM.

Mycoplasma pneumoniae central nervous system infections

PURPOSE OF REVIEW

Mycoplasma pneumoniae is associated with a wide range of central nervous system diseases, most importantly with childhood encephalitis. This review summarizes and discusses recent findings in the field of M. pneumoniae central nervous system infections in context with previously published findings, with reference to clinical spectrum, pathogenesis, diagnosis, and treatment.

RECENT FINDINGS

Further insight into the pathogenesis has been provided by studies on cytokine production and autoantibody formation. Some new manifestations have been described (e.g. Kluver-Bucy syndrome, intracranial hypertension). Anecdotal descriptions on the association of M. pneumoniae with uncommon neurologic diseases remain to be confirmed by additional reports, however, especially when aetiologic diagnosis relied exclusively on serology. New knowledge on treatment options targeting the immune system has been provided by isolated reports. Recent diagnostic advances refer to general methods (polymerase chain reaction, serology), without specific reference to neurologic disease.

SUMMARY

M. pneumoniae must be considered as causative agent of various neurologic diseases. The recent literature shows, however, that the clinical spectrum of M. pneumoniae central nervous system disease is still not well defined. In addition, the main future challenges are the investigation of the pathogenesis of M. pneumoniae central nervous system disease and the establishment of therapeutic approaches.