Mycoplasma pneumoniae meningoencephalitis and cerebellitis with antiganglioside antibodies.

A male patient with acute meningoencephalitis and cerebellitis associated with Mycoplasma pneumoniae infection is described. T2-weighted MRI demonstrated a high-intensity lesion involving the deep white matter of the right cerebellar hemisphere, which was not enhanced on injection of gadolinium. Brain perfusion scintigraphy revealed hypoperfusion in the bilateral cerebellar hemisphere. Polymerase chain reaction analysis using M. pneumoniae-specific primers failed to reveal the existence of the M. pneumoniae genome in cerebrospinal fluid. Conversely, serum antibodies to gangliosides (GM1, GM2, and GT1b) were detected, suggesting a mycoplasma-related neurologic disorder mediated by an immunologic mechanism. These findings support the hypothesis that vasculopathy and demyelination caused by an immunologic mechanism play an important role in the pathogeneses of neurologic disorders associated with M. pneumoniae infection.