Isolated tongue tremor after removal of cerebellar pilocytic astrocytoma: Functional analysis with SPECT study.

Tongue tremor is a rare form of focal tremor. Even though the dysfunction of the dentato-rubro-olivary circular pathway has been proposed as its mechanism, the origin of the rhythmic activities remains unknown. We experienced a case of isolated tongue tremor after the removal of a cerebellar pilocytic astrocytoma. To localize the activated structures corresponding to the isolated tongue tremor, we analyzed subtracted ictal SPECT coregistered to MRI (SISCOM). SISCOM demonstrated multiregional hyperperfusion including the Guillain-Mollaret triangular and extratriangular structures. The activation of the inferior olive and red nucleus and accompanying extratriangular structures might be related to the isolated tongue tremor. (c) 2007 Movement Disorder Society.