Cavernous malformation of the mammillary bodies: neuropsychological implications. Case report.

The authors present the first documented case of a cavernous malformation of the mammillary bodies. A 34-year-old woman presented with a 2-month history of headaches and acute memory changes. Magnetic resonance imaging studies demonstrated a retrochiasmatic interpeduncular lesion that was initially thought to be a craniopharyngioma. Operative resection confirmed the diagnosis of a cavernous malformation. This particular case is unique in its destruction of the mammillary bodies and presents further evidence of the relationship of these regions to memory. This report is also the first to document results of pre- and postoperative neuropsychological evaluations that specifically address the memory deficits created by destruction of the mammillary bodies.

Intracranial cryosurgery in a canine model: a pilot study.

Although virtually abandoned decades ago following the introduction of levodopa for the treatment of movement disorders, intracranial cryosurgery potentially offers a simple and accurate means of destroying deep-seated lesions when coupled with computed tomographic-stereotaxic placement techniques. We performed a pilot investigation of the size and histology of brain cryolesions in six dogs, using a 3-mm probe maintained at -160 degrees C for 6 minutes while simiultaneously monitoring the process by real-time ultrasound. Lesion diameter was 1.4 +/- 0.1 cm at less than or equal to 2 days but enlarged to 2.25 +/- 0.21 cm at 1 week, primarily at the expense of white matter. Ultrasound appearance of the lesion was characterized by a hyperechoic ice ball, the size of which consistently underestimated true size (determined by histology). By microscopy, the lesion was a hemorrhagic infarction that incited little surrounding edema and exhibited a sharp transitional zone. These data indicate that the cryosurgical probe can lesion significant volumes of brain in a reproducible and discrete fashion with minimal reaction to the surrounding tissue. Further work is required to clarify the observed "growth" of lesion size between days 2 and 7.