Cortical alterations of brain metabolism, as seen in PET, obviously depend on the nature of the damage (either mechanical, toxic, anoxic, or other). However, some subcortical abnormalities seem to occur rather frequently regardless of the extension, position and cause of the damage. In particular, relative cerebellar vermis activation seems to be frequently encountered. The aim of this work was to determine the incidence of this pattern in a heterogeneous population of brain trauma, and to compare it on a quantitative basis with a group of age-sex matched controls. The case records of this study consist of 58 consecutive patients, 44 males, 14 females, age 14–69 (median 34) 44 traumatic, 8 anoxic, 4 vascular and 2 toxic injuries. In the trauma group, the visualization of the cerebellar vermis was readily appreciable as a consistent majority of cases. In particular, the mean vermis/cerebellum ratio (calculated by appropriate ROI positioning) was 1.26 ± 0.17 SD (range 0.92–1.82); in the control group the same parameters showed much less dispersion: average 0.92 ± 0.06, range 0.80–1.10 (P < 0.005). If, on the basis of the normal group data, a cut-off value of 1 is accepted for the v/c ratio, it is noted that 54/57 trauma patients (95%) showed a ratio above this value. In conclusion, a hypermetabolic cerebellar vermis is a common finding in a damaged brain, regardless of the nature of the trauma (probably due to the relative preservation compared with other structures of alternative metabolic pathways), and seems to be the hallmark of the injured brain.
From the Divisions of *Nuclear Medicine and †Physical Medicine and Rehabilitation, Ospedale S. Bortolo, Vicenza, Italy.
Accepted for publication August 28, 2006; revision accepted February 26, 2007.
This manuscript is not currently submitted elsewhere. All iconographic materials originate from the authors. This research is not sponsored, and has been conducted in accordance to the local current laws and ethical recommendations.
Reprints: Andrea Lupi, MD, Division of Nuclear Medicine, Ospedale S. Bortolo, Via M. Rodolfi, 36100 Vicenza, Italy. E-mail: firstname.lastname@example.org.