“Cerebellar peduncle quarter notes” formed by the superior and middle cerebellar peduncles: comparison with a diffusion tensor study of spinocerebellar degeneration

Purpose To investigate morphological changes of the superior and middle cerebellar peduncles (SCP, MCP) in spinocerebellar degeneration (SCD) by observing “cerebellar peduncle quarter notes”. Materials and Methods We examined 21 patients with SCD, including nine patients with multiple system atrophy cerebellar type (MSA-C), and 24 controls. We measured SCP angle and performed diffusion tensor analysis to quantify the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the MCP. We quantified the relationship between SCP angle and the ADC and FA of the MCP, and compared these variables between MSA-C patients and controls. Results There was statistically significant negative correlation between SCP angle and FA of the MCP, and a positive correlation between SCP angle and the ADC of the MCP. Mean SCP angle was larger among MSA-C patients than among normal controls. Conclusions SCP angle tended to be larger among patients with severe degeneration of the MCP. The SCP angle, quantified by observing “cerebellar peduncle quarter notes”, may be a simple index for evaluation of degeneration of the MCP.