On the variability of the human flocculus and paraflocculus accessorius

Area of Science:

• Neuroanatomy
• Human Morphology

Background:

• The cerebellum plays a crucial role in motor control and cognitive functions.
• Understanding the detailed morphology of cerebellar structures like the flocculus and accessory paraflocculus is essential for neuroanatomical studies.

Purpose of the Study:

• To macroscopically examine 42 human cerebelli.
• To determine the general morphology and variability of the flocculus and accessory paraflocculus.

Main Methods:

• Macroscopic examination of 42 human cerebelli.
• Quantitative analysis of folia and subfolia in the flocculus and accessory paraflocculus.
• Calculation of coefficients of variability for morphological features.

Main Results:

• The flocculus exhibited a mean of 14.2 folia and 7.0 subfolia with a variability coefficient of 22.1% and 47.4%, respectively.
• The accessory paraflocculus showed a mean of 4.2 folia and 2.0 subfolia, with significantly higher variability coefficients (50.2% and 102.8%).
• Accessory paraflocculus conformation ranged from a single lamella to a flocculus-like cluster, with no correlation between the variability of the two structures.

Conclusions:

• The accessory paraflocculus demonstrates marked morphological variability in humans.
• This variability may be linked to the phylogenetic evolution of these cerebellar structures.
• Further research is warranted to explore the functional implications of this observed variability.