Internal capsule: The homunculus distribution in the posterior limb.

INTRODUCTION: In our experience, sometimes, the symptom of patients who suffered from infarction in internal capsule (IC) do not necessarily fit the classical fiber distribution. This study aims to explain this phenomenon.

METHODS AND MATERIALS: A total of 34 patients with infarction lesions in the IC were included in this study, according to the clinical symptom, divided into three groups, group A (more severe weakness of the foot than the hand), group B (more severe weakness of the hand than the foot) and group C (equal weakness of hand and foot), and group Y (with facial nerve paresis) and group N (without facial nerve paresis). Measurements included the length ratio and the angle degree of infarction lesions compared with the posterior limb of the IC (PLIC).

RESULTS: The length ratio of infarction lesions is significant difference between group A and group B ( p  = .027), the angle degree of infarction lesions is significant difference between group Y and group N ( p  = .038).

CONCLUSION: From our results, we can conclude that the hand fibers are located laterally to foot fibers in the short axis of the posterior limb of the IC, and the face fibers are located in the premedial part of the posterior limb of the internal capsule.