Literature DB >> 28293471

Internal capsule: The homunculus distribution in the posterior limb.

Cheng Qian1, Fei Tan1.   

Abstract

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.

Entities:  

Keywords:  Homunculus; Infarction; internal capsule; posterior limb of the internal capsule

Mesh:

Year:  2017        PMID: 28293471      PMCID: PMC5346518          DOI: 10.1002/brb3.629

Source DB:  PubMed          Journal:  Brain Behav            Impact factor:   2.708


Introduction

The internal capsule (IC) is an important structure in the brain that consists of descending and ascending fibers tracts. It is generally thought that the two main descending fibers tracts, the corticobulbar tract and the corticospinal tract, descend separately through the genu (Charcot, 1883) and through the anterior third of the posterior limb of the internal capsule (PLIC) (Dejerine, 1901; Foerster, 1936). In the PLIC, corticospinal tracts are organized along a long axis, meaning that hand fibers are located anteromedial to foot fibers (Bertrand, Blundell, & Musella, 1965; Carpenter, 1983). However, in our experience, some patients suffer from infarction in the IC, and their symptoms do not necessarily fit the classical fiber distribution. This study aims to address this phenomenon by analyzing the infarction lesion and clinical symptoms of patients who suffered acute infarction in the IC.

Materials and Methods

This article is based on 34 patients who visited the neurological departments of two hospital centers belonging to the Shengjing Hospital of China Medical University between 26/06/2010 and 05/12/2015. Inclusion criteria were as follows: acute infarction, single lesion in the IC, and performed magnetic resonance diffusion‐weighted imaging (MR‐DWI). Exclusion criteria were as follows: presence of any other brain disease, previous paresis, a history of drug dependency, and presence of a psychiatric disorder. The study was approved by the ethics committee of Shengjing Hospital of China Medical University.

MR acquisition

MR images were acquired using MR Philips 1.5T, MR Philips 3.0T or MR GE 3.0T. Diffusion‐weighted imaging (DWI) is a form of MR imaging based upon measuring the random Brownian motion of water molecules within a voxel of tissue and is essential for the diagnosis of acute infarctions.

Data measurements

The length ratio of infarction lesion compared PLIC: As the Figure 1 shows, four point are marked, “AD” represent the length of PLIC, “BC” represent the length of the infarction lesion, and the length of “AD”, “AB” and “AC” are measured, further, the ratios of infarction lesion compared PLIC, “AB/AD” and “AC/AD” are calculated.
Figure 1

Ratios of “AB/AD” and “AC/AD” “AD” represents the length

Ratios of “AB/AD” and “AC/AD” “AD” represents the length The angle degree of infarction lesion compared PLIC: The Figure 2 shows the measurement of the angle degree of infarction lesion compared PLIC, “∠AOB”, in which “AO” represents perpendicular bisector of the short axis of posterior limb, “BO” represents the long axis of infarction lesion, and if the “BO” is at the thalamus side, the degree is negative, reversely, if the “BO” is at the putamen side, the degree is positive.
Figure 2

Angle degree of “∠AOB” “AO” represents the perpen

Angle degree of “∠AOB” “AO” represents the perpen All figures were analyzed by Digimizer software.

Statistical analysis

As Figure 3 shows, 34 patients were divided into three groups, A, B, and C. Group A consisted of patients with a more severe weakness of the foot than the hand, group B represents a more severe weakness of the hand than the foot, and group C represents equal weakness of hand and foot. Furthermore, based on whether the patients suffered from facial nerve paresis, 34 patients were divided into group Y (with facial nerve paresis) and group N (without facial nerve paresis).
Figure 3

MR images of a total of 34 patients

MR images of a total of 34 patients Welch's t test was used to compare the mean values of group A, B, C and group Y, N, with p < .05 indicating statistical significance, and box‐plots would be presented when there was any statistical significance.

Results

Table 1 shows demographic and clinical data of the 34 patients.
Table 1

Demographic and clinical data of the 34 patients

No.AgeSexHanda Foota Face paresisb Tongue paresisb Dysarthriab AB/ADAC/AD∠AOB
A173M5−4+0000.2190.6193.206
A259M5−30000.3940.8127.458
A356M5−40000.4290.873−6.468
A469M540010.5320.901−5.767
A566F3−2−0000.5390.818−0.616
A691F54−0000.5490.945−4.228
A783M540000.5710.8−20.518
A871F5−4−1000.2390.777−4.619
A941M5−4−1100.5530.902−8.037
B147F13−1100.2550.6680.459
B271F340000.263, 0.435c 0.81, 0.535c 5.752
B371M340110.3880.8145.503
B469F4−5−1010.4430.7776.866
B561M341000.60.90125.442
B659M45−1010.4830.916−2.392
C180F5−5−0000.1710.5080.013
C284M5−5−0000.1890.778−2.445
C361M550000.4280.755−2.961
C465M550000.4340.8155.791
C587F550010.4450.6692.695
C669M330000.5370.8251.35
C764F55−0000.5410.9390.075
C857F550000.5480.8740.071
C1054M550010.5870.9064.821
C956M440000.5680.97−0.202
C1156F5−5−0000.6720.844−11.694
C1258M5−5−10100.5647.742
C1344M5−5−1010.3660.788−11.702
C1441M4−4−1110.4070.8620.699
C1549M441110.220.814.096
C1653M551010.2640.6647.53
C1754M551010.3080.7833.408
C1860M5−5−1110.3360.8460.352
C1973F441100.4060.943−14.306

The myodynamia of the hand and foot.

“1” means that patient had symptom, “0” means no.

B2 had two lesions in the IC, the total length proportion of two lesion was 0.263–0.81, and between 0.435 and 0.535, there was a gap.

Demographic and clinical data of the 34 patients The myodynamia of the hand and foot. “1” means that patient had symptom, “0” means no. B2 had two lesions in the IC, the total length proportion of two lesion was 0.263–0.81, and between 0.435 and 0.535, there was a gap. The Figure 4 shows the differences between the angle degree of infarction lesion, “∠AOB”, of group A and group B, and the means of “∠AOB” of group A and group B are −4.399, 3.905, the p value is lower than .05, having significant difference. While the means of “AB/AD” and “AC/AD” have no significant difference according to the p value (Table 2).
Figure 4

Boxplots of group A and group B

Table 2

Group A and group B

A N, Mean SDBa N, Mean SD p Value
AB/AD 9, 0.447 0.137 6, 0.405 0.133 .543
AC/AD 9, 0.827 0.096 6, 0.814 0.090 .849
∠AOB 9, −4.399 7.842 6, 7.842 9.746 .027

B2 is consider as one lesion, the AB/AD is 0.263, the AC/AD is 0.81.

Boxplots of group A and group B Group A and group B B2 is consider as one lesion, the AB/AD is 0.263, the AC/AD is 0.81. Meanwhile the Figure 5 shows the differences between the length ratio of infarction lesion of group Y and group N, and the means of “AB/AD” of group Y and group N are 0.348, 0.46, the p value is lower than .05, having significant difference, while the means of “AC/AD” and”∠AOB” have no significant difference according to the p value (Table 3).
Figure 5

Boxplots of group Y and group N

Table 3

Group N and group Y

N N, Mean SDY N, Mean SD p Value
AB/AD 19a, 0.46 0.14 14, 0.349 0.154 .038
AC/AD 19, 0.814 0.115 14, 0.8 0.11 .729
∠AOB 19, −1.259 6.658 14, 1.11 9.83 .415

B2 is excluded.

Boxplots of group Y and group N Group N and group Y B2 is excluded.

Discussion

The difference between “∠AOB” of group A and group B suggests that the hand fibers locate laterally to foot fibers in the short axis of PLIC. And the mean “AB/AD” of group N, 0.46, suggests that the face fibers locate in the anteromedial portion of the PLIC. In the other way, the 0.348, the mean “AB/AD” of group Y suggests that face fibers cannot just locate in the anterior third of PLIC, let alone the genu of IC. In brief, there are two main findings: first, hand fibers seem to be located laterally to foot fibers in the short axis of PLIC; second, face fibers are likely located in the anteromedial portion of the posterior limb of the IC. Neither of these two findings fits the classical distribution of descending fibers in the PLIC, supporting previous studies casting doubt on the classical anatomy (Englander, Netsky, & Adelman, 1975; Kretschmann, 1988; Yagishita, Nakano, Oda, & Hirano, 1994). Holodny, Gor, Watts, Gutin, and Ulu (2005) demonstrated that the corticospinal tracts are located in the posterior third quarter of the PLIC and that hand fibers are located anterolateral to foot fibers. Yim et al. (2013) suggested that the corticobulbar tracts pass through the median of the PLIC instead of the genu. Moreover, they calculated the ratio of the lesion compared with the PLIC and found that the most overlapping area was the median of the PLIC. However, a recent study (Duerden, Finnis, Peters, & Sadikot, 2011) investigating the somatotopic organization and probabilistic mapping of motor responses in the IC found a contrasting result. Using electrophysiology, the authors found that face fibers were located anteromedial to hand responses, while foot fibers lied posterolateral to the hand representation. Interestingly, 45% of total leg responses co‐occurred with arm responses. On the one hand, this indicates overlap between leg fibers and hand fibers in the IC; on the other hand, this might be the reason why their result conflicts with both Holodny et al. (2005) study and this study. Or perhaps, they are all right, the difference just means the different level of the structure of IC. It is well‐known that somatotopy of hand is located lateral to the foot in the centrum semiovale (Seo, Chang, & Jang, 2012; Zolal et al., 2012), but in the brainstem, the distribution is reversed, meaning that somatotopy of hand is located medial to the foot (Hong, Son, & Jang, 2010; Kwon, Hong, & Jang, 2011). So the rotation does have to take place in the median between precentral gyrus and brain stem, and IC is just the median. However, most of our patients had lesions in the cranial dorsal part of the internal capsule, where the pyramidal tract may not be completely rotated yet.

Limitations

This study has some limitations. First, the sample size was relatively small. Second, the measurement of the angle degree of “∠AOB” has several human errors, as the long axis of the lesion was difficult to draw, especially the line of OB. Third, patient images were obtained using different MRI scanners, 1.5 T and 3.0 T, leading to potential differences in infarction margins between the two MRI machines. Fourth, IC images of patients were not obtained in the same horizontal section, potentially changing the relative location of the genu of the IC (Axer & Keyserlingk, 2000).

Conclusion

This study suggests two main findings: first, hand fibers seem to be located laterally to foot fibers in the short axis of the PLIC; second, face fibers are likely located in the anteromedial portion of the posterior limb of the IC. Given the importance of the structure, even small lesions of the IC can lead to severe outcomes, emphasizing the need for further studies to provide novel insights in fiber distributions.
  12 in total

1.  Mapping of fiber orientation in human internal capsule by means of polarized light and confocal scanning laser microscopy.

Authors:  H Axer; D G Keyserlingk
Journal:  J Neurosci Methods       Date:  2000-01-15       Impact factor: 2.390

2.  ELECTRICAL EXPLORATION OF THE INTERNAL CAPSULE AND NEIGHBOURING STRUCTURES DURING STEREOTAXIC PROCEDURES.

Authors:  G BERTRAND; J BLUNDELL; R MUSELLA
Journal:  J Neurosurg       Date:  1965-04       Impact factor: 5.115

3.  Diffusion-tensor MR tractography of somatotopic organization of corticospinal tracts in the internal capsule: initial anatomic results in contradistinction to prior reports.

Authors:  Andrei I Holodny; Devang M Gor; Richard Watts; Philip H Gutin; Aziz M Ulug
Journal:  Radiology       Date:  2005-01-21       Impact factor: 11.105

4.  Somatotopic location of corticospinal tract at pons in human brain: a diffusion tensor tractography study.

Authors:  Ji Heon Hong; Su Min Son; Sung Ho Jang
Journal:  Neuroimage       Date:  2010-03-04       Impact factor: 6.556

5.  Anatomic location and somatotopic arrangement of the corticospinal tract at the cerebral peduncle in the human brain.

Authors:  H G Kwon; J H Hong; S H Jang
Journal:  AJNR Am J Neuroradiol       Date:  2011-09-08       Impact factor: 3.825

6.  Three-dimensional somatotopic organization and probabilistic mapping of motor responses from the human internal capsule.

Authors:  Emma G Duerden; Kirk W Finnis; Terry M Peters; Abbas F Sadikot
Journal:  J Neurosurg       Date:  2011-03-04       Impact factor: 5.115

7.  Anatomy of the supraventricular portion of the pyramidal tract.

Authors:  Amir Zolal; Petr Vachata; Aleš Hejčl; Robert Bartoš; Alberto Malucelli; Martina Nováková; Milouš Derner; Martin Sameš
Journal:  Acta Neurochir (Wien)       Date:  2012-04-12       Impact factor: 2.216

8.  Anatomical location of the corticospinal tract according to somatotopies in the centrum semiovale.

Authors:  Jeong Pyo Seo; Pyung-Hun Chang; Sung Ho Jang
Journal:  Neurosci Lett       Date:  2012-06-28       Impact factor: 3.046

9.  Location of human pyramidal tract in the internal capsule: anatomic evidence.

Authors:  R N Englander; M G Netsky; L S Adelman
Journal:  Neurology       Date:  1975-09       Impact factor: 9.910

10.  Distribution of the corticobulbar tract in the internal capsule.

Authors:  Soo Hwan Yim; Jong Hun Kim; Zee-A Han; Seun Jeon; Jeong Hee Cho; Gyu Sik Kim; Sun-Ah Choi; Jun Hong Lee
Journal:  J Neurol Sci       Date:  2013-07-31       Impact factor: 3.181

View more
  4 in total

1.  Temporal Dynamics of Brain White Matter Plasticity in Sighted Subjects during Tactile Braille Learning: A Longitudinal Diffusion Tensor Imaging Study.

Authors:  Malwina Molendowska; Jacek Matuszewski; Bartosz Kossowski; Łukasz Bola; Anna Banaszkiewicz; Małgorzata Paplińska; Katarzyna Jednoróg; Bogdan Draganski; Artur Marchewka
Journal:  J Neurosci       Date:  2021-07-12       Impact factor: 6.167

Review 2.  Chinese Cerebrovascular Neurosurgery Society and Chinese Interventional & Hybrid Operation Society, of Chinese Stroke Association Clinical Practice Guidelines for Management of Brain Arteriovenous Malformations in Eloquent Areas.

Authors:  Mingze Wang; Yuming Jiao; Chaofan Zeng; Chaoqi Zhang; Qiheng He; Yi Yang; Wenjun Tu; Hancheng Qiu; Huaizhang Shi; Dong Zhang; Dezhi Kang; Shuo Wang; A-Li Liu; Weijian Jiang; Yong Cao; Jizong Zhao
Journal:  Front Neurol       Date:  2021-06-09       Impact factor: 4.003

3.  White Matter Neuroplasticity: Motor Learning Activates the Internal Capsule and Reduces Hemodynamic Response Variability.

Authors:  Tory O Frizzell; Lukas A Grajauskas; Careesa C Liu; Sujoy Ghosh Hajra; Xiaowei Song; Ryan C N D'Arcy
Journal:  Front Hum Neurosci       Date:  2020-10-26       Impact factor: 3.169

4.  Prognosis prediction of motor outcome in hemiparetic patients with anterior choroidal artery infarction: Radiologic and transcranial magnetic stimulation prognostic validation studies (STROBE).

Authors:  Sung Ho Jang; Jun Lee; Jae Woon Kim; Kyu Tae Choi
Journal:  Medicine (Baltimore)       Date:  2021-12-23       Impact factor: 1.817

  4 in total

北京卡尤迪生物科技股份有限公司 © 2022-2023.