E Gupta, R Lalwani, C Babu, S Aneja
age related changes., body, corpus callosum, genu, mri, rostrum, splenium
E Gupta, R Lalwani, C Babu, S Aneja. Age Related Changes Of Corpus Callosum By MRI In Females. The Internet Journal of Neurology. 2009 Volume 13 Number 1.
The morphologic characteristics of brain in humans appear to be sensitive to the effects of both age and sex, and data suggest that these 2 variables may interact over the life span to influence brain size. These morphometrical data can provide a useful context to interpret changes in regional brain structure associated with aging. The corpus callosum is the largest commissure of the brain. It is seen as thick, curved white band on medial surface of sagittaly bisected brain. It is 10 cm long and consist of the
There are disputed claims about the difference in the size of the human corpus callosum in men and women and the relationship of any such differences to gender differences in human behaviour and cognition. RB Bean, a Philadelphia anatomist, suggested in 1906 that the “exceptional size of the corpus callosum may mean exceptional intellectual activity” and claimed differences in size between males and females and between races, although these were refuted by Franklin Mall, the director of his own laboratory. Of much more substantial popular impact was a 1982
The corpus callosum is a structure of the mammalian brain in the longitudinal fissure that connects the left and right cerebral hemispheres. It is the largest white matter structure in the brain, consisting of 200-250 million contra lateral axonal projections. It is a wide, flat bundle of axons beneath the cortex. Much of the inter-hemispheric communication in the brain is conducted across the corpus callosum. Monotremes and marsupials do not have a corpus callosum. It is 10 cm long and consist of the
MR imaging enables the in vivo study of cerebral structure and function. Several neuroimaging studies have used the midsagittal area of the corpus callosum to show differences in morphology related to sex, handedness , aging and pathologic states. The corpus callosum has been shown to be altered in conditions such as schizophrenia, dyslexia, even when visual assessment of the MR images reveals normal findings. In pathologic states such as multiple sclerosis and Alzheimer disease, quantitative measures of the corpus callosum have been proposed as useful indicators of disease progression. Several studies indicate that the size and shape of the corpus callosum (CC) in human brain are correlated to sex, age, brain growth and degeneration , handedness , and to various types of brain dysfunction .
Material And Method
A total of 120 females of age ranging from 20 to 85 years , who attended OPD of Radio-diagnosis of Sardar Vallabh Bhai Patel Hospital, Meerut and visited NMC Sky Scanning centre, were studied by Magnetic Resonance Imaging (Mid-sagittal imaging) by 1.5 Tesla Machine of G. G. company with LCD projector. Informed consent was taken from the patients. Subjects were divided into two groups – adult (20-60 years) & Senile group (> 60 years). The subjects of the MRI were normal volunteers or patients referred for suspected or known central nervous system diseases.
In this study various parameters of corpus callosum measured in females in mid-sagittal plane of magnetic resonance imaging were-
1. Thickness of various parts of corpus callosum at its maximum level (genu, rostrum, body and splenium).
2. Maximum length and maximum width of corpus callosum.
3. Distance of corpus callosum from frontal pole and occipital pole of cerebral hemisphere.
Comparison of these parameters were done between adults (20-60 years) and senile (>60 years) age groups of females. The results were statistically analyzed by using unpaired student ‘t’ test with Welch correction. Probability ‘p’ value ≤0.05 and ‘t’ value ≥ 1.96 is considered significant. All parameters were measured in millimeter (mm).
The various observations of this study are shown in following tables
S-Significant, NS- Non significant, VS- Very significant, ES- Extremely significant, ( ) – No of cases of females in adult and senile age groups.
NS- Non significant, S- significant, ( ) – No of cases of females in adult and senile age groups.
The present study shows a significant difference in thickness of rostrum and genu parts of Corpus callosum in adult & senile age groups of Females and the thickness decreases with age also significant difference is seen in maximum width between the above two groups again thickness decreases with age.
Changes in callosal size in aging adults are controversial. Doraiswamy et al (1991) and Weis et al (1986) have shown senescent effects over 3rd-8 th decades. Salat et al (1997) and Davatzikos et al (1998) found aging effects in elderly subjects especially those exceeding 55 years. Studies by Weis et al (1986) and Salat et al(1997) have shown greater vulnerability to aging in anterior than posterior regions of CC. This is particularly marked in women (Salat et al,1997) while Johnosn et al(1994) found greater vulnerability of men compared to women in older decades.
Salat et al (1997) reported that among elderly subjects (age range
65-95 years) age related atrophy of the anterior and middle sectors of the CC occurred in women but not in men. These findings correlate with the present study as the thickness of rostrum and genu has decreased wih age.
Witelson (1989) observed that the callosal size decreased with chronological age in males. Cowell et al (1992) have also documented that men exhibit maximum callosal width in their early 20’s with a relatively rapid decline thereafter. The present study reveals ht in females also the thickness of different parts of corpus callosum decreased significantly with chronological age especially after 60 yrs.
Corpus callosum, being the major structure connecting both the hemispheres, is likely to be affected by the physiologic as well as pathological changes occurring in the cortical and sub cortical regions of brain. Therefore different sub regions of the CC may be affected depending upon the region of the brain involved, as fiber systems connecting corresponding hemispheric regions pass through specific callosal sub regions. Therefore, alteration in CC morphology may give a clue towards diagnosis of specific disease processes. A knowledge of CC morphology and the gender as well as age related changes, thus is likely to be helpful in providing baseline data for the diagnosis of presence and progression of disease.
This is a random prospective study and further work is still required to assess the more specific age as well as gender related differences.