Table 3.

Comparison of morphometric measurements and volumetric calculations in patients with CM-I, CM-I/TCS, and LLCT/TCS

Variable	Normal controls	CM-I	CM-I/TCS	LLCT/TCS
Total no. of patients	75	280	228	30
Sex (male/female)	20 / 55	78 / 202	40 / 188	12 / 18
Mean age (y)	31.7 ± 11.8	33.7 ± 10.4	31.5 ± 12.4	31.0 ± 12.5
Brain structures
BSL (mm)	51.6 ± 2.32	52.1 ± 2.57	57.5 ± 2.22 ^*, ^‡	54.8 ± 2.28 ^*
TH (mm)	−3.4 ± 2.71	11.5 ± 4.41 ^*	8.4 ± 2.45 ^*	3.5 ± 1.04 ^*
4VH^a (mm)	4.2 ± 3.14	5.1 ± 3.13	8.1 ± 2.27 ^*, ^‡	5.2 ± 2.32 ^*
Occipital bone size
Clivus
Axial length (mm)	47.0 ± 2.17	38.4 ± 3.21 ^†	45.7 ± 2.85	46.3 ± 2.87
Supraocciput
Axial length (mm)	47.7 ± 2.52	39.7 ± 3.87 ^†	47.0 ± 2.77	47.4 ± 2.56
Occipital condyle
Axial length right (mm)	24.1 ± 1.65	18.7 ± 3.40 ^†	23.3 ± 2.61	23.8 ± 2.71
Axial length left (mm)	24.3 ± 1.54	19.1 ± 3.56 ^†	23.5 ± 2.78	23.9 ± 2.83
Width between occipital condyles (mm)	50.5 ± 2.48	47.2 ± 3.12 ^†	55.2 ± 3.34 ^*	54.1 ± 2.74 ^*
FM
Anterior-posterior diameter (mm)	32.1 ± 3.17	32.8 ± 3.72	37.6 ± 2.56 ^*, ^‡	35.0 ± 2.54 ^*
Transverse diameter (mm)	29.6 ± 3.74	26.1 ± 3.04 ^†	34.8 ± 3.28 ^*	33.6 ± 3.15 ^*
Area (mm²)	787.7 ± 118.4	655.7 ± 121.8 ^†	1028.5 ± 122.8 ^*	923.2 ± 120.8 ^*
Volumetric analysis
PCFV (ml)	189.1 ± 7.84	164.6 ± 8.17 ^†	186.2 ± 8.60	188.7 ± 8.64
PFBV (ml)	151.8 ± 3.14	148.7 ± 4.76	152.8 ± 4.46	152.7 ± 4.31
CSF space (ml)	37.2 ± 5.57	15.8 ± 8.41 ^†	33.4 ± 4.71	35.8 ± 4.57

Mean values are expressed as ± SDs.

Distance between Twining’s line and posterior apex of fourth ventricle.

Significant differences (larger) as compared to normal controls (P < .001).

^†

Significant differences (smaller) as compared to normal controls (P < .001).

^‡

Significant differences (larger) as compared to LLCT/TCS group (P < .01).