Table 1
Location of hypertrophic pachymeningitis
| Supratentorial | Cavernous sinus |
| Orbital apex | |
| Superior orbital fissure | |
| Sphenoid wing | |
| Cerebral convexity | |
| Tentorium cerebelli | |
| Falx cerebri | |
| Anterior and middle fossae | |
| Infratentorial | Posterior fossa |
| Foramen magnum | |
| Diffuse | Throughout the calvarium |
| Spinal canal | Spinal canal |
Table 2
Demographic data and clinical presentations of idiopathic HP and secondary HP patients
| IHP | Secondary HP | P | |
|---|---|---|---|
| n (%) | n (%) | ||
| Number of patients | 23 (68) | 11 (32) | |
| Age (mean, range) (years) | 46 (20–68) | 55 (8–79) | 0.235 |
| Male | 8 (35) | 4 (36) | 1.00 |
| Female | 15 (65) | 7 (64) | |
| Neurological symptoms | |||
| Headache | 15 (65) | 2(18) | 0.026* |
| 1.00 | |||
| Duration (mean, range) (months) | 6.6 (0.1–120) | 0.5 (1.5–4.0) | |
| Neurological deficits | 20 (87) | 9 (82) | |
| - CN I | 0 | 1 (9) | |
| - CN II | 9 (39) | 2 (18) | |
| - CN III | 8 (35) | 3 (27) | |
| - CN IV | 5 (22) | 1 (9) | |
| - CN V | 6 (26) | 1 (9) | |
| - CN VI | 6 (26) | 0 | |
| - CN VII | 1 (4) | 3 (27) | |
| - Others (both arms weakness and left hemiparesis) | 1 (4) | 2 (18) |
[i] *P by Fisher’s exact test
Figure 1
Idiopathic hypertrophic pachymeningitis (IHP). Axial T1-weighted image (A), axial T2-weighted image (B) shows an infiltrative T1 iso-intense, T2 hypointense lesion (arrow) involving left cavernous sinus with extension through left superior orbital fissure to left orbit, along left sphenoid ridge, left middle and posterior cranial fossae. Homogeneous enhancement is shown in axial (C) and coronal (D) gadolinium-enhanced T1-weighted images.
Figure 2
Primary dural lymphoma. Coronal T2-weighted image (A) shows hyperintense undulated thickened dura along the right cerebral convexity, anterior cranial fossa, and anterior falx cerebri (arrow). Axial (B) and coronal (C) gadolinium-enhanced T1-weighted images show homogeneously enhanced dural thickening.
Figure 3
IgG4-related pachymeningitis. Coronal T2-weighted image (A) shows dark intensity dural thickening involving right tentorium cerebelli (arrow). Axial (B) and sagittal (C) gadolinium-enhanced T1-weighted images demonstrate mildly heterogeneous enhancement of the thickened dura involving right medial temporal region, right Meckel’s cave, and along anterior part of right tentorium cerebelli (arrow).
Table 3
Configurations and locations of dural thickening in idiopathic HP and secondary HP groups
| Characteristics | Idiopathic HP | Secondary HP | P |
|---|---|---|---|
| (N = 23) | (N = 11) | ||
| n (%) | n (%) | ||
| Configurations | |||
| Linear/smooth | 12 (52) | 6 (55) | 1.00 |
| Nodular/undulated | 11 (48) | 5 (45) | 1.00 |
| Locations | |||
| Supratentorial lesions | 22 (96) | 11 (100) | 1.00 |
| Cavernous sinus | 13 (57) | 6 (55) | 1.00 |
| Orbital apex | 4 (17) | 4 (36) | 0.388 |
| Supraorbital foramen | 1 (4) | 0 | 1.00 |
| Sphenoid wing | 2 (9) | 2 (18) | 0.58 |
| Cerebral convexity | 8 (35) | 7 (64) | 0.151 |
| Tentorium cerebelli | 9 (39) | 5 (46) | 1.00 |
| Falx cerebri | 4 (17) | 2 (18) | 1.00 |
| Anterior and middle cranial fossae | 3 (13) | 6 (55) | 0.033* |
| Infratentorial lesions | 6 (26) | 0 | 0.145 |
| Posterior fossa | 6 (26) | 0 | 0.145 |
| Foramen magnum | 0 | 0 | |
| Diffuse | 6 (26) | 0 | 0.145 |
| Spinal canal | 1 (4) | 0 | 1.00 |
Figure 4
Idiopathic hypertrophic pachymeningitis (IHP) with T2-rim pattern. Axial T1-weighted image (A) and T2-weighted image (B) show T1 iso-intense and central T2 hyperintense with peripheral dark T2 intense (T2-rim pattern) of the thickened dura along right frontal and right temporal convexity (arrow). Axial (C) and coronal (D) gadolinium-enhanced T1-weighted images demonstrate rim enhancement (white arrows). Smooth and homogeneous enhanced thickened dura at left anterior cranial fossa (black arrows) is also observed.
Table 4
Signal intensity of dural thickening in idiopathic HP and secondary HP groups
| Signal intensity | IHP | Secondary HP | P |
|---|---|---|---|
| (N = 23) | (N = 11) | ||
| n (%) | n (%) | ||
| T1-weighted image | 15 (65) | 9 (82) | 0.784 |
| Iso-intensity | 7 (30) | 2 (18) | |
| Hypo-intensity and dark intensity | 1 (4) | 0 | |
| Hyperintensity | |||
| T2-weighted image | 5 (22) | 3 (27) | 0.148 |
| Iso-intensity | 12 (52) | 3 (27) | |
| Hypo-intensity and dark intensity | 3 (13) | 5 (46) | |
| Hyperintensity | 3 (13) | 0 | |
| T2-rim pattern | |||
| Diffusion-weighted image | 12 | 10 | 0.455 |
| Restricted diffusion | 0 | 1 (10) | |
| No restricted diffusion | 12 (100) | 9 (90) | |
| Enhancement pattern | 16 (70) | 5 (46) | 0.344 |
| Homogeneous | 5 (22) | 5 (46) | |
| Heterogeneous | 2 (9) | 1 (9) | |
| Rim | |||
| T2 hypo-/dark intensity with | 12 | 3 | 0.014* |
| Homogeneous enhancement | 9 (75) | 0 | |
| Heterogeneous enhancement | 2 (17) | 3 (100) | |
| Rim enhancement | 1 (8) | 0 |
[i] *P by Fisher’s exact test