Answer for BIR CoW 19 Sep 2021
Hypertrophic Pachymeningitis
Findings
T2 hypointense dural thickening seen in right tentorial region and extending superior to the pineal region. Extensive T2 hypointensity seen in retroclival region (thickness of 10 mm) extending to anterior cervical subarachnoid region. Similar T2 hypointensity also seen in posterior foramen magnum region and extending inferior to upper cervical region. Extensive dural thickening causing severe foramen magnum and cervical canal stenosis with spinal cord compression (lntramedullary T2 hyperintensity) at C1 and C2 level. The lesion measures 4.4 (cranio caudal) x 1.3 (anteroposterior) x 29 (transverse) cm. Empty sella seen. Mild perioptic subarachnoid space distension seen on both sides. On contrast administration, near homogenous enhancement of lesion with few linear central hypointensity noted. No abnomal T1 hyperintensity / restricted diffusion noted. IMPRESSION: Extensive T2 hypointense dural thickening involving retroclival, tentorial and foramen magnum region as described, causing cervico medullary compression. Above features are suggestive of Hypertrophic pachymeningitis (likely IgG related spectrum disease also to be ruled out) FOLLOW UP: Patient was found to have IGg4 antibodies positive in serology and anti TPO (Thyroid Peroxidase) antibodies positive Patient was started iv steroids and continued tapering with oral prednisolone. Patient has significant clinical improvement.
Discussion
Hypertrophic pachymeningitis is an extremely rare fibrosing inflammatory process involving the dura mater and, often, the tentorium. Numerous pathologic entities can produce thickening of the pachymeninges; thus idiopathic pachymeningitis is a diagnosis of exclusion. The underlying and neighboring leptomeninges (pia mater, arachnoid mater) become opaque and thickened as well. These changes in the meninges can be identified in a variety of neoplastic, autoimmune and infectious disease processes. If an exhaustive work-up fails to identify the cause of the meningeal changes, a diagnosis of Idiopathic pachymeningitis is made. IHP is a rare disorder affecting men more often than women with peak prevalence occurring in the 6th decade of life. Chronic headaches, often resembling chronic migraines with or without other neurologic manifestations, are the most common presenting symptom of IHP Other neurologic symptoms of IHP include cranial nerve palsies (cranial nerves(IV–VIII), cerebellar ataxia, seizures, and neuroophthalmic symptoms such as visual field loss, complete blindness, optic neuropathy, and increased intracranial pressure with papilledema Contrast material– enhanced computed tomography (CT) reveals diffuse thickening and enhancement of the duramater. Typically, IHP demonstrates smooth or nodular dural thickening that is isointense or hypointense with both T1- and T2-weighted sequences. It also shows avid enhancement after intravenous administration of contrast material. These signal intensity characteristics are due to the fibrosis and necrosis of the dura mater. “Eiffel by night” sign classically described for reactivation in idiopathic chronic hypertrophic pachymeningitis. Involvement of falx and tentorium with hypertrophied dura gives the appearance of the illuminated Eiffel tower by night on contrast enhanced coronal sections of T1 weighted image.
Findings
T2 hypointense dural thickening seen in right tentorial region and extending superior to the pineal region. Extensive T2 hypointensity seen in retroclival region (thickness of 10 mm) extending to anterior cervical subarachnoid region. Similar T2 hypointensity also seen in posterior foramen magnum region and extending inferior to upper cervical region. Extensive dural thickening causing severe foramen magnum and cervical canal stenosis with spinal cord compression (lntramedullary T2 hyperintensity) at C1 and C2 level. The lesion measures 4.4 (cranio caudal) x 1.3 (anteroposterior) x 29 (transverse) cm. Empty sella seen. Mild perioptic subarachnoid space distension seen on both sides. On contrast administration, near homogenous enhancement of lesion with few linear central hypointensity noted. No abnomal T1 hyperintensity / restricted diffusion noted. IMPRESSION: Extensive T2 hypointense dural thickening involving retroclival, tentorial and foramen magnum region as described, causing cervico medullary compression. Above features are suggestive of Hypertrophic pachymeningitis (likely IgG related spectrum disease also to be ruled out) FOLLOW UP: Patient was found to have IGg4 antibodies positive in serology and anti TPO (Thyroid Peroxidase) antibodies positive Patient was started iv steroids and continued tapering with oral prednisolone. Patient has significant clinical improvement.
Discussion
Hypertrophic pachymeningitis is an extremely rare fibrosing inflammatory process involving the dura mater and, often, the tentorium. Numerous pathologic entities can produce thickening of the pachymeninges; thus idiopathic pachymeningitis is a diagnosis of exclusion. The underlying and neighboring leptomeninges (pia mater, arachnoid mater) become opaque and thickened as well. These changes in the meninges can be identified in a variety of neoplastic, autoimmune and infectious disease processes. If an exhaustive work-up fails to identify the cause of the meningeal changes, a diagnosis of Idiopathic pachymeningitis is made. IHP is a rare disorder affecting men more often than women with peak prevalence occurring in the 6th decade of life. Chronic headaches, often resembling chronic migraines with or without other neurologic manifestations, are the most common presenting symptom of IHP Other neurologic symptoms of IHP include cranial nerve palsies (cranial nerves(IV–VIII), cerebellar ataxia, seizures, and neuroophthalmic symptoms such as visual field loss, complete blindness, optic neuropathy, and increased intracranial pressure with papilledema Contrast material– enhanced computed tomography (CT) reveals diffuse thickening and enhancement of the duramater. Typically, IHP demonstrates smooth or nodular dural thickening that is isointense or hypointense with both T1- and T2-weighted sequences. It also shows avid enhancement after intravenous administration of contrast material. These signal intensity characteristics are due to the fibrosis and necrosis of the dura mater. “Eiffel by night” sign classically described for reactivation in idiopathic chronic hypertrophic pachymeningitis. Involvement of falx and tentorium with hypertrophied dura gives the appearance of the illuminated Eiffel tower by night on contrast enhanced coronal sections of T1 weighted image.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
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Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!