Clinical And Imaging Features Of Hypertrophic Pachymeningitis

Objective Hypertrophic pachymeningitis (HP) is a rare disease characterized byinflammation, localized or diffuse thickening of the dura mater. The etiology andclinical manifestations of patients with HP are complex. The diagnosis and treatmentoften involve multiple disciplines, such as neurology, neurosurgery, oncology,otorhinolaryngology, rheumatology and so on. Thus it’s apt to be misdiagnosed. Priorstudies have shown that the prognosis of HP was closely related to the duration ofdisease and the effectiveness of treatment, and the degree of neurological deficit that leftover was positively correlated with the course of disease before the correct diagnosisand treatment. Thus, the early diagnosis and treatment of patients with HP are of vitalimportance. The diagnosis of HP depends on the imaging manifestation, especiallyenhanced MRI. The purpose of this study is to explore the general clinical and imagingcharacteristics and atypical manifestations neglected compared with those of the casespreviously reported in literature, decrease the clinical misdiagnosis rate, providereference and guidance for the diagnosis and treatment of HP, and improve the clinicaloutcome of HP patients.Methods Our retrospective study included10patients with HP that admitted to ourhospital from Feb2007to Feb2012, and all of them were diagnosised by enhancedMRI scan. Medical records were read over, then all relevant clinical data were recorded,including the general information such as gender, age and telephone number; the diseasecourse, symptoms, signs and previous medical history; the laboratory tests results, suchas white blood cell (WBC), anti-streptolysin (ASO), rheumatoid factor (RF), erythro -cyte sedimentation rate (ESR), C-reactive protein (CRP), antinuclear antibodies (ANA),immunoglobulin (Ig), anti-neutrophil cytoplasmic antibodies (ANCA)，tumor twelve(C12), cerebrospinal fluid (CSF) and so on; the treatment strategies and therapeuticeffect during hospitalization. Besides, all the imaging data were copied in thedepartment of radiology, and read by an experienced director of radiology departmentand neurology chief physician respectively. Then the neuroimaging performance of eachpatient was clarified, including the lesions location of the dura mater or spinal duramater, the signal feature of the lesions in the MRI scan and enhanced MRI scan, theinvolvement of adjacent structures and so on. Combined with the literature, the etiology,clinical, radiographic, treatment strategies and therapeutic effects were discussed, andthe general and special characteristics of this disease were summarized and analyzed.Results Among10cases of HP patients, there were4males and6females, aged from30to67years old, with an average of50.4years old. The course of desease was2weeks to2years, with an average of7months. The onset of HP was subacute or chronic.Headache (8cases) and diplopia (2cases) were the first symptoms. The mainmanifestations included: headache in9cases; cranial nerve palsy in7cases (cranialnerve examination showed that VIII damaged in6cases, VII damaged in4cases, II, III,IV, V and VI damaged in3cases respectively, IX and X damaged in1cases respectively.That is, there were facial paralysis, hearing loss in4cases respectively, tinnitus, visionloss, diplopia in3cases respectively, vertigo in2cases, numbness next to the nose skin,prosopalgia, prosopalgia accompanied with temporal numbness, bulbar palsy in1caserespectively); epilepsy, ataxia, lower extremity weakness associated with paraesthesia in1case respectively. MRI showed thickened dura mater in4cases, and with the signalshypointense or isointense on T1WI and hypointense on T2WI; widened cavernous sinusshadow in2cases, and with the signals hypointense on T1WI; and hyperintense onT2WI in middle ear cavity and maxillary sinuscavity in2cases respectively. Contrast-enhanced MRI showed that9cases of10patients had localized dural materinvolvement (1case with T8-T12spinal dura mater hypertrophy), including the parietallobe involvement in5cases, the temporal lobe and tentorial involvement in4casesrespectively, the frontal lobe, cavernous sinus, cerebral falx involvement in2casesrespectively. The remaining1case had diffuse dural mater involvement (combined withcervical spinal dura mater hypertrophy); the lesions were in the left side of the duralesions in3cases, right side in2cases, bilateral in4cases, and the front part of thecerebral falx in1case. The thickened dura mater of10patients had an obviousenhancement in a banded or nodular pattern, without extending to the sulci gyrus.2ofthe10patients were accompanied with cervical or thoracic spinal dura materhypertrophy and enhancement respectively.9of the10patients were treated withcorticosteroids, then headache were relieved. Peripheral facial paralysis was left behindin4cases, blurred vision and poor hearing were left behind in1case respectively.Conclusions HP might occur at any age. Headache and cranial nerve palsy are themain symptoms. MRI shows a characteristic thickened dura mater in a banded ornodular pattern, with the dural or spinal or both of them involvement. The thickeneddura mater was usually hypointense or isointense on T1WI and hypointense on T2WI,and enhanced strongly after paramagnetic contrast injection. Combined with clinicaldata, precise diagnosis usually can be conducted. The therapy withantibiotics,corticosteroids or immunosu-ppressants were effective. Besides, surgicaldecompression can be adopted if necessary.