Cranial neuropathy because of IgG4-related pachymeningitis; intracranial and spinal mass lesions

Description

A 64-year-old man suffering from chronic heart failure developed gradually worsening dysphagia 1 month before. Physical examinations revealed no abnormalities, such as proptosis and parotid swelling. Neurological examinations revealed hoarseness, poor soft palate elevation and right-sided atrophy of the tongue and sternocleidomastoid muscle. The patient's DTRs were slightly hypoactive, but no pathological reflexes were elicited. Cerebellar systems were intact, and there was no muscle weakness in the four extremities. Gadolinium-enhanced MRI disclosed mass lesions in the right skull base and thoracic spine, though clinical symptoms suggestive of myelopathy were absent (figure 1: arrows). Cerebrospinal fluid (CSF) contained 14 cells (mono: 3, poly 11)/mm³, and 260 mg/dl of protein. Laboratory examinations demonstrated that serum IgG4 was elevated to 221 mg/dl (normal < 104 mg/dl). Systemic CT examinations showed slight swelling of both kidneys that was compatible with an IgG4-related renal disorder, but no other organ involvements were detected. Open biopsy of the thoracic lesion was performed, and pathological investigations revealed non-specific granulation with inflammatory infiltrates (figure 2A). Immunohistochemical examinations showed IgG4-positive plasma cells (figure 2B). Subsequently, steroid pulse therapy and tapering of oral prednisolone were administered. Three weeks after completing steroid treatment, the patient's manifestations and radiological findings were markedly improved (figure 2 C,D). Recently, IgG4-related diseases characterised by infiltration of IgG4-positive plasma cells and sclerosing changes in organs have emerged as a distinct new disease entity.¹ Among the features of this entity, central nervous system involvements due to pachymeningitis has received considerable clinical attention in making the differential diagnosis and determining pathogenesis.^{2 3}

Figure 1.

MRIs on admission.

Figure 2.

Pathological findings (A, B) and MRIs after steroid treatment (C, D).

Learning points.

• IgG4-related pachymeningitis could involve spinal cord.

• Pathological examination is necessary.

• Treatment with prednisolone should be effective.