IgG4-related disease (IgG4-RD) is a multisystem disorder, which can affect nearly every organ system. Although involvement of the nervous system is commonly described, systematic descriptions of neurological involvement are rare.
Our objective was to describe the characteristics of patients diagnosed with IgG4-RD presenting with neurologic involvement.
Patients with IgG4-RD were retrospectively identified by screening medical records of all patients, who had signed general consent, treated at the outpatient neurology clinic of our university hospital.
Since 2012, we found 12 cases of IgG4-RD of whom eight cases presented with neurologic manifestations. Of those 6/8 (75%) patients were male. Mean age at symptom onset was 62 years (range: 35 - 81 years). In 2/8 (25%) of patients, neurologic presentation was the only disease manifestation and consisted of pachymeningitis, cranial neuropathy affecting cranial nerves II, V and VII, peripheral neuropathy, myalgia, carotid stenosis and cerebral ischemia. Lumbar puncture was performed in 5/8 (62%) patients and showed elevated cell count in 1 patient (range: 2- 9 M/l). Mean serum IgG4 concentration was 4.58 g/l (range 1.35 - 12.3 g/l) and was elevated in 7/8 patients. In the patient with normal IgG4 values biopsy was compatible with IgG4-RD. Total serum IgG was elevated in 4/8 (50%) patients with a mean of 14.9 g/l (range 8.92 – 21.6 g/l). Immunotherapy was started in 7/8 (87%) patients. Three patients received a high dose steroid monotherapy; other treatments were rituximab, methotrexate and leflunomide. Under these therapies, the outcome was favorable in 4/8 (50%) of patients, 3/8 (38%) remained unchanged and one patient succumbed to an unrelated pathology (colorectal cancer).
IgG4-related neurologic disease can manifest with multisystem involvement, but isolated neurologic manifestation is possible. If diagnosis is considered in patients with normal IgG4 levels biopsy should be obtained.