MRI findings of autoimmune glial fibrillary acidic protein astrocytopathy involving infratentorial: Case report

Area postrema syndrome in patients with autoimmune glial fibrillary acidic protein astrocytopathy

Objective

Area postrema syndrome (APS) is a relatively rare symptom of autoimmune glial fibrillary acidic protein astrocytopathy (A-GFAP-A). This study aimed to report the APS in GFAP-immunoglobulin G (GFAP-IgG) positive patients.

Methods

We retrospectively analyzed the clinical data of APS in GFAP-IgG positive patients and reviewed relevant literature. Moreover, we compared these data with APS patients in aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4-IgG+ NMOSD).

Results

7 of 75 (9.3%) GFAP-IgG positive patients experienced APS, including 4 females and 3 males. The median age of onset was 42 years (range, 12-71 years). All patients presented with APS as their initial manifestation. Nausea and vomiting were observed in all 7 patients, while hiccups occurred in 5 patients. The median duration of APS episodes was 12 days (range, 6-40 days). None of the patients experienced isolated APS episodes during their illness. AQP4-IgG was positive in 2 patients. 5 patients had dorsal medulla oblongata lesions, while 3 patients showed an "inverted V" sign on axial images. In addition, 5 patients presented with longitudinally extensive linear or patchy lesions in cervical spinal cord extending to area postrema on sagittal images. All APS attacks completely disappeared after immunotherapy. Compared with the APS in AQP4 + NMOSD, APS in A-GFAP-A had a lower proportion of females (33.3% vs. 80%, p = 0.003), more hiccups (81% vs. 50%, p = 0.037), more leptomeningeal enhancement (61.9% vs. 5%, p = 0.000), higher CSF white blood cell count (median 120 vs. 10 cells/mm3, p = 0.000) and protein (median 0.949 vs. 0.407 g/L, p = 0.000). Furthermore, fewer patients with A-GFAP-A received long-term immunotherapy (19% vs. 65%, p = 0.003).

Conclusion

APS often occurs as an initial manifestation of A-GFAP-A. MRI examination and antibody testing should be performed in suspected patients to avoid misdiagnosis.

Diagnostic challenges in SLIPPERS syndrome: Case report

Background

SLIPPERS (Supratentorial Lymphocytic Inflammation with Parenchymal Perivascular Enhancement Responsive to Steroids) is a rare variant of a syndrome called CLIPPERS (Chronic Lymphocytic Inflammation with Ponsine Perivascular Enhancement Responsive to Steroids). SLIPPERS is characterized by distinct supratentorial lesions that share radiological and pathological characteristics with CLIPPERS. The ongoing issue is whether these syndromes should be considered as a distinct disease entity or simply a form for a variety of underlying conditions such as granulomatosis, vasculitis, and infectious diseases.

Case

We present a unique case of SLIPPERS observed in a 26-year-old woman with no notable medical or familial background. Laboratory findings ruled out certain diseases from the list of differentials and cranial MRI showed T2 hyperintense areas with linear-patchy enhancements, a pattern consistent with SLIPPERS syndrome. Consequently, patient was diagnosed with SLIPPERS syndrome and received methylprednisolone therapy.

Conclusion

Both SLIPPERS and CLIPPERS are complicated syndromes posing diagnostic challenges and requiring careful investigation to avoid misdiagnosis. Following a thorough differential diagnosis, appropriate treatment can be initiated, and follow-up is required.

Clinical and neuroimaging phenotypes of autoimmune glial fibrillary acidic protein astrocytopathy: A systematic review and meta-analysis

OBJECTIVE

This study was undertaken to provide a comprehensive review of neuroimaging characteristics and corresponding clinical phenotypes of autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A), a rare but severe neuroinflammatory disorder, to facilitate early diagnosis and appropriate treatment.

METHODS

A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis)-conforming systematic review and meta-analysis was performed on all available data from January 2016 to June 2023. Clinical and neuroimaging phenotypes were extracted for both adult and paediatric forms.

RESULTS

A total of 93 studies with 681 cases (55% males; median age = 46, range = 1-103 years) were included. Of these, 13 studies with a total of 535 cases were eligible for the meta-analysis. Clinically, GFAP-A was often preceded by a viral prodromal state (45% of cases) and manifested as meningitis, encephalitis, and/or myelitis. The most common symptoms were headache, fever, and movement disturbances. Coexisting autoantibodies (45%) and neoplasms (18%) were relatively frequent. Corticosteroid treatment resulted in partial/complete remission in a majority of cases (83%). Neuroimaging often revealed T2/fluid-attenuated inversion recovery (FLAIR) hyperintensities (74%) as well as perivascular (45%) and/or leptomeningeal (30%) enhancement. Spinal cord abnormalities were also frequent (49%), most commonly manifesting as longitudinally extensive myelitis. There were 88 paediatric cases; they had less prominent neuroimaging findings with lower frequencies of both T2/FLAIR hyperintensities (38%) and contrast enhancement (19%).

CONCLUSIONS

This systematic review and meta-analysis provide high-level evidence for clinical and imaging phenotypes of GFAP-A, which will benefit the identification and clinical workup of suspected cases. Differential diagnostic cues to distinguish GFAP-A from common clinical and imaging mimics are provided as well as suitable magnetic resonance imaging protocol recommendations.