F-18 FDG PET Findings for Vogt-Koyanagi-Harada Disease

Abstract

Vogt-Koyanagi-Harada disease is a rare multisystemic granulomatous autoimmune disorder affecting pigmented tissues such as the choroid, meninges, inner ear, and the skin. Neurologic symptoms are usually mild. Clinical manifestations include generalized muscle weakness, headache, meningismus, vertigo, decreased visual acuity, hearing loss and mental changes ranging from mild confusion to psychosis, hemiparesis, dysarthria, and aphasia. Seizures are very rare. We describe a case of ¹⁸F-fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET) and software-fused PET-magnetic resonance imaging (MRI) in Vogt-Koyanagi-Harada disease with seizure.

Fig. 1.

A 47-year-old man visited the neurology clinic, presenting with three episodes of generalized tonic-clonic seizures. Cerebrospinal fluid study for evaluation of meningitis was normal. On brain diffusion magnetic resonance imaging (MRI) for excluding central nervous system infection and metabolic encephalitis, there were multifocal sulcal high signal intensity (SI) suggestive of meningitis or leptomeningeal metastasis (a, b). To exclude primary malignancy, ¹⁸F-fluorodeoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) was performed from the vertex to thigh. There were multifocal FDG uptake areas along the cerebral sulci. Software-fused PET-MRI images (c, d) and PET images (e, f) show focal FDG uptake in corresponding sulcal high SI areas on MRI. The patient also complained of redness of bilateral eyes (anterior uveitis and optic disc swelling), hearing loss and alopecia from 6 months ago. The abovementioned symptoms fulfilled the diagnostic criteria for Vogt-Koyanagi-Harada (VKH) disease. The patient underwent steroid pulse therapy and his symptoms improved gradually. One month follow-up MRI images showed regressed sulcal high SI. VKH disease can be categorized into three levels, on the basis of clinical examination. The complete disease is bilateral ocular involvement with neurologic/auditory findings and integumentary finding. Incomplete disease is bilateral ocular involvement with either neurologic/auditory findings or integumentary finding. Probable disease is isolated ocular disease [1]. The pathophysiology of VKH disease has not yet been elucidated, although T cell-mediated autoimmune disorder against self-antigens in melanocytes is strongly suggested [2]. Neurologic symptoms in VKH disease are variable, but usually mild. Headache, muscle weakness, meningismus, vertigo, hearing loss, and mental changes can be noted, while seizures are very rare [3]. The focal FDG uptake in leptomeninges may be related to granulomatous change against leptomeningeal melanin-containing cells. MRI findings of VKH disease with neurologic symptoms were reported. Most cases showed pachymeningeal or leptomeningeal enhancement and thickening [4–6]. Some showed parenchymal involvement and hyperintense lesions in periventricular white matter [7]. To the best of our knowledge, this is the first case in the literature of brain involvement from VKH disease demonstrated on F-18 FDG PET and software-fused PET-MRI

Compliance with Ethical Standards

Conflicts of Interest

The authors Hye Lim Park, Ie Ryung Yoo, and Sonya Youngju Park declare that they have no conflict of interest.

Ethical Statement

This study was performed in accordance with the regulations of our hospital’s Institutional Review Board, which approved the retrospective design and waived the requirement for informed consent. All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation and with the Helsinki Declaration of 1975, as revised in 2000.