Clinicopathological variability in neurodegeneration with brain iron accumulation

Abstract

Neurodegeneration with brain iron accumulation (NBIA) is a rare, progressive neurodegenerative disorder with extrapyramidal and cognitive clinical symptoms characterized by iron accumulation predominantly in the globus pallidus, cs well as extensive axonal spheroids in various regions of the brain. Recent studies indicate multiple genetic causes, however the illness can occur without obvious genetic background. The most frequent genetic form is the pantothene kinase associated neurodegeneration (PKAN) with mutation in the pantothenate kinase 2 (PANK2) gene. Further forms include phosphoslipase A2 (PLA2G6) gene mutation, neuroferritinopathy, and aceruloplasminaemia. To demonstrate the phenotypic variability associated with NBIA we present two patients. In the first patient iron deposition in the globus pallidus and axonal spheroids throughout the whole brain confirmed the neuropathological diagnosis of NBIA. Based on the long duration (27 years), the relatively late onset (at age of 13) of the disease, and the symmetrical hypointensity in the globus pallidus, without the eye-of-the-tiger sign in cranial MRI, this case most likely represented an idiopathic form of NBIA but atypical PKAN may be also considered. In our second patient, who is still alive after duration of 9 years, MRI revealed the typical eye-of-the-tiger phenomenon that supported the clinical diagnosis of NBIA and wcs highly suggestive of PKAN. Since NBIA shows similarities with other neurodegenerative disorders, genetic examination may be essential in the diagnosis of this disease, however, cranial MRI together with the clinical picture may be highly indicative of NBIA.