Abstract
A 47-year-old man with a 15-year history of bipolar disorder treated with anti-depressants, lithium carbonate or neuroleptics was admitted because of marked difficulty in gait and speech. At the age 45, he was unable to walk without bilateral assists and became a wheel-chair state. There was no family history and his mother, father and younger sister were neurologically free.
General physical examinations revealed no abnormalities. Neurologically, he was moderately demented (mini mental state examination: 18/30) and showed bilateral horizontal gaze nystagmus, parkinsonism, cerebellar ataxia, dysarthria and moderate spastic paraparesis. No involuntary movements were noted. Wet blood smear showed acanthocytes, while blood chemistries revealed no abnormalities including levels of serum creatine kinase, hepatic enzymes and blood beta-lipoprotein. Kell antigen expressions of the red blood cells were within normal limit. Western blot analysis with anti-chorein antibody detected normal chorein expression levels of the red blood cells. Cranial MRI showed severe symmetric atrophy of the frontotemporal lobes, caudate nuclei, putamen, and brainstem. Also, MRI-gradient echo showed symmetric iron accumulation in the medial portion of the globus pallidus without surrounding high intensity areas, so called "eye-of-the-tiger sign". Genetic analyses revealed no mutations in the PANK2 and PLA2G6 genes. Therefore, he was diagnosed as idiopathic neurodegeneration with brain iron accumulation (NBIA). These findings suggest that NBIA is heterogeneous and other additional genes remain to be found.
