Andersen-Tawil syndrome (ATS) is a rare familial potassium channelopathy characterized by the clinical triad of periodic paralysis, cardiac arrhythmia and dysmorphic facial/skeletal features. The majority of ATS patients are caused by mutations of the KCNJ2 gene, which encodes the inward-rectifying potassium channel protein Kir2.1. However, the effects of the KCNJ2 mutation on the central nervous system are rarely studied. In this report, we describe a heterozygous missense mutation (p.Thr192Ile) in the KCNJ2 gene, which segregates with the disease phenotype in an ATS family. It is noted that in addition to the classical clinical phenotypes of ATS, the index patient exhibited major depression and pyramidal tract signs with diffuse periventricular white matter lesions without contrast enhancement. This mutation and the unusual clinical manifestations observed underscore the phenotypic complexity underlying ATS. Our observations expand the current knowledge of the phenotypic variability of ATS caused by the KCNJ2 mutation. Patients with ATS, especially those carrying the KCNJ2 mutations, should be monitored for their potential neuropsychiatric system involvement.

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In this report, we describe a case of pyrrolizidine alkaloid-related Budd-Chiari syndrome in Hong Kong. A 10-month-old boy presented with ascites, right pleural effusion, and hepatomegaly after consumption of herbal drinks for 3 months. His clinical (including imaging) features were compatible with Budd-Chiari syndrome. Budd-Chiari syndrome is a rare disease entity in paediatric patients. In our case, extensive workup performed to look for the underlying cause of Budd-Chiari syndrome was unrevealing, except for toxic pyrrolizidine alkaloid exposure in his herbal drinks.

Madelung's disease (multiple symmetric lipomatosis) is a rare disease characterized by abnormal diffuse lipomatosis in proximal upper limbs and neck. Previous reports have shown that this disease is associated with alcoholism, polyneuropathy, mitochondrial disease, and glucose intolerance. Here, we describe a 46-year-old man having Madelung's disease associated with polyneuropathy and symptomatic hypokalemia. He presented with insidious-onset weakness and numbness in lower limbs for 7 years and recent deterioration of symptoms. Proximal weakness improved with potassium supplement. Our observation may extend the phenotype of Madelung's disease to hypokalemic periodic paralysis.

Background: Bilateral high-grade internal carotid artery (ICA) stenosis is critical for brain perfusion, and mechanisms of cerebral infarct induced by bilateral high-grade ICA stenosis can be investigated by the infarct patterns on diffusion-weighted imaging (DWI). Methods: From January 2006 to October 2010, we retrospectively enrolled 21 acute infarct patients with bilateral high-grade ICA stenosis. The infarct patterns were divided into territory, cortical border-zone and internal border-zone by DWI. Results: The milder ICA stenosis side had a lower risk of ischemic stroke (4 of 20). None of the 8 patients with bilateral severe ICA stenosis (70–99%) suffered ischemic stroke ipsilateral to the milder ICA stenosis side. No single infarct mechanism was prominent: 10 of 21 infarcts were cortical border-zone pattern, followed by internal border-zone (7 of 21) and territory. The difference in frequency of bilateral severe ICA stenosis between the three infarct mechanisms was not significant (p = 0.856). Conclusions: Cerebral infarcts occurred less frequently in the ipsilateral to milder ICA stenosis side, especially in bilateral severe ICA stenosis. The similar frequencies and hemodynamic status between the three infarct pattern groups indicated that both artery-to-artery emboli and being hemodynamically compromised contribute synergistically to bilateral ICA stenosis.