Department of Clinical Chemistry, Royal Cornwall Hospital, Truro, Cornwall, UK.
Ann Clin Biochem. 2011 Jul;48(Pt 4):383-5. doi: 10.1258/acb.2011.010282. Epub 2011 Apr 27.
A 50-year-old man presented with a four-year history of unsteadiness, with recent falls and tingling in his fingers. Neurological examination found an ataxic gait, with a positive Romberg's sign. There was distal wasting and weakness in all four limbs and impaired co-ordination, with pseudoathetosis in the arms. Initial investigations showed a normochromic, normocytic anaemia, leucopenia, neutropenia and a low vitamin B(12) (172 ng/L). Treatment with intramuscular cobalamin injections showed no clinical improvement. Further investigations showed an undetectable caeruloplasmin (<0.085 g/L), a very low serum copper (1.1 μmol/L) and a markedly raised serum zinc concentration (36.2 μmol/L). On detailed questioning it became apparent that he had ill-fitting dentures requiring excessive use of denture fixative with high zinc content. The patient was switched to a non-zinc containing denture fixative and commenced copper supplementation. Although within three months the bone marrow suppression had resolved, there was no clinical improvement in neurological presentation. Questioning a patient about their denture fixative usage and checking if zinc is an ingredient may be considered during an investigation for myelopolyneuropathy when vitamin B(12) deficiency is not a cause.
一位 50 岁男性，诉四年不稳定性病史，近期有跌倒和手指刺痛。神经系统检查发现共济失调步态，Romberg 征阳性。四肢远端有消瘦和无力，协调受损，手臂有假性手足徐动症。初步检查显示正细胞正色素性贫血、白细胞减少、中性粒细胞减少和维生素 B(12)水平低（172ng/L）。肌内注射钴胺素治疗无临床改善。进一步检查显示铜蓝蛋白极低（<0.085g/L）、血清铜极低（1.1μmol/L）和血清锌浓度明显升高（36.2μmol/L）。详细询问后发现，他的义齿不合适，需要大量使用含高锌的义齿固定剂。患者改用不含锌的义齿固定剂，并开始补充铜。尽管三个月内骨髓抑制得到缓解，但神经系统表现仍无临床改善。当维生素 B(12)缺乏不是病因时，在对多发性神经病进行检查时，可能会考虑询问患者关于义齿固定剂使用情况，并检查锌是否为成分之一。
