Hiromatsu K, Kobayashi T, Fujii N, Itoyama Y, Goto I, Murakami J
Department of Neurology, Faculty of Medicine, Kyushu University 60, Fukuoka, Japan.
J Neurol Sci. 1994 Apr;122(2):144-7. doi: 10.1016/0022-510x(94)90291-7.
We describe a 21-year-old man presenting with proximal muscle weakness associated with hypernatremia. His manifestations other than muscle weakness included dry skin, loss of axillary and pubic hair, decreased libido and loss of thirst sensation. His serum sodium level was elevated to 169-171 mEq./l but all other electrolytes were normal. In addition, serum CK was elevated and an EMG study showed myogenic changes. Endocrinological studies revealed hypothalamic hypopituitarism, while MRI revealed a suprasellar mass. A partial correction of hypernatremia led to an immediate recovery of the muscle weakness as well as a normalization of both the serum CK level and EMG findings, suggesting a direct association between the muscle weakness and hypernatremia. The phosphocreatine/inorganic phosphorus (PCr/Pi) ratios in the resting calf muscle, obtained using 31P magnetic resonance spectroscopy (MRS), were very low during the state of muscle weakness, while they returned to nearly normal values after clinical improvement, suggesting that the muscle weakness in hypernatremic state was caused by a depletion of the intramuscular energy stores, probably due to an overworking Na-K pump to correct the intracellular electrolyte imbalance.
我们描述了一名21岁男性，他出现近端肌无力并伴有高钠血症。除肌无力外，他的表现还包括皮肤干燥、腋毛和阴毛脱落、性欲减退以及口渴感丧失。他的血清钠水平升高至169 - 171 mEq./l，但其他所有电解质均正常。此外，血清肌酸激酶（CK）升高，肌电图（EMG）检查显示有肌源性改变。内分泌学研究揭示为下丘脑性垂体功能减退，而磁共振成像（MRI）显示鞍上有肿块。高钠血症的部分纠正导致肌无力立即恢复，血清CK水平和EMG结果也恢复正常，这表明肌无力与高钠血症之间存在直接关联。使用磷-31磁共振波谱（MRS）测得的静息小腿肌肉中的磷酸肌酸/无机磷（PCr/Pi）比值在肌无力状态下非常低，而在临床改善后恢复到接近正常的值，这表明高钠血症状态下的肌无力是由肌肉内能量储备耗竭引起的，可能是由于钠钾泵过度工作以纠正细胞内电解质失衡所致。
