[A case of hypokalemic myopathy mimicking hemiparesis].

We report the case of an 86-year-old female with licorice-induced hypokalemic myopathy. For four years, she had been taking two kinds of Chinese medicines containing licorice. The patient presented with difficulty in holding her head up and proximal-dominant tetraparesis with significant laterality. In manual muscle tests, the right extremities showed grade 2/5 and the left extremities, grade 4/5. The general reflexes were decreased, and the bilateral Chaddock's reflexes were repeatedly positive. The sensory, cerebellar and autonomic systems were normal and discrete movements of all extremities were well preserved. Laboratory tests showed elevated levels of CK (559 IU/1), hypokalemia (1.6 mEq/1), and metabolic alkalosis (pH 7.51, base excess 10.9 mmol/1). Magnetic resonance imaging showed mild compression of the spinal cord due to cervical spondylosis. Electromyography revealed myopathic patterns in the deltoid muscle. Steady clinical recovery was noted following treatment including cessation of licorice intake and administration of potassium supplementation. Neck weakness, tetraparesis with laterality and Chaddock's reflexes were diminished. We conclude that the pathologic reflex was caused by the aggravation of cervical spondylotic myelopathy due to neck weakness and that tetraparesis with laterality was caused by hypokalemic myopathy.