[Optimal dose of levodopa-carbidopa intestinal gel in the treatment of diphasic dyskinesia and freezing of gait].

A 58-year-old man who was diagnosed with Parkinson's disease (PD) at age 46 developed levodopa-induced motor complications seven years after diagnosis, along with dyskinesia. Treatment with levodopa-carbidopa intestinal gel (LCIG) was introduced at age 57. His dyskinesia and freezing of gait (FOG) worsened after the introduction of LCIG. Considering the pathophysiological mechanism of diphasic dyskinesia, the dose of levodopa was increased since it was considered necessary to exceed the upper threshold of diphasic dyskinesia. As a result, dyskinesia and FOG became severe and he was admitted to our hospital. After reducing the levodopa equivalent dose to control the dyskinesia to an almost negligible level, his FOG also improved and his activities of daily living improved markedly. This case highlights the difficulty in treating dyskinesia and FOG in advanced-stage PD patients with a narrow therapeutic window.

[A Case of Immune-Mediated Necrotizing Myopathy Associated with Primary Sjögren Syndrome].

A 66-year-old woman visited our hospital complaining of shortness of breath during exertion and progressive weakness in all her limb muscles. On admission, we noted muscle weakness in her trunk and in her proximal limb muscles, although, her muscle MRI showed no remarkable findings. However, her serum CK level (2,747U/L) was above the normal range. Histopathological examination of muscle biopsy, performed from the left biceps brachii muscle, revealed immune-mediated necrotizing myopathy (IMNM). Her serum samples were negative for myositis-associated autoantibodies (MAAs), anti-SRP, and HMGCR antibodies. However, as the anti-SS-A antibody level in her serum was high (53.2U/mL), we conducted the salivary gland biopsy and the Schirmer test on her eyes. We found lymphocytes infiltration in her salivary gland tissue, and thus, she was diagnosed with primary Sjögren syndrome (SjS). We also observed necrotizing myopathy associated with the SjS. Following her treatment with oral steroids, her symptoms and CK level improved. Although, inflammatory myositis frequently occurs in association with general collagen diseases, necrotizing myopathy has rarely been observed secondary to SjS. We report here this rare case study along with the review of the relevant literature. (Received June 24, 2020; Accepted October 12, 2020; Published February 1, 2021).