Objective: Oculopharyngodistal myopathy (OPDM) has been reported as a rare, adult-onset hereditary muscle disease. Patients show progressive oculopharyngeal and distal limb muscle involvement. As the genetic defect underlying OPDM is not known yet, the diagnosis currently rests upon clinical and histopathological features. This study was aimed at investigating patterns of muscle alterations of OPDM patients by MRI and to search for possible clues to make differential diagnosis by using a non-invasive method. Ma te ri als and Met hods: Facial, upper and lower extremity muscles of 10 patients with OPDM, followed by the Neuromuscular Unit, Department of Neurology, Istanbul Faculty of Medicine, who had undergone detailed evaluation with manual muscle testing and who had different disease severity were evaluated with MRI using conventional T1 and T2 weighted axial images. The degree of muscle involvement on MRI was evaluated according to a modified 5-point scale in extremities and 6-point scale in facial muscles. Re sults: The mean age of onset was 20.1±8.2 years (range 7-39 years) and the mean disease duration was 14.5±12.4 years (range 2-41 years). Seven patients showed dominantly distal, one patient dominantly proximal weakness and two patients had no weakness. The patients without weakness had normal imaging, but facial muscle MRI from one of them revealed mild involvement. Zygomatic and nasal muscles were the most severely and earliest involved muscles in face. MRI of all patients with muscle weakness showed a consistent selective extremity muscle involvement pattern. Distal extremity muscles were more affected than proximal muscles. Earliest and most sever changes were found in semimembranosus, biceps femoris and medial head of gastrocnemius, soleus. Interestingly, sartorius, gracilis and semitendinous muscles and the lateral head of gastrocnemius were well-preserved in OPDM. Conclusion: Muscle MRI by showing selective involvement of exteremity muscle may be a non-invasive tool in the differential diagnosis of OPDM. (Turkish Journal of Neurology 2014; 20:121-125) Amaç: Okülofaringodistal miyopati (OFDM) erişkin başlangıçlı, nadir, kalıtsal bir kas hastalığıdır. Hastalarda yavaş ilerleyici okülofaringeal tutulum ve distal kaslarda zaaf gözlenir. Altta yatan genetik defektin henüz bilinmemesi nedeniyle OFDM'de tanı günümüzde klinik ve histopatolojik özelliklere dayanmaktadır. Bu çalışmada, OFDM'li hastalarda noninvazif bir yöntem olan manyetik rezonans görüntüleme (MRG) ile kaslardaki değişiklikleri araştırmak ve ayrıcı tanı ipuçları sağlamak amaçlanmıştır. Ge reç ve Yön tem: İstanbul Üniversitesi İstanbul Tıp Fakültesi, Nöroloji Ana Bilim Dalı, Nöromüsküler Hastalıklar Polikliniğinden takipli, farklı hastalık şiddet ve süresine sahip, ayrıntılı nörolojik muayene yapılmış olan 10 OFDM'li hastanın yüz kasları ile üst ve alt ekstremite kasları konvansiyonel T1 ve T2 ağırlıklı aksiyel kesitler alınarak görüntülenmiştir. Yağlı dejenerasyon miktarı göz önünde tutularak ekstremite kaslarına ait olan görüntüler 5, yüz ka...