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Alien hand syndrome is a rare neurological condition in which a person's hand makes purposeful-looking movements that they do not feel they started. It can appear when a stroke, tumour, surgery or disease damages the corpus callosum, the bridge between the brain's two halves, or the areas that plan movement.

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The German neurologist Kurt Goldstein described the first case in 1908: after a stroke, a woman's left hand behaved as if it belonged to someone else. The condition became better known through people whose corpus callosum had been cut to control severe epilepsy. In a typical scene, one hand buttons a shirt while the other undoes the buttons, or a hand grips an object and will not let go. The affected hand still feels touch, so the problem is not paralysis: what breaks is the link between the brain circuits that plan and make movements and those that give us the feeling 'I am doing this'. It is sometimes nicknamed Dr Strangelove syndrome, after the character in Stanley Kubrick's 1964 film whose gloved hand acts on its own.

Türkçe oku
Yabancı el sendromu nadir görülen bir nörolojik rahatsızlıktır: kişinin eli amaçlı gibi görünen hareketler yapar, ama kişi bu hareketleri kendisinin başlattığını hissetmez. Beynin iki yarısını birbirine bağlayan korpus kallozum ya da hareketi planlayan bölgeler felç, tümör, ameliyat veya bir hastalık yüzünden zarar gördüğünde ortaya çıkabilir.

İlk vakayı 1908'de Alman nörolog Kurt Goldstein tanımladı: felç geçiren bir kadının sol eli, sanki başka birine aitmiş gibi davranıyordu. Durum, ağır epilepsiyi denetim altına almak için korpus kallozumu kesilen hastalar sayesinde daha iyi tanındı. Tipik bir örnekte bir el gömleğin düğmelerini iliklerken öbür el onları çözer ya da el bir nesneyi kavrar ve bırakmaz. Etkilenen el dokunmayı hissetmeye devam eder, yani sorun felç değildir. Bozulan şey, hareketi planlayıp yapan beyin devreleriyle bize “bunu ben yapıyorum” duygusunu veren devreler arasındaki bağdır. Sendrom, Stanley Kubrick'in 1964 tarihli filminde eldivenli eli kendi kendine hareket eden karaktere atfen bazen “Dr. Strangelove sendromu” diye de anılır.

Sources and further reading

Background reading: Alien hand syndrome
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