Reversible and unilateral corticospinal tract disease secondary to autoimmune free-T3-thyrotoxicosis

68-year-old female patient with no significant medical history presents with a 3-month history of progressive neurological symptoms, which began with left eye ptosis, blurred vision and non-painful jaw discomfort, followed by left spastic weakness and hyper-reflexia with positive Babinski and Hoffman signs. An elevated T3 level, a positive peroxidase and an antigraves antibody level led to an ultrasound, which confirmed a sub acute-chronic autoimmune thyroiditis. A nerve conduction studies/electromyogram showed normal motor and sensory velocity conduction with a small amplitude compound motor action potential, indicative of likely axonal damage. Following treatment with carbimazole, the neurological symptoms greatly improved. The authors concluded that the left pyramidal syndrome was secondary to autoimmune free T3-thyrotoxicosis.