Objective: Low-level somatic mosaicism in the brain has been shown to be a major genetic cause of intractable focal epilepsy. However, how a relatively few mutation-carrying neurons are able to induce epileptogenesis at the local network level remains poorly understood. Methods: To probe the origin of epileptogenesis, we measured the excitability of neurons with MTOR mutation and nearby nonmutated neurons recorded by whole-cell patch-clamp and array-based electrodes comparing the topographic distribution of mutation. Computational simulation is used to understand neural network-level changes based on electrophysiological properties. To examine the underlying mechanism, we measured inhibitory and excitatory synaptic inputs in mutated neurons and nearby neurons by electrophysiological and histological methods using the mouse model and postoperative human brain tissue for cortical dysplasia. To explain non-cell-autonomous hyperexcitability, an inhibitor of adenosine kinase was injected into mice to enhance adenosine signaling and to mitigate hyperactivity of nearby nonmutated neurons. Results: We generated mice with a low-level somatic mutation in MTOR presenting spontaneous seizures. The seizuretriggering hyperexcitability originated from nonmutated neurons near mutation-carrying neurons, which proved to be less excitable than nonmutated neurons. Interestingly, the net balance between excitatory and inhibitory synaptic inputs onto mutated neurons remained unchanged. Additionally, we found that inhibition of adenosine kinase, which affects adenosine metabolism and neuronal excitability, reduced the hyperexcitability of nonmutated neurons. Interpretation: This study shows that neurons carrying somatic mutations in MTOR lead to focal epileptogenesis via non-cell-autonomous hyperexcitability of nearby nonmutated neurons.

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Malnutrition associated vitamin D deficiency contributes to the calcium loss from bone and results in osteoporosis and osteomalacia at final stage. Osteomalacia is characterized with softening of bone secondary to defective bone mineralization. Here, we report a case of possible osteomalacia caused by prolonged lactation and severe malnutrition in 35-year-old female. She was a housewife and her body mass index was 11.8 kg/m2. She was diagnosed with severe osteoporosis in regular health check-up 2 years ago, but did not take any medication. Nine months ago, she had been treated with anti-tuberculosis medications for 6 month due to active pulmonary tuberculosis. After complete remission of pulmonary tuberculosis, she had lost her appetite severely. Furthermore, she felt gait difficulty and suffered from generalized bone pain. On serologic examination, hypocalcemia, hypophosphatemia, high alkaline phosphatase, low vitamin D3 and high parathyroid hormone level were seen. In the bone mineral density, Z-score from her lumbar spine was -6.5. She was treated with oral calcium and vitamin D3 intramuscularly. After 1 year treatment, she felt significant improvement in bone pain and could walk alone. Also her serum calcium, phosphate and vitamin D3 level are all normalized.

Isolated hypogonadotropic hypogonadism (IHH) is known to decrease bone mineral density due to deficiency of sex steroid hormone. Graves' disease is also an important cause of secondary osteoporosis. However, IHH does not preclude the development of primary hyperthyroidism caused by Graves' disease, leading to more severe osteoporosis rapidly. Here, we describe the first case of 35-year-old Asian female patient with IHH accompanied by Graves' disease and osteoporosis-induced multiple fractures. Endocrine laboratory findings revealed preserved anterior pituitary functions except for secretion of gonadotropins and showed primary hyperthyroidism with positive autoantibodies. Sella magnetic resonance imaging showed slightly small sized pituitary gland without mass lesion. Dual energy X-ray absorptiometry revealed severe osteoporosis in lumbar spine and femur neck of the patient. Plain film radiography of the pelvis and shoulder revealed a displaced and nondisplaced fracture, respectively. After surgical fixation with screws for the femoral fracture, the patient was treated with antithyroid medication, calcium, and vitamin D until now and has been recovering fairly well. We report a patient of IHH with Graves' disease and multiple fractures that is a first case in Korea.