Indium-Gallium-Zinc Oxide-Based Synaptic Charge Trap Flash for Spiking Neural Network-Restricted Boltzmann Machine.

Recently, neuromorphic computing has been proposed to overcome the drawbacks of the current von Neumann computing architecture. Especially, spiking neural network (SNN) has received significant attention due to its ability to mimic the spike-driven behavior of biological neurons and synapses, potentially leading to low-power consumption and other advantages. In this work, we designed the indium-gallium-zinc oxide (IGZO) channel charge-trap flash (CTF) synaptic device based on a HfO2/Al2O3/Si3N4/Al2O3 layer. Our IGZO-based CTF device exhibits synaptic functions with 128 levels of synaptic weight states and spike-timing-dependent plasticity. The SNN-restricted Boltzmann machine was used to simulate the fabricated CTF device to evaluate the efficiency for the SNN system, achieving the high pattern-recognition accuracy of 83.9%. We believe that our results show the suitability of the fabricated IGZO CTF device as a synaptic device for neuromorphic computing.

Intraosseous cavernous angioma of the petrous bone.

OBJECTIVE: Intraosseous cavernous angioma (CA) of the petrous bone is rare and preoperative diagnosis can be challenging, especially when its epicenter is outside the internal auditory canal (IAC) or geniculate ganglion. METHODS: A 45-year-old man presented to our clinic with right-sided hearing loss, tinnitus, and unsteadiness. Neuroimaging revealed a right posterior petrous mass. Aggressive subtotal resection with decompression of the IAC was achieved through a right suboccipital craniotomy. Histopathological findings were consistent with CA. CONCLUSION: As was the case with this patient, we believe that CA should be included in the differential diagnosis of petrous region pathology with bony involvement. Surgery is warranted due to its expansive nature and to decompress the adjacent neural structures.

Craniovertebral junction tuberculosis with atlantoaxial dislocation : a case report and review of the literature.

Craniovertebral junction (CVJ) tuberculosis is a rare disease, potentially causing severe instability and neurological deficits. The authors present a case of CVJ tuberculosis with atlantoaxial dislocation and retropharyngeal abscess in a 28-year-old man with neck pain and quadriparesis. Radiological evaluations showed a widespread extradural lesion around the clivus, C1, and C2. Two stage operations with transoral decompression and posterior occipitocervical fusion were performed. The pathological findings confirmed the diagnosis of tuberculosis. Treatment options in CVJ tuberculosis are controversial without well-defined guidelines. But radical operation (anterior decompression and posterior fusion and fixation) is necessary in patient with neurological deficit due to cord compression, extensive bone destruction, and instability or dislocation. The diagnosis and treatment options are discussed.

Pleomorphic xanthoastrocytoma with an intracystic hemorrhage : a case report and literature review.

Pleomorphic xanthoastrocytoma (PXA) has been considered as a low grade tumor of adolescents and young adults. Although this tumor often shows cystic component, the hemorrhage within the cyst is extremely rare. The authors report a rare case of cystic PXA with a hemorrhage within the cyst and the mural nodule in the left frontal lobe. A 64-year-old male presented with a week history of the right side hemiparesis. After gross total resection of the tumor, the patient was fully recovered from neurological deficit. It is suggested that this typically benign tumor could be presented with hemorrhage, causing a rapid neurological deterioration. Prompt surgical intervention, especially total removal of the tumor can provide an excellent functional recovery.

Major depression with psychosis after resection of a giant middle fossa hemangiopericytoma.

BACKGROUND: Postoperative onset of acute major depression in a patient with no previous history of psychiatric disorder is highly unexpected after skull base surgery. CASE DESCRIPTION: A 38-year-old woman with no previous physical or mental illness presented with a 3-month history of left ear pain, short-term memory disturbance, and motor dysphasia. Magnetic resonance imaging revealed a large extraaxial tumor in the left middle fossa. Left temporal craniotomy was performed, achieving complete tumor resection. The patient showed signs of confusion, disorientation, and severe depression 3 days after the surgery. She developed insomnia and auditory hallucinations along with expressed suicidal ideation, then deteriorated rapidly, necessitating a transfer to a psychiatric unit. In spite of the intensive treatment with antidepressive and antipsychotic medications, she continued to have prolonged psychotic symptoms and depression for several months after surgery. CONCLUSION: Although the incidence is rare, psychiatric complications should be anticipated in patients undergoing resection of a large skull base tumor affecting the temporal lobe. The exact mechanism in this process is not clear; however, it is important to clinically differentiate treatable etiologies such as steroid-induced psychosis and postoperative delirium.

Spinal cord hemangioblastoma: surgical strategy and clinical outcome.

BACKGROUND AND AIM: The authors present a retrospective analysis of 14 patients treated for spinal cord hemangioblastoma (SCH). This study was conducted to evaluate and compare the difference of functional outcomes associated with the extent of surgical removal of the tumor. METHODS: Eleven patients were male and three were female, with a mean age of 37.2 years (19-62 years). Pre- and postoperative magnetic resonance imaging was performed in all cases. Preoperative angiography was performed in 11 cases and preoperative embolization in four. The follow-up period ranged from 15 to 161 months (median, 47 months). RESULTS: Thirteen patients had intramedullary tumor, and the remaining one had an extradural lesion. All patients underwent surgical removal, and total removal (TR) was achieved in 10 cases. In four patients with preoperative embolization, intraoperative bleeding was minimal and TR was possible. In three of four patients without TR, their functional outcomes were aggravated postoperatively. At the last follow-up (15-161 months), eight patients were improved, three were stationary, and three deteriorated. All patients who showed improvements underwent TR. The statistical analysis showed that TR produced a significantly better outcome than incomplete removal (p = 0.015). CONCLUSION: TR resulted in a better outcome for SCH. Preoperative embolization could be effective in the reduction of intraoperative bleeding and facilitate TR with an improved surgical outcome.