Dyspnoea due to spinal subarachnoid-pleural fistula.

We report a case of a 72-year-old woman who underwent transthoracic discectomy for a giant disc herniation at T9-T10 level causing significant cord compromise. Following removal of her non-suction chest drain, she was transferred to the acute spinal-orthogeriatric unit where she was under regular review by elderly care physicians as part of their spinal liaison role. Approximately four weeks after the operation, she started becoming dyspnoeic and her chest X-ray showed moderate left-sided pleural effusion which tested positive for ß2-transferrin, a sensitive marker of cerebrospinal fluid, supporting a diagnosis of subarachnoid-pleural fistula. This is a very unusual cause of breathlessness in a postoperative patient.

Dysphagia due to necrotizing otitis externa.

An 88-year-old man presented with delirium, and subsequently developed hoarseness and oropharyngeal dysphagia. This was due to skull-based osteomyelitis from necrotizing otitis externa (NOE), causing lower cranial nerve (X, XII) palsies and venous sinus thrombosis. Diagnosis was delayed as the patient reported no otalgia, had an almost normal looking external auditory canal and was not diabetic. He deteriorated and died despite intravenous antibiotics. We need a high index of suspicion for NOE and its complications in patients presenting with otolaryngeal symptoms.

Uncommon cause of chest pain in a postoperative spinal patient.

An 84-year-old woman with previous spinal operations including vertebroplasty and lumbar decompressions was admitted electively under the spinal team for right-sided L4/5 decompression for worsening back pain which she undergoes using a posterior approach. Postoperatively, she develops stabbing upper central chest pain and given unremarkable chest X-ray, ECG and cardiac troponin, she undergoes a CT pulmonary angiogram which shows a fracture of the upper part of sternum but no pulmonary embolism. There is no history of recent trauma and this is deemed to be secondary to prolonged spinal surgery in the prone position in a patient with osteopenic bones. To date, we have not come across a case of spontaneous sternal fracture as a complication of spinal surgery at our regional spinal unit. Most cases of sternal fractures are secondary to blunt anterior chest wall trauma with spontaneous fractures and stress fractures being rare.

Novel synchronization technique for two parallel connected sparkgap switches.

In this article a novel way of synchronizing two parallel connected sparkgap switches with accuracies of 1-5 ns for high frequency pulsed power applications is described. The circuit design of a synchronized sparkgap switch circuit is discussed. The circuit uses a combination of one master sparkgap and a set of inductor and capacitors to synchronize two sparkgaps and can be controlled via an IGBT switch. Critical issues for circuit design are presented together with analytical calculations and simulations. Experimental verification of the novel topology is carried out in a prototype experimental setup. Results showing nanosecond level of accuracy in synchronization are reported in this paper along with simulations and analysis.