Akihiro Oikawa

Phrenic nerve stimulation for diaphragm pacing with a spinal cord stimulator: Technical note

BACKGROUND Diaphragm pacing with electrical stimulation of the phrenic nerve is an established treatment for central hypoventilation syndrome. The device, however, is not readily available, at least in Japan. We used the spinal cord stimulator for pain control for phrenic nerve stimulation. The purpose of this study is to evaluate the efficacy and feasibility of phrenic pacing with the compromise method. METHODS We implanted a stimulator for spinal cord stimulation (Itrel 3 or X-trel, Medtronic, MN) in 4 patients with chronic hypoventilation because of brainstem dysfunction of various origins. The stimulation electrode was placed along the right phrenic nerve in the neck, and the device was implanted in the anterior chest. We used the cyclic mode, and set the parameters at 1 second ramp up, 2 seconds on, 3 seconds off. The pulse width and the frequency were set at 150 microsec and 21 Hz, respectively. The amplitude of the output was adjusted to obtain sufficient tidal volume and to maintain PaCO(2) at around 40 mm Hg. RESULTS During the follow-up period from 6 to 19 months (mean 8.3 months), stable and sufficient ventilation were observed in all patients without complications. One patient with sleep apnea syndrome used the device only at night and became free from a respirator. Three patients who were completely respirator-dependent became ambulatory during the daytime. CONCLUSION Though longer follow-up is necessary, diaphragm pacing by stimulation of the phrenic nerve with the spinal cord stimulator is feasible for a treatment of central hypoventilation syndrome.

Acute epidural hematoma developing during twist-drill craniostomy: a complication of percutaneous subdural tapping for the treatment of chronic subdural hematoma

BACKGROUND This case illustrates that although percutaneous subdural tapping for patients with chronic subdural hematoma (CSDH) is successful and minimally invasive, it can be complicated by acute epidural hematoma. CASE PRESENTATION A 62-year-old woman presented with headache two months after minor head trauma. Computed tomography (CT) scanning revealed CSDH with mixed density on the right side. Prior to percutaneous subdural tapping, twist-drill craniostomy was performed at the parietal tuber. When the drill-needle reached the dura mater, the patient began to complain of headache, which was followed by altered consciousness. CT scanning disclosed acute epidural hematoma abutting the CSDH; both hematomas were evacuated by emergency craniotomy. At surgery, no definite bleeding source was identified apart from oozing on the dura mater. CONCLUSION Hemorrhagic complications after percutaneous subdural tapping are rare. The formation of acute epidural hematoma during twist-drill craniostomy has not been reported in the literature. This complication can occur when the blunt tip of the drill-needle remains on the dura mater without penetrating into the subdural hematoma cavity.

Schwannoma arising from the tentorium at an unusual location: case report.

OBJECTIVE AND IMPORTANCE We present a case of schwannoma attached to the tentorium. CLINICAL PRESENTATION A 41-year-old woman without evidence of neurofibromatosis presented with a 3-month history of headache, positional vertigo, and truncal ataxia. Magnetic resonance imaging revealed an extra-axial cystic mass lesion in the left anteromedial cerebellar region with a dural tail sign. INTERVENTION The tumor was removed completely by retrosigmoid craniotomy. Dense adhesion of the tumor to the inferior surface of the tentorium was confirmed during surgery. On light microscopic study, this neoplasm was composed of spindle cells and showed palisaded structures. Immunohistochemically, the tumor cells stained positive for S-100 protein and vimentin. Reticulin staining revealed a pericellular pattern of distribution of reticulin fibers. Electron microscopy confirmed the presence of a basement membrane encompassing the tumor cells. From these findings, the tumor was diagnosed as a schwannoma arising from the tentorium. CONCLUSION To our knowledge, this case report is the first to describe a schwannoma arising from the tentorium. Our case report indicates that schwannoma is a possible pathology in the differential diagnosis of dura-based tumors.

Infected subdural haematoma due to Salmonella enterica serovar Typhimurium in an adult.

A 65-year-old man with a history of alcoholism and gastrectomy was diagnosed with an infected subdural haematoma due to Salmonella enterica serovar Typhimurium. He was successfully treated with surgical drainage and intravenous ceftriaxone. To our knowledge, there has been no detailed case report in English of infected subdural haematoma or subdural empyema due to Salmonella Typhimurium in adults.

Extreme night bradycardia developing after malfunction of a lumboperitoneal shunt

Abstract.Case report: An 8-year-old boy who was treated for hydrocephalus with lumboperitoneal shunting presented with extreme night bradycardia. Results and conclusion: The night bradycardia disappeared after shunt revision, suggesting that the probable cause was secondary to long-lasting increased intracranial pressure (ICP). Long-lasting increased ICP is known to be associated with papilledema, but it has rarely been reported to induce night bradycardia in clinical practice. Extreme night bradycardia in this setting is not only a clinical sign of increased ICP but also a possible cause of cardiogenic sudden death, which must be borne in mind in the management of patients with shunted hydrocephalus.

Resolution of Carotid Artery Stenosis After Medical Treatment: Case Report

There exists a definite racial difference in the incidence of extracranial carotid artery stenosis.8) Generally, extracranial internal carotid artery lesions are less frequent and milder in Japanese stroke patients than in American stroke patients.5) Recently, however, increase in the occurrence of this disease is noted in Japanese people. This is considered to be a consequence of the westernization of lifestyle in Japan, which is most prominently reflected in the daily diet.2)9)12) We present a Japanese man who developed symptomatic stenosis of the extracranial internal carotid artery. This patient, who has long been living in the United States and taking an American style daily diet, is unique in that complete resolution of the symptomatic carotid artery stenosis on angiography was achieved after conservative treatment. The efficacy of dietotherapy is stressed, and the mechanism of this phenomenon is discussed.