Ryogo Anei

Publications (4)1.48 Total impact

• Article: Hydrocephalus due to diffuse villous hyperplasia of the choroid plexus.

  Ryogo Anei, Yoshimitsu Hayashi, Satoru Hiroshima, Nobuyuki Mitsui, Ryosuke Orimoto, Genki Uemori, Masato Saito, Masao Sato, Hajime Wada, Akira Hododuka, Kyousuke Kamada
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  ABSTRACT: An 8-month-old female presented with hydrocephalus caused by cerebrospinal fluid (CSF) overproduction due to bilateral choroid plexus enlargement, which was clinically diagnosed as diffuse villous hyperplasia of the choroid plexus, but differentiation from bilateral choroid plexus papilloma was difficult. She initially underwent ventriculoperitoneal shunt surgery, but developed marked retention of ascites. Therefore, the peritoneal end of the shunt was removed for external drainage, but excessive CSF (1,500 ml/day) was collected. Computed tomography and magnetic resonance imaging revealed marked symmetric enhancement of the choroid plexuses in the bilateral lateral ventricles. Thallium-201 chloride single-photon emission computed tomography showed pronounced uptake on both early and delayed images, and good washout. CSF examination revealed no abnormalities such as atypical cells, and a ventriculoatrial shunt was inserted, achieving good control of the hydrocephalus.
  Neurologia medico-chirurgica 01/2011; 51(6):437-41. · 0.61 Impact Factor
• Article: [A case of brain herniation due to delayed bone flap sinking].

  Ryogo Anei, Genki Uemori, Ryosuke Orimoto, Masato Saito, Satosi Hirosima, Nobuyuki Mitsui, Yosimitu Hayasi, Masao Sato, Akira Hododuka, Kyousuke Kamada
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  ABSTRACT: Marked depression of the skin flap after external decompressive craniotomy, affecting the brain function, is known as sinking flap syndrome. However, to our knowledge, there have been no reports of delayed sinking of the entire bone flap after the procedure, inducing neurological symptoms. We encountered a patient with neurological symptoms due to sinking of the entire bone flap 15 years after the first operation. A 59-year-old male underwent clipping by craniotomy due to subarachnoid hemorrhage resulting from the rupture of a left internal carotid aneurysm 15 years earlier. He was discharged, but developed paresis in the right upper and lower limbs 6 months before symptom onset. CT showed sinking of the free bone flap, while MRI revealed left uncal herniation. After uncal resection and free flap fixation, the symptoms improved. This case confirmed the necessity of firm bone flap fixation at the time of cranial closure.
  No shinkei geka. Neurological surgery 10/2010; 38(10):923-6. · 0.13 Impact Factor
• Article: Effectiveness of brain hypothermia treatment in patients with severe subarachnoid hemorrhage: comparisons at a single facility.

  Ryogo Anei, Hideki Sakai, Koji Iihara, Izumi Nagata
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  ABSTRACT: The effectiveness of hypothermia treatment for severe subarachnoid hemorrhage (SAH) was evaluated at the same facility under the same director. A total of 187 patients with SAH, 67 admitted before the introduction of hypothermia treatment in May 1999 (early cases) and 120 treated thereafter (late cases), were transported to the National Cardiovascular Center and treated in the acute phase between November 1997 and September 2001. Brain hypothermia treatment was performed in 19 patients of the 120 late cases, 10 males and 9 females aged 33-72 years (mean 57. 6 years), treated by direct surgery in 15 and endovascular surgery in 4. The indications for hypothermia treatment were age of 75 years or younger, SAH due to rupture of a cerebral aneurysm, Japan Coma Scale score of 100 or higher, and initiation of treatment within 24 hours after the onset. The body core temperature was sustained at 34°C for 48 hours, rewarming was performed over 48 hours, and normothermia was maintained thereafter. The outcome, evaluated according to the modified Rankin scale (m-RS) on transfer to another hospital or after 3 months, was m-RS 3 in 1 patient, m-RS 4 in 4, m-RS 5 in 3, and death in 11. Before the introduction of hypothermia treatment (early period), 16 patients showed the indications for the treatment, and their outcomes were m-RS 3 in 2, m-RS 4 in 3, m-RS 5 in 2, and death in 9. Cerebral vasospasm was important as a prognostic factor, markedly deteriorating the outcome. Hyperthermia after therapeutic hypothermia induced brain swelling and markedly affecting the outcome. Brain hypothermia treatment did not improve the outcome of severe SAH compared with the period before its introduction. The emphasis in treating severe SAH should be placed on the maintenance of normothermia to prevent brain swelling and elimination of factors that may induce cerebral vasospasm, rather than interventional hypothermia for aggressive brain protection.
  Neurologia medico-chirurgica 01/2010; 50(10):879-83. · 0.61 Impact Factor
• Article: [Embolic complications associated with neurovascular intervention: prospective evaluation by use of diffusion-weighted MR imaging].

  Hideki Sakai, Nobuyuki Sakai, Toshio Higashi, Koji Iihara, Jun Takahashi, Shuji Kogure, Ryogo Anei, Naoaki Yamada, Satoshi Imakita, Izumi Nagata
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  ABSTRACT: The most serious complication of neurovascular interventions is distal cerebral embolism. Diffusion-weighted MR imaging (DWI) appears to be the most sensitive technique for detecting early and small ischemic lesions. To evaluate the incidence and radiological features of embolic events associated with neuro-intervention, we applied DWI to screening for procedure-related ischemic lesions including silent embolisms. One hundred and thirty-seven patients who have received 154 neuro-interventional procedures were studied with DWI before and within 5 days after treatment. Imaging was performed, using single-shot echo-planar imaging with b value of 1000-1100 sec/mm2. DWI findings were classified into 5 groups by size and location of lesions: type 0 (n = 71), no lesions; I (n = 33), lesions in border-zone regions only; II (n = 9), lesions at perforator territories mainly; III (n = 29), small territorial lesions (< 5 mm); IV (n = 12), large territorial lesions (> or = 5 mm). DWI detected procedure-related lesions in 83 of 154 procedures (53.9%), 36 of which demonstrated new neurological symptoms during and/or after procedures. The parent artery occlusion for cerebral aneurysms had a higher incidence of symptomatic embolisms than other procedures. In 71 of 154 procedures (46.1%), DWI detected no lesions (type 0). Although type I was the most frequent pattern presented, it included few neurological symptoms. Type III often resulted in transient symptoms, and type II and IV tended to induce strokes. Because ischemic lesions detected by DWI were likely to arise in border-zone territories by parent artery occlusions, we considered that hypoperfusion as well as emboli were involved in the evolution of cerebral infarctions. Thus, DWI is a useful method to detect silent embolisms, and to determine the safety of neuro-intervention and the mechanism of embolic ischemia.
  No shinkei geka. Neurological surgery 02/2002; 30(1):43-9. · 0.13 Impact Factor