Tomoyuki Koizumi

Publications (5)6.53 Total impact

• Article: Right temporal lobe plays a role in verbal memory.

  Nobusada Shinoura, Akira Midorikawa, Kotoyo Kurokawa, Toshiyuki Onodera, Masanobu Tsukada, Ryozi Yamada, Yusuke Tabei, Tomoyuki Koizumi, Mizuho Yoshida, Seiko Saito, Kazuo Yagi
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  ABSTRACT: Comparison of preoperative and postoperative neurological functions in patients undergoing resection of brain tumors, in combination with data from diffusion tensor imaging (DTI) studies, can provide direct evidence of anatomical localization of brain function. The goal of the present study was to use these techniques to characterize memory function of the right temporal lobe in five patients with right temporal lobe brain tumors. Memory function was tested using the Wechsler Memory Scale-Revised (WMS-R) before and after surgery in five patients with right temporal lobe brain tumors. Preoperative DTI was performed in four of five cases. In all cases, general and verbal memory, including verbal paired association, significantly improved after surgery (P<0.05). The right inferior longitudinal fasciculus (ILF) was compressed by the tumor in all cases. These results suggest that the right temporal lobe plays a role in verbal memory and that this function may be associated with the right ILF.
  Neurological Research 09/2011; 33(7):734-8. · 1.52 Impact Factor
• Article: Damage of left temporal lobe resulting in conversion of speech to Sutra, a Buddhist prayer stored in the right hemisphere.

  Nobusada Shinoura, Toshiyuki Onodera, Kotoyo Kurokawa, Masanobu Tsukada, Ryozi Yamada, Yusuke Tabei, Tomoyuki Koizumi, Kazuo Yagi
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  ABSTRACT: The present study describes a case of a right-handed 74-year-old woman with a brain tumor who showed conversion of speech to Sutra, a Buddhist prayer, which was stored in the right hemisphere according to the Wada test. After surgery, relative improvement in the speech disorder was observed, and frequency of speech production of simple normal words with normal phonology increased. These observations indicate that damage to left temporal lobe resulted in conversion of speech to Sutra, and that Sutra was stored in this patient's right hemisphere.
  Neurocase 02/2010; 16(4):317-20. · 1.11 Impact Factor
• Article: Damage of white matter in the parietal lobe results in anomic alexia of kana.

  Nobusada Shinoura, Yuichi Suzuki, Masanobu Tsukada, Ryozi Yamada, Yusuke Tabei, Tomoyuki Koizumi, Kazuo Yagi
  The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 01/2010; 37(1):113-7. · 0.97 Impact Factor
• Article: Damage to the upper portion of area 19 and the deep white matter in the left inferior parietal lobe, including the superior longitudinal fasciculus, results in alexia with agraphia.

  Nobusada Shinoura, Toshiyuki Onodera, Kotoyo Kurokawa, Masanobu Tsukada, Ryozi Yamada, Yusuke Tabei, Tomoyuki Koizumi, Kazuo Yagi
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  ABSTRACT: Analysis of lesions and symptoms in patients with brain tumors combined with information from diffusion tensor imaging provides direct evidence of the anatomical localization of brain function. Using these methods, we evaluated 8 patients who underwent surgery for metastatic brain tumors located in the left occipital lobes between 2007 and 2009. Preoperatively, 4 patients (cases 1-4) had alexia with agraphia while the other 4 patients (cases 5-8) did not. Tractography for the superior longitudinal fasciculus (SLF) was performed before surgery in case 1. The common brain tumors in cases 1-4 were located in the upper portion of area 19, and peritumor edema in that area resulted in compromise of the deep white matter of the inferior parietal lobe (IPL). The SLF was compressed and disrupted in the white matter of the IPL near the upper portion of area 19 in case 1. In cases 5-8, the brain tumors were not located in the upper portion of area 19. These results suggest that damage to the upper portion of area 19 and to the white matter in the left IPL, including the SLF, resulted in alexia with agraphia.
  European Neurology 01/2010; 64(4):224-9. · 1.81 Impact Factor
• Article: Deficits in the left inferior longitudinal fasciculus results in impairments in object naming.

  Nobusada Shinoura, Yuichi Suzuki, Masanobu Tsukada, Mizuho Yoshida, Ryozi Yamada, Yusuke Tabei, Kuniaki Saito, Tomoyuki Koizumi, Kazuo Yagi
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  ABSTRACT: The functional characteristics of the left inferior longitudinal fasciculus (ILF) remain unclear. The present study describes a case of a right-handed 74-year-old woman with a brain tumor who showed marked deterioration in object naming ability after invasion of the tumor into the medial region of the left posterior (middle and inferior) temporal lobe just beside the atrium of the lateral ventricle. Diffusion tensor imaging showed possible interruption of the left ILF after invasion of tumor at this site. By contrast, the left superior longitudinal fasciculus (SLF) remained intact after invasion of tumor, and the inferior fronto-occipital fasciculus (IFOF) was already disrupted prior to tumor invasion. These observations indicate that intact ILF function may be required for object naming ability.
  Neurocase 11/2009; 16(2):135-9. · 1.11 Impact Factor