Ken Sugiyama

Long-term effect of low-frequency repetitive transcranial magnetic stimulation over the unaffected posterior parietal cortex in patients with unilateral spatial neglect.

OBJECTIVE To explore long-term effects on unilateral spatial neglect of low-frequency repetitive transcranial magnetic stimulation (rTMS) over the unaffected posterior parietal cortex. DESIGN Uncontrolled pilot study. SUBJECTS Two chronic-phase patients with left-sided unilateral spatial neglect from cerebral infarction. METHODS Six rTMS sessions were undertaken for 2 weeks. Each session included 900 stimuli applied over P5 at an intensity of 95% motor thresholds and a frequency of 0.9 Hz. The Behavioural Inattention Test, either the Mini-Mental State Examination or the Revised Hasegawa Dementia Scale, Brunnstrom Recovery Stage, and Barthel Index were evaluated at 2-week intervals until 6 weeks after rTMS sessions. Single-photon emission computed tomography was performed 2 weeks before and after rTMS. RESULTS Behavioural Inattention Test scores improved remarkably, especially from 2 to 4 weeks after rTMS sessions. At 6 weeks, Behavioural Inattention Test scores still remained above pre-rTMS levels. Other clinical evaluations as well as single-photon emission computed tomography showed no significant change during the study. CONCLUSION In this small pilot study, low-frequency rTMS over the unaffected posterior parietal cortex decreased unilateral spatial neglect for at least 6 weeks.

Diffusion tensor imaging fiber tractography for evaluating diffuse axonal injury.

Patients with Diffuse axonal injury (DAI) frequently exhibit cognitive disorders chronically. Radiologic recognition of DAI can help understand the clinical syndrome and to make treatment decisions. However, CT and conventional MRI are often normal or demonstrate lesions that are poorly related to the cognitive disorders. Recently, diffusion tensor imaging (DTI) fiber tractography has been shown to be useful in detecting various types of white matter damage. The aim of this study was to evaluate the feasibility of using DTI fiber tractography to detect lesions in DAI patients, and to correlate the DAI lesions with the cognitive disorders. We investigated two patients with chronic DAI. Both had impaired intelligence, as well as attention and memory disorders that restricted their activities of daily living. In both patients, DTI fiber tractography revealed interruption of the white matter fibers in the corpus collosum and the fornix, while no lesions were found on conventional MRI. The interruption of the fornix which involves the circuit of Papez potentially correlates with the memory disorder. Therefore, DTI fiber tractography may be a useful technique for the evaluation of DAI patients with cognitive disorders.

Clinical utility of diffusion tensor imaging and fibre tractography for evaluating diffuse axonal injury with hemiparesis.

Although diffuse axonal injury (DAI) frequently manifests as cognitive and/or motor disorders, abnormal brain findings are generally undetected by conventional imaging techniques. Here we report the case of a patient with DAI and hemiparesis. Although conventional MRI revealed no abnormalities, diffusion tensor imaging (DTI) and fibre tractography (FT) revealed the lesion speculated to be responsible for hemiparesis. A 37-year-old woman fell down the stairs, sustaining a traumatic injury to the head. Subsequently, she presented with mild cognitive disorders and left hemiparesis. DTI fractional anisotropy revealed changes in the right cerebral peduncle, the right posterior limb of the internal capsule, and the right corona radiata when compared with the corresponding structures observed on the patients left side and in healthy controls. On FT evaluation, the right corticospinal tract (CST) was poorly visualised as compared with the left CST as well as the CST in healthy controls. These findings were considered as evidence that the patients left hemiparesis stemmed from DAI-induced axonal damage in the right CST. Thus, DTI and FT represent useful techniques for the evaluation of patients with DAI and motor disorders.

P19-16 Clinical utility of diffusion tensor imaging for evaluating patients with diffuse axonal injury and cognitive disorders

fMRI experiment showed that left frontal and middle frontal gyrus near BA 10 and BA 46 were activated. Furthermore, cingulate gyrus (BA 23) and corpus callosum (BA 29, 30), and so on were also activated. The reaction time of Yes response was a fairly shorter than that of No response about 50 ms in the MEG experiment. From the results of these experiments, it was estimated that the activation area of working memory was changing through cigulate gyrus to frontal area. It was also suggested that the difference of the reaction time (50 ms) for the judgment of Yes or No response could be affected by the priming effect.

Development of involuntary movements after ventriculoperitoneal shunting for normal pressure hydrocephalus in a patient with chronic-phase thalamic haemorrhage

Background: Delayed-onset involuntary movements have been described after thalamic stroke. Methods: We treated a patient with involuntary movements that increased after ventriculoperitoneal shunting (VPS) for normal pressure hydrocephalus (NPH) following thalamic haemorrage. One and one-half years after right thalamic and intraventricular haemorrhage, NPH suggested clinical evaluation and neuroimaging studies in a 56-year-old man. Results: Hemidystonia and pseudochoreoathetosis were evident in the left arm, leg and trunk. Proprioceptive impairment and mild cerebellar dysfunction affected the left upper and lower extremity. Yet the patient could walk unassisted and carry out activities of daily living (ADL) rated as 90 points according to the Barthel Index (BI). Lumbar puncture lessened both gait disturbance and cognitive impairment. After VPS, cognition and urinary continence improved, but involuntary movements worsened, precluding unaided ambulation and decreasing the BI score to 65 points. Computed tomography after VPS showed resolution of NPH, while single-photon emission computed tomography showed increased cerebral blood flow after VPS. Conclusion: Increased cerebral blood flow after VPS is suspected to have promoted development of abnormal neuronal circuitry.

P31.16 The utility of diffusion tensor brain fiber tracking to evaluate diffuse axonal injury: Imaging potentially correlates with cognitive disorder

P31.16 The utility of diffusion tensor brain fiber tracking to evaluate diffuse axonal injury: Imaging potentially correlates with cognitive disorder K. Sugiyama , T. Kondo , M. Endo , H. Watanabe , K. Shindo , K. Nishijima , Y. Furusawa , T. Mori , S.I. Izumi 1 1 Tohoku University Graduate School of Medicine, Physical Medicine and Rehabilitation, Japan 2 Tohoku Kouseinenkin General Hospital, Neurology, Japan 3 Tohoku Kouseinenkin General Hospital, Physical Medicine and Rehabilitation, Japan