Aiko Osawa

Efficacy of a hybrid assistive limb in post-stroke hemiplegic patients: a preliminary report

BackgroundRobotic devices are expected to be widely used in various applications including support for the independent mobility of the elderly with muscle weakness and people with impaired motor function as well as support for nursing care that involves heavy laborious work. We evaluated the effects of a hybrid assistive limb robot suit on the gait of stroke patients undergoing rehabilitation.MethodsThe study group comprised 16 stroke patients with severe hemiplegia. All patients underwent gait training. Four patients required assistance, and 12 needed supervision while walking. The stride length, walking speed and physiological cost index on wearing the hybrid assistive limb suit and a knee-ankle-foot orthosis were compared.ResultsThe hybrid assistive limb suit increased the stride length and walking speed in 4 of 16 patients. The patients whose walking speed decreased on wearing the hybrid assistive limb suit either had not received sufficient gait training or had an established gait pattern with a knee-ankle-foot orthosis using a quad cane. The physiological cost index increased after wearing the hybrid assistive limb suit in 12 patients, but removal of the suit led to a decrease in the physiological cost index values to equivalent levels prior to the use of the suit.ConclusionsAlthough the hybrid assistive limb suit is not useful for all hemiplegic patients, it may increase the walking speed and affect the walking ability. Further investigation would clarify its indication for the possibility of gait training.

Functional lesions in dysphagia due to acute stroke: discordance between abnormal findings of bedside swallowing assessment and aspiration on videofluorography.

IntroductionBedside swallowing assessments are often used to assess dysphagia. However, in some patients, aspiration pneumonia occurs without any problems on bedside swallowing assessments and some patients do not suffer aspiration pneumonia despite abnormal results of bedside swallowing assessments in acute stroke. To detect the differences of lesions related to bedside swallowing assessment abnormality and aspiration, we investigated swallowing-related functional lesions in terms of cerebral blood flow in patients with dysphagia after stroke.MethodsThe study included 50 acute stroke patients who underwent bedside swallowing assessments and videofluorography as well as single-photon emission computed tomography (CT) at approximately the same time. Bedside swallowing assessments included repetitive saliva swallowing test and modified water swallowing test as dry and wet swallowing tasks. The presence or absence of aspiration was assessed using videofluorography. We divided patients into three subgroups based on the outcomes of the bedside swallowing assessments and presence or absence of aspiration. Statistical image analysis was performed using single-photon emission CT to determine their relationship with bedside swallowing assessments and videofluorography results.ResultsTwenty-seven (54.0xa0%) and 28 (56.0xa0%) patients had abnormal repetitive saliva swallowing test and modified water swallowing test results. Videofluorography indicated aspiration in 35 (70.0xa0%) patients. In comparing patients with and without abnormal results on each test, the groups with abnormal repetitive saliva swallowing test, abnormal modified water swallowing test, and aspiration demonstrated lower cerebral blood flow in the left precuneus, left insula, and anterior cingulate gyrus, respectively.ConclusionsBased on the analysis of cerebral blood flow, functional lesions differed across abnormal repetitive saliva swallowing test and abnormal modified water swallowing test findings and aspiration on videofluorography, and each test may assess different functions among the many processes involved in swallowing.

Functional outcome in patients with pontine infarction after acute rehabilitation

We examined the clinical features of patients with pontine infarction in the acute stage and the factors affecting functional prognosis and outcome. Lesions, neurological manifestations at initial physical status examinations, cognitive function, swallowing function and outcome [activities of daily living (ADL), status of nutritional intake at discharge and destination after discharge] were evaluated in 68 patients (47 males and 21 females) who had pontine lesions with acute phase cerebral infarction. The mean length of stay was 24.4xa0days. The symptoms (number of patients) observed included paralysis (50), dysarthria (47), ataxia (18), diplopia (11), dysphagia (49) and poor cognitive performance (37). The types of lesions (number of patients) included lacunar infarcts in the ventral pontine area (15), lacunar infarcts in the dorsal pontine area (13) and large lacunar infarcts (LLIs) (41). After hospital discharge, 23 patients were discharged home, 44 were transferred to another hospital and 1 died. Twenty-three patients were on a regular diet, 22 were receiving a dysphagia diet and 22 were on enteral feeding at discharge. Patients with LLIs more frequently had poor cognitive performance, paralysis, dysphagia at discharge and a tendency for a longer length of stay compared with patients who had lacunar infarct. Most patients who returned home were those who were younger in age, had fewer neurological symptoms, had better cognitive function and ADL performance, and could ingest food. In an acute hospital, age, neurological symptoms, ADL, cognitive function, and dysphagia were considered important factors for determining the outcome in patients with pontine infarction.

Efficacy of Cilostazol in Preventing Aspiration Pneumonia in Acute Cerebral Infarction

This retrospective study examined the effectiveness of cilostazol in preventing aspiration pneumonia in patients with acute cerebral infarction. The 189 subjects ranged in age from 31 to 95 years and included 57 with small-artery occlusion, 107 with large-artery atherothrombosis, and 25 with other disorders. Patients with cardiogenic cerebral embolism or preexisting pneumonia at the time of hospital admission were excluded from the analysis. Neurologic symptoms, cognitive function, and swallowing function were assessed at the first clinical examination, and the ability to perform activities of daily living was assessed at both hospital admission and discharge. Outcome and food intake status were also assessed at hospital discharge. Pneumonia was detected in 27 of 189 subjects (14.3%), in 20 subjects during nasogastric tube feeding implemented because of oral intake difficulties (fasting group) and in 7 subjects after initiation of oral feeding (oral intake group). Cilostazol was administered to 48 of the 189 subjects (25.4%). The incidence of pneumonia was 6.3% (3 of 48) in patients who received cilostazol, compared with 17% (24 of 141) in those who did not receive cilostazol. Our data suggest that cilostazol appears to prevent the occurrence of pneumonia in both the chronic and acute stages of cerebral infarction.

Functional dissociation between Kana and Kanji: agraphia following a thalamic hemorrhage

We report the case of a 61-year-old woman with a left thalamic hemorrhage causing agraphia of Kanji (morphograms). Single-photon emission computed tomography (SPECT) showed a decrease in the blood flow in the left thalamus from the superior temporal convolution to the parietal lobe, as well as in the frontal lobe while computed tomography showed no remarkable lesions in the cortex. The agraphia in this case may be due to the thalamic lesion itself, but the SPECT findings strongly suggest that a secondary cortical lesion may be involved in producing the higher cognitive disorder.

Agraphia caused by left thalamic hemorrhage.

A 71-year-old right-handed man was admitted to our hospital with right hemiparesis and sensory impairment associated with mild aphasia. Although aphasia gradually resolved within 2 weeks after stroke onset, his writing ability remained disturbed. A computed tomography (CT) scan at stroke onset revealed a hematoma in the left thalamus, but no cortical lesions were observed. Further, a single-photon emission CT (SPECT) scan showed decreased blood flow in the left thalamus, in the cortical region extending from the left superior temporal gyrus to the parietal lobe, and in the frontal lobe. It is possible that agraphia may have directly resulted from the thalamic lesion, but SPECT findings strongly suggested that a general decrease in left cortical function concomitant with a disruption of the thalamocortical and cortico-thalamocortical projection fibers produced these cognitive deficits.

Diffusion tensor MR imaging of the pyramidal tract can predict the need for orthosis in hemiplegic patients with hemorrhagic stroke

Diffusion tensor magnetic resonance (MR) imaging was used to evaluate motor functions in stroke patients. The aim of this study was to clarify whether imaging can be used to predict orthotic needs in patients with hemiplegia. We studied 25 patients (age range, 16–78xa0years) with intracerebral hemorrhages (putamen 15, thalamus 7, frontal subcortex 3). Diffusion tensor MR imaging was undertaken on admission at rehabilitation hospital for stroke patients. The fractional anisotropy (FA) value of the pyramidal tract was calculated. We compared the FA value in the ROI of the cerebral peduncle with the necessity for orthosis at discharge from the rehabilitation hospital. As a result, the FA values of the affected side in patients who needed orthosis at discharge were lower than those in patients who did not need orthosis. There was no significant difference in the FA values of the unaffected side. We concluded that the need for orthosis in patients with hemiplegia after stroke rehabilitation could be predicted using the diffusion tensor MR images of corticospinal tractography.

Pure alexia caused by separate lesions of the splenium and optic radiation

Pure alexia is severe difficulty in reading and understanding written language but with normal oral language and writing abilities. We report a patient with pure alexia caused by two different infarct lesions in the left lateral thalamus and the left splenium of the corpus callosum. A 56-year-old right-handed man was admitted to hospital with right homonymous hemianopia associated with pure alexia. He could write kana characters but not kanji. His cranial magnetic resonance imaging revealed two different infarct lesions in the left optic radiation and the left splenium of the corpus callosum. Magnetic resonance angiography showed mild stenosis at the origin of the right vertebral artery and stenosis of the left distal posterior cerebral artery. The mechanism of developing pure alexia can be simply explained by disconnection. We assumed that agraphia of kanji was caused by the effect of ischemia and edema following transient obstruction in branches from the distal posterior cerebral artery.

Association between Microbleeds Observed on T2*-weighted Magnetic Resonance Images and Dysphagia in Patients with Acute Supratentorial Cerebral Hemorrhage

BACKGROUNDnApproximately one-half of all patients with acute intracerebral hemorrhage (ICH) develop dysphagia that can lead to pneumonia or fatal outcomes; however, there are no reports about the relationship between swallowing function and cerebral microbleeds (CMBs) in these patients. Therefore, we investigated whether CMBs were associated with dysphagia in patients with ICH.nnnMETHODSnA total of 100 patients (mean age, 65.1 ± 14.1 years; range, 36-95 years) with acute supratentorial ICH were included in this study. CMBs were detected on T2*-weighted magnetic resonance imaging performed during admission using a 1.5-T scanner (mean duration from onset to magnetic resonance imaging, 12.6 ± 8.4 days). We assessed swallowing function by using bedside swallowing assessments on admission and by monitoring the mode of nutritional intake at discharge in relation to the number and location of CMBs.nnnRESULTSnCMBs were detected in 60 of the 100 patients (60%) and were related to dysphagia. The number of CMBs and dysphagia were not related, but a significant relationship was observed in the presence of bilateral hematomas and CMBs.nnnCONCLUSIONSnIn addition to assessing just the presence or absence of CMBs, clinicians should identify the presence of bilateral or deep lesions in patients with ICH from the perspective of swallowing dysfunction.

Bilateral Caudate Nucleus Infarction Associated with a Missing A1 Segment

We describe a case of bilateral caudate nucleus infarction caused by cardioembolic stroke associated with a variant circle of Willis. The patient was an 81-year-old man with atrial fibrillation who presented with a sudden disturbance of consciousness. When he became more alert a few days later, he was abulic with no spontaneous speech or activity. A magnetic resonance imaging scan of the brain revealed cerebral infarction of bilateral caudate nucleus heads and the left frontal lobe. The left A1 segment was absent on 3-dimensional computed tomography angiography. One year later, abulia had completely resolved. Bilateral caudate nucleus infarction with variant circle of Willis is rare.