Hiroyasu Sasajima

Intramedullary spinal cord germinoma: case report and review of the literature.

We discuss the case of a patient with a recurring intramedullary spinal cord germinoma of the lower thoracic spinal cord, which was successfully excised. A primary intramedullary spinal cord germinoma is very rare, and only four other cases have been reported in the literature. All five cases are reviewed regarding the appearance of the germinomas, their neuroradiological features, and their histopathological findings. We also discuss treatment choices for germinomas of the spinal cord.

Multitensor Tractography Enables Better Depiction of Motor Pathways: Initial Clinical Experience Using Diffusion-Weighted MR Imaging with Standard b-Value

BACKGROUND AND PURPOSE: The purpose of this work was to test the feasibility of using high angular resolution diffusion imaging (HARDI)-based multitensor tractography to depict motor pathways in patients with brain tumors. MATERIALS AND METHODS: Ten patients (6 males and 4 females) with a mean age of 52 years (range, 9–77 years) were scanned using a 1.5T clinical MR unit. Single-shot echo-planar imaging was used for diffusion-weighted imaging (repetition time, 6000 ms; excitation time, 88 ms) with a diffusion-sensitizing gradient in 32 orientations and a b-value of 1000 s/mm2. Data postprocessing was performed using both the conventional single- and multitensor methods. The depiction rate of the 5 major components of the motor pathways, that is, the lower extremity, trunk, hand, face, and tongue, was assessed. RESULTS: Motor fibers on both lesional and contralesional sides were successfully depicted by both the single-tensor and multitensor techniques. However, with the single-tensor model, the depiction of motor pathways was typically limited to the fibers of trunk areas. With the multitensor technique, at least 4 of 5 major fiber bundles arising from the primary motor cortex could be identified. CONCLUSION: HARDI-based multitensor tractography using a standard b-value (1000 s/mm2) can depict the fiber tracts from the face and tongue regions of the primary motor cortex.

Moyamoya patients exhibit higher brain temperatures than normal controls.

The balance between heat production (metabolism) and heat removal (blood flow) helps in keeping the temperature of the brain constant. In patients with moyamoya disease, this balance may be disturbed. The purpose of this study was to assess the thermal pathophysiology of the brain in patients with moyamoya disease. The study included 12 consecutive patients with moyamoya disease and 10 controls. Temperature was measured by image postprocessing of diffusion-weighted images. Our noninvasive thermometry showed that the ventricular temperature of moyamoya disease patients was higher than that of normal controls. The mean temperature difference of 1.1°C between the two groups was significant. Patients with moyamoya disease tend to have elevated ventricular temperatures, which may represent a mismatch between cerebral metabolism and perfusion.

Incidental Acute Infarcts Identified on Diffusion-Weighted Images: A University Hospital-Based Study

BACKGROUND AND PURPOSE: Pathogenesis of leukoaraiosis is incompletely understood and accumulation of small infarctions may be one of the possible sources of such white matter lesions. Thus, the purpose of this study was to identify the rate of incident infarction as depicted on diffusion-weighted images (DWIs) obtained from a general patient population. MATERIALS AND METHODS: During the 4-year study period, a total of 60 patients (36 men and 24 women) had an incidental DWI-defined infarction without overt clinical symptoms suggestive of a stroke or a transient ischemic attack. All of the MR images were obtained by using a similar protocol on 2 identical 1.5T whole-body scanners. The patients vascular risk factors, as well as the presence of white matter lesions (WMLs) on MR imaging and atheromatous changes on MR angiography, were assessed retrospectively. The incidental DWI-defined infarcts were also characterized in terms of their lateralization, lobe, and specific location. RESULTS: A total of 16,206 consecutive brain MR images were done during the study period; the overall incidence of incidental infarcts was 0.37%. Most of these patients with an incidental infarct had vascular risk factors and WMLs on MR images. Most of these patients (80%) had a single lesion on DWI. A total of 88 lesions were identified; most were located in the white matter of the supratentorial brain, primarily in the frontoparietal lobes. There were also lesions involving the brain stem (n = 2). The lesions involving cerebrum were more commonly located in the right side (right to left = 52:34). CONCLUSION: Small, DWI-defined acute brain infarctions can be found incidentally in an asymptomatic population; this finding may account, at least in part, for the pathogenesis of WMLs identified on MR imaging.

A Case of Diastematomyelia Associated with Myeloschisis in a Hemicord

We report a case of myeloschisis on the right hemicord in a patient with diastematomyelia. The patient was a female neonate with myeloschisis visible at birth in the upper lumbar region. Radiological examination, including three-dimensional CT and MRI, clearly revealed a bony septum as well as the myeloschisis on the right hemicord, which enabled us to make a precise preoperative diagnosis of this complex anomaly. Closure of the myeloschisis and removal of the septum were successfully accomplished in one stage to prevent subsequent infection and neurological deterioration. The presence of combined diastematomyelia and myeloschisis is consistent with the hypothesis of an ontogenic basis of development and emphasizes the importance of early imaging for diagnosis in this complex anomaly.

Strategies to prevent positioning-related complications associated with the lateral suboccipital approach.

The lateral positioning used for the lateral suboccipital surgical approach is associated with various pathophysiologic complications. Strategies to avoid complications including an excessive load on the cervical vertebra and countermeasures against pressure ulcer development are needed. We retrospectively investigated positioning-related complications in 71 patients with cerebellopontine angle lesions undergoing surgery in our department between January 2003 and December 2010 using the lateral suboccipital approach. One patient postoperatively developed rhabdomyolysis, and another presented with transient peroneal nerve palsy on the unaffected side. Stage I and II pressure ulcers were noted in 22 and 12 patients, respectively, although neither stage III nor more severe pressure ulcers occurred. No patients experienced cervical vertebra and spinal cord impairments, brachial plexus palsy, or ulnar nerve palsy associated with rotation and flexion of the neck. Strategies to prevent positioning-related complications, associated with lateral positioning for the lateral suboccipital surgical approach, include the following: atraumatic fixation of the neck focusing on jugular venous perfusion and airway pressure, trunk rotation, and sufficient relief of weightbearing and protection of nerves including the peripheral nerves of all four extremities.

Effect of vascular stenosis on perfusion-weighted imaging; differences between calculation algorithms

To determine the most suitable postprocessing technique for magnetic resonance (MR) perfusion imaging in patients with vascular stenosis, by comparing the cerebral blood flow (CBF) maps of single photon emission tomography (SPECT) and perfusion MR imaging (MRI).

Neurological symptoms in a patient with isolated adrenocorticotropin deficiency: case report and literature review

BackgroundIsolated adrenocorticotropic hormone (ACTH) deficiency is a pituitary disorder characterized by reduction only in the secretion of ACTH. Although the underlying mechanism remains to be elucidated, numbers of cases with this entity have been increasing. We experienced a case presenting with gait disturbance necessitating differential diagnosis from idiopathic normal pressure hydrocephalus (iNPH).Case presentationA 69-year-old female with a complaint of difficulty walking and suspected to have iNPH at a prior hospital was referred to our department. For the prior three years, she had suffered from a progressive gait disturbance. Magnetic resonance imaging (MRI) revealed global ventricular dilatation. The typical features of the gait in iNPH cases were all identifiable. Neuropsychological dementia scale tests showed deterioration. However, the major feature of a disproportionately enlarged subarachnoid-space on MRI was not obvious. The patient developed progressively worsening fatigue during hospitalization. Her symptoms resembled those of hypothalamic-pituitary tumor patients. Serum ACTH and cortisol levels were low. While corticotrophin releasing hormone stress tests showed no response, other stress tests using thyrotropin releasing hormone, luteinizing hormone releasing hormone, and growth hormone releasing hormone yielded normal responses, indicating a diagnosis of isolated ACTH deficiency. We initiated corticosteroid therapy, and her gait disturbance improved promptly.ConclusionIsolated ACTH deficiency may have major significance to the differential diagnosis of iNPH. Early consideration of this entity is anticipated to facilitate making an early diagnosis.

Medical Comics as Tools to Aid in Obtaining Informed Consent for Stroke Care

AbstractInformed consent has now become common in medical practice. However, a gap still exists between doctors and patients in the understanding of clinical conditions. We designed medical comics about “subarachnoid hemorrhage” and “intracerebral hemorrhage” to help doctors obtain informed consent intuitively, quickly, and comprehensively.Between September 2010 and September 2012, we carried out a questionnaire survey about medical comics with the families of patients who had suffered an intracerebral or subarachnoid hemorrhage. The questionnaire consisted of 6 questions inquiring about their mental condition, reading time, usefulness of the comics in understanding brain function and anatomy, pathogenesis, doctors explanation, and applicability of these comics.The results showed that 93.8% responders would prefer or strongly prefer the use of comics in other medical situations. When considering the level of understanding of brain function and anatomy, pathology of disease, and doctors explanation, 81.3%, 75.0%, and 68.8% of responders, respectively, rated these comics as very useful or useful.We think that the visual and narrative illustrations in medical comics would be more helpful for patients than a lengthy explanation by a doctor. Most of the responders hoped that medical comics would be applied to other medical cases. Thus, medical comics could work as a new communication tool between doctors and patients.

Unusual Presentations of Pediatric Skull Hemangiomas: Report of Two Cases

BACKGROUND Intraosseous hemangioma is a rare bone tumor, accounting for 0.7%-1.0% of all bone tumors. It can occur at any age, but only 9% of cases are younger than 10 years old. Although this tumor is usually slow-growing and clinically silent, we experienced 2 pediatric patients undergoing surgery for skull hemangioma who presented with uncommon clinical manifestations. CASE DECRIPTION Case 1 was a 9-year-old boy who presented with sudden onset of headache and was referred to our hospital. Radiologic images revealed an osteolytic oval lesion in the right parietal bone and acute subdural hemorrhage in the right cerebral hemisphere. The right parietal lesion was removed surgically. The lesion was found to have grown into the dura and to be adherent to the pia matter. The removed lesion was histologically confirmed to be a hemangioma. Case 2 was an 8-year-old girl who was referred to our hospital with an elastic mass that had been slowly enlarging for 7 years. Radiologic images revealed an osteolytic oval lesion in the right parietal bone. Surgical removal was thus planned. The lesion was found to be attached to the dura, and we removed the lesion with the surrounding bone and attached dura. Histologic examination confirmed the lesion to be a hemangioma. CONCLUSIONS Although skull hemangiomas show clinical heterogeneity, surgical removal is usually diagnostic and leads to good patient outcomes. On occasion, however, this tumor causes secondary changes in the dura, such that dural incision and dural plasty should be planned in advance of lesion removal.