Prevalence and development of idiopathic normal pressure hydrocephalus: A 16-year longitudinal study in Japan.

OBJECTIVE: We previously investigated the preclinical state of idiopathic normal pressure hydrocephalus (iNPH): asymptomatic ventriculomegaly with features of iNPH on magnetic resonance imaging (AVIM) found in community inhabitants. The aim of the study was to determine how iNPH develops longitudinally. MATERIALS AND METHODS: A previous longitudinal prospective community-based cohort study was initiated in 2000. The 271 70 year-old participants were followed up in 2016 at the age of 86 years. At this time, 104 participants could be reached for clinical examinations and brain magnetic resonance imaging (MRI). iNPH in this study was diagnosed if the participant had more than one symptom in the clinical triad and disproportionately enlarged subarachnoid space hydrocephalus (DESH) on MRI, fulfilling at least an Evans index >0.3 (ventricular enlargement, VE) and a narrowing of the subarachnoid space at the high convexity (tight high convexity, THC). Asymptomatic VE (AVE) plus THC were considered AVIM. RESULTS: Longitudinally throughout 16 years, 11 patients with iNPH were found. The hospital consultation rate was only 9%. Five of the eight patients with AVIM (62.5%) and six of 30 with AVE (20.0%) developed iNPH. Cross-sectionally, eight patients had iNPH (8/104, 7.7% prevalence at the age of 86) in 2016. Disease development was classified into THC-preceding and VE-preceding iNPH. One VE-preceding iNPH case was considered a comorbidity of Alzheimer's dementia. CONCLUSION: Idiopathic normal pressure hydrocephalus had a high prevalence among octogenarians in the evaluated community. iNPH developed not only via AVIM but also via AVE, the latter was also frequent in the elderly.

Characterization of the Growth of Deep and Subcortical White Matter Hyperintensity on MR Imaging: A Retrospective Cohort Study.

PURPOSE: In elderly patients, deep and subcortical white matter hyperintense lesions are frequently observed on MRI; however, the growth process of these lesions is unclear. The aims of this retrospective cohort study were to elucidate the growth characteristics of deep and subcortical white matter hyperintense lesions, and to insight their etiology. MATERIALS AND METHODS: We enrolled 103 patients (1610 lesions) whose deep and subcortical white matter hyperintense lesions were monitored for 3 or more years by MRI examination. The area of each hyperintense lesion was measured using a tracing method in the first and last MRI examinations. The annual rate of increase in the area of each lesion was calculated, and using the Pearson product-moment correlation coefficient the correlation between the annual rate of increase in area and the interval between the first and last MRI examinations was determined. RESULTS: The paired t-test showed a significant increase in the mean area of all the deep and subcortical white matter hyperintense lesions between the first and last MRI examinations (P < 0.001). However, hyperintense lesions had decreased in the area or disappeared in 227 (14.1%) lesions in the last MRI examination, particularly in patients with diabetes. The mean annual rate of increase in area of all hyperintense lesions was 0.013 ± 0.021 cm2 per year. The annual rate of increase in area and the interval between the first and last MRI examinations showed a weak negative correlation (r = -0.121; P < 0.01). CONCLUSION: Decrease in the area and the disappearance of the subcortical white matter hyperintense lesions, and a decline in the annual rate of increase in the lesion area with time suggest that the interstitial fluid accumulation associated with dysfunctional drainage around the vessels may be involved in the possible etiologies of deep and subcortical white matter hyperintense lesions.

Correlation between volume and morphological changes in the hippocampal formation in Alzheimer's disease: rounding of the outline of the hippocampal body on coronal MR images.

INTRODUCTION: The aim of this study was to investigate whether the outline of the hippocampal body becomes rounded on coronal magnetic resonance imaging (MRI) as the volume of the hippocampal formation decreases in Alzheimer's disease (AD). METHODS: Institutional review board approval of the study protocol was obtained, and all subjects provided informed consent for the mini-mental state examination (MMSE) and MRI. The MRI and MMSE were prospectively performed in all 103 subjects (27 men and 76 women; mean age ± standard deviation, 77.7 ± 7.8 years) who had AD or were concerned about having of dementia and who consulted our institute over 1 year. The subjects included 14 non-dementia cases (MMSE score ≥ 28) and 89 AD cases (MMSE score ≤ 27). The total volume of the bilateral hippocampal formation (VHF) was assessed with a tracing method, and the ratio of the VHF to the intracranial volume (RVHF) and the rounding ratio (RR) of the hippocampal body (mean ratio of its short dimension to the long dimension in the bilateral hippocampal body) were calculated. Using Spearman's correlation coefficient, the correlations between RR and VHF and between RR and RVHF were assessed. RESULTS: Correlation coefficients between RR and VHF and between RR and RVHF were -0.419 (p < 0.01) and -0.418 (p < 0.01), respectively. There was a significant negative correlation between RR and the volume of the hippocampal formation. CONCLUSION: The outline of the body of the hippocampal formation becomes rounded on coronal images as its volume decreases in AD.

Smaller brain size likely in young adults (<40 years old) with depressive symptoms compared to healthy controls: a retrospective study.

PURPOSE: The aim of this study was to determine whether the brain size of young patients with depressive symptoms is smaller than that of healthy controls using magnetic resonance imaging (MRI). MATERIALS AND METHODS: We retrospectively evaluated brain size by calculating the ratio of the brain area to that of the skull (the brain-to-skull ratio) on routine MRI scans including the splenium of the corpus callosum obtained from 19 patients <40 years old with depressive symptoms in 2009. The controls were 12 healthy individuals <40 years old who underwent MRI for medical examinations. RESULTS: The mean brain-to-skull ratio of the control group was 0.850 ± 0.022 (range 0.822-0.889), and that of the patient group was 0.819 ± 0.041 (range 0.756-0.878). An unpaired t-test showed a significant difference in the brain-to-skull ratios between these groups (P = 0.011). In particular, in 7 of the 19 patients with longer duration of illness and more severe symptoms, the brainto-skull ratio was 89%-92% of the mean ratio of the control group. CONCLUSION: The brain size of young patients with depressive symptoms appears to be smaller than that of healthy controls.

Rounding of the hippocampus in Alzheimer's disease: a study by routine coronal magnetic resonance imaging.

PURPOSE: On routine coronal images, we have recognized atrophied hippocampi that appear round in patients with Alzheimer's disease (AD). The purpose of this study was to evaluate rounding of the hippocampus in patients with AD and to elucidate whether this change is a useful radiological marker of atrophy of the hippocampus. MATERIALS AND METHODS: We enrolled 14 patients with moderate AD (Mini-Mental State Examination score 16.2 +/- 3.3) and 15 patients without dementia or neurological deficits as the control group. For measurement of the hippocampus, we used T2-weighted coronal images parallel to the floor of the fourth ventricle. Two observers measured the dimensions of the long and short axes of the hippocampal body of 28 hippocampi from 14 patients with AD and 30 hippocampi from 15 controls. As a marker of rounding of the hippocampal body, we calculated the ratio of the short axis length to the long axis length (the rounding ratio) of the hippocampus. RESULTS: We observed apparent atrophy of the long axis of the hippocampus in patients with AD. An unpaired t-test indicated significant differences in the long axis length and the rounding ratio between the control and AD groups (P < 0.01) in the measurements of both observers. However, there was no significant difference in the short axis length. With a threshold of 0.7 in the rounding ratio, the sensitivity was 85.7% and the specificity was 66.7%. CONCLUSION: The hippocampus appears round on coronal images in the presence of moderate AD. The rounding ratio of the hippocampus is a useful and facile indicator of hippocampal atrophy.

Upper midbrain profile sign and cingulate sulcus sign: MRI findings on sagittal images in idiopathic normal-pressure hydrocephalus, Alzheimer's disease, and progressive supranuclear palsy.

PURPOSE: On magnetic resonance imaging (MRI) sagittal sections, we sometimes encounter abnormal aspects of the superior profile of the midbrain and the cingulate sulcus in patients with dementia. In this preliminary study, we refer to these findings as the "upper midbrain profile sign" and the "cingulate sulcus sign." We prospectively evaluated the usefulness of these signs for the diagnosis of idiopathic normal-pressure hydrocephalus (iNPH), Alzheimer's disease (AD) and progressive supranuclear palsy (PSP). MATERIALS AND METHODS: We evaluated the upper midbrain profile sign and the cingulate sulcus sign on MRI sagittal images obtained from 21 people with headaches but no neurological deficit (controls), 10 iNPH patients, 11 AD patients, and 5 PSP patients. The upper midbrain profile sign indicated a concave shape to the superior profile of the midbrain on mid-sagittal images, and the cingulate sulcus sign indicated a narrow, tight aspect of the posterior part of the cingulate sulcus on paramedian-sagittal images. RESULTS: These signs were never seen in any images from the controls. The upper midbrain profile sign was seen in 7 of 10 patients with iNPH, 5 of 11 with AD, and 3 of 5 with PSP. The cingulate sulcus sign was seen in all 10 patients with iNPH but was never seen in any patient with AD or PSP. CONCLUSION: The upper midbrain profile sign could support a diagnosis of PSP but cannot discriminate among iNPH, AD, and PSP. In contrast, the cingulate sulcus sign has a very high sensitivity for iNPH and should facilitate the distinction of iNPH from other dementias. In the clinical setting, it is momentous to evaluate these signs easily by one simple MRI sequence.

MR findings of cerebral white matter in Cockayne syndrome.

The characteristic magnetic resonance (MR) findings of Cockayne syndrome have been reported; however, the corresponding characteristics on diffusion-weighted and fluid-attenuated inversion recovery (FLAIR) imaging are yet to be documented. In this adult case with Cockayne syndrome, we identified small patchy subcortical lesions visualized as areas of high intensity on diffusion-weighted images and low intensity on FLAIR images. It is possible that these findings reflect active demyelinating lesions.

Cerebellar atrophy attributed to cerebellitis in two patients.

In a review of magnetic resonance (MR) images from patients with spinocerebellar degeneration (SCD), we found 2 rare patients considered to be in late-stage cerebellitis who showed isolated cerebellar atrophy. The patients were negative for the spinocerebellar ataxia (SCA) genes and had no symptoms of hypothyroidism, history of malignant tumors, or history of alcohol and drug (phenytoin) abuse, which may cause cerebellar atrophy. MR images demonstrated generalized atrophy of the cerebellum, excluding the brainstem or cerebrum. In these cases, moreover, slightly high intensities were noted in the affected cerebellar cortices on fluid-attenuated inversion recovery (FLAIR) images. The distribution of widening of the folia and cortical high intensities on FLAIR images might be important clues with which to diagnose late-stage cerebellitis.

Asymptomatic hereditary Alexander's disease caused by a novel mutation in GFAP.

We report on a family with dominantly inherited asymptomatic Alexander's disease due to a novel Glial fibrillary acidic protein (GFAP) mutation. The proband, a 16-month-old boy, presented with megalocephaly and brain magnetic resonance imaging (MRI) showing the typical findings of Alexander's disease. Molecular analysis showed that he was a heterozygote of the L331P mutation of GFAP. His mother and sister, without megalocephaly or other neurological abnormalities, were also heterozygotes of the mutation and their brain magnetic resonance imaging showed mild changes in the caudates and deep frontal white matters. These results suggest the existence of a forme fruste of Alexander's disease. The L331P mutation may be associated with the mild phenotype of Alexander's disease. To elucidate the genotype-phenotype correlation in Alexander's disease, molecular diagnosis and MRI examination are required for many patients and their families.

[Usefulness of 3D conformal radiation therapy for reduction of radiation-induced white matter injury].

PURPOSE: The usefulness of three-dimensional conformal radiation therapy(3DCRT) in decreasing radiation-induced white matter changes(WMC) was assessed. MATERIAL AND METHODS: Thirty-seven patients(age 5-77 years, mean 42 years; male/female = 11/26) with primary intracranial tumors received 40 Gy or more, and were followed up with MRI for more than one year. Thirty-four patients underwent chemotherapy(with a platinum drug, 16; without a platinum drug, 18). Nineteen were treated with 3DCRT (radiation dose, range 60-64 Gy, mean 60.2 Gy; maximum width of radiation field, range 7-16 cm, mean 12.5 cm) and 18 were treated with non-3DCRT (radiation dose, range 40-62.4 Gy, mean 53.4 Gy; maximum width of radiation field, range 4-19 cm, mean 12.3 cm). RESULTS: WMC occurred in 37% of the 3DCRT group and 50% of the non-3DCRT group. Among the patients with WMC, Karnofsky performance scale(KPS) deteriorated in none of the 3DCRT group, whereas KPS deteriorated in 3 of 9 in the non-3DCRT group. All the patients with deterioration of KPS were at least 50 years of age. KPS did not strictly correlate with the severity of white matter changes on MRI. Chemotherapy with a platinum drug increased the incidence of WMC. Age(< 50 years vs. > or = 50 years), gender, radiation technique(3DCRT vs. non-3DCRT), radiation dose(< 60 Gy vs. > or = 60 Gy), maximum field-size(< 12 cm vs. > or = 12 cm), and maximum boost-field size(< 10 cm vs. > or = 10 cm) were not relevant to the incidence and severity of WMC. CONCLUSION: Though 3DCRT did not decrease the incidence and severity of white matter change on MRI, it may be useful to preserve the KPS, especially for older patients.

Morning glory sign: a particular MR finding in progressive supranuclear palsy.

BACKGROUND AND PURPOSE: We have encountered a peculiar atrophic change in the midbrain in some patients with parkinsonian syndromes. We discovered these patients had vertical supranuclear gaze-palsy, an eye movement disorder. The purpose of this study was to elucidate whether this atrophic pattern of the midbrain (which we have termed morning glory sign) is related to the vertical eye movement disorder, in particular to progressive supranuclear palsy (PSP). METHODS: We reviewed T2-weighted axial images obtained from 42 patients with parkinsonian syndromes, including five patients with PSP, 23 patients with Parkinson's disease, and 14 patients with multiple system atrophy (MSA). We focused on a specific atrophy of the midbrain, the morning glory sign, which is a concavity of the lateral margin of the tegmentum of the midbrain. RESULTS: The morning glory sign was detected in four of the five patients with PSP and in one (striatonigral degeneration; SND) of the14 patients with MSA. All morning glory sign patients had vertical supranuclear gaze-palsy, as did the one PSP patient without the morning glory sign. Vertical supranuclear gaze-palsy was seen in no other patients (23 patients with Parkinson's disease and 13 patients with MSA) who lacked the morning glory sign. CONCLUSIONS: Morphologically, the morning glory sign is believed to be related to vertical supranuclear gaze-palsy. This sign should be considered a useful clue when diagnosing PSP.

Morphology of the inner structure of the hippocampal formation in Alzheimer disease.

BACKGROUND AND PURPOSE: To our knowledge, inner structural alterations of the hippocampus have never been demonstrated because of the lack of contrast between the hippocampus proper and the superficial medullary lamina. We sought to demonstrate the anatomic details of the inner hippocampus and to elucidate its alterations in Alzheimer disease (AD) in vivo. METHODS: We obtained multishot diffusion- and T2-weighted MR images in 14 healthy control subjects and 26 patients with mild or moderate AD (diagnosis based on Mini-Mental Status Examination scores). We measured the width of the subiculum, CA1 and CA3-4, and the height of CA3-4 on coronal images. RESULTS: The subiculum and hippocampus proper were demonstrated as whirlpool-shaped hyperintense areas, and the superficial medullary lamina was visible as a hypointense structure along the inner margin of the hippocampus proper. Regarding the width of the subiculum and CA1, intergroup analysis revealed significant differences between the control and mild or moderate AD groups. In the width of CA3-4, we found no significant difference between the control and mild AD groups; however, differences between the control and moderate AD groups and between the mild and moderate AD groups were significant. In the height of CA3-4, we observed no significant differences between groups. CONCLUSION: We clearly visualized the inner structure of the hippocampal formation by using multishot diffusion-weighted imaging. The subiculum and CA1 are the most vulnerable regions in AD, and atrophy of these structures was evident in both mild and moderate AD.

[Basi-parallel anatomical scanning (BPAS) MRI: a simple MRI technique for demonstrating the surface appearance of the intracranial vertebrobasilar artery].

We modified surface anatomy scanning (SAS) MRI to reveal the surface appearance of the vertebrobasilar artery in the cistern. Two-cm-thick heavily T2-weighted coronal imaging using the fast spin-echo sequence with gray-scale reversal in post-processing was best for our purposes. Basi-parallel anatomical scanning (BPAS) MRI could clearly demonstrate fusiform aneurysm and its disappearance at the acutely occluded segment of the dissected vertebral artery. This simple MRI scanning technique can provide useful information on vertebrobasilar vascular lesions especially in patients with arterial dissection.

Topographical alterations of the midbrain and the substantia nigra following unilateral posteroventral pallidotomy in patients with Parkinson's disease using routine and multishot diffusion-weighted magnetic resonance imaging.

To determine whether posteroventral pallidotomy (PVP) induces topographical changes of the ipsilateral midbrain and degeneration of the substantia nigra in Parkinson's disease patients, we obtained magnetic resonance (MR) images of 18 patients who had undergone PVP and measured the width of the cerebral peduncle at the mid-point of the inner margin. Then, we assessed MR signal changes in the substantia nigra on T2-weighted images in all patients and on multishot diffusion-weighted images in seven patients. In MR images taken within 1 year of PVP, a comparison between the ratio of the ipsilateral side/contralateral side of the cerebral peduncle of patients after PVP and that of the unaffected side/affected side in the preoperative images revealed no significant difference ( P>0.05). In MR images 1 to 2 years after PVP, there was a significant difference in the ratio of the cerebral peduncle ( P<0.01). A significant difference was still evident in MR images more than 2 years after PVP ( P<0.001). On T2-weighted images obtained within 1 year of PVP, an area of patchy high signal appeared in the posterolateral region of the ipsilateral substantia nigra in six of 13 patients. However, there was no signal change in the substantia nigra in any T2-weighted images more than 1 year after PVP. Multishot diffusion-weighted images obtained from all six patients more than 1 year after PVP revealed an abnormal area of high signal in the posterolateral region of the ipsilateral substantia nigra, however, within 1 year of PVP such a signal change was not seen. PVP would induce degeneration of the ipsilateral substantia nigra and atrophy of the ipsilateral midbrain.

Granular cell tumor of the spinal nerve root: MR findings.

We report granular cell tumor in the right SI nerve root, a location which has not been reported previously. The tumor showed heterogeneous hypointensity on T2-weighted images and heterogeneous enhancement. MRI also demonstrated the precise relation between the tumor and the nerve root.