A pilot clinical study of low-intensity transcranial focused ultrasound in Alzheimer’s disease

Purpose@#Increasing attention has been paid to low-intensity transcranial focused ultrasound (tFUS) for its potential therapeutic effects in Alzheimer's disease (AD). While preclinical studies have shown promising therapeutic effects of low-intensity tFUS in AD models, its efficacy and safety remain unclear in humans. In this pilot study, we investigated the effects of low-intensity tFUS on blood-brain barrier opening, the regional cerebral metabolic rate of glucose (rCMRglu), and cognition in patients with AD. @*Methods@#After receiving institutional review board approval, four patients with AD received tFUS to the hippocampus immediately after an intravenous injection of a microbubble ultrasound contrast agent. Sonication was delivered at low-intensity, at a pressure level below the threshold for blood-brain barrier opening. Patients underwent brain magnetic resonance imaging, 18F-fluoro-2-deoxyglucose positron emission tomography, and neuropsychological assessments before and after the tFUS procedure. A whole-brain voxel-wise paired t test was conducted to compare rCMRglu before and after tFUS. @*Results@#The sonication, as anticipated, did not show evidence of active blood-brain barrier opening on T1 dynamic contrast-enhanced magnetic resonance imaging. rCMRglu in the superior frontal gyrus (P<0.001), middle cingulate gyrus (P<0.001), and fusiform gyrus increased after tFUS (P=0.001). Patients demonstrated mild improvement in measures of memory, executive, and global cognitive function following tFUS. No adverse events were reported. @*Conclusion@#These results suggest that hippocampal sonication with low-intensity tFUS may have beneficial effects on cerebral glucose metabolism and cognitive function in patients with AD. Further larger studies are needed to confirm the therapeutic efficacy of tFUS in AD.

Brain Perfusion Correlates of Apathy in Alzheimer's Disease

BACKGROUND AND PURPOSE: Apathy is one of the most common neuropsychiatric symptoms in patients with Alzheimer's disease (AD). It may have adverse impacts on the progression of AD. However, its neurobiological underpinnings remain unclear. The objective of this study was to investigate differences in regional cerebral blood flow (rCBF) between AD patients with apathy and those without apathy. METHODS: Sixty-six apathetic AD patients and 66 AD patients without apathy completed Neuropsychiatric Inventory (NPI) and underwent technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT) scans. Voxel-wise differences in rCBF between the 2 groups were examined. Association between rCBF and levels of apathy in the apathetic group was also assessed. RESULTS: AD patients with apathy showed lower rCBF in the bilateral orbitofrontal cortex, left putamen, left nucleus accumbens, left thalamus, and bilateral insula than those without (all p < 0.005). Mean perfusion across all significant clusters showed a negative linear correlation with NPI apathy score in AD patients with apathy (β = −0.25; p = 0.04). CONCLUSIONS: Hypoperfusion in the prefrontal, striatal, and insular areas may be neural correlates of apathy in AD patients.

Associations between Brain Perfusion and Sleep Disturbance in Patients with Alzheimer's Disease

BACKGROUND AND PURPOSE: Although sleep disturbances are common and considered a major burden for patients with Alzheimer's disease (AD), the fundamental mechanisms underlying the development and maintenance of sleep disturbance in AD patients have yet to be elucidated. The aim of this study was to examine the correlation between regional cerebral blood flow (rCBF) and sleep disturbance in AD patients using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT). METHODS: A total of 140 AD patients were included in this cross-sectional study. Seventy patients were assigned to the AD with sleep loss (SL) group and the rest were assigned to the AD without SL group. SL was measured using the sleep subscale of the Neuropsychiatric Inventory. A whole-brain voxel-wise analysis of brain SPECT data was conducted to compare the rCBF between the two groups. RESULTS: The two groups did not differ in demographic characteristics, severity of dementia, general cognitive function, and neuropsychiatric symptoms, with the exception of sleep disturbances. The SPECT imaging analysis displayed decreased perfusion in the bilateral inferior frontal gyrus, bilateral temporal pole, and right precentral gyrus in the AD patients with SL group compared with the AD patients without SL group. It also revealed increased perfusion in the right precuneus, right occipital pole, and left middle occipital gyrus in the AD with SL group compared with the AD without SL group. CONCLUSIONS: The AD patients who experienced sleep disturbance had notably decreased perfusion in the frontal and temporal lobes and increased rCBF in the parietal and occipital regions. The findings of this study suggest that functional alterations in these brain areas may be the underlying neural correlates of sleep disturbance in AD patients.

Cerebral Perfusion Changes after Acetyl-L-Carnitine Treatment in Early Alzheimer's Disease Using Single Photon Emission Computed Tomography

BACKGROUND AND PURPOSE: Although acetyl-L-carnitine (ALC) treatment may have beneficial effects on Alzheimer's disease (AD), its underlying neural correlates remain unclear. The purpose of this study was to investigate cerebral perfusion changes after ALC treatment in AD patients using technetium-99m hexamethylpropylene amine oxime single photon emission computed tomography (SPECT). METHODS: A total of 18 patients with early AD were prospectively recruited and treated with ALC at 1.5 g/day for 1.4±0.3 years. At baseline and follow-up, brain SPECT, Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), Global Deterioration Scale (GDS), and Neuropsychiatric Inventory (NPI) were used to assess participants. After ALC administration, changes in brain perfusion, severity of dementia, cognitive performance, and neuropsychiatric disturbances were examined. RESULTS: After ALC administration, changes in scores of MMSE, CDR, GDS, and NPI were not statistically significant (p>0.05). Voxel-wise whole-brain image analysis revealed that perfusion was significantly (p<0.001) increased in the right precuneus whereas perfusion was reduced in the left inferior temporal gyrus (p<0.001), the right middle frontal gyrus (p<0.001), and the right insular cortex (p=0.001) at follow-up. CONCLUSIONS: Although previous studies have suggested that AD patients generally demonstrate progressive deterioration in brain perfusion and clinical symptoms, this study reveals that the perfusion of the precuneus is increased in AD patients after ALC administration and their cognitive and neuropsychiatric symptoms are not aggravated. Further studies are warranted to determine the potential association between perfusion increase in the precuneus and clinical symptoms after ALC treatment in AD patients.

Changes in Regional Cerebral Perfusion after Nicergoline Treatment in Early Alzheimer's Disease: A Pilot Study

BACKGROUND AND PURPOSE: Nicergoline is an ergoline derivative that is used to treat cognitive deficits in cerebrovascular disease and various forms of dementia. Although therapeutic effects of nicergoline have been established, little is known about its effects on cerebral perfusion in Alzheimer's disease (AD). The aim of this study was to examine the role of nicergoline in regional cerebral blood flow (rCBF) of AD patients using technetium-99m hexa-methyl-propylene-amine-oxime single photon emission computed tomography (SPECT). METHODS: Sixteen patients with early AD underwent a comprehensive clinical assessment including cognitive testing and SPECT scans before and after nicergoline treatment. Nicergoline (30 mg twice daily) was administered for an average duration of 1.5 years. Clinical and cognitive functioning was assessed using the Mini-Mental State Examination, Clinical Dementia Rating (CDR), CDR-Sum of Boxes, Global Deterioration Scale, Barthel Activities of Daily Living Index, Instrumental Activities of Daily Living, and Geriatric Depression Scale. RESULTS: Nicergoline treatment induced changes in the severity of dementia, cognitive function, activities of daily living, and depressive symptoms, which were not statistically significant. During the follow-up, the patients showed significant increases in their relative rCBF in the superior frontal gyrus, precentral gyrus, and postcentral gyrus. CONCLUSIONS: Nicergoline treatment improves perfusion of the frontal and parietal regions in early AD patients. It is possible that the increased perfusion in the superior frontal gyrus may be related to the mechanisms that delay or prevent progressive deterioration of cognitive functions in AD.

Ischemic Stroke Associated with Orthostasis in an Advanced Parkinson's Disease Patient with Orthostatic Hypotension

No abstract available.

Papillary Meningioma Presenting as Rapidly Progressive Dementia and Parkinsonism

There are a variety of different causes of parkinsonism including PD, secondary parkinsonism, and the parkinsonism plus syndromes. Secondary parkinsonism is caused by structural, toxic, metabolic, or infectious mechanisms. Among structural causes, intracranial neoplasms are a rare cause of secondary parkinsonism. Moreover, there are almost never case reports with intracranial space-occupying lesions resulting in parkinsonism associated with rapid cognitive impairment. Therefore, we report herein a 37-year-old woman diagnosed with papillary meningioma who presented with parkinsonism associated with rapidly progressive cognitive impairment mimicking diffuse Lewy body disease.

Differences of Regional Cerebral Blood Flow between Early Alzheimer's Disease and Parkinson's Disease Associated with Dementia on 99mTc-Hexamethyl Propylene Amine Oxime Perfusion Single Photon Emission Computed Tomography

BACKGROUND: Alzheimer's disease (AD) and Parkinson's disease associated with dementia (PDD) are considered to be frequent types of cortical and subcortical dementia. Definitive diagnosis of neurodegenerative diseases is impossible without biopsy. Single photon emission computed tomography (SPECT) of the brain has long been used for years with cognitive disorders. Nevertheless, differential brain perfusion of patients with PDD and AD who exhibit mild dementia has not been reported. Therefore, we investigated the differences in the cerebral perfusional pattern using perfusion SPECT between mild AD and mild PDD to help clarify the diagnosis in the early stage of these dementias, since accurate diagnosis is crucial in decision regarding treatment, appropriate advice, management and prognosis. METHODS: Thirty-one patients with mild PDD and 32 patients with mild probable AD were enrolled in this study. All subjects underwent 99mTc-hexamethyl propylene amine oxime perfusion SPECT and general neuropsychological tests, and these data including perfusion images were analyzed. RESULTS: Perfusion SPECT showed hypoperfusion in frontal, parietal and temporal regions in both PDD and AD patients with mild dementia. Hypoperfusion in the occipital and cerebellar regions was significantly apparent in only PDD patients. CONCLUSION: Comparison of mild PDD with mild AD showed a significantly decreased perfusion in the occipital and cerebellar region in patients with mild PDD. Cerebral perfusion in the occipital region and the cerebellum could be a crucial differential diagnostic method of these diseases in the early phase. Further studies are needed for a definitive conclusion.