Three presenile patients in which neuropsychological and neuroimaging examinations suggest possible progression to dementia with Lewy bodies

We report three presenile patients who were initially suspected of having Alzheimer's disease (AD) or being in the prodromal stage of AD, regardless of visuoperceptual dysfunctions in daily living, because they lacked the core features and prodromal non‐motor symptoms of dementia with Lewy bodies. Subsequently, progression to dementia with Lewy bodies was suspected based on neuropsychological and neuroimaging findings; additionally, one of the three patients suffered from visual hallucinations. Neuropsychological examinations such as subjective contours, cube copying and block design in the Wechsler Adult Intelligence Scale‐III revealed visuoperceptual dysfunction in all three patients even when other cognitive functions were rather preserved. Brain magnetic resonance imaging revealed no significant brain atrophy, including in the parieto‐occipital area and the hippocampus, while brain ¹⁸F‐fluorodeoxyglucose positron emission tomography demonstrated right dominant metabolic reductions in the occipital lobe, including the primary visual cortex, in all three patients. We suggest the possibility of progression to dementia with Lewy bodies, but not AD or posterior cortical atrophy. Regardless of the presence of core features and prodromal non‐motor symptoms, this progression is suggested when there are difficulties only in higher‐level visual processing such as subjective contours and block design in the Wechsler Adult Intelligence Scale‐III, no significant atrophy of the parieto‐occipital area and hippocampus on brain magnetic resonance imaging, and hypometabolism in the occipital lobe including the primary visual cortex on brain ¹⁸F‐fluorodeoxyglucose positron emission tomography.     

Dementia with Lewy bodies presenting as Logopenic variant primary progressive Aphasia

ABSTRACT

We report a patient presenting with clinical features of logopenic variant primary progressive aphasia (lvPPA) who was later diagnosed with probable dementia with Lewy bodies. LvPPA is a neurodegenerative disease that is characterized by anomia, word-finding difficulty, impaired comprehension, and phonological errors. The most common underlying pathology for lvPPA is Alzheimer’s disease. However, our patient with clinical features of logopenic progressive aphasia was later diagnosed with probable dementia with Lewy bodies. This case demonstrates that lvPPA can also be an initial manifestation of a phenotype of dementia with Lewy bodies.     

Evaluating atypical dementia syndromes using positron emission tomography with carbon 11 labeled Pittsburgh Compound B

CONTEXT: A progressive decline in episodic memory affecting activities of daily living is the usual clinical presentation of Alzheimer disease. However, patients presenting with atypical or focal clinical symptoms such as language or visuospatial dysfunction often pose a diagnostic challenge. OBJECTIVE: To explore the presence and topography of beta amyloid (Abeta) as measured by carbon 11-labeled Pittsburgh Compound B ((11)C-PiB) in patients with atypical presentations of dementia. DESIGN, SETTING, AND PARTICIPANTS: At a tertiary referral center for memory disorders, 15 healthy controls, 10 patients with Alzheimer disease, a patient with primary progressive aphasia (PPA), and a patient with posterior cortical atrophy (PCA) underwent (11)C-PiB positron emission tomographic studies. Retention of (11)C-PiB was compared between different groups using statistical parametric mapping. MAIN OUTCOME MEASURE: The topography of cortical (11)C-PiB binding in atypical vs typical Alzheimer disease. RESULTS: Cortical (11)C-PiB binding was higher in the group with Alzheimer disease and in the patients with PPA and PCA than the controls (P < .001). Both patients with atypical dementia had a similar (11)C-PiB binding pattern to Alzheimer disease although (11)C-PiB retention was higher on the left cerebral hemisphere in the patient with PPA (P < .01) and higher in the occipital cortex in the patient with PCA (P < .01). CONCLUSIONS: The presence of distinctive focal (11)C-PiB retention patterns was demonstrated in 2 patients with atypical onset of dementia. Pittsburgh Compound B has the potential to facilitate differential diagnosis of dementia and identify patients who could benefit from specific therapeutic strategies aimed at beta amyloid reduction.     

Slowly progressive aphasia without generalized dementia: studies with positron emission tomography

Slowly progressive aphasia without generalized dementia is a degenerative syndrome selectively affecting dominant hemisphere language areas. We report changes in regional glucose metabolism measured by positron emission tomography in two patients with this condition. Striking abnormalities of glucose utilization in the left cerebral cortex were demonstrated in both patients. The findings of other neurodiagnostic studies were relatively unremarkable. The first patient had a 3-year history of progressive anomia and impaired auditory verbal recall. An electroencephalogram was normal, and computed tomography showed mild left perisylvian atrophy. Positron emission tomography revealed profound hypometabolism in the left temporal regions. The second patient also had a 3-year history of progressive anomia. Electroencephalography, computed tomography, and magnetic resonance imaging scans were normal. Positron emission tomography showed a major reduction in left parietal glucose utilization, with a lesser decrement in left temporal metabolism. Neither patient demonstrated significant contralateral or global abnormalities such as those reported in positron emission tomographic studies of Alzheimer's disease with or without focal clinical features. These observations support the concept of adult-onset progressive aphasia without dementia as a clinical syndrome distinct from Alzheimer's disease.     

Frontotemporal lobar degeneration and dementia with Lewy bodies: Clinicopathological issues associated with antemortem diagnosis

Currently, the clinical diagnostic criteria of frontotemporal lobar degeneration (FTLD) and dementia with Lewy bodies (DLB) are well known to neurologists and psychiatrists. However, the accuracy of the clinical diagnosis of these diseases in autopsy series is not always adequate. For example, FTLD is a syndrome rather than a clinicopathological disease entity that is comprised of various pathological substrates, including Pick's disease, FTLD with microtubule-associated protein tau gene mutation, FTLD with tau-negative ubiquitin-positive inclusions (FTLD-U), FTLD-U with progranulin gene mutation, corticobasal degeneration, basophilic inclusion body disease, and neuronal intermediate filament inclusion disease. Whether these underlying pathologies can be identified clinically is one of the greatest interests in neuropathological research. The pathophysiological relationship between Lewy pathology and Alzheimer pathology in DLB is explored with interest because it may be associated with the accuracy of clinical diagnoses. For example, although Lewy pathology may progress from the brain stem nuclei to the cerebral cortex in Parkinson's disease, recent studies have demonstrated that the progression pattern in DLB is not always identical to that in Parkinson's disease. It is also considered that the progression pattern of Lewy pathology correlates with the evolution of clinical symptoms and that the progression pattern of Lewy pathology may be altered when Alzheimer pathology coexists. In the present paper, the clinicopathological features of two demented cases are presented, and some pathological issues associated with the clinical diagnosis of FTLD and DLB are discussed.     

Research evaluation and prospective diagnosis of dementia with Lewy bodies.

OBJECTIVE: To evaluate the relative merits of recently developed criteria for dementia with Lewy bodies (DLBs) in a longitudinal study of dementia. DESIGN: The diagnosis of DLBs was used in combination with other clinical diagnosis. Patients were classified primarily based on the NINCDS-ADRDA (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association) clinical criteria for probable or possible Alzheimer disease, or with other disease process that can cause dementia (eg, Parkinson disease), and secondarily according to the consensus guidelines for DLBs. This "double" clinical diagnosis was implemented to capture different pathological entities. The neuropathological diagnosis of Lewy bodies was made with monoclonal antibodies against alpha-synuclein. SETTING: Multidisciplinary research clinic. RESULTS: Prospective application of the consensus guidelines for DLBs from January 1, 1997, to September 29, 2000, identified 11 patients having the diagnosis of probable DLBs and 35 having possible DLBs. The diagnosis of probable or possible DLBs was associated with probable Alzheimer disease in 34 patients, with possible Alzheimer disease in 5 patients, with Parkinson disease in 2 patients, and with other disease processes in 2 patients. Three patients were diagnosed as having probable DLBs alone. An autopsy was performed in 26 of the cases who were clinically examined during the study period. Cortical Lewy bodies were identified in 13 cases; 4 had had premortem diagnosis of DLBs (sensitivity, 30.7%; specificity, 100%). CONCLUSIONS: The prospective validation of the clinical criteria for DLBs showed poor accuracy in this series. We believe that current criteria for DLBs are useful when DLBs occur in isolation, but have low sensitivity when Lewy bodies coexist with the pathological abnormalities of Alzheimer disease.     

Progressive apraxic agraphia with micrographia presenting as corticobasal syndrome showing extensive Pittsburgh compound B uptake

A 65-year-old woman developed progressive apraxic agraphia, characterized by poorly formed graphemes, a kanji (Japanese morphograms) recall impairment, relatively preserved oral spelling of kanji characters, and incorrect stroke sequences on writing accompanied by micrographia over a 3-year period. She also showed minor degrees of rigidity, limb-kinetic apraxia, and ideomotor apraxia of the left hand. Although asymmetric rigidity and limb-kinetic apraxia strongly suggested corticobasal degeneration, ¹¹C-Pittsburgh compound B positron emission tomography (PiB-PET) showed the predominantly right-sided accumulation of amyloid β in the cortices and striatum. ¹⁸F-fluoro-deoxy-glucose PET and single photon emission computed tomography with a ^99mTc-ethylcysteinate dimer (ECD-SPECT) also revealed predominantly right-sided hypometabolism and hypoperfusion in the primary sensorimotor cortex, posterior cingulate gyrus, temporoparietal cortices, frontal cortices, thalamus, and basal ganglia, a pattern characteristic of both corticobasal degeneration and Alzheimer’s disease. The findings suggest that progressive apraxic agraphia with micrographia presenting as corticobasal syndrome can show an Alzheimer’s disease pathology. It is also suggested that ideomotor apraxia of the left hand can occur without a callosal lesion, and is caused by hypometabolism or hypoperfusion in the right frontal and parietal cortices, as revealed by PET and SPECT.     

Diffuse Lewy body disease

Diffuse Lewy body disease (DLBD) has been studied from various viewpoints and, although clinical diagnostic criteria for DLBD have been proposed, diagnosis remains difficult. DLBD has been reported to be the second most common form of dementia in the aged, following Alzheimer‐type dementia. It has, however, been clinically under‐diagnosed. Therefore, the search for diagnostic markers for DLBD must continue. Very recently, ‘dementia with Lewy bodies’ (DLB) was proposed as a generic term for various forms of dementia with Lewy bodies, including DLBD and similar disorders. Cortical Lewy bodies are the most important pathologic marker for diagnosis of DLBD. At present, however, the mechanism responsible for cortical Lewy body formation has yet to be disclosed.     

Neuroimaging as a diagnostic tool in dementia with Lewy bodies

Due to similar presenting symptoms, many physicians find it difficult to distinguish cases of dementia with Lewy bodies (DLB) from Alzheimer's disease or Parkinson's disease with dementia. The pathologic diagnosis of DLB has improved because of the discovery of probes for alpha-synuclein, a protein found in Lewy bodies. However, pathologic diagnosis can be employed postmortem only, and therefore diagnostic techniques that can be employed to guide patient management are still needed. Consensus criteria have been developed for establishing a clinical diagnosis of DLB, but they lack sensitivity. Therefore, a review of the recent literature was conducted to establish whether neuroimaging studies are useful diagnostic tools to help differentiate these syndromes. At least six types of tests can be used to image the brain of patients with dementia. Structural studies (x-ray, magnetic resonance imaging and computerized tomography) can disclose the presence of stroke sequelae and other lesions, whereas functional studies (magnetic resonance spectroscopy, positron emission tomography and single-photon emission computed tomography) can disclose metabolic and blood flow alterations that may be characteristic for different types of dementia. Although more formal studies are needed to confirm that these imaging techniques are reliable diagnostic tools for DLB and permit the establishment of guidelines for their use, neuroimaging techniques currently are being employed in practice to differentiate dementia types as a guide to treatment.     

Metabolic impairment of brain metabolism in patients with Lewy body dementia

A reliable assessment of dementia is essential for a differentiated treatment. Recent studies have demonstrated a poor accuracy of clinical criteria for diagnosis of Lewy body dementia. Diffuse Lewy body disease (LBD) is the second most common cause of senile degenerative dementia and is characterized histologically by the occurrence of Lewy bodies in allocortical, neocortical and subcortical structures. Seven male patients (mean age 81 years) with clinically suspected diffuse LBD were investigated with 18F-fluorodeoxyglucose (FDG)-PET using a Siemens ECAT-ART PET-scanner. The 18F-FDG-PET showed a diffuse glucose hypometabolism in the entire cerebral cortex with relative sparing of the primary sensory-motor cortex in all patients. This diffuse metabolic impairment in the entire cortex with relative sparing of central region seems to be a typical pattern for LBD, distinct from Alzheimer's disease.     

Functional imaging in Parkinson's disease and dementia with Lewy bodies

Functional imaging modalities (positron emission tomography, single photon emission tomography, magnetic resonance spectroscopy, and functional magnetic resonance) allow aspects of regional cerebral function to be evaluated in various neuropsychiatric disorders. This review will summarize the use of such techniques in current imaging studies involving Parkinson's disease and dementia with Lewy bodies, with respect to assessing regional changes, using them in differential diagnosis, and monitoring disease progression and treatment effects.     

Early detection of dementia with Lewy bodies in patients with amnestic mild cognitive impairment using 123I-MIBG cardiac scintigraphy

Increasing clinical attention has been focused on cardiac sympathetic denervation for the differential diagnosis of dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) with the development of [123I] metaiodobenzylguanidine (MIBG) scintigraphy. Decreased MIBG uptake, which reflects cardiac sympathetic denervation, has been detected in DLB, but not in AD. However, the time course of detected cardiac sympathetic degeneration is poorly understood in DLB. Herein, the authors report two patients with a clinical diagnosis of amnestic mild cognitive impairment (MCI) who had cardiac sympathetic denervation, detected by cardiac (123)I-MIBG scintigraphy, without the core clinical features of DLB. One amnestic MCI patient had nocturnal dream enactment behavior, consistent with clinically probable REM sleep behavior disorder (RBD), and converted to probable DLB with the development of recurrent visual hallucination and spontaneous parkinsonism two years after MCI is diagnosed. The other amnestic MCI patient exhibited occipital metabolic reduction on [18F]-fluoro-d-glucose (FDG) positron emission tomography (PET) scan, which is the preferentially affected region in DLB patients, although she had no core or suggestive clinical features of DLB. Both patients had abnormal findings on electrocardiogram at annual health checkups despite having no cardiac-related symptoms. Detailed clinical examinations, including angiography and echocardiogram, revealed no overt etiology, supporting the idea that cardiac sympathetic denervation is due to underlying Lewy body disease. The clinical courses of these patients suggest that (123)I-MIBG cardiac scintigraphy is useful for the detection of DLB in the predementia phase, even before core clinical features appear.     

Präsenile Demenz vom Alzheimer-Typ mit sekundärem Parkinson-Syndrom

This case report describes long-term occupational exposure to agricultural insecticides, herbicides, and pesticides as possible environmental risk factors of Alzheimer's disease (AD) and Parkinson's syndrome in a 59-year-old man. Initially the patient complained about disturbances in concentration, mnestic deficits, and problems finding words. In the further course of the disease, he developed Parkinson's syndrome with predominant hypokinesia and rigor in addition to mild-to-moderate dementia. Low levels of beta-amyloid 1-42 were found in the CSF. Electroencephalography showed left frontotemporal theta waves. Cranial MRI revealed general brain atrophy with a maximum biparietally. In cerebral positron emission tomography, general hypometabolism was found with maxima biparietally and left frontally. The possible differential diagnosis of AD and Parkinson's syndrome is discussed.     

Neuroimaging in dementia with Lewy bodies: metabolism,neurochemistry, and morphology

Dementia with Lewy bodies (DLB) is recognized as one of the most common forms of neurodegenerative dementia. Neuroimaging contributes to a better understanding of the pathophysiology of DLB by examining alterations in brain metabolism, neurochemisty, and morphology in living patients. Neuroimaging can provide objective and quantifiable antemortem markers for the presence of and the progression of DLB and permits differentiation from other dementias. This article reviews current neuroimaging findings in DLB with particular attention to occipital hypometabolism, dopaminergic and cholinergic deficits, and medial temporal lobe atrophy as measured by positron emission tomography, single-photon emission computed tomography, and magnetic resonance imaging.     

An Electron Microscopic Study on Atypical Presenile Dementia with Numerous Lewy Bodies in the Cerebral Cortex

Abstract: A report was made of an autopsied case of presenile dementia presenting the clinically characteristic symptoms of Alzheimer's disease and Pick's disease. The neuropathological findings were senile changes, namely, numerous senile plaques, neurofibrillary tangles, granulovacuolar degeneration and Pick bodies, etc., and numerous Lewy bodies in the brain stem and in the cerebral cortex. We studied mainly the ultrastructure of Lewy bodies in the cerebral cortex in this paper. The features of ultrastructural components of Lewy bodies presented types which might correspond to the various profiles of Lewy bodies observed by a light microscope. In addition, we studied the senile changes in the cerebral cortex ultrastructurally and considered that some relationship possibly existed between Lewy bodies and senile changes.     

Cortical Lewy body dementia: clinical features and classification.

Seven patients, aged 65-72 years, are described with dementia and cortical Lewy bodies. In one patient a Parkinsonian syndrome was followed by dementia and motor neuron disease. In the remaining six patients dementia was accompanied by dysphasia, dyspraxia and agnosia. One developed a Parkinsonian syndrome before the dementia, in three cases a Parkinsonian syndrome occurred later, and in two cases not at all. All patients showed Lewy bodies and cell loss in the substantia nigra, locus coeruleus and dorsal vagal nucleus, as in Parkinson's disease. The severity of cell loss in the nucleus basalis varied from mild to severe. Lewy bodies were also present in the parahippocampus and cerebral cortex, but Alzheimer-type pathology was mild or absent, and insufficient for a diagnosis of Alzheimer's disease. Patients with moderate or severe dementia, some with temporal or parietal features, may have cortical Lewy body disease, Alzheimer's disease, or a combination of the two. Cortical Lewy body disease may be associated with dementia in Parkinson's disease more often than realised, but is not necessarily associated with extensive Alzheimer pathology.     

Surface dyslexia in chinese

abstract

We report a diagnostically challenging case of a 64-year-old man with a history of remote head trauma who developed mild behavioral changes and dyscalculia. He was diagnosed with clinical Alzheimer’s disease (AD), with additional features consistent with behavioral variant frontotemporal dementia. Structural magnetic resonance imaging revealed atrophy in bilateral frontal and parietal cortices and hippocampi on visual inspection and left frontal pole and bilateral anterior temporal encephalomalacia, suspected to be due to head trauma. Consistent with the diagnosis of Alzheimer’s pathology, positron emission tomography (PET) with Pittsburgh compound B suggested the presence of beta-amyloid. Fluorodeoxyglucose PET demonstrated hypometabolism in bilateral frontal and temporoparietal cortices. Voxel-based morphometry showed atrophy predominant in ventral frontal regions (bilateral orbitofrontal cortex, pregenual anterior cingulate/medial superior frontal gyrus), bilateral mid cingulate, bilateral lateral temporal cortex, and posterior insula. Bilateral caudate, thalamus, hippocampi, and cerebellum were prominently atrophied. Unexpectedly, a pathologic hexanucleotide repeat expansion in C9ORF72 was identified in this patient. This report underscores the clinical variability in C9ORF72 expansion carriers and the need to consider mixed pathologies, particularly when imaging studies are inconsistent with a single syndrome or pathology.     

Molecular imaging with Pittsburgh Compound B confirmed at autopsy: a case report

OBJECTIVE: To determine the correspondence between uptake of Pittsburgh Compound B (PiB) in life and measures of beta-amyloid (Abeta) in postmortem tissue analysis. Patient A 76-year-old man with a clinical diagnosis of dementia with Lewy bodies underwent fluorodeoxyglucose (18)F and PiB positron emission tomographic brain scans. Imaging revealed marked region specific binding of PiB and abnormal fluorodeoxyglucose uptake. Intervention Autopsy was performed 3 months after the PiB scan. RESULTS: Autopsy confirmed the clinical diagnosis; in addition, there was severe cerebral amyloid angiopathy and only moderate numbers of parenchymal Abeta plaques. Biochemical measures revealed a positive correlation between Abeta levels and regional PiB binding. CONCLUSION: This report confirms that PiB detects Abeta in the living patient and demonstrates that amyloid deposited as cerebral amyloid angiopathy can be the dominant source of signal.     

Occipital glucose metabolism in dementia with lewy bodies with and without Parkinsonism: a study using positron emission tomography

Reduction of glucose metabolism in the occipital lobe is reported in dementia with Lewy bodies (DLB) and Parkinson's disease. If dysfunction of the nigrostriatal system is responsible for occipital hypometabolism, (1) DLB patients with parkinsonism would show a lower occipital metabolism than do patients without parkinsonism, and (2) DLB patients without parkinsonism would show an occipital metabolism comparable to those of normal subjects and patients with Alzheimer's disease (AD). To examine these hypotheses, we studied the regional cerebral metabolic rate of glucose (rCMRglc) in patients with a clinical diagnosis of DLB or AD, using (18)F-fluorodeoxyglucose and positron emission tomography. The subjects consisted of 15 DLB patients with parkinsonism, 7 DLB patients without parkinsonism and 7 AD patients without parkinsonism. The medial and lateral occipital rCMRglc was significantly lower in the DLB patients without parkinsonism than in the AD patients. There were no significant differences in occipital metabolic rates between the DLB groups with and without parkinsonism. DLB patients without parkinsonism showed a significant reduction of occipital glucose metabolism which is comparable with that of DLB patients with parkinsonism. The neurobiological bases of occipital hypometabolism in DLB may be pathological processes in the brainstem or basal forebrain structures other than the nigrostriatal system.     

Diffuse occipital hypometabolism on [18F]‐FDG PET scans in patients with idiopathic REM sleep behavior disorder: Prodromal dementia with Lewy bodies?

Background: Previous longitudinal studies have revealed that specific patterns on [¹⁸F]‐fluoro‐d ‐glucose (FDG) positron emission tomography (PET) scans in patients with amnesic mild cognitive impairment can predict Alzheimer's disease (AD). However, the significance of particular patterns on [¹⁸F]‐FDG PET scans in prodromal patients with dementia with Lewy bodies (DLB) remains unclear. Methods: Based on the prevailing evidence that rapid eye movement (REM) sleep behavior disorder (RBD) often precedes the onset of DLB, [¹⁸F]‐FDG PET scans of nine non‐demented patients reporting recurrent nocturnal dream‐enactment behavior in our memory clinic were compared with the normative database using three‐dimensional stereotactic surface projection (3D‐SSP) images. All patients underwent clinical and neuropsychological examinations as well as cardiac [¹²³I]‐metaiodobenzylguanidine ([¹²³I]‐MIBG) scintigraphy. Results: Four patients were found to have diffuse areas of reduced cerebral metabolic rate of glucose (CMRglc), predominantly in the occipital lobe, which is the preferentially affected region in DLB patients. In constrast, five patients showed no such occipital hypometabolism; instead, these five patients showed hypometabolism in the left anterior cingulate gyrus (Broadmann area (BA) 24), right frontal lobe (BA 32) and right anterior temporal lobe (BA 38), which are the preferentially affected regions in Parkinson's disease rather than DLB. The extent of the reduction in CMRglc in the left occipital lobe was correlated with scores on the Bender Gestalt Test, which reflects visuospatial ability, but not with global cognitive measures. All patients showed reduced cardiac [¹²³I]‐MIBG levels, consistent with underlying Lewy body disease. Conclusion: These variations in [¹⁸F]‐FDG PET scans raise the possibility that the specific pattern of CMRglc reduction may predict developing DLB in patients with idiopathic RBD. Further follow‐up studies are needed, particularly on patients with diffuse occipital hypometabolism.