Frontal lobe degeneration of non-Alzheimer type. Structural characteristics, diagnostic criteria and relation to other frontotemporal dementias.

Frontal lobe degenerative dementias, the second largest degenerative dementia group after Alzheimer's disease, is dominated by frontal lobe degeneration of non-Alzheimer type. It is classified in a group also containing Pick's disease, progressive aphasia and dementia in motor neuron disease. Frontal lobe degeneration of non-Alzheimer type is clinically marked by frontal lobe symptoms and frontotemporal reduction of blood flow. From a histopathological point of view it is characterized by gliosis, microvacuolation, neuronal atrophy-loss and 40-50% loss of synapses in three superficial cortical laminae of the frontal convexity and anterior temporal cortex, while the deeper laminae are little or not changed. The structural changes of Alzheimer's disease including amyloid, Levy body dementia and Pick's disease are entirely lacking. A strong heredity points to a genetic cause as yet undefined.

Decreased monoamine metabolites in frontotemporal dementia and Alzheimer's disease.

The concentrations of the monoamine metabolites homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol (HMPG) in the cerebrospinal fluid (CSF) of patients with clinical frontotemporal dementia (FTD; n = 30), early onset Alzheimer's disease (EAD; n = 33), late onset Alzheimer's disease (LAD, n = 27) and normal controls (n = 31) were determined using HPLC. ANCOVA showed no significant effect of neuroleptic medication, extrapyramidal signs, myoclonia or gender on the CSF levels of the monoamine metabolites. Homovanillic acid was significantly reduced in all diagnostic groups (FTD, p = 0.0002; EAD, p = 0.016; LAD, p = 0.013). 5-Hydroxyindoleacetic acid was significantly reduced in EAD (p = 0.013) and in LAD (p = 0.0014), and HMPG was reduced in LAD only (p = 0.020). HMPG was significantly higher in FTD compared to EAD (p = 0.0005) and LAD (p = 0.0003). CSF-5-HIAA was significantly reduced in patients with antidepressant medication (p = 0.006). ANCOVA within the FTD group showed no significant effect of neuroleptic or antidepressant medication, extrapyramidal signs, myoclonia, gender or FTD subtype on the CSF levels of the monoamine metabolites. The results suggest that CSF-HMPG might differentiate FTD from EAD and LAD, but not from normals.

Frontotemporal lobar degeneration: a consensus on clinical diagnostic criteria.

OBJECTIVE: To improve clinical recognition and provide research diagnostic criteria for three clinical syndromes associated with frontotemporal lobar degeneration. METHODS: Consensus criteria for the three prototypic syndromes-frontotemporal dementia, progressive nonfluent aphasia, and semantic dementia-were developed by members of an international workshop on frontotemporal lobar degeneration. These criteria build on earlier published clinical diagnostic guidelines for frontotemporal dementia produced by some of the workshop members. RESULTS: The consensus criteria specify core and supportive features for each of the three prototypic clinical syndromes and provide broad inclusion and exclusion criteria for the generic entity of frontotemporal lobar degeneration. The criteria are presented in lists, and operational definitions for features are provided in the text. CONCLUSIONS: The criteria ought to provide the foundation for research work into the neuropsychology, neuropathology, genetics, molecular biology, and epidemiology of these important clinical disorders that account for a substantial proportion of cases of primary degenerative dementia occurring before the age of 65 years.

Brain function in spider phobia.

Measurements of regional cerebral blood flow (rCBF) were performed in 16 women suffering from spider phobia. The non-invasive 133Xe inhalation method, giving information about the blood flow of superficial areas, was used. The subjects were studied under three conditions: during resting, when exposed to a videotape showing nature scenery, and finally when watching a video with living spiders. During the rCBF measurements the subjects' behaviour was registered systematically and respiration, blood pressure, Pco2, and heart rate were monitored. Eight subjects who showed and reported severe panic during the spider exposure had marked rCBF decreases in frontal areas, especially in the right hemisphere. The remaining eight subjects displayed a more efficient control of their emotions and became frightened, but not panic-stricken, during the spider exposure. These showed a consistent rCBF increase in the right frontal area compared to neutral stimulation. Thus, results revealed significant functional changes in the frontal cortex in subjects with spider phobia during phobogenic exposure. It seems likely that these frontal changes are related to the experience and control of phobic anxiety.

Blood pressure and drug treatment in clinically diagnosed Lewy body dementia and Alzheimer's disease.

The aim of the study was to investigate arterial blood pressure (BP) and the use of pharmacological treatment in patients with Lewy body dementia (cLBD) and Alzheimer's disease (cAD) diagnosed on clinical grounds. BP and pharmacological treatment was analysed based on the medical records of 200 deceased dementia patients. Forty-eight cases with LBD and 45 AD were diagnosed using clinical criteria. The patients, who died between 1985 and 1994, were part of a prospective longitudinal dementia project. The majority of the cases were examined and cared for at the psychogeriatric and psychiatric departments. BP levels were very similar at an early stage of dementia but there was a marked decrease during the course of dementia in cAD and cLBD. The cLBD cases became hypotensive during the course of dementia to a significantly greater extent and also had a more pronounced drop in systolic BP at orthostatic testing compared to the cAD cases. cLBD and cAD were prescribed neuroleptics and medication potentially associated with hypotension to the same extent. The total number of these drugs was however higher in cLBD than in cAD. Antiparkinsonian treatment was, as expected, more common in cLBD compared to cAD. The findings suggest that insufficient BP regulation and drug treatment could affect the clinical picture of dementia, particularly in cLBD patients.

[Harmonization of dementia diagnoses--a necessary quality assurance]. / Harmonisering av demensdiagnoser--en nödvändig kvalitetssäkring.

Classification and registration of diseases is necessary in order to monitor the proliferation of diseases in a population. Despite the presence of an international framework for classification of diseases (ICD 10) which has been approved by the Swedish authorities, the guidelines provided are not observed in the area of dementia diseases. Different diagnoses can be used to describe the same condition, and "dementia unspecified" is sometimes employed when a specified diagnosis could have been used. In order to refine consensus regarding the use of different diagnoses in the dementia field, representatives for the Swedish University hospitals and medical faculties propose a unified description of a limited number of dementia diagnoses.

Attempts to improve absolute quantification of cerebral blood flow in dynamic susceptibility contrast magnetic resonance imaging: a simplified T1-weighted steady-state cerebral blood volume approach.

BACKGROUND: Attempts to retrieve absolute values of cerebral blood flow (CBF) by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) have typically resulted in overestimations. PURPOSE: To improve DSC-MRI CBF estimates by calibrating the DSC-MRI-based cerebral blood volume (CBV) with a corresponding T1-weighted (T1W) steady-state (ss) CBV estimate. MATERIAL AND METHODS: 17 volunteers were investigated by DSC-MRI and 133Xe SPECT. Steady-state CBV calculation, assuming no water exchange, was accomplished using signal values from blood and tissue, before and after contrast agent, obtained by T1W spin-echo imaging. Using steady-state and DSC-MRI CBV estimates, a calibration factor K = CBV(ss)/CBV(DSC) was obtained for each individual. Average whole-brain CBF(DSC) was calculated, and the corrected MRI-based CBF estimate was given by CBF(ss) = K x CBF(DSC). RESULTS: Average whole-brain SPECT CBF was 40.1+/-6.9 ml/min x 100 g, while the corresponding uncorrected DSC-MRI-based value was 69.2+/-13.8 ml/min x 100 g. After correction with the calibration factor, a CBF(ss) of 42.7+/-14.0 ml/min x 100 g was obtained. The linear fit to CBF(ss)-versus-CBF(SPECT) data was close to proportionality (R = 0.52). CONCLUSION: Calibration by steady-state CBV reduced the population average CBF to a reasonable level, and a modest linear correlation with the reference 133Xe SPECT technique was observed. Possible explanations for the limited accuracy are, for example, large-vessel partial-volume effects, low post-contrast signal enhancement in T1W images, and water-exchange effects.

Functional imaging of the frontal lobes in organic dementia. Regional cerebral blood flow findings in normals, in patients with frontotemporal dementia and in patients with Alzheimer's disease, performing a word fluency test.

Patterns of functional cortical activation were studied by means of regional cerebral blood flow measurements, performed during rest and during a word fluency task in normal subjects (n = 22), in patients with Alzheimer's disease (n = 17), and in patients with frontotemporal dementia (n = 15). Although all groups showed a significant activation of the Broca's area during word production, the activation of the dorsolateral prefrontal cortex was clearly subnormal in both dementia groups. The frontal dysfunction was not explained by number of words produced, illness duration, or age. Thus, the results demonstrate that the word fluency task is a sensitive measure of frontal lobe function, and its incorporation in imaging studies may facilitate the detection of subtle functional impairment of the frontal lobes in organic dementia.

Functional activation of the frontal lobes. Regional cerebral blood flow findings in normals and in patients with frontal lobe dementia performing a word fluency test.

The present study examined the utility of the Word Fluency Test (WFT) as a frontal-lobe-activating test in brain imaging. Regional cerebral blood flow (rCBF) was measured during rest and during the WFT in 49 healthy volunteers and in 15 patients with frontal lobe dementia (FLD). The results showed a highly significant frontal lobe activation in 85% of the normal subjects. This finding was not related to age or to the level of performance on the WFT. A significant frontal activation was seen in 13 of the 15 FLD patients. The frontal flow increase did not reach normal levels, and was not related to age, illness duration or severity of clinical symptoms. The results suggest that the WFT is an ideal test to use in conjunction with functional imaging in normals as well as in patients with organic dementia.

Orthostatic hypotension and low blood pressure in organic dementia: a study of prevalence and related clinical characteristics.

OBJECTIVE: To determine the prevalence of orthostatic hypotension (OH), low blood pressure and dizziness, falls and fractures in patients with organic dementia. DESIGN: We prospectively studied 151 patients, assessing the prevalence of OH, hypertension, heart disorders, diabetes mellitus and the use of medication possibly associated with OH. SETTING: The patients were admitted to our psychogeriatric clinic as part of routine clinical investigation of their dementia. PATIENTS: Forty-six patients with Alzheimer's disease (AD), 28 patients with frontotemporal dementia (FTD) and 77 patients with vascular dementia (VaD) were investigated. MAIN OUTCOME MEASURE: Due to the paucity of information about the prevalence of OH in organic dementia, this study is mainly explorative in nature, thus preventing explicit hypothesis formulation. However, clinical impressions indicated a higher prevalence of OH in organic dementia than normally seen in healthy elderly. RESULTS: OH/low blood pressure was present in 39-52% of the patients. The majority reached their maximum systolic decrease within 5 minutes of standing, but in 20-30% the maximum blood pressure drop occurred after 5 minutes or later. In 38%, the systolic blood pressure drop was more than 40 mm Hg. Hypertension and heart disease was found only in AD and VaD, with no difference between those with and without OH/low blood pressure. Falls and fractures were common in orthostatic and hypotensive patients, with an incidence of more than 50% in AD and VaD. CONCLUSIONS: The results support our clinical impressions that OH and low blood pressure is common and an important factor in organic dementia.

Frontal lobe degeneration of non-Alzheimer type.

In a longitudinal prospective study of dementias, several hundred cases have been examined from a clinical, brain imaging, neurochemical and neuropathological point of view. Frontal lobe degeneration of non-Alzheimer type (FLD) was the second most common primary degenerative dementia found in about 10% of the material. FLD has a consistent pathology and a characteristic clinical picture, which have been described by several independent research groups. The cortical degeneration mainly involves frontal or frontotemporal grey matter, without the circumscribed or knife-blade atrophy seen in Pick's disease. The degeneration involves predominantly frontal areas, including the insula and cingulate gyrus in its anterior parts. The striate body is normal or only slightly altered. The pathological changes are non-specific, with neuronal loss, slight gliosis and spongiosis but none or few senile plaques, tangles, congophilic vessels or Pick cells. Pathological changes are in some respects similar to those in amyotrophic lateral sclerosis. FLD is a slowly progressive dementia with personality changes, lack of insight, disinhibition, stereotypy and later apathy. There is also progressive dynamic aphasia which ends in mutism and amimia. Memory, spatial ability and receptive language functions are comparatively spared. Psychotic symptoms, emotional reactions, hypochondriasis and a Klüver-Bucy-like syndrome are sometimes observed. Electroencephalography is normal, at least during the early stage, while functional brain imaging such as regional cerebral blood flow reflects the frontal pathology. It is possible to achieve early diagnosis and differentiation from Alzheimer's disease and cerebrovascular dementia by clinical examination with neuropsychological assessment supported by brain imaging, and in the future probably various biological markers. The aetiology is unknown but there is a positive family history for dementia of similar type in about 50% of post-mortem verified cases.

Spectrum of frontal lobe dementia in a Swedish family.

The etiology of frontal lobe dementia of non-Alzheimer type (FLD) is still unknown. There is strong evidence of genetic factors with positive heredity. In this paper, a Swedish family, with several generations affected by FLD is described. In 3 patients typical FLD was confirmed postmortem. The clinical and neuropathological similarities between the patients are impressive.

Neuropsychological findings in frontal lobe dementia.

Neuropsychological investigations were performed on 18 patients with a clinical diagnosis of frontal lobe dementia supported by regional cerebral blood flow measurements. Nature and degree of cognitive impairment were examined with a comprehensive test battery. The results of the neuropsychological assessment could be described as three levels of cognitive impairment. The increasing levels of cognitive impairment were accompanied by corresponding levels of reduced cerebral blood flow in frontotemporal areas. No apparent relationship emerged between impairment level and illness duration, indicating a considerable individual variation in the clinical course of frontal lobe dementia.

Clinical Lewy body dementia and the impact of vascular components.

OBJECTIVE: To study the prevalence of patients fulfilling the clinical consensus criteria for dementia with Lewy bodies (DLB) in a dementia population followed up with postmortem examination. To compare the clinical and neuropathological findings in the clinical Lewy body dementia (LBD) group with findings in a clinically defined group with Alzheimer's disease (AD). DESIGN: Medical records from 200 patients were studied retrospectively. Clinical consensus criteria for DLB and clinical criteria for other dementias were applied. SETTING: The majority of the cases were examined and cared for in psychogeriatric and psychiatric departments. PATIENTS: The patients, who died between 1985 and 1994, were part of a longitudinal dementia project. Each case was neuropathologically examined. Main outcome measures Prevalence of clinical signs and neuropathology was compared between the clinical groups. RESULTS: Forty-eight (24%) patients fulfilled the clinical criteria for DLB while 45 (22%) fulfilled the clinical criteria for Alzheimer's disease. The clinical LBD group had a higher Hachinski score compared to the clinical AD group. They also showed a tendency towards a 'frontal profile' with disinhibition, confusion, personality change and vocally disruptive behaviour. More than 80% of the AD and LBD groups respectively exhibited Alzheimer pathology. The LBD group had frontal white matter pathology and degeneration of the substantia nigra more often than the clinical AD group. Both LBD and AD groups showed a progressive and marked increase in severity of dementia and decrease in ADL capacity according to an evaluation based on the Berger scale and Katz index. The condition of the LBD group was significantly worse earlier in dementia. CONCLUSION: The results of this study indicate that patients fulfilling the clinical criteria for DLB also exhibit clinical features of possible vascular origin and a frontal profile. Subcortical vascular pathology, nigral degeneration and AD pathology in this group could partly explain the clinical features used to define DLB.

Neuropathological correlates to clinically defined dementia with Lewy bodies.

OBJECTIVES: To analyse the neuropathological changes behind clinically defined dementia with Lewy bodies (clinDLB) compared with clinically diagnosed Alzheimer's disease (clinAD). METHODS: The prevalence of neuropathological findings in 48 clinDLB and 45 clinAD cases was compared. Sixteen clinDLB and 10 clinAD cases were reassessed with alpha-synuclein staining for Lewy bodies (LB). RESULTS: Alzheimer pathology was found in 81% of the clinDLB and 93% of the clinAD cases. The clinDLB group had a higher prevalence of frontal white matter pathology, mostly of ischemic type, and a more severe degeneration of the substantia nigra compared with the clinAD group. In hematoxylin-eosin staining, LBs were identified in seven (15%) of the clinDLB and in four (9%) of the clinAD group. In alpha-synuclein staining, 38% of the clinDLB and 40% of the clinAD cases exhibited LBs. The cases without LBs, in the clinDLB group, had AD pathology in combination with frontal white matter disease. Vascular pathology of significant degree was prevalent in more than 40% of all the cases with verified LBs regardless of clinical diagnosis. CONCLUSION: Consecutive dementia cases, fulfilling the clinical consensus criteria for DLB, may exhibit combinations of neuropathological changes which in themselves can explain the clinical picture of DLB even when LBs are absent.

Regional cerebral blood flow in frontal lobe dementia of non-Alzheimer type.

Twenty-five out of 26 cases of autopsy-verified frontal lobe degeneration of non-Alzheimer type (FLD) were found to have focal frontal or frontotemporal blood flow reductions involving both hemispheres. The deviant case had an asymmetric frontal pathology only apparent on the right side. Focal reduction of blood flow in the frontal lobes is, however, a common and unspecific flow abnormality found in e.g. Pick's disease. Creutzfeldt-Jakob's disease, and in some cases of Alzheimer's disease. Low frontal flow has also been reported in schizophrenia and in toxic encephalopathy. Since a characteristic feature of FLD is a steady progress of the pathology, serial flow measurements extending over several years are especially informative.

Performance on neuropsychological tests related to single photon emission computerised tomography findings in frontotemporal dementia.

BACKGROUND: This study examines relations between regional cerebral blood flow (rCBF) and neuropsychological test results, age at onset and duration of disease in patients with frontotemporal-type dementia (FTD). METHOD: Sixteen patients with a diagnosis of probable FTD were examined using single photon emission computerised tomography (SPECT) with 99mTc-HMPAO as the tracer. The rCBF of 14 regions of interest relative to cerebellar blood flow was calculated. Psychological tests assessing language, verbal fluency, memory and visuospatial constructive ability were given. RESULTS: Correlations were demonstrated between a global impairment score and relative blood flow in lateral frontal, medial frontal and left orbital frontal areas. Verbal fluency scores correlated with left lateral frontal, medial frontal and left anterior inferior temporal blood flow. No relationships between decrease in CBF and age at onset or duration of disease, or between impaired cognitive function and age at onset or duration of disease were found. CONCLUSIONS: The present study demonstrates a close coupling between reduced rCBF and specific neuropsychological deficits in FTD.