Non-Alzheimer degenerative dementias

Treatment of Alzheimer's Disease: Current Management and Experimental Therapeutics

Alzheimer's disease (AD) is a major cause of morbidity in the elderly. AD affects aver 5 million persons in the United States, but because it increases in incidence in the elderly, and the "graying" population, AD is projected to increase in prevalence by many-fold over the coming decades. AD causes progressive mental impairment, resulting in the inability of persons to care for themselves. As a consequence, AD results in enormous costs to society due to both lost productivity, and required care. Thus, improved management and treatment is essential. In this review we will briefly review current understanding of the disease, including roles of beta-amyloid and tau proteins. We will then discuss current therapies in use, including the evidence for treatments with supplements, established drugs, and investigational therapeutic strategies, recently completed and ongoing.

Grief experiences of 3 caregiving wives of veterans with dementia

Three wives share their experiences of caregiving for husbands with dementia. The 3 husbands, aged 51, 71, and 84, developed dementia following years of devoted military service. To present lived experiences of caregiving wives', meanings attributed to caregiving are investigated, variations in caregiving and grieving experiences are explored, and therapeutic implications are offered. Through case study approach and with issues of caregiver grief considered, we introduce life course and ambiguous loss theoretical perspectives. Emergent qualitative themes and quantitative inventory ratings indicate significant differences in caregiver grief response depend on care-recipient age. Practice implications and directions for future care recipient, age-related research are presented.

The spectrum of recurrent thoughts and behaviors in frontotemporal dementia

This article describes the spectrum of recurrent thoughts and behaviors that can result from frontotemporal dementia (FTD) and its variants. Although repetitive behaviors can result from a range of brain disorders, FTD is the most common neurologic cause of new-onset recurrent thoughts and behaviors in middle or late life. Patients with FTD can manifest typical or bizarre compulsions, hoarding, verbal and motor stereotypies and complex tics; self-injurious acts, perseverations; and fixed, obsessional thoughts. The frequency and variability of these repetitive behaviors suggest a common disturbance of orbitofrontal-basal ganglia circuits involved in response inhibition. The amelioration of these recurrent events with the administration of serotonin selective reuptake inhibitors further suggests a serotonergic deficit.

Neurophysiologie de la dégénérescence corticobasale

INTRODUCTION

Corticobasal degeneration (CBD) is a neurodegenerative disorder of mid- to late-adult life. From a clinical standpoint, CBD is characterized by (i) an insidious onset and a slowly progressing, unilateral, levodopa-unresponsive parkinsonian syndrome with dystonia or myoclonus and (ii) cerebral features such as apraxia, alien limb phenomena and cortical sensory loss. Decisive clinical diagnostic criteria are not available and thus a neuropathological study remains essential for accurate CBD diagnosis. Consequently, additional non-clinical criteria must be identified in order to improve diagnosis while patients are still alive.

BACKGROUND

Electrophysiological exploration can yield functional information on a number of brain structures (both cortical and sub-cortical) involved in CBD. The disorder features a specific cortical (frontoparietal) alteration which could help with differential diagnoses for other extrapyramidal syndromes. Hence, exploration of a patient's myoclonus can provide some specific arguments for CBD. Indeed, myoclonus displays a number of clinical and electromyographical characteristics which are consistent with a cortical origin (a shorter latency of the cortical C response, for example). However, some typical cortical features are missing (giant somesthesic evoked potentials, and cortical potentials preceding myoclonus in jerk-locked back-averaging studies). Some authors explain these abnormalities in terms of a sub-cortical origin for the myoclonus. The frontoparietal alteration in CBD has also been explored in studies of oculomotor movement. Indeed, asymmetric lengthening of the lateral ocular saccade latency argues more in favour of CBD than progressive supranuclear palsy. Moreover, cognitive function is also compromised in the early stages of CBD, although it is sometimes difficult to distinguish between CBD, PSP and frontotemporal dementia. Studying cognitive potentials enables one to confirm subcorticofrontal abnormalities and to dissociate CBD patterns from PSP patterns. Other electrophysiological tests (such as the exploration of dysautonomia, the palmomental reflex and the blink reflex) produce results which overlap with those seen in extrapyramidal syndromes and synucleinopathies (polysomnography), prompting discussion of the physiopathological mechanisms of these various diseases.

CONCLUSION

Electrophysiological exploration is of value for diagnosing CBD in general and for studying specific, frontoparietal dysfunctions in particular. These techniques could also significantly contribute to our understanding of the physiopathology of CBD.

Combining the Memory Impairment Screen and the Isaacs Set Test: A Practical Tool for Screening Dementias

OBJECTIVES

To assess the accuracy of combining the Memory Impairment Screen (MIS) with the Isaacs Set Test (IST) in distinguishing subjects with dementia from controls without dementia.

DESIGN

The weighted sum of MIS and IST scores was calculated, and the logical "or" rule combination was performed using two different patient and control samples. Combination results were compared with each test used alone and with Mini-Mental State Examination to detect all types of dementias.

SETTING

Database of the Regional Network for Diagnostic Aid and Management of Patients with Cognitive Impairment in the Franche-Comté, France, geographical area.

PARTICIPANTS

A cohort of 444 patients with Alzheimer's disease, non-Alzheimer's dementia, and reversible dementia and 311 controls.

MEASUREMENTS

Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the combination of these two tests.

RESULTS

The weighted sum had overall sensitivities of 0.92 and 0.84 for mild cases, with a specificity of 0.92. The "or" rule had overall sensitivities of 0.92 and 0.89 for mild cases, with a specificity of 0.90. This pairing requires no more than 5 minutes. Its scoring is simple with the "or" rule combination.

CONCLUSIONS

The combination of MIS and IST could be a useful tool for screening dementias. The "or" rule combination seems particularly adapted to medical practice.

Neuropsychological differences between frontotemporal dementia and Alzheimer's disease: a review

This paper surveys the similarities and differences between frontotemporal dementia (FTD) and Alzheimer's disease (AD). The review covers findings primarily from neuropsychological studies on memory, language, attention/executive function, and visuospatial abilities. However, neuropsychiatric and neuroimaging data are also briefly discussed. Distinguishing features of both FTD and AD are described in order to present a comprehensive clinical picture of these dementing diseases, which is essential for the process of differential diagnosis. The cause of specific cognitive deficits is also considered. Our comprehensive review of the empirical literature reveals that AD is characterized by early memory loss and visuospatial problems, while among the main features of FTD are behavioral abnormalities and executive dysfunctions.

Neuropsychology for movement disorders neurosurgery

The neuropsychologist plays a crucial role in three phases of the neurosurgical treatment of movement disorder patients, namely screening, outcome evaluation and research. In screening patients, the differential diagnosis of dementia, impact of depression or other psychiatric conditions, and the influence of disease and medication-induced symptoms on cognitive performance must be determined. Postoperatively, systematic evaluations elucidate the cognitive costs or benefits of the procedure. The neuropsychologist is then able to provide feedback and counselling to the professional staff, patient and family to inform management strategies. Neuropsychologists also study alteration of cognitive processing due to lesions or stimulation, which, in tandem with functional imaging, shed light on plasticity in cortical and subcortical processing.

Frontotemporal lobar degeneration: a study in Japan

Frontotemporal lobar degeneration is the most common form of cortical dementia occurring in the presenium after Alzheimer's disease. We analyzed two types of frontotemporal dementia (FTD) and semantic dementia (SD) selected from a consecutive series of outpatients based on neuropsychological symptoms, psychiatric symptoms and abnormal behavior. In our series of 134 patients with primary degenerative dementia, there were 16 cases of FTD and 6 cases of SD. Patients with subgroups of FTD and patients with SD were distinguishable only by the presence of aphasia in the latter group. They were not distinguishable from one another by other neuropsychological examinations, behavioral abnormalities or psychiatric symptoms assessed with the Neuropsychiatric Inventory.

Recent developments in Alzheimer's disease

Alzheimer's disease is the most frequent form of dementia and it is estimated that its prevalence will quadruple by the year 2050. In the past decade, a number of important new developments have provided insight in the pathogenesis, improved diagnosis and allowed therapy of dementia. Several new mutations in the amyloid protein precursor gene, presenilin-1 and -2 genes and the influence of the apolipoprotein E gene isotypes on the disease phenotype have been described. The role of secretases in the generation of amyloid in senile plaques has been determined and this may provide important new therapeutic approaches in the future. The role of vascular lesions in the development of dementia and relationship with the Lewy body variant of Alzheimer's disease have been refined. Acetylcholine is deficient in Alzheimer's disease and can be supplemented in part by treatment with acetylcholinesterase inhibitors. Recently, surprising results of vaccination with amyloid in a transgenic mouse model have opened a completely new perspective in the prevention and treatment of Alzheimer's disease.

Parkinson's disease with late Pick's dementia

We report a case in which typical clinical features of idiopathic Parkinson's disease existed for seven years prior to the development of significant behavioral and cognitive changes and severe dementia. The patient presented with right-sided resting tremor, bradykinesia, and rigidity, which were highly responsive to levodopa. Serial neuropsychological evaluation revealed no evidence of dementia until late in the disease. The patient deteriorated rapidly eight years into the disease, requiring full care. She died 16 years after symptom onset and post-mortem neuropathological analysis revealed Lewy body Parkinson's disease and Pick's disease. To our knowledge, this is the first non-familial case with this combination of clinical history and pathologically confirmed disease to be reported in the literature. The absence of a family history of any neurological disease sets this case apart from the recently described genetic cases of frontotemporal dementia with Parkinsonism linked to chromosome 17. In addition, the relatively late onset of dementia in frontotemporal dementia is atypical. While there is considerable debate regarding the cause of dementia in idiopathic Parkinson's disease, our case illustrates that Pick's disease is one such cause.

Magnetic resonance imaging and magnetic resonance spectroscopy in dementias

This article reviews recent studies of magnetic resonance imaging and magnetic resonance spectroscopy in dementia, including Alzheimer's disease, frontotemporal dementia, dementia with Lewy bodies, idiopathic Parkinson's disease, Huntington's disease, and vascular dementia. Magnetic resonance imaging and magnetic resonance spectroscopy can detect structural alteration and biochemical abnormalities in the brain of demented subjects and may help in the differential diagnosis and early detection of affected individuals, monitoring disease progression, and evaluation of therapeutic effect.

Neuropsychologic assessment of patients for movement disorder surgery

The neuropsychologic evaluation of patients under consideration for movement disorder surgery is recognized as being an essential component of the preoperative process. Patients with early-stage concomitant dementia must be identified and the relative risk of postoperative cognitive decline evaluated. Knowledge of the patterns of an individual's strengths and weaknesses might also be a factor in deciding on a neurosurgical procedure. Although the advent of pallidal deep brain stimulation (DBS) has possibly resulted in reduced risk of induced cognitive impairment, even this procedure has been associated with negative sequelae. DBS within the subthalamic nucleus is becoming the method of choice and this may lead to cognitive and behavioral compromise, especially in the elderly patient. The team considering the establishment of neurosurgical treatment is often at a loss to decide how much neuropsychologic testing is required to determine relative risks of cognitive or behavioral morbidity as a consequence of the procedure. A brief summary of expected outcome and of pertinent family process and psychodynamic issues are addressed. This article is intended to serve as a guide to permit clinicians to choose the appropriate length and depth of neuropsychologic assessment, but also to highlight the confounding factors often present in these patients.

Tau pathology: a marker of neurodegenerative disorders

Tau is not only a basic component of neurofibrillary degeneration, but is also an aetiological factor, as demonstrated by mutations on the tau gene responsible for frontotemporal dementias with parkinsonism linked to chromosome 17. Polymorphisms on the tau gene and the hierarchical invasion of neocortical areas by tau pathology in numerous sporadic neurodegenerative diseases also suggest that tau pathology is a primary pathogenic event in non-familial dementing diseases and a lead for solid diagnostic and therapeutic approaches.

Corticobasal ganglionic degeneration and/or frontotemporal dementia? A report of two overlap cases and review of literature

OBJECTIVE

According to the existing viewpoint, Corticobasal degeneration (CBD) is thought of as a predominantly extrapyramidal motor disorder that is distinct and unrelated to frontotemporal dementia (FTD), the most common form of non-Alzheimer dementias. A lack of understanding of the aetiopathogenesis, and poor correlation between the pathology and the clinical syndromes, has resulted in a disparity in the classification of cases of non-Alzheimer dementias. This report intends to highlight the overlap between FTD and CBD in the light of the evolution of these terms, and to discuss the implications of these findings on the nosology of CBD and the classification of non-Alzheimer dementias.

METHODS AND RESULTS

Two cases who presented with cognitive dysfunction, which, on comprehensive neuropsychological testing warranted an antemortem diagnosis of FTD are reported. A detailed necropsy study of their brains, however, favoured a pathological diagnosis of CBD. The literature on the overlap between CBD and FTD is also reviewed.

CONCLUSIONS

Firstly, evidence is emerging to suggest that the clear distinction drawn between FTD and CBD by the existing viewpoint, needs revision. Secondly, until such time that a comprehensive classification of non-Alzheimer dementias is evolved, it may be better to distinguish between the clinical and pathological levels of description and to classify cases, in vivo, on the basis of the clinical phenotype.

FTDP-17: an early-onset phenotype with parkinsonism and epileptic seizures caused by a novel mutation

Recently, mutations in the tau gene on chromosome 17 were found causative for autosomal dominantly inherited frontotemporal dementia and parkinsonism (FTDP-17). We describe a family carrying a missense mutation at nucleotide 1137 C --> T, resulting in the amino acid substitution P301S. Methods of investigations include clinical, electrophysiological, and imaging techniques. This kindred presents with a novel phenotype characterized by an early onset of rapidly progressive frontotemporal dementia and parkinsonism in combination with epileptic seizures. We define the dopaminergic deficits as being predominantly presynaptic by the use of single-photon emission computed tomography with a dopamine transporter ligand. The association of this early-onset phenotype with P301S mutation is not entirely consistent with current criteria for the diagnosis of frontotemporal dementias and may encourage the search for tau mutations in diseases similar but not identical to FTDP-17. Also, the change from proline to serine suggests that this mutation might contribute to tau hyperphosphorylation.

The clinical picture of frontotemporal dementia: diagnosis and follow-up

Frontotemporal dementia (FTD) was diagnosed in 74 outpatients with a standardized assessment including neuropsychological tests, behavioural scale, structural and functional imaging. Clinical characteristics were consistent with the literature data. The cohort was followed for 2-6 years to determine the reliable variable for evaluating the progression of FTD. Every fourth patient died after a mean duration of 7 years. At first, FTD manifests itself in behavioural changes with relatively stable global cognition although language, verbal fluency and memory tests were reliable tools to follow the progression of the disease. Below 18 of Mini-Mental State Examination, mutism and apathy prevented from neuropsychological testing within the next 6 months. Behavioural disorders evolved with time but restlessness and hyperorality were long-lasting. Imaging showed the progression of a consistent pattern of anterior abnormalities with frequent leukoaraiosis.

Biochemical and molecular characterization of neurofibrillary degeneration in frontotemporal dementias

Neurofibrillary degeneration (NFD) is a degenerating process characterized by the intraneuronal aggregation of abnormal tau proteins. These proteins have a biochemical signature which is disease-specific. They also have a neocortical distribution which is typical of the disease. Pathological tau proteins have been analyzed qualitatively and quantitatively in all diseases that may present the clinical symptoms of frontotemporal dementias. In Alzheimer's disease, a disease with sometimes a frontal predominance, paired helical filaments (PHF) of neurofibrillary tangles are made of hyperphosphorylated tau, named PHF-tau. Their electrophoretic profile consists of four main bands (tau 55, 64, 69, 74 kD), resulting from the presence of the six tau isoforms. In Pick's disease the phosphorylated tau from Pick bodies are made of two major components (tau 55, 64 kD) and a minor 69 kD resulting from the lack of tau isoforms with the translated exon 10 (E10-). Corticobasal degeneration (CBD) also has a different pattern of tau variants, with tau 64, 69 components and a minor tau 74. Pathological tau proteins that aggregate in CBD (and progressive supranuclear palsy) are exclusively made of E10+ tau isoforms. In frontotemporal dementias non-Alzheimer, non-Pick (Lund and Manchester criteria), we did not observe the presence of pathological tau proteins in 2 cases, but a third one presented a particular pattern of tau, with soluble pathological tau in frontotemporal areas. These data show that this group could be heterogeneous. In conclusion, the biochemical signature of tau distinguishes four classes of frontotemporal dementia. The characteristic tau phenotypes observed are linked to the specific neuronal networks that are affected in each disease.