Participation of the limbic system and its associated areas in the dementia of amyotrophic lateral sclerosis

Neuropathology of Speech Network Distinguishes Bulbar From Nonbulbar Amyotrophic Lateral Sclerosis

Bulbar amyotrophic lateral sclerosis (ALS) is a debilitating neurodegenerative subtype affecting speech and swallowing motor functions as well as associated with the burden of cognitive deficits. The neuroanatomical underpinnings of bulbar ALS are not well understood. The aim of this study was to compare neuropathology of the speech network (SpN) between 3 cases of bulbar-onset ALS (bALS), 3 cases of spinal-onset ALS (sALS) with antemortem bulbar ALS (sALSwB) against 3 sALS without antemortem bulbar ALS (sALSnoB) and 3 controls. Regional distribution and severity of neuronal loss, TDP-43 (transactive response DNA-binding protein of 43 kDa), and tau proteinopathy were examined. All 3 bALS cases showed marked neuronal loss and severe proteinopathy across most SpN regions; sALSwB cases showed no neuronal loss but mild and variable TDP-43 pathology in focal regions; sALSnoB cases demonstrated an absence of pathology. Two bALS cases had coexisting tauopathy in SpN regions, which was not noted in any sALS cases. The findings suggested that bALS may have a distinct neuropathological signature characterized by marked neuronal loss and polypathology in the SpN. Milder TDP-43 pathology in the SpN for sALSwB cases suggested a link between severity of bulbar ALS and SpN damage. Findings support a clinicopathologic link between bulbar symptoms and pathology in the SpN.

The neuropathological signature of bulbar-onset ALS: A systematic review

ALS is a multisystem disorder affecting motor and cognitive functions. Bulbar-onset ALS (bALS) may be preferentially associated with cognitive and language impairments, compared with spinal-onset ALS (sALS), stemming from a potentially unique neuropathology. The objective of this systematic review was to compare neuropathology findings reported for bALS and sALS subtypes in studies of cadaveric brains. Using Cochrane guidelines, we reviewed articles in MEDLINE, Embase, and PsycINFO databases using standardized search terms for ALS and neuropathology, from inception until July 16th 2016. 17 studies were accepted for analysis. The analysis revealed that both subtypes presented with involvement in motor and frontotemporal cortices, deep cortical structures, and cerebellum and were characterized by neuronal loss, spongiosis, myelin pallor, and ubiquitin+ and TDP43+ inclusion bodies. Changes in Broca and Wernicke areas - regions associated with speech and language processing - were noted exclusively in bALS. Further, some bALS cases presented with atypical pathology such as neurofibrillary tangles and basophilic inclusions, which were not found in sALS cases. Given the limited number of studies, all with methodological biases, further work is required to better understand neuropathology of ALS subtypes.

The Wobbler mouse model of amyotrophic lateral sclerosis (ALS) displays hippocampal hyperexcitability, and reduced number of interneurons, but no presynaptic vesicle release impairments

Amyotrophic lateral sclerosis (ALS) is the most common adult-onset motor neuron disease. It is a fatal degenerative disease, best recognized for its debilitating neuromuscular effects. ALS however also induces cognitive impairments in as many as 50% of affected individuals. Moreover, many ALS patients demonstrate cortical hyperexcitability, which has been shown to precede the onset of clinical symptoms. The wobbler mouse is a model of ALS, and like ALS patients the wobbler mouse displays cortical hyperexcitability. Here we investigated if the neocortical aberrations of the wobbler mouse also occur in the hippocampus. Consequently, we performed extracellular field excitatory postsynaptic potential recordings in the CA1 region of the hippocampus on acute brain slices from symptomatic (P45-P60) and presymptomatic (P17-P21) wobbler mice. Significant increased excitation of hippocampal synapses was revealed by leftward shifted input/output-curves in both symptomatic and presymptomatic wobbler mice, and substantiated by population spike occurrence analyses, demonstrating that the increased synaptic excitation precedes the onset of visible phenotypic symptoms in the mouse. Synaptic facilitation tested by paired-pulse facilitation and trains in wobbler and control mice showed no differences, suggesting the absence of presynaptic defects. Immunohistochemical staining revealed that symptomatic wobbler mice have a lower number of parvalbumin positive interneurons when compared to controls and presymptomatic mice. This study reveals that the wobbler mouse model of ALS exhibits hippocampal hyperexcitability. We suggest that the hyperexcitability could be caused by increased excitatory synaptic transmission and a concomitant reduced inhibition due to a decreased number of parvalbumin positive interneurons. Thus we substantiate that wobbler brain impairments are not confined to the motor cortex, but extend to the hippocampus. Importantly, we have revealed more details of the early pathophysiology in asymptomatic animals, and studies like the present may facilitate the development of novel treatment strategies for earlier intervention in ALS patients in the future.

Dysfunctions within limbic-motor networks in amyotrophic lateral sclerosis

Previous studies have shown that affective symptoms are part of the clinical picture in amyotrophic lateral sclerosis (ALS), the most common motor neuron disorder in elderly people. Diffuse neurodegeneration of limbic regions (e.g., prefrontal cortex [PFC], amygdala) was demonstrated in ALS post-mortem, although the mechanisms of emotional dysregulation in ALS in vivo remain unclear. Using functional imaging, we assessed the brain responses to emotional faces in 11 cognitively unimpaired ALS patients and 12 healthy controls (HCs). We tested whether regional activities and connectivity patterns in the limbic system differed between ALS patients and HCs and whether the variability in clinical measures modulated the neuroimaging data. Relative to HCs, ALS patients displayed greater activation in a series of PFC areas and altered left amygdala-PFC connectivity. Anxiety modulated the right amygdala-PFC connectivity in HCs but not in ALS patients. Reduced right premotor cortex activity and altered left amygdala-supplementary motor area connectivity were associated with longer disease duration and greater disease severity, respectively. Our findings demonstrate dysfunctions of the limbic system in ALS patients at early stages of the disease, and extend our knowledge about the interplay between emotional brain areas and the regions traditionally implicated in motor control.

Degeneration of the mid-cingulate cortex in amyotrophic lateral sclerosis detected in vivo with MR spectroscopy

BACKGROUND AND PURPOSE

Various lines of evidence implicate cerebral involvement beyond the motor cortex in ALS, including the cingulate gyrus and the thalamus. The purpose of this study was to assess neurodegeneration in these regions in vivo by using MRSI.

MATERIALS AND METHODS

Fourteen patients with ALS and 14 healthy controls underwent MRSI by using a coronal acquisition scheme. The NAA/Cho ratio was quantified in the MCC, thalamus, and motor cortex (PCG).

RESULTS

NAA/Cho was reduced in the MCC in patients with ALS compared with the controls (P = .0004). There was no difference in NAA/Cho in the thalamus (P = .59). We also found a strong correlation of NAA/Cho among the PCG, MCC, and the thalamus in controls, which was absent in patients with ALS.

CONCLUSIONS

Neurodegeneration beyond the motor cortex is present in the MCC in ALS. The significant correlation of NAA/Cho among the PCG, MCC, and the thalamus in healthy subjects likely reflects the neuronal connectivity among these regions. The loss of these relationships in patients with ALS suggests that such connectivity is not responsible for the pattern of degeneration in these regions.

Sporadic amyotrophic lateral sclerosis with pallido-nigro-luysian degeneration: a TDP-43 immunohistochemical study

Recently, Nishihira et al. demonstrated the presence of two types of TDP-43 pathology in sporadic amyotrophic lateral sclerosis (ALS) (Acta Neuropathol 2008; 116: 169-182). Type 1 represents the TDP-43 distribution pattern observed in classic ALS, whereas type 2 shows the presence of TDP-43 inclusions in the frontotemporal cortex, hippocampal formation, neostriatum and substantia nigra and is significantly associated with dementia. However, ALS with pallido-nigro-luysian degeneration (PNLD) is very rare. We recently encountered a case of ALS with PNLD of 9 years duration, in which the patient received artificial respiratory support for 6 years. In our case, neuronal loss and TDP-43-positive neuronal cytoplasmic inclusions were found in the globus pallidus, substantia nigra and subthalamic nucleus. Neither neuronal loss nor TDP-43-immunoreactive inclusions were found in the frontotemporal cortex and hippocampus. These findings suggest that the pallido-nigro-luysian system is also involved in the disease process of ALS and that ALS with PNLD is different from ALS with dementia based on the distribution pattern of neuronal loss and TDP-43 accumulation.

Frontotemporal dementia presenting as schizophrenia-like psychosis in young people: clinicopathological series and review of cases

BACKGROUND

Few studies have investigated the relationship between schizophrenia and frontotemporal dementia.

AIMS

To investigate this relationship through a clinicopathological investigation of young-onset frontotemporal dementia and a review of the case literature.

METHOD

Cases of young-onset frontotemporal dementia were identified within the local brain bank. The clinical course and pathological findings were collated. For the literature review, cases of frontotemporal dementia identified through Medline were selected according to defined criteria. The demographic, clinical, pathological and genetic characteristics of cases presenting with a psychotic illness were identified.

RESULTS

In the case series, 5 of 17 patients with frontotemporal dementia had presented with a psychotic illness (schizophrenia/schizoaffective disorder n=4, bipolar disorder n=1) an average of 5 years prior to the dementia diagnosis. Patients with schizophrenia exhibited changes consistent with TDP-43 and ubiquitin-positive frontotemporal dementia. In the cases review, a third of patients aged 30 years or under and a quarter of those aged 40 years or under had been diagnosed with psychosis at presentation.

CONCLUSIONS

Patients with young-onset frontotemporal dementia may be diagnosed with a psychotic illness years before the dementia diagnosis is made. These findings have implications for clinicians and for our further understanding of the neurobiology of psychotic illness.

Sporadic amyotrophic lateral sclerosis: two pathological patterns shown by analysis of distribution of TDP-43-immunoreactive neuronal and glial cytoplasmic inclusions

A nuclear protein, 43-kDa TAR DNA-binding protein (TDP-43), was recently identified as a component of the ubiquitinated inclusions (UIs) in frontotemporal lobar degeneration (FTLD-U) and sporadic amyotrophic lateral sclerosis (SALS). In the present study using immunohistochemistry, we examined various regions of the nervous system in a series of 35 SALS cases using a polyclonal antibody against TDP-43. Seven of the 35 cases had disease durations of more than 10 years with artificial respiratory support (ARS; duration: 69-156 months). In all cases, TDP-43-immunoreactive (ir) neuronal and glial cytoplasmic inclusions (NCIs and GCIs) were found together in many regions, including the histologically affected lower motor neuron nuclei. Cluster analysis of the distribution pattern of TDP-43-ir NCIs for cases without ARS (n = 28) identified two types (type 1, n = 16; type 2, n = 12). Type 2 was distinguished from type 1 by the presence of TDP-43-ir NCIs in the frontotemporal cortex, hippocampal formation, neostriatum and substantia nigra, and was significantly associated with dementia. Eleven of the 28 cases showed UIs in the hippocampal dentate granule cells, all of which had type-2 distribution pattern. Cases with ARS (n = 7) were also classified into the same types (type 1, n = 5; type 2, n = 2). Cases having type-1 distribution pattern (n = 21) showed no evident neuronal loss in most of the non-motor neuron nuclei where TDP-43-ir NCIs were present, whereas cases having type-2 distribution pattern (n = 14) often showed evident neuronal loss in the frontotemporal cortices, amygdaloid nuclei and substantia nigra. These findings indicate that SALS is a multisystem degenerative disease widely affecting both neurons and glial cells with a heterogeneous pattern of TDP-43-ir NCI distribution (SALS showing type-2 distribution pattern being closely linked to FTLD-U), and that long-term survival supported by a respirator has no apparent influence on the TDP-43 neuronal distribution pattern.

TDP-43-immunoreactive neuronal and glial inclusions in the neostriatum in amyotrophic lateral sclerosis with and without dementia

TDP-43 is a major component of ubiquitin-positive, tau-negative inclusions in amyotrophic lateral sclerosis (ALS), and frontotemporal lobar degeneration. We immunohistochemically examined the neostriatum from 14 cases of classic ALS (cALS), six cases of ALS with dementia (ALS-D), and 20 control subjects. TDP-43-positive, crescent or circular inclusions were found in neostriatal small neurons in 19 of 20 cases of ALS, but not in controls. Two types of inclusions were found in the large neurons: ubiquitin-positive, TDP-43-negative rod-like inclusions, and ubiquitin- and TDP-43-positive pleomorphic inclusions. The latter were specific to ALS; they were found in seven cases of cALS and in all of ALS-D. TDP-43-positive glial inclusions were also found in 12 cases of cALS and in all of ALS-D. These TDP-43-positive neuronal and glial inclusions were more numerous in ALS-D than cALS. In ALS-D, neuronal loss in the substantia nigra was found in all the cases, whereas mild gliosis without obvious neuronal loss was noted in the neostriaum in only two cases. These findings suggest that the neostriatum is also involved in the disease process of ALS with and without dementia.

Relation between cognitive dysfunction and reduced vital capacity in amyotrophic lateral sclerosis

BACKGROUND

Many patients with amyotrophic lateral sclerosis (ALS) with cognitive impairment have fronto-temporal dysfunction. Whereas in some patients with ALS the fronto-temporal dysfunction is undoubtedly due to the degenerative process associated with the disease, in others dysfunction cannot be accounted for by an irreversible degenerative process alone, as it also appears to involve a reversible process. We hypothesised that reduced vital capacity can be a key contributor to the fronto-temporal dysfunction observed in patients with ALS.

OBJECTIVE

To investigate the association between fronto-temporal dysfunction and reduced vital capacity in ALS.

METHODS

16 consecutive patients who conformed to a diagnosis of definite or probable ALS (El escorial criteria) were grouped by vital capacity, and their clinical characteristics and cognitive functions, including disease duration, attention, executive function and memory, were measured.

RESULTS

Patients with a reduced vital capacity performed significantly poorer in memory retention (p = 0.028), retrieval efficacy (p = 0.003), spoken verbal fluency (p = 0.03) and spoken verbal fluency indexes (p = 0.016) than those with a normal vital capacity.

CONCLUSION

The fronto-temporal dysfunction in ALS might be attributable to potentially reversible secondary effects associated with reduced vital capacity, as well as to the primary degenerative process.

Cognition and amyotrophic lateral sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is classically described as a pure motor disease; however, there is growing evidence of a range of cognitive impairment. Cognitive abnormalities include deficiencies in frontal executive skills, varying from mild deficits to meeting criteria for diagnosis of frontotemporal dementia (FTD). Cognitive impairment occurs in sporadic and familial forms of ALS. Patients may present with cognitive deficits before, after, or at the onset of motor neuron disease. Structural and functional imaging studies have shown extramotor cortical degeneration corresponding to levels of frontal executive impairment on neuropsychologic testing. In addition, ALS and a subset of FTD patients display common pathological findings on immunohistochemistry staining. It is believed that these disorders represent a continuum between motor and nonmotor cortical degeneration. The purpose of this article is to review the literature on cognitive deficits in ALS. Identifying changes in cognition is critical for physicians and caregivers of ALS patients, as cognitive decline may interfere with patient compliance. Diagnosis and treatment of cognitive symptoms in ALS patients may improve quality of life.

Amygdala size in amyotrophic lateral sclerosis without dementia: an in vivo study using MRI volumetry

Background

Evidence for extra-motor involvement in non-demented patients with amyotrophic lateral sclerosis (ALS) has been provided by multiple studies, in particular neuropathological studies have demonstrated neuronal loss in the amygdala. The aim of this study was to investigate possible alterations of amygdala volumes in vivo.

Methods

Twenty-two moderately disabled patients with definite ALS without cognitive or behavioural deficits and 22 age-matched healthy controls were included. Amygdala and total brain volumes were measured by region-of-interest-based volumetry in 3-D MRI.

Results

A trend was observed with reduced amygdala size in the ALS group, since mean absolute and brain size-corrected amygdala volumes were 6.9% and 7.6% lower in the patient group compared to those in normal controls (P = 0.086 and P = 0.110), respectively.

Conclusion

Volumetrically identifiable alterations of the amygdala can be mapped in vivo and may be associated with psychopathological findings in later stages of ALS.

"Forme fruste" of amyotrophic lateral sclerosis with dementia: a report of five autopsy cases without dementia and with ubiquitinated intraneuronal inclusions

We clinicopathologically investigated five autopsy cases of ALS without dementia and with ubiquitinated intraneuronal inclusions. The age at onset of symptoms ranged from 52 to 81 years and the duration of the disease was from 10 months to 3 years, 3 months. All five patients initially developed lower motor neuron signs, including bulbar signs, and upper motor neuron signs were found in the middle to late clinical stages, but dementia was not observed in all five cases. Thus, the clinical diagnoses of all five patients were ALS without dementia. Neuropathological examination of all five cases revealed not only obvious degeneration of upper motor neurons with neuronal loss of Betz cells, but also lower motor neuron involvement associated with Bunina bodies. In addition, ubiquitin-immunoreactive intraneuronal inclusions in the hippocampal dentate granular cells and degeneration of the substantia nigra were observed in all five cases. Furthermore, neuronal loss with astrocytosis in the dorsomedial portion of the anterior first temporal gyrus was observed in all three cases in which this structure was examined. Neuronal loss with astrocytosis in the subiculum was found in four cases. Neuronal loss of the parahippocampal gyrus was observed in three of the five autopsy cases, and amygdala involvement was encountered in three of four cases in which this structure was investigated. Based on these clinicopathological findings and a review of the published literature, we concluded that our five cases were ALS without dementia, but with pathological hallmarks compatible with ALS with dementia. We also concluded that there is a "forme fruste" of ALS with dementia showing no overt dementia clinically.

Disease-related regressive alterations of forebrain cholinergic system in SOD1 mutant transgenic mice

Transgenic mice carrying the human mutated SOD1 gene with a glycine/alanine substitution at codon 93 (G93A) are a widely used model for the fatal human disease amyotrophic lateral sclerosis (ALS). In these transgenic mice, we carried out a neurochemical study not only restricted to the primarily affected regions, the cervical and lumbar segments of the spinal cord, but also to several other brain regions. At symptomatic (110 and 125 days of age), but not at pre-symptomatic (55 days of age) stages, we found significant decreases in catalytic activity of the cholinergic enzyme, choline acetyltransferase (ChAT) in the hippocampus, olfactory cortex and fronto-parietal cortex. In parallel, we observed a decreased number of basal forebrain cholinergic neurons projecting to these areas. No alterations of the cholinergic markers were noticed in the striatum and the cerebellum. A widespread marker for GABAergic neurons, glutamate decarboxylase (GAD), was unaffected in all the areas examined. Alteration of cholinergic markers in forebrain areas was paralleled by concomitant alterations in the spinal cord and brainstem, as a consequence of progressive apoptotic elimination of cholinergic motor neuron. Gestational supplementation of choline, while able to result in long-term enhancement of cholinergic activity, did not improve transgenic mice lifespan nor counteracted cholinergic impairment in brain regions and spinal cord.

Cognitive function in bulbar- and spinal-onset amyotrophic lateral sclerosis. A longitudinal study in 52 patients

We performed a longitudinal study of frontal and temporal lobe functions in patients with amyotrophic lateral sclerosis (ALS) and compared the evolution of cognitive performance with that of motor deficits in patients with spinal and bulbar-onset of the disease. Fifty two patients suffering from sporadic ALS according to the El Escorial criteria were examined; 37 patients had a spinal, 15 a bulbar onset of the disease. The data profile included examinations at entry (E1), every four months at follow-up (E2, E3, E4) and after 18 months (E5), if possible. Neuropsychological testing covered the domains of executive functions, memory and attentional control. ALS patients showed executive dysfunctions that were most prominently represented by deficits of non-verbal and verbal fluency and concept formation. Memory-related deficits were also present but less expressed. The same held true for phasic and tonic alertness and divided attention. In contrast to motor functions declining concomitantly with disease progression, cognitive deficits appeared in early disease, were essentially present at initial testing and did not substantially decline on follow-up. A subgroup analysis revealed that bulbar-onset ALS patients performed consistently poorer in many cognitive tests than spinal-onset ones with special reference to verbal and non-verbal fluency and interference control. This subgroup difference persisted or even increased throughout follow-up. We conclude that there is a fronto-temporal pattern of cognitive dysfunction in ALS expressing itself early in the course of the disease and mainly with bulbar forms. The cognitive deficits do not progress in synchrony with motor decline, but distinctly more slowly. We suggest that cognitive dysfunctions reflect functional and possibly morphological deficits outside the primary motor system that is specific for the nature and evolution of the disease and might also give clues to etiopathogenesis.

Changes in memory for emotional material in amyotrophic lateral sclerosis (ALS)

The current study sought to examine the performance of non-demented ALS patients on neuropsychological tests involving emotional perception and memory. Nineteen non-demented patients with ALS were compared with 20 healthy controls on assessments of facial expression recognition, social judgement ratings of faces and recognition memory for emotional words. Patients and controls were well matched to exclude a range of potentially confounding variables. The patients and controls demonstrated significant differences on only one test of cognitive functioning. The ALS group demonstrated a failure to show the normative pattern of enhanced recognition memory for emotional words compared to neutral words and produced higher scores than controls on recognition memory for neutral words. These findings suggest that patients with ALS show a different pattern of cognitive performance with respect to memory for emotional material when compared to healthy adults.

Characterization of amyotrophic lateral sclerosis and frontotemporal dementia

Amyotrophic lateral sclerosis (ALS) produces progressive weakness, muscular wasting, and spasticity leading to death from respiratory failure at a median of 3 years after onset. ALS and frontotemporal dementia (FTD) overlap in both familial and sporadic cases of ALS. When both occur in families, the affected members may have only ALS, only FTD, or both. This suggests a relationship in the cause of these disorders. We investigated the frequency of ALS in FTD patients and of FTD in ALS patients and found the overlap to be more common than had previously been reported. We report the features of cognitive impairment and pattern of motor involvement in these ALS-FTD patients, and the degree of overlap in both populations.

Word retrieval in amyotrophic lateral sclerosis: a functional magnetic resonance imaging study

The cognitive impairment revealed in some non- demented amyotrophic lateral sclerosis (ALS) patients is characterized by executive dysfunction with widely repeated deficits on tests of verbal (letter) fluency. However, conflicting evidence exists of an impairment on other word retrieval tasks, such as confrontation naming, which do not place heavy demands on executive processes. Previous research has demonstrated intact confrontation naming in the presence of verbal fluency deficits, although naming deficits have been described in other studies. In this investigation, functional MRI (fMRI) techniques were employed to explore whether word retrieval deficits and underlying cerebral abnormalities were specific to letter fluency, which are more likely to indicate executive dysfunction, or were also present in confrontation naming, indicating language dysfunction. Twenty-eight non-demented ALS patients were compared with 18 healthy controls. The two groups were matched for age, intelligence quotient, years of education, and anxiety and depression scores. Two compressed-sequence overt fMRI activation paradigms were employed, letter fluency and confrontation naming, which were developed for use with an older and potentially impaired population. In ALS patients relative to controls, the letter fluency fMRI task revealed significantly impaired activation in the middle and inferior frontal gyri and anterior cingulate gyrus, in addition to regions of the parietal and temporal lobes. The confrontation naming fMRI task also revealed impaired activation in less extensive prefrontal regions, including the inferior frontal gyrus and regions of the temporal, parietal and occipital lobes. These changes were present despite matched performance between patients and controls during each activation paradigm. The pattern of dysfunction corresponded to the presence of cognitive deficits on both letter fluency and confrontation naming in the ALS group. This study provides evidence of cerebral abnormalities in ALS in the network of regions involved in language and executive functions. Moreover, the findings further illustrate the heterogeneity of cognitive and cerebral change in ALS.

Amyotrophic lateral sclerosis with dementia: the clinicopathological spectrum

Amyotrophic lateral sclerosis with dementia (ALS-D) is a non-Alzheimer-type dementia characterized by both frontotemporal degeneration and motor neuron disease and marked by ubiquitin-positive, tau- and alpha-synuclein-negative intraneuronal inclusions and dystrophic neurites. New neuropathological diagnostic criteria for ALS-D are proposed on the basis of the present investigation of 28 autopsy cases. Clinical features included those of typical ALS-D, primary lateral sclerosis, atypical ALS with frontotemporal atrophy and atypical Pick's disease without Pick's bodies. Macroscopically anterior frontotemporal atrophy was observed involving or not involving the precentral gyrus. Microscopically non-specific neuronal loss and gliosis with spongiosis were seen, particularly in superficial layers II and III of the frontotemporal cortices. Diffuse fibrous gliosis was seen in the frontotemporal white matter. The substantia nigra and amygdala showed neuronal loss and gliosis. In all 28 cases, degeneration of both the lower and upper motor neuron systems, consistent with classic sporadic ALS, was present. The distribution and degree of degenerative frontotemporal lesions and motor neuron disturbance were of various patterns. Ubiquitin-positive and tau- and alpha-synuclein negative intraneuronal inclusions and dystrophic neurites in extramotor cortices were observed in all cases. Furthermore, ubiquitin-positive inclusions in lower motor neurons were found in all cases. The distribution pattern and density differed between neuronal inclusions and dystrophic neurites and correlated with clinicopathological phenotypes. Therefore, the ALS-D spectrum may be broader than that previously recognized, extending to primary lateral sclerosis, atypical ALS and to atypical Pick's disease without Pick bodies. Further investigation is needed to determine the characteristics of the ubiquitinated component in ALS-D.

Neuronal loss in familial frontotemporal dementia with ubiquitin-positive, tau-negative inclusions

The neuronal density in the frontal, temporal, and parietal lobes was determined in nine cases of familial frontotemporal dementia with ubiquitin-positive, tau-negative inclusions (FTDU). The mean age at onset was 56.9 +/- 2.2 years and the duration of disease was 6.7 +/- 0.5 years. The mean age at death was 63.6 +/- 2.2 years. There was substantial loss (34%) of brain weight (877 +/- 73 g) in the familial cases in comparison with 10 normal aged controls (1326 +/- 50 g, P < 0.001). All of the familial FTDU cases showed atrophy of the frontal, temporal, and parietal lobes; neuronal loss; vacuolation in superficial laminae; reactive astrocytosis; and ubiquitin-positive, tau-negative intracytoplasmic and intranuclear inclusions and dystrophic neurites in varying sites and numbers. Neuronal loss was estimated in nine cases of familial FTDU and in 10 aged controls using a stereological probe, the optical "disector," and a computerized stereology system (CAST-Grid, Olympus, Denmark). There was a significant reduction in neuronal density in the frontal lobe (22.3 +/- 3.8 x 10(3)/mm(3)) of familial FTDU in comparison to aged controls (33.1 +/- 1.7 x 10(3) per mm(3), P < 0.05). An estimate of the relative numbers of neurons was calculated by multiplying the numerical density by the cortical thickness, which showed a striking loss of neurons of 56% in the frontal lobe, 52% loss in the temporal lobe, and a 49% loss in the parietal lobe of familial FTDU when compared to controls. This study shows that familial FTDU has profound focal neuronal loss in multiple association areas that relate to the clinical symptoms characteristic of the disease.

Sporadic amyotrophic lateral sclerosis with circumscribed temporal atrophy: a report of an autopsy case without dementia and with ubiquitinated intraneuronal inclusions

This report concerns an autopsy case of amyotrophic lateral sclerosis (ALS) with circumscribed temporal atrophy. The patient was a Japanese woman without hereditary burden who was 71-year-old at the time of death. She developed dysarthria and gait disturbance at age 69, followed by dysphagia. A neurological examination about 1 year 11 months after the onset of the disease revealed absence of character change and of dementia. Neuroradiological examination disclosed circumscribed atrophy of the anterior part of the right temporal lobe. The patient died of respiratory failure 2 years after the disease onset. No respirator administration was performed throughout the clinical course. Macroscopically, neuropathological examination showed circumscribed atrophy of the right first temporal gyrus. Histologically, there was neuronal loss in the cerebral cortex, including the first temporal gyrus, the parahippocampal gyrus, subiculum, amygdala, substantia nigra, brain stem motor nuclei, and anterior horns of the spinal cord, in addition to loss of Betz cells, obvious degeneration of the pyramidal tracts, and the presence of Bunina bodies. Ubiquitin-immunoreactive intraneuronal inclusions were present in the hippocampal dentate granular cells, frontotemporal cortical layer II neurons, and motor neurons in the brain stem and spinal cord. Based on these clinicopathological findings and a review of the literature, we concluded that our case was atypical ALS without dementia, showing temporal lobe atrophy macroscopically, in addition to pathological hallmarks compatible with ALS with dementia. We also note the possibility that there is a forme fruste of ALS with dementia showing no overt dementia clinically.

Glucose hypometabolism and neuropathological correlates in brains of dementia with Lewy bodies

Cerebral glucose metabolism using positron emission tomography (PET) with (18)F-fluorodeoxyglucose was examined in 11 patients with probable Alzheimer's disease (AD), 6 patients with probable, and 1 patient with autopsy-confirmed dementia with Lewy bodies (DLB) as well as in 10 age-matched normal control subjects. Among widespread cortical regions showing glucose hypometabolism in the DLB group, the metabolic reduction was most pronounced in the visual association cortex compared to that in the AD group. Using a metabolic ratio of 0.92 in the visual association cortex as a cutoff (mean-2 SD of normal control subjects), DLB could be distinguished from AD with a sensitivity of 86% and a specificity of 91%. In contrast, apolipoprotein E4 allele frequency and cerebrospinal fluid tau levels did not differ significantly between the two groups. In order to further dissect out neuropathological correlates of the dysfunctional occipital lobe, postmortem brains from 19 patients with AD and 17 with DLB as well as 11 brains from normal controls were examined. A distinct and extensive spongiform change with coexisting gliosis was variably noted throughout cerebral white matter with relative sparing of gray matter in DLB. Notably, the white matter spongiform change and gliosis was most prominently and consistently found in the occipital region of DLB, and the severity of the spongiform change in each brain region generally paralleled to the regional difference in reduced glucose metabolism between the living AD and DLB patients. These findings suggest that (1) among several potential antemortem biomarkers in the diagnosis of DLB, measures of the glucose metabolism in the occipital cortex may be an informative diagnostic aid to distinguish DLB from AD; and (2) a pathological process that generates widespread spongiform change and gliosis in long projection fibers may contribute, at least in part, to the characteristic imaging features of DLB.

Medial temporal lobe metabolic impairment in dementia associated with motor neuron disease

In the course of their disease certain patients with frontotemporal dementia (FTD) develop clinical features compatible with a motor neuron disease (FTD-MND). Previous reports have suggested that the functional pattern is similar in FTD and FTD-MND. However, some neuropathological studies suggest greater involvement of medial temporal regions in FTD-MND than in FTD. Using statistical parametric mapping (SPM96), we compared the metabolic patterns obtained at rest with positron emission tomography in 10 FTD patients and three FTD-MND patients with those obtained from 46 healthy subjects (HS). Mean age, duration of illness and dementia stage did not differ statistically between the FTD and FTD-MND groups. In comparison with HS, both groups showed frontal and anterior temporal hypometabolism at P<0.001. When the FTD-MND group was compared to the FTD group, significant hypometabolism was only observed in bilateral amygdala, bilateral hippocampus, and bilateral enthorinal and parahippocampal regions (Brodmann's areas, BA 28/36) at P<0.005. We found no significant differences in regional glucose uptake when FTD patients were contrasted to FTD-MND patients. Our results suggest statistically comparable frontal and lateral temporal hypometabolism in both conditions but greater impairment of medial temporal lobe activity in FTD-MND. Our results and a review of the literature support the hypothesis that there is a functional continuum between classical motor neuron disease (cMND), FTD-MND, and FTD.

Selective attention is impaired in amyotrophic lateral sclerosis--a study of event-related EEG potentials

In humans, selective attention is assumed to be under control of the frontal lobe. A significant proportion of patients with amyotrophic lateral sclerosis (ALS) shows impairments in various tasks touching frontal lobe function. We, therefore, undertook a study of event-related EEG potentials (ERPs) in eight non-demented ALS patients in order to investigate a possible deficit of auditory selective attention: tones were presented in random sequence to the left or right ear, one of which was to be attended. The negative shift of the ERPs evoked by attended tones in relation to unattended tones ('processing negativity': PN) was smaller in ALS patients than in age-matched healthy control persons. This was true for Fz and Cz and for both a slow and a fast presentation rate of the tones. In the patients, reduced PN amplitude correlated with functional motor impairment. The utility of ERP testing to assess impaired frontal lobe function is shown for the first time in ALS patients. The results of our study fit to recent positron emission tomography (PET) and fMRI data.

Neuronal inclusions in the dentate fascia in patients with multiple system atrophy

Ubiquitin-immunoreactive neuronal inclusions in the granular cells in the dentate fascia (UNIDs) of patients with multiple system atrophy (MSA) were examined for immunohistochemical and ultrastructural characterization especially in comparison with those which were recently reported for amyotrophic lateral sclerosis with dementia (ALS-D). Eight of 23 MSA patients had UNIDs which were also identified by Gallyas-Braak impregnation but immunonegative for other antibodies including against tau, neurofilaments, and alphaB crystallin. Ultrastructurally, loosely aggregated fibrils without limiting membrane located around the nucleus, which was confirmed by the results of ubiquitin-immunoelectron microscopy. The formation of UNIDs in MSA and ALS-D was suggested to be caused by different types of degeneration because UNIDs in MSA differ from these in ALS-D in terms of their stainability by Gallyas-Braak impregnation and ultrastructurally. In this study hippocampal involvement in MSA differing from ALS-D was clarified.

Relation between cognitive dysfunction and pseudobulbar palsy in amyotrophic lateral sclerosis

OBJECTIVES

To examine the relation between cognitive dysfunction and pseudobulbar features in patients with amyotrophic lateral sclerosis (ALS).

METHODS

The performance of two patient groups, ALS with pseudobulbar palsy (n = 24) and ALS without pseudobulbar palsy (n = 28), was compared with 28 healthy age matched controls on an extensive neuropsychological battery. Tests used were the national adult reading test, short form of the WAIS-R, recognition memory test, Kendrick object learning test, paired associate learning, Wisconsin card sorting test, verbal fluency, Stroop and negative priming tests, a random movement joystick test, and a computerised Tower of Hanoi test.

RESULTS

Tests of executive function showed a pronounced deficit on written verbal fluency in both ALS groups in comparison to controls, which tended to be more prominent in patients with ALS with pseudobulbar palsy. The random movement joystick test (a non-verbal test of intrinsic movement generation) showed an impairment in the generation of random sequences in patients with pseudobulbar palsy only. The computerised Tower of Hanoi showed a subtle planning impairment (shorter planning times) in all the patients with ALS compared with controls on trials requiring more complex solutions. In addition the pseudobulbar patients displayed shorter planning times on complex trials, and tended to solve these trials less accurately. There was also evidence of a deficit for all patients with ALS in comparison with controls on total errors and number of categories achieved on the Wisconsin card sorting test and a strong tendency towards an impairment on a task of selective attention and cognitive inhibition (negative priming). A word recognition memory deficit was showed across both ALS groups.

CONCLUSIONS

This study elicited cognitive deficits (involving predominantly executive processes, with some evidence of memory impairment) in patients with ALS and further strengthened the link between ALS and frontal lobe dysfunction, this being more prominent in patients with pseudobulbar palsy. However, cognitive impairments suggestive of extramotor cortical involvement were not exclusive to this subgroup.