Unusual cases of multiple symmetrical lipomatosis with neurological disorders

Multiple symmetrical lipomatosis (MSL) is a rare disorder of unknown etiology defined as the presence of multiple and symmetrical fatty accumulations, usually involving the upper trunk, neck and head. Frequently associated findings include diabetes mellitus, hyperlipidemia, liver disease, hypothyroidism and polyneuropathy of unknown origin, but nevertheless, there are published reports of cognitive disorders in patients with MSL. We describe two unusual cases (38-year-old and 45-year-old Greek men) of MSL who presented with polyneuropathy and memory disorders. This is the first description of memory disorders in patients with MSL. We propose that Mini-Mental State Examination and assessment of cognitive functions should be performed for all patients with MSL. The underlying mechanism in our patients remains unknown, and this question should be the subject of a future study.

Self-reported symptoms of depression and memory dysfunction in survivors of ARDS

BACKGROUND

Survivors of ARDS have well documented physical limitations, but psychological effects are less clear. We determined the prevalence of self-reported depression and memory dysfunction in ARDS survivors.

METHODS

Six to 48 (median 22) months after ICU discharge, we administered instruments assessing depression symptoms (Beck Depression Inventory-II [BDI-II]) and memory dysfunction (Memory Assessment Clinics Self-Rating Scale [MAC-S]) to 82 ARDS patients who were enrolled in a prospective cohort study in four university-affiliated ICUs.

RESULTS

Sixty-one (74%), 64 (78%), and 61 (74%) patients fully completed the BDI-II, MAC-S (Ability subscale), and MAC-S (Frequency of Occurrence subscale) instruments. Responders (similar to nonresponders) were young (median 42 years, interquartile range [IQR] 35 to 56), with high admission illness severity and organ dysfunction. The median BDI-II score was 12 (IQR 5 to 25). Twenty-five (41%) patients reported moderate-severe depression symptoms and were less likely to return to work than those with minimal-mild symptoms (8/25 [32%] vs 25/36 [69%]; p = 0.005). Median MAC-S (Ability) and MAC-S (Frequency of Occurrence) scores were 76 (IQR 61 to 93) and 91 (IQR 77 to 102), respectively; 8%, 16%, and 20% scored > 2, > 1.5, and > 1 SD(s), respectively, below age-adjusted population norms for each subscale. BDI-II and MAC-S scores were negatively correlated (Spearman coefficient -0.58 and -0.50 for Ability and Frequency of Occurrence subscales, respectively; p < 0.0001). Univariable analyses showed no demographic or illness-severity predictors of BDI-II (including the Cognitive subscale) or MAC-S (both subscales); results were similar when restricted to patients whose primary language was English.

CONCLUSIONS

ARDS survivors report a high prevalence of depression symptoms and a lower prevalence of memory dysfunction 6 to 48 months after ICU discharge. Depression symptoms may hinder the return to work, or patients may report these symptoms because of inability to re-enter the workforce.

Cerebellar pathology does not impair performance on identification or categorization tasks

In comparison to the basal ganglia, prefrontal cortex, and medial temporal lobes, the cerebellum has been absent from recent research on the neural substrates of categorization and identification, two prominent tasks in the learning and memory literature. To investigate the contribution of the cerebellum to these tasks, we tested patients with cerebellar pathology (seven with bilateral degeneration, six with unilateral lesions, and two with midline damage) on rule-based and information-integration categorization tasks and an identification task. In rule-based tasks, it is assumed that participants learn the categories through an explicit reasoning process. In information-integration tasks, optimal performance requires the integration of information from multiple stimulus dimensions, and participants are typically unaware of the decision strategy. The identification task, in contrast, required participants to learn arbitrary, color-word associations. The cerebellar patients performed similar to matched controls on all three tasks and performance did not vary with the extent of cerebellar pathology. Although the interpretation of these null results requires caution, these data contribute to the current debate on cerebellar contributions to cognition by providing boundary conditions on understanding the neural substrates of categorization and identification, and help define the functional domain of the cerebellum in learning and memory.

Not all repetition is alike: different benefits of repetition in amnesia and normal memory

While it is well known that repetition can enhance memory in amnesia, little is known about which forms of repetition are most beneficial. This study compared the effect on recognition memory of repetition of words in the same semantic context and in varied semantic contexts. To gain insight into the mechanisms by which these forms of repetition affect performance, participants were asked to make Remember/Know judgments during recognition. These judgments were used to make inferences about the contribution of recollection and familiarity to performance. For individuals with intact memory, the two forms of repetition were equally beneficial to overall recognition, and were associated with both enhanced Remember and Know responses. However, varied repetition was associated with a higher likelihood of Remember responses than was fixed repetition. The two forms of repetition also conferred equivalent benefits on overall recognition in amnesia, but in both cases, this enhancement was manifest exclusively in enhanced Know responses. We conclude that the repetition of information, and especially repetition in varied contexts, enhances recollection in individuals with intact memory, but exclusively affects familiarity in patients with severe amnesia.

Memory impairment, executive dysfunction, and intellectual decline in preclinical Alzheimer's disease

In the Baltimore Longitudinal Study of Aging (BLSA), we examined the temporal unfolding of declining performance on tests of episodic memory (Free Recall on the Free and Cued Selective Reminding Test), executive function (Category Fluency, Letter Fluency, and Trails), and Verbal Intelligence (Nelson, 1982; American Version of the Nelson Adult Reading Test [AMNART]) before the diagnosis of dementia in 92 subjects with incident Alzheimer's disease (AD) followed for up to 15 years before diagnosis. To examine the preclinical onset of cognitive decline, we aligned subjects at the time of initial AD diagnosis and examined the cognitive course preceding diagnosis. We found that declines in performance on tests of episodic memory accelerated 7 years before diagnosis. Declining performance on tests of executive function accelerated 2-3 years before diagnosis, and verbal intelligence declined in close proximity to diagnosis. This cognitive profile is compatible with pathologic data suggesting that structures which mediate memory are affected earlier than frontal structures during the preclinical onset of AD. It also supports the view that VIQ as estimated by the AMNART does not decline during the preclinical onset of AD.

Hormonal treatment, mild cognitive impairment and Alzheimer's disease

A plethora of in vitro and in vivo studies have supported the neuroprotective role of estrogens and their impact on the neurotransmitter systems implicated in cognition. Recent hormonal replacement therapy (HRT) trials in non-demented postmenopausal women suggest a temporary positive effect (notably on verbal memory), and four meta-analyses converge to suggest a possible protective effect in relation to Alzheimer's disease (reducing risk by 29 to 44%). However, data from the only large randomized controlled trial published to date, the Women's Health Initiative Memory Study, did not confirm these observations and have even suggested an increase in dementia risk for women using HRT compared to controls. Apart from methodological differences, one key shortcoming of this trial has probably been the focus on late-onset (postmenopausal) hormonal changes, i.e. at a time when the neurodegenerative process has already begun and without taking into account individual lifetime exposure to hormone variability. Multifactorial models based on an exhaustive view of all hormonal events throughout the reproductive life (rather than on a specific exposure to a given steroid) together with other risk factors (notably genetic risk factors related to estrogen receptor polymorphisms) should be explored to clarify the role of hormonal risk factors, or protective factors for cognitive dysfunction and dementia.

Parallel loss of hippocampal LTD and cognitive flexibility in a genetic model of hyperdopaminergia

Dopamine-mediated neurotransmission has been implicated in the modulation of synaptic plasticity and in the mechanisms underlying learning and memory. In the present study, we tested different forms of activity-dependent neuronal and behavioral plasticity in knockout mice for the dopamine transporter (DAT-KO), which constitute a unique genetic model of constitutive hyperdopaminergia. We report that DAT-KO mice exhibit slightly increased long-term potentiation and severely decreased long-term depression at hippocampal CA3-CA1 excitatory synapses. Mutant mice also show impaired adaptation to environmental changes in the Morris watermaze. Both the electrophysiological and behavioral phenotypes are reversed by the dopamine antagonist haloperidol, suggesting that hyperdopaminergia is involved in these deficits. These findings support the modulation by dopamine of synaptic plasticity and cognitive flexibility. The behavioral deficits seen in DAT-KO mice are reminiscent of the deficits in executive functions observed in dopamine-related neuropsychiatric disorders, suggesting that the study of DAT-KO mice can contribute to the understanding of the molecular basis of these disorders.

Targeting the gastrin-releasing peptide receptor pathway to treat cognitive dysfunctionassociated with Alzheimer's Disease

Increasing evidence indicates that bombesin (BB)-like peptides (BLPs), such as the gastrin-releasing peptide (GRP) and its receptor (GRPR), might play a role in neurological and psychiatric disorders. The present study reviews findings from animal and human studies suggesting that the GRPR should be considered a target for the treatment of cognitive dysfunction in patients with Alzheimer’s disease (AD). Abnormalities in GRPR-triggered signaling have been described in both fibroblasts from patients with AD, and in transgenic mouse models of AD. Pharmacological and genetic preclinical studies have indicated that BLPs and the GRPR are importantly involved in regulating cognitive function. Moreover, drugs acting at the GRPR have been shown to enhance memory and ameliorate cognitive dysfunction in experimental models of amnesia associated with AD. Taken together, these findings support the view that the GRPR is a novel therapeutic target for the treatment of memory deficits associated with AD.

Neuropsychological and neuroimaging changes in preclinical Alzheimer's disease

Alzheimer's disease (AD) is a common, devastating form of dementia. With the advent of promising symptomatic treatment, the importance of recognizing AD at its very earliest stages has increased. We review the extant neuropsychological and neuroimaging literature on preclinical AD, focusing on longitudinal studies of initially nondemented individuals and cross-sectional investigations comparing at-risk with normal individuals. We systematically reviewed 91 studies of neuropsychological functioning, structural neuroimaging, or functional neuroimaging in preclinical AD. The neuropsychological studies indicated that preclinical AD might be characterized by subtle deficits in a broad range of neuropsychological domains, particularly in attention, learning and memory, executive functioning, processing speed, and language. Recent findings from neuroimaging research suggest that volume loss and cerebral blood flow or metabolic changes, particularly in the temporal lobe, may be detected before the onset of dementia. There exist several markers of a preclinical period of AD, in which specific cognitive and biochemical changes precede the clinical manifestations. The preclinical indicators of AD reflect early compromise of generalized brain integrity and temporal lobe functioning in particular.

Memory tests in first-degree adult relatives of schizophrenic patients: a meta-analysis

BACKGROUND

Memory deficits have been clearly demonstrated in schizophrenic patients. However, studies of memory performances in their relatives compared to normal controls provide conflicting results. A meta-analysis was carried out to synthesize all the published data. Unlike previous meta-analyses, which were based on composite scores, we analyzed each memory test separately. This prevents theoretically questionable choices in grouping variables, leads to results with clearer implications for applied research (e.g. the best choice of a test according to its sensitivity) and is more productive in suggesting explanatory hypotheses.

METHOD

We initially selected 77 potentially relevant articles, but only 19 met our inclusion criteria. These articles provided data on eight different tasks, from five different memory tests: four tests from the Wechsler Memory Scale (WMS) and the California Verbal Learning Test (CVLT). For each task, we assessed data homogeneity, identified the outliers if any and then estimated effect sizes and tested publication bias using funnel plots.

RESULTS

Adult relatives of schizophrenic patients were significantly impaired on most, but not all, tasks. The largest deficits were observed for the verbal paired associates test, the logical stories the digit span forward test and the digit span backward test. We found no significant differences in tasks of delayed recall, when deficits in immediate conditions (reflecting encoding) were taken into account.

CONCLUSIONS

Adult relatives of schizophrenic patients have wide but not severe memory impairments. The size of estimated effects suggests that encoding processes are impaired, whereas storage and retrieval processes are relatively unaffected.

Development of an interactive tailored information application to improve patient medication adherence

Medication adherence is increasingly recognized as an important health care problem. Although various factors have been related to adherence, patients' understanding of their illness and the influence of treatment on it has been shown to affect treatment adherence. Individually tailoring information provided to patients has a greater im-pact on patient behavior than providing generic information. This paper details the development of an interactive software application that provides individually-tailored information to patients treated with cholinesterase inhibitor medications for memory disorders. The application allows clinician input of information on patient level of health literacy and allows patients to choose among multiple questions related to their illness and its treatment. Output then includes answers to questions in Spanish and English at low or high literacy levels. Pilot data show a high degree of acceptability to users and an association with high sustained levels of adherence.

A case of psychogenic fugue: I understand, aber ich verstehe nichts

Psychogenic fugue is a disorder of memory that occurs following emotional or psychological trauma and results in a loss of one's personal past including personal identity. This paper reports a case of psychogenic fugue in which the individual lost access not only to his autobiographical memories but also to his native German language. A series of experiments compared his performance on a variety of memory and language tests to several groups of control participants including German-English bilinguals who performed the tasks normally or simulated amnesia for the German language. Neuropsychological, behavioral, electrophysiological and functional neuroimaging tests converged on the conclusion that this individual suffered an episode of psychogenic fugue, during which he lost explicit knowledge of his personal past and his native language. At the same time, he appeared to retain implicit knowledge of autobiographical facts and of the semantic or associative structure of the German language. The patient's poor performance on tests of executive control and reduced activation of frontal compared to parietal brain regions during lexical decision were suggestive of reduced frontal function, consistent with models of psychogenic fugue proposed by Kopelman and Markovitsch.

Spontaneously hypertensive rats: further evaluation of age-related memory performance and cholinergic marker expression

OBJECTIVE

The spontaneously hypertensive rat (SHR), often used to study cardiovascular disease processes, may also be utilized to model certain central nervous system changes associated with memory disorders. Previous work in our laboratory indicated that central nicotinic acetylcholine receptors are markedly diminished and that memory-related task performance is impaired in this rodent phenotype. Due to the well-documented importance of the central cholinergic system to memory processes and its vulnerability to the effects of aging, it was of interest to measure other cholinergic markers and to further evaluate memory function in older SHRs.

METHOD

Radial arm maze performance was used to assess working memory, quantitative receptor autoradiography with [3H]-pirenzipine, [3H]-AFDX-384 and [3H]-epibatidine (combined with cytisine) was used to determine the densities of muscarinic-M1 and -M2 and nicotinic cholinergic alpha3 receptors, respectively. Immunoblotting experiments were also used to determine the expression of the presynaptic cholinergic markers, choline acetyltransferase and the vesicular acetylcholine transporter.

RESULTS

Radial arm maze performance was impaired in hypertensive (compared with normotensive Wistar and Wistar-Kyoto) rats, regardless of age. M1 binding was increased in frontal and prefrontal cortical areas in SHR (p < 0.05), whereas M2 densities were higher in the hypertensive phenotype in the caudate putamen. A lower expression of alpha3-containing nicotinic receptors was observed in the superior colliculus in SHRs. Age-related differences in the expression of the vesicular acetylcholine transporter were noted in the hippocampus.

CONCLUSION

The SHR may be useful to model some aspects (particularly hypertension-related) of memory disorders, especially those in which cholinergic function is altered.