Impairment not only in remembering but also in knowing previously seen faces and words in schizophrenia

Patients with schizophrenia have pronounced deficits in face recognition memory that severely hamper their social skills. The functional mechanisms of these impairments remain unknown. According to the dual-process theory, recognition memory comprises two distinct components: recollection and familiarity. Studies using the Remember/Know procedure in patients with schizophrenia showed impairments in conscious recollection as measured by remember responses, but not in familiarity as measured by know responses. Unfortunately, none of these studies used face material. We investigated both recognition memory components using words and faces and the ‘Remember/Know’ procedure in 25 patients with schizophrenia and 24 control participants. In the same task, size congruency of stimuli was manipulated between the study and test phases to have a selective impact on know responses for faces. Patients reported fewer remember responses than controls. Size changes between the study and the test affected know responses in controls but not in patients. These results reveal that patients with schizophrenia are impaired in terms of their ability to recollect details about previously seen faces as they are for words.     

Diaschisis after thalamic stroke: a comparison of metabolic and structural changes in a patient with amnesic syndrome

Introduction –  We present a patient with a left anteromedial thalamic lesion with an amnesic syndrome. The patient underwent neuropsychological testing, cerebrospinal fluid (CSF) analyses, magnetic resonance imaging (MRI) [T2, flair, and diffusion tensor imaging (DTI)] and [18F]-2-fluoro-deoxy- d -glucose positron emission tomography (FDG-PET) to assess indirect effects of thalamic lesions on cortical function.
Case report –  A 67-year-old right-handed woman was admitted to a university-based memory unit because of memory and concentration problems. Neuropsychological testing revealed dysfunction of episodic memory, semantic memory and working memory. General intellectual function and attention capacity were preserved. MRI revealed an anteromedial thalamic lesion in the left hemisphere. FDG-PET showed decreased uptake in the frontal, parietal and temporal lobes of the left hemisphere. Regions of interest (ROI) in white matter were selected and left and right hemispheres were compared. Fractional anisotropy (FA) in ROI representing thalamo-cortical connections were decreased in the left hemisphere when compared with the right.
Conclusion –  The results show the importance of a network that include the anterior and dorsomedian nuclei, which influence the activity in areas of the cortex responsible for memory processes. The imaging findings suggest that areas of cortical diaschisis after thalamic infarction correspond to areas affected by thalamo-cortical fibre loss as measured with FA.     

The eyes remember it: oculography and pupillometry during recollection in three amnesic patients

Two patients (TC and SS) with lesions that included the hippocampal regions (predominantly on the left side) were severely impaired in their recall of simple, verbally stated facts. However, both patients remembered spatial information that was temporally associated with semantic information. Specifically, TC and SS could not recall explicitly the content of an episode, but their spontaneous oculomotor behavior showed that they retained some information about the event as their gaze automatically returned to the locations on the computer screen where visual information had been paired to verbally presented information. Thus, this spatial information is implicit, automatically retrieved, and eye-based, as when one patient (TC) was asked to point with the finger to the same positions he was impaired. In addition, in an old/new recognition task, TC and SS and an additional patient, OB, showed significant changes in eye pupil diameter when viewing novel visual stimuli compared to stimuli that they had previously seen, also when they (incorrectly) declared with confidence that an old item was new. The spared memory of these patients, despite severe amnesia for the learning episodes, is characterized by a re-enactment of previous eye fixations that were associated with each (forgotten) episode and physiological responses (as indexed by pupillometry) to previously seen stimuli. Such spared memory can be seen as a type of "snapshot" memory, which automatically processes eye-based spatial information and whose content remains implicit. Finally, we surmise on the basis of the neuroanatomical findings of these patients, that neural substrates in the spared (right) hemisphere might support both the eye fixations' re-enactment and implicit visual pattern recognition.     

I don't know what I know: Evidence of preserved semantic knowledge but impaired metalinguistic knowledge in adults with probable Alzheimer's disease

Abstract

This paper will address the current practice of speech therapists setting homework for aphasic patients.     

Semantic acquisition in childhood amnesic syndrome: a prospective study

Amnesic patients can acquire new semantic knowledge despite a profound deficit of episodic memory. Although retrospective studies have been carried out on adults and children, prospective studies have been restricted to adults. The aim of the present work was to assess the acquisition of new semantic knowledge in amnesic children. The semantic protocol, composed of short, illustrated texts, was based on an original methodology which included an assessment of episodic memory on two occasions. Two amnesic children acquired new concepts despite major episodic disturbance, illustrated notably by a lack of recollection in episodic tasks. Our findings lend weight to the assumption that forming new semantic knowledge does not necessarily involve episodic memory, and provide methodological pointers for children's neuropsychological rehabilitation.     

Remembering and knowing in a patient with preserved recognition and impaired recall

ROB is a patient who has a severe deficit in recalling recently presented verbal material following rupture and repair of an anterior communicating artery aneurysm [Hanley JR, Davies ADM, Downes J, Mayes A. Cognitive Neuropsychology 1994;11:543-78; Hanley JR, Davies ADM. In: Parkin A, editor. Case Studies in the Neuropsychology of Memory. Hillsdale, NJ: Lawrence Erlbaum, 1997. p. 111-26]. Despite this, her performance on tests of recognition memory is comfortably within the normal range. In the present series of experiments, we investigated whether or not ROB's performance on tests of recognition memory might be associated with a disproportionately large number of correct decisions made on the basis of familiarity rather than contextual retrieval [e.g. Mandler G. Psychological Review 1980;87:252-71]. Contrary to this hypothesis, the results showed that ROB made a high proportion of remember decisions relative to know decisions in recognition [cf. Gardiner JM. Memory & Cognition 1988;16:309-13] and produced a high recollection score when conscious recollection and familiarity were placed in opposition to one another [cf. Jacoby LL, Woloshyn V, Kelley C. Journal of Experimental Psychology: General 1989;118:115-25.]. ROB's recognition memory performance therefore appears to be qualitatively as well as quantitatively similar to that found in the normal population. As ROB has suffered damage to both the fornix and the anterior thalamus, the results of the present study are consistent with the claim that damage to the extended hippocampal system has a much more severe effect on recall than on recognition [Aggleton JP, Shaw C. Neuropsychologia 1996;34:51-62; Aggleton JP, Saunders RC. Memory 1997;5:49-71]. The present results provide no support, however, for the additional suggestion [Aggleton JP, Brown MW. Behavioral and Brain Sciences 1999;22:425-56.] that the extended hippocampal system is necessary for recognition memory decisions that are based on contextual retrieval.     

Chiari type I malformation in a patient with Poland's syndrome

Chiari malformation type I and Poland's syndrome are two rare diseases and their simultaneous presentation had not been previously described in the literature. We report the case of a 27 year old male with history of Poland's syndrome, who referred headache and motor impairment of the intrinsic muscles of the left hand. In a cervical spine MR a Chiari I malformation with syringomyelia from C1 to T2 was found, which was treated by foramen magnum decompression, dural plasty and removal of the posterior arch of the atlas. A discussion of the embryological mechanisms that might be involved in the coexistence of these two entities is presented, emphasizing the role of para-axial mesoderm.     

'Not knowing where I am doesn't mean I don't know what I like': cognitive impairment and quality of life responses in elderly people.

OBJECTIVE: To elucidate the extent to which elderly people with cognitive impairment are able to answer questions about their quality of life.Design and setting308 elderly residents were interviewed within 2 weeks of admission to one of 30 residential or nursing homes in north-west England.MEASURES: The Mini-Mental State Examination (MMSE), the Lancashire Quality of Life Profile (Residential) (LQOLP(R)), the Crichton Royal Behaviour Rating Scale (CRBRS) and the HONOS-65+.RESULTS: Of the 308 subjects, LQOLP(R) interviews were attempted with 213 who scored 10 or over on the MMSE. Of the 213, 77.5% were found to be 'interviewable', ie able to answer the majority of questions in the LQOLP(R) and in doing so to give answers in which the interviewer had confidence. Of the seven cognitive domains measured by the MMSE, visual construction and registration were not significantly associated with interviewability. While orientation to time and recall were significantly associated with interviewability, many interviewable respondents had poor scores in these domains. No respondents were interviewable who scored less than 2 (out of 5) for orientation to place or less than 3 (out of 8) for language or less than 2 (out of 5) for attention. CONCLUSIONS: A high proportion of elderly people can answer questions about their quality of life, even in the presence of significant cognitive deficits.     

“I remember it as if it were yesterday”: Memory for recent events in patients with semantic dementia

Patients with semantic dementia (SD), who have an incontrovertible deficit in semantic memory, are reported to show good day-to-day memory for recent events; but experimental evidence on their anterograde episodic memory/new learning is somewhat sparse and does not always tell a consistent story. We describe the performance of five SD patients, relative to controls, on (a) a range of semantic memory measures that predictably revealed substantial impairment, and (b) a newly designed naturalistic and incidental episodic task, which included information regarding the items and context of the semantic tasks. As a group, the patients’ episodic memory for these natural events was good, even after a 24-h delay, although case-by-case analysis revealed some heterogeneity in performance. These findings are discussed with regard to the neural substrate of episodic memory and psychological models of long-term memory.     

Selective alteration of native, but not second language articulation in a patient with foreign accent syndrome

The present study deals with a right-handed female polyglot suffering from a Foreign Accent Syndrome (FAS) which affects her native language (L1), but not her other languages learnt since the age of 12. She had a small infarct in the left corona radiata as the result of a carotid occlusion. Her L1 was Spanish, but she also had a good command of French, English and Catalan (L2). Aphasia tests did not reveal any other significant alteration in any language. Analyses of pre-morbid and post-morbid voice recordings revealed that FAS affected Spanish dramatically, but no important changes were observed for French. Results were interpreted as showing that different brain areas control articulation of L1 and L2 learnt after a critical period.     

Balloon cells and dysmorphic neurons in the hippocampus associated with epileptic amnesic syndrome: a case report

Recently, we encountered a 39-year-old woman with typical epileptic amnesic syndrome. The patient underwent right anterior temporal lobectomy, which removed the right hippocampus. The patient's resected hippocampus showed typical histological features of Ammon's horn sclerosis (AHS) with dysmorphic neurons. In addition, the prominent balloon cells, admixed with dysmorphic neurons, were noted in the hippocampus. To our knowledge, this is the first reported case showing AHS with balloon cells. The presence of balloon cells reinforces the hypothesis that AHS itself might be a maldevelopment disorder.     

The amnesic Korsakoff syndrome: a study of selective and divided attention.

Groups of control and amnesic Korsakoff patients were given dichotic lists consisting of word-number pairs with instructions to (a) divide attention between ears and report by stimulus category, and (b) focus attention and report by ear. The performance of Korsakoff patients was inferior to controls both on the number of category reports and on the ear reported second in the selective attention condition. The lower accuracy with category reports is consistent with the results of other studies suggesting an impairment of semantic feature processing in Korsakoff patients. The deficit on the ear reported second is discussed in terms of proactive interference.     

Auditory event-related potentials in an amnesic patient with a left temporal lobe lesion.

We studied auditory event-related potentials (ERPs) in correlation with Rey's auditory verbal learning test (AVLT) in an amnesic patient with a left temporal lobe lesion. On the AVLT, the number of words recalled was limited to immediate memory capacity (nine words) throughout five trials, and recall after interference was remarkably decreased. In the ERPs, the P300 component was elicited normally, but no N400 component was apparent. Present findings suggest that these two ERP components may be associated with independent processes and support the view that the N400 may index a neural process involved in transfer of information from immediate memory to long-term storage.     

Cotard's syndrome in a patient with coexistent Capgras' syndrome, syndrome of subjective doubles, and palinopsia

The hallmark of Cotard's syndrome is the delusion of being dead. It is usually seen in affective disorders, and its existence as a separate entity is controversial. A patient is described who presented with paranoid schizophrenia, Cotard's syndrome, the misidentification syndromes of Capgras and subjective doubles, and palinopsia (visual perseveration). Focal theories for these conditions are briefly outlined and the patient is discussed with reference to them. It is proposed that this case supports the concept that Cotard's syndrome is a distinct disorder. The possibility of cerebral dysfunction in the confluence of the parietal, temporal, and occipital regions accounting for this specific clinical presentation is considered.     

Late-onset Leigh syndrome in a patient with mitochondrial complex I NDUFS8 mutations

Analysis of the complex I NDUFS8 gene from Leigh syndrome patients with isolated complex I deficiency revealed that one patient with late-onset disease and partial complex I defect was a compound heterozygote for two novel mutations in NDUFS8 gene. Western blot analysis revealed a deficiency in the NDUFS8 polypeptide, but also reductions in other nuclear subunits of complex I, suggesting that this subunit is essential for either the assembly or stability of complex I.     

Spatial deficits in an amnesic patient with hippocampal damage: questioning the multiple trace theory

Mediotemporal lobe structures are involved in both spatial processing and long-term memory. Patient M.R. suffers from amnesia, due to bilateral hippocampal lesion and temporoparietal atrophy following carbon monoxide poisoning. We compared his performance in immediate spatial memory tasks with the performance of ten healthy matched participants. Using an immediate reproduction of path, we observed a dissociation between his performance in three allocentric tasks and in five egocentric-updating tasks. His performance was always impaired on tasks requiring the use of an egocentric-updating representation but remained preserved on allocentric tasks. These results fit with the hypothesis that the hippocampus plays a role in spatial memory, but they also suggest that allocentric deficits previously observed in amnesia might actually reflect deficits in egocentric-updating processes. Furthermore, the co-occurrence of deficits in episodic long-term memory and short-term egocentric-updating representation without any short-term allocentric deficit suggests a new link between the mnemonic and navigational roles of the hippocampus. The Cognitive Map theory, the Multiple Trace theory, as well as further models linking spatial and nonspatial functions of the hippocampus are discussed.     

Infantile spasms syndrome,West syndrome and related phenotypes: What we know in 2013

The current spectrum of disorders associated to clinical spasms with onset in infancy is wider than previously thought; accordingly, its terminology has changed. Nowadays, the term Infantile spasms syndrome (ISs) defines an epileptic syndrome occurring in children younger than 1 year (rarely older than 2 years), with clinical (epileptic: i.e., associated to an epileptiform EEG) spasms usually occurring in clusters whose most characteristic EEG finding is hypsarrhythmia [the spasms are often associated with developmental arrest or regression]. The term West syndrome (WS) refers to a form (a subset) of ISs, characterised by the combination of clustered spasms and hypsarrhythmia on an EEG and delayed brain development or regression [currently, it is no longer required that delayed development occur before the onset of spasms]. Less usually, spasms may occur singly rather than in clusters [infantile spasms single-spasm variant (ISSV)], hypsarrhythmia can be (incidentally) recorded without any evidence of clinical spasms [hypsarrhythmia without infantile spasms (HWIS)] or typical clinical spasms may manifest in absence of hypsarrhythmia [infantile spasms without hypsarrhythmia (ISW)]. There is a growing evidence that ISs and related phenotypes may result, besides from acquired events, from disturbances in key genetic pathways of brain development: specifically, in the gene regulatory network of GABAergic forebrain dorsal–ventral development, and abnormalities in molecules expressed at the synapse. Children with these genetic associations also have phenotypes beyond epilepsy, including dysmorphic features, autism, movement disorders and systemic malformations. The prognosis depends on: (a) the cause, which gives origin to the attacks (the complex malformation forms being more severe); (b) the EEG pattern(s); (c) the appearance of seizures prior to the spasms; and (d) the rapid response to treatment. Currently, the first-line treatment includes the adrenocorticotropic hormone ACTH and vigabatrin. In the near future the gold standard could be the development of new therapies that target specific pathways of pathogenesis. In this article we review the past and growing number of clinical, genetic, molecular and therapeutic discoveries on this expanding topic.