Self-rated anosognosia score may be a sensitive and predictive indicator for progressive brain atrophy in amyotrophic lateral sclerosis: an X-ray computed tomographic study

We investigated whether a self-rated anosognosia score can be an indicator for progression of brain atrophy in patients with amyotrophic lateral sclerosis (ALS). Scores for 16 patients were compared with the ventricular areas of the bilateral anterior and inferior horns measured on x-ray computed tomography. Longitudinal enlargement was expressed as a monthly increase in size: (ventricular size at the initial scan - ventricular size at the follow-up scan)/scan interval (months). The anosognosia scores ranged from -4 to 3 and 3-18 in patients with and without frontotemporal lobar degeneration (FTLD), respectively (p = 0.0011). Anosognosia scores were significantly correlated with sizes of anterior (r = 0.704, p = 0.0016) and inferior (r = 0.898, p < 0.0001) horns. In non-demented patients for whom follow-up CT scans were available (n = 7), the scores were significantly correlated with the longitudinal increase in inferior horn size (r = 0.754, p = 0.0496), but not with that of anterior horn size (r = -0.166, p = 0.7111). In conclusion, anosognosia in ALS is associated with greater anterior and inferior horn sizes, reflecting frontotemporal lobar atrophy. Moreover, mild anosognosia in ALS patients without FTLD may predict impending inferior horn enlargement, reflecting medial temporal atrophy.

Agnosias: recognition disorders in patients with brain tumors

Two main varieties of recognition disorders are distinguished in neuropsychology: agnosias and semantic disorders. The term agnosias is generally used to denote recognition defects limited to a single perceptual modality (which is itself apparently intact), whereas the term semantic disorders is used to denote recognition defects involving all the sensory modalities in a roughly similar manner. Brain tumors can be one of the aetiologies underlying agnosias and semantic disorders. However, due to the heterogeneity and the rarity of recognition disorders, their investigation can be useful only to suggest or exclude the oncological nature of a brain lesion, but not to systematically monitor the clinical outcome in tumor patients. Furthermore, the relevance of recognition disorders as a hint toward a diagnosis of brain tumor varies according to the type of agnosia and of semantic disorder and the localization of the underlying brain pathology. The hypothesis that a variety of agnosia (or of semantic disorder) may be due to a neoplastic lesion can, therefore, be advanced if it is consistent with our knowledge about the usual localization and the growing patterns of different types of brain tumors.

Right hemisphere syndromes

Stroke is the leading cause of acquired motor disability in the adult. Neuropsychological sequelae are common after vascular brain injury. While left cortical signs and symptoms are clearly evident at neurological examination, right hemispheric dysfunction must be carefully pursued and sometimes can be underrecognized. Indeed, patients with right hemispheric strokes present later to an emergency department and have a lower chance of receiving intravenous recombinant tissue plasminogen activator. For a better comprehension of clinical signs and symptoms in right acute hemispheric stroke, in this chapter we present a review of the principle clinical syndromes.

Visual agnosia and posterior cerebral artery infarcts: an anatomical-clinical study

Background

To evaluate systematically the cognitive deficits following posterior cerebral artery (PCA) strokes, especially agnosic visual disorders, and to study anatomical-clinical correlations.

Methods and Findings

We investigated 31 patients at the chronic stage (mean duration of 29.1 months post infarct) with standardized cognitive tests. New experimental tests were used to assess visual impairments for words, faces, houses, and objects. Forty-one healthy subjects participated as controls. Brain lesions were normalized, combined, and related to occipitotemporal areas responsive to specific visual categories, including words (VWFA), faces (FFA and OFA), houses (PPA) and common objects (LOC). Lesions were located in the left hemisphere in 15 patients, in the right in 13, and bilaterally in 3. Visual field defects were found in 23 patients. Twenty patients had a visual disorder in at least one of the experimental tests (9 with faces, 10 with houses, 7 with phones, 3 with words). Six patients had a deficit just for a single category of stimulus. The regions of maximum overlap of brain lesions associated with a deficit for a given category of stimuli were contiguous to the peaks of the corresponding functional areas as identified in normal subjects. However, the strength of anatomical-clinical correlations was greater for words than for faces or houses, probably due to the stronger lateralization of the VWFA, as compared to the FFA or the PPA.

Conclusions

Agnosic visual disorders following PCA infarcts are more frequent than previously reported. Dedicated batteries of tests, such as those developed here, are required to identify such deficits, which may escape clinical notice. The spatial relationships of lesions and of regions activated in normal subjects predict the nature of the deficits, although individual variability and bilaterally represented systems may blur those correlations.

Auditory agnosia due to long-term severe hydrocephalus caused by spina bifida - specific auditory pathway versus nonspecific auditory pathway

A 27-year-old female showed auditory agnosia after long-term severe hydrocephalus due to congenital spina bifida. After years of hydrocephalus, she gradually suffered from hearing loss in her right ear at 19 years of age, followed by her left ear. During the time when she retained some ability to hear, she experienced severe difficulty in distinguishing verbal, environmental, and musical instrumental sounds. However, her auditory brainstem response and distortion product otoacoustic emissions were largely intact in the left ear. Her bilateral auditory cortices were preserved, as shown by neuroimaging, whereas her auditory radiations were severely damaged owing to progressive hydrocephalus. Although she had a complete bilateral hearing loss, she felt great pleasure when exposed to music. After years of self-training to read lips, she regained fluent ability to communicate. Clinical manifestations of this patient indicate that auditory agnosia can occur after long-term hydrocephalus due to spina bifida; the secondary auditory pathway may play a role in both auditory perception and hearing rehabilitation.

[A case of transient auditory agnosia and schizophrenia]

We report a case of transient functional auditory agnosia and schizophrenia and discuss their relationship. A 30-year-old woman with schizophrenia reporting bilateral hearing loss was found in history taking to be able to hear but could neither understand speech nor discriminate among environmental sounds. Audiometry clarified normal but low speech discrimination. Otoacoustic emission and auditory brainstem response were normal. Magnetic resonance imaging (MRI) elsewhere evidenced no abnormal findings. We assumed that taking care of her grandparents who had been discharged from the hospital had unduly stressed her, and her condition improved shortly after she stopped caring for them, returned home and started taking a minor tranquilizer.

Agnosic or semantic impairment in very mild Alzheimer's disease?

The present study investigated object recognition impairment and the existence of category effects in patients with mild Alzheimer's disease. A battery of tests was designed to assess the deterioration of semantic memory and/or the existence of agnosia by evaluating visual and auditory naming, knowledge of structural descriptions (pre-semantic representation of an object within each perceptual system) and conceptual knowledge. The group of Alzheimer's patients were impaired in all experimental tests as compared to healthy participants. This result suggests an impairment of multiple levels of object integration processing even at an early stage of the disease. The patients also demonstrated a category effect with massive difficulties in recognizing human actions and musical instruments as compared to the other categories. This study provides an innovative clinical tool for exploring the recognition of visual and auditory objects at different levels of representation, allowing for the description of early signs of Alzheimer disease.

[Associative visual agnosia. The less visible consequences of a cerebral infarction]

After a cerebral infarction, some patients acutely demonstrate contralateral hemiplegia, or aphasia. Those are the obvious symptoms of a cerebral infarction. However, less visible but burdensome consequences may go unnoticed without closer investigation. The importance of a thorough clinical examination is exemplified by a single case study of a 72-year-old, right-handed male. Two years before he had suffered from an ischemic stroke in the territory of the left posterior cerebral artery, with right homonymous hemianopia and global alexia (i.e., impairment in letter recognition and profound impairment of reading) without agraphia. Naming was impaired on visual presentation (20%-39% correct), but improved significantly after tactile presentation (87% correct) or verbal definition (89%). Pre-semantic visual processing was normal (correct matching of different views of the same object), as was his access to structural knowledge from vision (he reliably distinguished real objects from non-objects). On a colour decision task he reliably indicated which of two items was coloured correctly. Though he was unable to mime how visually presented objects were used, he more reliably matched pictures of objects with pictures of a mime artist gesturing the use of the object. He obtained normal scores on word definition (WAIS-III), synonym judgment and word-picture matching tasks with perceptual and semantic distractors. He however failed when he had to match physically dissimilar specimens of the same object or when he had to decide which two of five objects were related associatively (Pyramids and Palm Trees Test). The patient thus showed a striking contrast in his intact ability to access knowledge of object shape or colour from vision and impaired functional and associative knowledge. As a result, he could not access a complete semantic representation, required for activating phonological representations to name visually presented objects. The pattern of impairments and preserved abilities is considered to be a specific difficulty to access a full semantic representation from an intact structural representation of visually presented objects, i.e., a form of visual object agnosia.

Lesson of the month (2). Is that your arm or mine?

We report a case of a 45-year-old man presenting with asomatognosia, or loss of body part ownership, when he experienced difficulty acknowledging that his arm was his own. His symptoms might easily have been considered to be of psychiatric origin. Instead they turned out to be due to highly focal stroke secondary to carotid dissection, an important and often missed cause of stroke in younger patients.

VATA-L: visual-analogue test assessing anosognosia for language impairment

Lack of awareness (anosognosia) for one's own language impairments has rarely been investigated, despite hampering language rehabilitation. Assessment of anosognosia by means of self-report is particularly complex, as a patient's language difficulties may seriously prevent or bias the assessment. Other methods, such as measures of self-correction and error detection, have provided valuable information, although they are an indirect form of assessment of anosognosia and are not exempt from methodological criticisms. In this study we report on a new tool, the VATA-L (Visual-Analogue Test for Anosognosia for Language impairment), geared at assessing explicit anosognosia for aphasia. The VATA-L compares the patient's self-evaluation with caregivers' evaluations of the patient's verbal communication abilities in a series of common situations. By means of non-verbal support and a system of check questions, this test minimizes some of the methodological limitations of existing diagnostic tools (e.g., structured interviews), enhancing reliability, and enabling assessment of patients with aphasia. Finally, normative data provided in the study allow a clearer interpretation of the patient's performance and facilitate assessment of anosognosia.

Long radiology workdays reduce detection and accommodation accuracy

PURPOSE

The aim of this study was to measure the diagnostic accuracy of fracture detection, visual accommodation, reading time, and subjective ratings of fatigue and visual strain before and after a day of clinical reading.

METHODS

Forty attending radiologists and radiology residents viewed 60 deidentified, HIPAA-compliant bone examinations, half with fractures, once before any clinical reading (early) and once after a day of clinical reading (late). Reading time was recorded. Visual accommodation (the ability to maintain focus) was measured before and after each reading session. Subjective ratings of symptoms of fatigue and oculomotor strain were collected. The study was approved by local institutional review boards.

RESULTS

Diagnostic accuracy was reduced significantly after a day of clinical reading, with average areas under the receiver operating characteristic curves of 0.885 for early reading and 0.852 for late reading (P < .05). After a day of image interpretation, visual accommodation was no more variable, though error in visual accommodation was greater (P < .01), and subjective ratings of fatigue were higher.

CONCLUSIONS

After a day of clinical reading, radiologists have reduced ability to focus, increased symptoms of fatigue and oculomotor strain, and reduced ability to detect fractures. Radiologists need to be aware of the effects of fatigue on diagnostic accuracy and take steps to mitigate these effects.

[Posterior cortical atrophy (Benson-syndrome)]

We present the characteristics of posterior cortical atrophy--a very rare cortical dementia--in a 69 year old woman's case. Our patient's symptoms began with a visual problem which was initially explained by ophthalmological disorder. After neurological exam visual agnosia was diagnosed apart from other cognitive disorder (alexia without agraphia, acalculia, prosopagnosia, constructional disorder, clock-time recognition disorder, dressing apraxia, visuospatial disorientation). The brain MRI showed bilateral asymmetric parieto-occipital atrophy which is characteristic of posterior cortical atrophy.

Self-estimation of performance time versus actual performance time in older adults with suspected mild cognitive impairment: a clinical perspective

BACKGROUND

Estimation of the passage of time has received marginal attention in contemporaneous psychiatric assessment and diagnosis. There is disagreement regarding the ability of older adults with dementia, particularly of the Alzheimers type, to estimate time passage, and there is lack of data concerning the ability of older adults in the early stages of cognitive impairment to estimate the passage of time.

OBJECTIVE

We investigated the hypothesis that individuals with mild dementia perform worse compared to those with no cognitive impairment, and that those with mild cognitive impairment (MCI) assume an intermediate position in terms of their ability to accurately estimate time passage. Another objective was to study demographic and clinical (cognitive, functional, psychiatric) predictors of self-estimation of performance time versus actual performance time.

METHOD

In the context of a comprehensive psychogeriatric evaluation, three performance time measures were established: actual performance time, subjective estimation of performance time, and accuracy of estimation of performance time.

RESULTS

102 consecutive persons with suspected MCI were assessed. Final cognitive diagnoses were: dementia 49 (48%), MCI 36 (35%), no cognitive impairment (NCI) 17 (17%). Whereas there were significant group differences (dementia, MCI, NCI) on all cognitive measures and on functional impairment, there were no significant group differences on the three time measures. With the exception of age, estimation of performance time was not associated with any of the other demographic and clinical variables.

CONCLUSION

Self-estimation of performance time versus actual performance time was not found impaired either in the dementia group or in the MCI group when compared to participants without cognitive impairment.

Babinski's anosognosia for hemiplegia in early twentieth-century French neurology

In 1914, Babinski first described "anosognosia"; a term he coined for a phenomenon involving unawareness of disability in hemiplegia. Historical roots of contemporary perspectives on anosognosia after stroke may be found in early discussions among French neurologists. Current notions and debate regarding the roles played by cognition, emotional factors, sensory loss and somatosensory neglect in anosognosia, and the distinctness of anosognosia as a symptom echo the theoretical dilemmas of an earlier past. Historical overview of the development of perspectives on anosognosia enriches our understanding of unawareness of disability.

Verbal intelligence in Neglect: the role of anosognosia for hemiplegia

AIM

General intelligence of patients with neglect has been poorly investigated and data at present are contrasting. Moreover it is not yet defined whether the presence of anosognosia for hemiplegia is associated with intellectual impairment in patients with neglect.

METHODS

In this prospective study the authors evaluated the verbal intelligence quotient in neglect patients. This study was carried out on 33 patients with left hemiparesis: 11 patients had neglect (group N), 11 had neglect + anosognosia (group N+A) and 11 had neither neglect nor anosognosia (control group).

RESULTS

Patients of group neglect + anosognosia had significantly lower verbal IQ (VIQ) and mini-mental state examination (MMSE) scores than those of neglect (respectively: P=0.004 and P=0.000) and control groups (respectively: P=0.041 and P=0.000). No significant differences were detected between neglect and control groups for VIQ and MMSE. In N+A group VIQ score was lower than 90 in 81.8% and MMSE score was lower than 24 in 100% of patients. Moreover, 18.2% of N+A patients had VIQ score lower than 80 and 45.4% had MMSE score lower than 18/30. Also 9.1% of neglect group had VIQ score lower than 90 and 36.4% MMSE scores less than 24/30, but none of these patients had VIQ and MMSE scores respectively lower than 80 and 18/30. Similar data were present in control group.

CONCLUSIONS

This study focuses on mental impairment in neglect + anosognosia patients and indicates that A for hemiplegia is a condition that more often occurs when severe mental impairment is present.

Pleasurable emotional response to music: a case of neurodegenerative generalized auditory agnosia

Recent functional neuroimaging studies implicate the network of mesolimbic structures known to be active in reward processing as the neural substrate of pleasure associated with listening to music. Psychoacoustic and lesion studies suggest that there is a widely distributed cortical network involved in processing discreet musical variables. Here we present the case of a young man with auditory agnosia as the consequence of cortical neurodegeneration who continues to experience pleasure when exposed to music. In a series of musical tasks, the subject was unable to accurately identify any of the perceptual components of music beyond simple pitch discrimination, including musical variables known to impact the perception of affect. The subject subsequently misidentified the musical character of personally familiar tunes presented experimentally, but continued to report that the activity of 'listening' to specific musical genres was an emotionally rewarding experience. The implications of this case for the evolving understanding of music perception, music misperception, music memory, and music-associated emotion are discussed.

[Visual perception deficits of cortical origin]

This work comprises of a literature review on visual perception distortions that have their origin in structural or functional irregularities of the brain, resulting in the cortex malfunction. The main area that we pay attention to is the brain cortex, but we should not forget, that diseases destructive to the lower brain structures also inevitably lead to secondary dysfunction of the cortex, and thus they have also been included in this paper. Cerebral vision disorders are a small percentage of caseload in either neurology or ophthalmology practice, yet they certainly are interesting for the cognitive scientists, as they open a window into the complex mechanisms of the cerebral clockwork. We are presenting examples of disorders, many of which engage the creative cooperation between specialists from different fields of neuroscience. Three kinds of disorders are presented: vision loss, agnosias and hallucinations. Among others there is some information on cortical blindness, blindsight, Anton's syndrome, hysterical blindness, apperceptive and associative agnosia, prosopagnosia, pure alexia, achromatopsia, Bonnet syndrome, Alice in Wonderland syndrome, peduncular halucinosis etc.

[Case of defective route finding following right anterior thalamic infarction]

Defective route finding is a symptom in which an indivisual demonstrates inhibility to find the way in the familiar places. This symptom arises from lesions at the right parieto-occipital region and the right posterior part of the splenium of the corpus callosum. We present a case of defective route finding resulting from the right anterior thalamic infarction. A 63-year-old right-handed man abruptly presented with difficulty in route finding on his way home. Neither spatial neglect nor agnosia was observed with pictures of his house and surrounding streets. Although there was an attention disturbance, his activities of daily living were spared. Brain MRI revealed a fresh infarction at the right anterior nucleus of the thalamus. Single photon emission computed tomography using 123I-methyltyrosine showed hypoperfusion at the right parieto-occipital region as well as the right thalamus. Neuropsychological tests showed visuospatial memory disturbance. To our knowledge, this is the first report of defective route finding caused by the right anterior thalamic infarction. The right anterior thalamic nucleus might be involved in the visuospatial recognition circuit.