A Rare Clinical Antity; Pure Gerstmann Syndrome.

Gerstmann syndrome is defined as a tetrad including agraphia, acalculia, finger agnosia, and right-left disorientation. In the case studies presented in the literature, it has been reported that Gerstmann syndrome usually appears as an incomplete tetrad of symptoms or accompanied by cognitive deficits including aphasia, alexia, apraxia and some perceptual disorders. Here, we present of the patient with left angular and supramarginal gyrus infarction affecting the parietal lobe. In addition to the symptoms mentioned above, the patient had alexia and anomic aphasia as well. We discussed the clinic appearance and reviewed the current literature.

Cognitive world: Neuropsychology of individual differences.

It is proposed that depending upon the specific pattern of cognitive abilities, each individual lives in an idiosyncratic "cognitive world." Brain pathology can be associated with some disturbed abilities, and frequently experiential changes (i.e., how the world is understood) are observed. Because these patients often are aware of their intellectual changes, they may represent excellent models to illustrate the diversity of cognitive interpretations an individual can have about the surrounding environmental conditions. Four neuropsychology cases are presented to illustrate this point: (a) prosopagnosia associated with spatial agnosia; (b) Gerstmann's syndrome; (c) dysexecutive syndrome due to a head injury; and, (d) patient with Capgras' syndrome associated with a left temporal cyst. It is further emphasized that non-brain damaged people present an enormous-but usually overlooked-dispersion in different cognitive domains, resulting in specific and idiosyncratic patterns of cognitive abilities. It is concluded that the concept of "cognitive world" in neuropsychology can parallel the concept of "perceptual world" introduced by von Uexküll in biology, which assumes that different animal species live in idiosyncratic perceptual worlds, available and knowable by the differences in their sensory system abilities. That is, different individuals live in idiosyncratic cognitive worlds, owing to their differences in cognitive abilities.

Distinct representations of symbolic ordinality and quantity: evidence from neuropsychological investigations in a Chinese patient with Gerstmann's syndrome.

A number of recent studies have shown conflicting evidence as to common or distinct representations between symbolic ordinality and quantity. We investigated this issue through a series of neuropsychological tests in a unique Chinese patient with the left angular gyrus and left supramarginal gyrus lesions. Behavioral experiments revealed that (1) the patient showed Gerstmann syndrome, with minimal anomia and alexia and (2) the patient showed the dissociation among number semantic representations with relatively preserved symbolic quantity knowledge and impaired processing of symbolic order meaning. Together with existing evidence in the literature, results of the current study suggest that there might be two separate cognitive representations of symbolic ordinality and quantity in logographic language according to this dissociation. Most importantly, another merit of this study is that the left angular gyrus and left supramarginal gyrus might be necessary to symbolic ordinality representation.

The enigma of Gerstmann's syndrome revisited: a telling tale of the vicissitudes of neuropsychology.

Eighty years ago, the Austrian neurologist Josef Gerstmann observed in a few patients a concomitant impairment in discriminating their own fingers, writing by hand, distinguishing left from right and performing calculations. He claimed that this tetrad of symptoms constituted a syndromal entity, assigned it to a lesion of the dominant parietal lobe and suggested that it was due to damage of a common functional denominator. Ever since, these claims have been debated and an astute synopsis and sceptical discussion was presented 40 years ago by MacDonald Critchley in this journal. Nonetheless, Gerstmann's syndrome has continued to intrigue both clinical neurologists and researchers in neuropsychology, and more frequently than not is described in textbooks as an example of parietal lobe damage. In this review, we revisit the chequered history of this syndrome, which can be seen as a case study of the dialectic evolution of concepts in neuropsychology. In light of several modern era findings of pure cases we conclude that it is legitimate to label the conjunction of symptoms first described by Gerstmann as a 'syndrome', but that it is very unlikely that damage to the same population of cortical neurons should account for all of the four symptoms. Instead, we propose that a pure form of Gerstmann's syndrome might arise from disconnection, via a lesion, to separate but co-localized fibre tracts in the subcortical parietal white matter, a hypothesis for which we have recently provided evidence using combined imaging of functional and structural organization in the healthy brain.

Finger recognition and gesture imitation in Gerstmann's syndrome.

We report the association between finger agnosia and gesture imitation deficits in a right-handed, right-hemisphere damaged patient with Gerstmann's syndrome (GS), a neuropsychological syndrome characterized by finger and toe agnosia, left-right disorientation and dyscalculia. No language deficits were found. The patient showed a gestural imitation deficit that specifically involved finger movements and postures. The association between finger recognition and imitation deficits suggests that both static and dynamic aspects of finger representations are impaired in GS. We suggest that GS is a disorder of body representation that involves hands and fingers, that is, the non-facial body parts most involved in social interactions.

The writing of arabic numerals, kanji, and kana in brain-damaged patients.

This study investigated the neural mechanisms involved in the writing of Arabic numerals, kanji, and kana. Tasks involving writing numerals in Arabic, kanji, and, kana were administered to four patients with Gerstmann's syndrome and to five Wernicke aphasics. The results indicated that the ability to write Arabic numerals was well preserved in the Wernicke aphasics despite their serious phonological disturbances. The patients with Gerstmann's syndrome, who have a deficit with the concept of number, could write kanji numerals better than Arabic and kana numerals. Unlike Arabic numerals (ideogram) and kana (syllabogram), kanji (morphogram) have both semantic and phonetic values. The results suggested that Arabic numerals may be somesthetic and linked directly to the concept of number bypassing phonological analysis.

Gerstmann syndrome in systemic lupus erythematosus: neuropsychological, neuroimaging and spectroscopic findings.

Gerstmann syndrome (GS) comprises four interlaced neuropsychological symptoms including finger agnosia, right-left confusion, agraphia, and acalculia. While GS is commonly associated with focal lesions to the region of the left angular gyrus, it has also been associated with numerous diffuse etiologies including atrophy, alcoholism, carbon monoxide poisoning, lead intoxication and anaphylactic shock. Thus, a vigorous debate has emerged as to whether GS represents a syndrome arising from general brain decline or a distinct and localizing lesion. We report a right-handed patient who developed neuropsychological dysfunction secondary to systemic lupus erythematosus (SLE). Neuropsychological evaluation found the patient to exhibit symptoms consistent with the GS tetrad, as well as general cognitive decline. Magnetic resonance imaging revealed a distinct focal lesion of the left parieto-occipital white matter underlying the angular gyrus as well as diffuse atrophy. (1)H-magnetic resonance spectroscopy revealed substantial metabolic derangement in a voxel placed within the visible lesion, although substantial metabolic derangement was observed in regions remote from the focal pathology. Thus, GS in this first case in SLE would appear to comprise a focal neurological tetrad of disorders within a more general pattern of cognitive decline and metabolic derangement.

A pure case of Gerstmann syndrome with a subangular lesion.

The four symptoms composing Gerstmann's syndrome were postulated to result from a common cognitive denominator (Grundstörung) by Gerstmann himself. He suggested that it is a disorder of the body schema restricted to the hand and fingers. The existence of a Grundstörung has since been contested. Here we suggest that a common psychoneurological factor does exist, but should be related to transformations of mental images rather than to the body schema. A patient (H.P.) was studied, who presented the four symptoms of Gerstmann's syndrome in the absence of any other neuropsychological disorders. MRI showed a focal ischaemic lesion, situated subcortically in the inferior part of the left angular gyrus and reaching the superior posterior region of T1. The cortical layers were spared and the lesion was seen to extend to the callosal fibres. On the basis of an extensive cognitive investigation, language, praxis, memory and intelligence disorders were excluded. The four remaining symptoms (finger agnosia, agraphia, right-left disorientation and dyscalculia) were investigated thoroughly with the aim of determining any characteristics that they might share. Detailed analyses of the tetrad showed that the impairment was consistently attributable to disorders of a spatial nature. Furthermore, cognitive tests necessitating mental rotation were equally shown to be impaired, confirming the essentially visuospatial origin of the disturbance. In the light of this report, the common cognitive denominator is hypothesized to be an impairment in mental manipulation of images and not in body schema.

Gerstmann's syndrome associated with chronic subdural haematoma: a case report.

We report a patient who exhibited Gerstmann's syndrome in association with a chronic subdural haematoma. A 71-year-old right-handed woman presented with mild right arm and leg weakness that began 2 weeks prior to admission. Neurological examination on admission revealed a mild right hemiparesis. Neuropsychological examination revealed right-left disorientation, finger agnosia, agraphia, and acalculia, but no language disturbance. A computerized tomographic (CT) scan revealed a large left frontoparietal, extra-axial hypodense fluid collection containing scattered hypodense foci. A left parietal evacuation of the haematoma was performed. Following surgery the patient dramatically improved. We suggest that the direct compression by the chronic subdural haematoma or a hemispheric pressure difference caused Gerstmann's syndrome. This is an unusual report of a Gerstmann's syndrome following chronic subdural haematoma.

Cerebral pathways for calculation: double dissociation between rote verbal and quantitative knowledge of arithmetic.

We describe two acalculic patients, one with a left subcortical lesion and the other with a right inferior parietal lesion and Gerstmann's syndrome. Both suffered from "pure anarithmetia": they could read arabic numerals and write them to dictation, but experienced a pronounced calculation deficit. On closer analysis, however, distinct deficits were found. The subcortical case suffered from a selective deficit of rote verbal knowledge, including but not limited to arithmetic tables, while her semantic knowledge of numerical quantities was intact. Conversely the inferior parietal case suffered from a category-specific impairment of quantitative numerical knowledge, particularly salient in subtraction and number bissection tasks, with preserved knowledge of rote arithmetic facts. This double dissociation suggests that numerical knowledge is processed in different formats within distinct cerebral pathways. We suggest that a left subcortical network contributes to the storage and retrieval of rote verbal arithmetic facts, while a bilateral inferior parietal network is dedicated to the mental manipulation of numerical quantities.

Right-left confusion in Gerstmann's syndrome: a model of body centered spatial orientation.

Gerstmann's syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia and right-left confusion and is associated with lesions of the dominant angular gyrus. The localizing value of this syndrome has been questioned because multiple mechanisms can account for each of the components of the syndrome. We present the case of a man who developed Gerstmann's syndrome following a focal infarct of the left angular gyrus. The patient's right-left confusion could not be accounted for by either an aphasia or a degraded body schema. A series of experiments that investigated the patient's spatial mapping system by progressively restricting the degrees of freedom for spatial rotation revealed an isolated defect in deriving the relative position of an object along the horizontal axis. Defective horizontal mapping can account for the other components of Gerstmann's syndrome because they all share a common dependency on relative horizontal positioning.

Gerstmann's syndrome.

Recent case reports describe the occurrence of a more or less pure Gerstmann syndrome in association with a focal lesion in the posterior perisylvian territory of the brain's left hemisphere. In addition, an electrocortical stimulation study reported the Gerstmann symptom combination and a number of other symptom combinations on stimulation of small areas in the left posterior parietotemporal cortex. The neuropsychological implications of these and other recent findings are considered in light of the variety of "syndromes" produced by lesions in this region, the rare occurrence of Gerstmann's syndrome, and its appearance as a consequence of lesions in diverse cerebral areas.

A specific deficit for numbers in a case of dense acalculia.

In this study we investigated the acalculic condition of a patient, C.G., with the classical signs of Gerstmann's Syndrome: finger agnosia; right-left disorientation; a profound agraphia (but with an equally profound alexia) and a remarkably dense acalculia. Using a series of number processing and number knowledge tasks, a selective impairment for numbers was demonstrated. Within the category of numbers C.G. showed a largely preserved ability to deal with numbers below 4, in all tasks and in all modalities, while she was totally unable to deal with numbers above 4. The consistency of responses and the ineffectiveness of cueing indicated that numbers above 4 were lost, rather than hard to access. Further testing showed that this impairment did not result from a more general semantic memory problem, a difficulty in understanding quantities or a deficit in reasoning abilities thought to underlie the concept of numbers. Difficulty with some other ordinal structures was also present, but appeared unrelated to those affecting numbers.

Gerstmann syndrome: a case report.

A case of Gerstmann syndrome following a trauma is presented. After one month the patient showed the four symptoms of the Gerstmann syndrome associated with slight visual memory and constructional praxis deficits. Eight months later, however, he showed only dyscalculia, dysgraphia, right-left disorientation and finger agnosia, in accordance with selective damage of the left angular gyrus revealed by CT scan. The findings seems to support the existence and the localizing value of Gerstmann syndrome.

Developmental Gerstmann's syndrome.

The tetrad of finger agnosia, dysgraphia, dyscalculia, and right-left disorientation make up Gerstmann's syndrome. The tetrad has been infrequently described in children with learning disability and has been called developmental Gerstmann's syndrome (DGS). Developmental Gerstmann's syndrome may occur in brain-damaged and apparently normal children. Five children in whom DGS occurred in association with brain abnormalities underwent long-term observation, which indicated persistence of the deficits. The identification of these cases suggests that DGS may not be as rare as previously thought and may often be unrecognized. Testing for the Gerstmann elements in learning-disabled children may identify otherwise undiagnosed cases of DGS and should be routinely employed in the neurologic examination. Until appropriate teaching methods for DGS are found, "bypassing" the deficits and utilizing the child's strengths, plus counseling, seem to offer an effective treatment approach.

Pure agraphia and Gerstmann's syndrome as a visuospatial-language dissociation: an experimental case study.

A right-handed man suffered a left parieto-occipital cerebral infarction, causing agraphia with Gerstmann's syndrome but without major aphasia, alexia, or apraxia. Oral spelling was superior to written spelling. Experiments were performed involving (1) analysis of errors in writing, (2) tasks of visual imagery, and (3) identifying letters drawn without leaving a visual trace. The results suggest that the agraphia and Gerstmann's syndrome are due to a dissociation of language skills and visuospatial skills caused by a dominant parieto-occipital lesion.

[Variants of Gerstmann's syndrome in children]. / Varianty sindroma Gerstmana u detei.

Neuropsychological study of backward schoolchildren with normal intellect revealed the cause of their school disadaptation, namely, a combined cortical disorder expressed in the form of discalculia and disgraphy (Gerstmann's syndrome). Histories of 3 children with this abnormality are described. The authors consider the clinical heterogeneity of the syndrome, its origin, and the use of intact intellectual abilities for adequate medico-pedagogical correction.

Transient neuropsychological abnormalities (including Gerstmann's syndrome) during cortical stimulation.

A patient with intractable partial seizures was intensively studied before surgical removal of the epileptogenic focus. A subdural electrode array was surgically placed over the left temporoparietal cortex to better localize the epileptogenic focus and localize cortical function. In addition to speech and sensory findings, acalculia, agraphia, right-left confusion, and finger agnosia were transiently produced by electrical stimulation in the perisylvian area. These findings and their relationship to the controversy surrounding Gerstmann's syndrome are discussed.

[Neuropsychologic contribution to dyslexia research. A review of important explanatory models and findings]. / Der neuropsychologische Beitrag zur Legasthenieforschung. Eine Ubersicht über wichtige Erklärungsmodelle und Befunde.

Since in a substantial proportion of reading-disabled children constitutional factors appear to play an important pathogenetic role, major contributions to a better understanding of dyslexia have long come from the fields of neuropsychology and behavioral neurology. In this overview an attempt is made to describe the most important hypotheses and models on which neuropsychological research on this problem has been based. The first section is devoted to a discussion of findings on acquisition of reading and spelling skills by brain-damaged children and on the effect of the localization of central nervous system lesions on reading disorders in children. Classic neurological disorders are seen in only a small proportion of children with reading retardation, however. Therefore the second section comprises a discussion of various hypotheses that have been developed to explain the particular performance profiles seen in children with dyslexia but with no evidence of brain damage, i.e. in those children who can be said to have a developmental disorder. It is emphasized that dyslexia is probably not a uniform syndrome but that rather different subgroups of reading-disabled children can be identified.