Benefits of a targeted rehabilitation of number transcoding in secondary acalculia: A single-case experimental design.

BACKGROUND: Despite its potentially significant functional and emotional impact, acalculia is still too rarely assessed and managed by speech and language therapists. Research on the rehabilitation of numerical transcoding remains scarce in the literature and, despite positive results, presents a low level of evidence. AIMS: The present study aims to evaluate the effectiveness of a targeted rehabilitation of numerical transcoding in two patients suffering from a chronic secondary acalculia. METHODS & PROCEDURES: Two post-brain injury females with secondary acalculia took part in a single-case experimental design with multiple baseline across subjects according to a three-phase experimental protocol: baseline involving global cognitive rehabilitation (5-7 measurements with randomized sequential introduction); targeted intervention (10 measurements); follow-up (2 immediate measurements and 1 month after the end of the intervention). Repeated outcome measures consisted of six lists composed of numbers of equivalent difficulty that were used alternately to assess numerical transcoding. We used a reverse digit span as a control measure to assess the specificity of the intervention. Rehabilitation lasted 5 weeks and consisted of errorless learning with colour cues, tables and number-words cards. OUTCOMES & RESULTS: During baseline period involving global cognitive rehabilitation, transcoding scores remained unchanged. In contrast, there was a significant improvement in scores for both patients during the intervention phase targeting transcoding and maintenance of benefits 1-month post-intervention. CONCLUSIONS & IMPLICATIONS: This study demonstrates that a specific rehabilitation targeting numerical transcoding following chronic secondary acalculia can be effective in improving transcoding skills. WHAT THIS PAPER ADDS: What is already known on the subject Transcoding difficulties in patients with acalculia can cause a significant disability in everyday life activities. In secondary acalculia, rehabilitation of cognitive functions associated with number processing (attention, working memory, language) is not sufficient for improvement of transcoding. What this paper adds to existing knowledge An intervention specifically targeting numerical transcoding significantly and durably improves the skills of patients with chronic secondary acalculia. What are the potential or actual clinical implications of this work? Procedural error-free intervention using colour cueing, tables, cards with number-words, copy and repetition seems effective to improve transcoding skills in chronic acalculia.

A qualitative study into the experience of living with acalculia after stroke and other forms of acquired brain injury.

Acalculia, an acquired disability following a brain injury, involves difficulty processing numerical information and/or calculations. Acalculia is not routinely screened for, and as a result there is a lack of understanding about the nature and prevalence and the impact of the condition. This qualitative study was initiated by stroke survivors with a strong interest in acalculia. Sixteen stroke/brain injury survivors with acalculia and seven carers were interviewed using semi-structured online interviews. Participants ranged in age, gender, time post-onset, country of residence and numeracy level prior to brain injury. Data were analysed using thematic analysis. Three main themes were identified: Awareness and Diagnosis; Emotional and Practical Impact (independence); Support, Coping Strategies and Self-training. Participants and carers repeatedly referred to the lack of awareness and treatment for acalculia and the impact acalculia has had on their lives and independence. Practical impacts included managing money, making appointments, using timetables, organizing social activities and employment, and managing medication. Our results highlight the urgent need to develop suitable assessments and interventions for acalculia and the scope for this to be Patient, Carer and Public involvement (PCPI)-led. The data also reveal useful strategies and suggestions regarding effective timing, targets and approaches for intervention.

Aphasia and Math: Deficits with Basic Number Comprehension and in Numerical Activities of Daily Living.

OBJECTIVE: In the present study, we explored numerical problems in individuals with aphasia. We investigate whether numerical deficits, usually accompanying aphasia, can be observed on number comprehension tasks that do not necessarily require an oral response. METHOD: Individuals with aphasia were classified into anterior, posterior, and global subgroups according to the lesion type. To investigate numerical cognition, we used a relatively recent tool, the Numerical Activities of Daily Living (NADL). RESULTS: The results showed that individuals with aphasia have problems with tasks of basic number comprehension as well as in most NADL. In the formal part of the NADL, anterior aphasic patients made comparatively more errors than the posterior aphasic patients. Global aphasic patients presented an invariably poor performance on almost all tasks. CONCLUSION: The results provide insight into how numerical deficits may impair an individual with aphasia in activities of daily living. This study is a preliminary attempt to start the validation process of the NADL for the Greek population.

Some evidence on Gerstmann's syndrome: A case study on a variant of the clinical disorder.

We describe the case of a bilingual patient with persistent symptoms largely, although not fully, consistent with those that are usually reported in Gerstmann's syndrome. Twenty months after a spontaneous primary intracranial hemorrhage, the patient was evaluated with a series of neuropsychological tasks and underwent an MRI investigation based on Diffusion Tensor Imaging probabilistic tractography. The patient suffered from dysgraphia (difficulty in the access to the graphemic representation of letter forms), autotopoagnosia (difficulties in locating body parts on verbal command), right-left confusion (difficulties in localizing right and left side of symmetrical body parts), and number processing/calculation impairments (predominant difficulties on transcoding tasks). Probabilistic tractography revealed a relatively spared superior longitudinal fasciculus and severe damage to the subcortical white matter connecting the angular gyrus with other parietal regions, such as the intraparietal sulcus and the supramarginal gyrus. Within the framework of the contemporary cognitive accounts of Gerstmann's syndrome, the case supports the assumption of an anatomical intraparietal disconnection more than a functional Grundstörung (core impairment).

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.

Tactile enumeration: A case study of acalculia.

Enumeration is one of the building blocks of arithmetic and fingers are used as a counting tool in early steps. Subitizing-fast and accurate enumeration of small quantities-has been vastly studied in the visual modality, but less in the tactile modality. We explored tactile enumeration using fingers, and gray matter (GM) changes using voxel-based morphometry (VBM), in acalculia. We examined JD, a 22-year-old female with acalculia following a stroke to the left inferior parietal cortex. JD and a neurologically healthy normal comparison (NC) group reported how many fingers were stimulated. JD was tested at several time points, including at acute and chronic phases. Using the sensory intact hand for tactile enumeration, JD showed deficit in the acute phase, compared to the NC group, and improvement in the chronic phase of (1) the RT slope of enumerating up to four stimuli, (2) enumerating neighboring fingers, and (3) arithmetic fluency performance. Moreover, VBM analysis showed a larger GM volume for JD relative to the NC group in the right middle occipital cortex, most profoundly in the chronic phase. JD's performance serves as a first glance of tactile enumeration in acalculia. Pattern-recognition-based results support the suggestion of subitizing being the enumeration process when using one hand. Moreover, the increase in GM in the occipital cortex lays the groundwork for studying the innate and primitive ability to perceive and evaluate sizes or amounts-"sense of magnitude"- as a multisensory magnitude area and as part of a recovery path for deficits in basic numerical abilities.

Acute stroke presenting with isolated acalculia.

Acalculia is defined as the inability to mentally manipulate numbers for simple calculations. It may occur in dementia, central nervous system (CNS) neoplasm, and stroke (Bermejo-Velasco and Castillo-Moreno, 2006). Lesions of the left parietal cortex are the principal cause. When acalculia occurs in stroke, it is generally associated with other deficits in speech, sensation, or motor function. We report the case of a 63-year-old male with a 1 day history of isolated acalculia that was found to have a left parietal lobe infarct with several smaller infarcts in the left occipital lobe. The diagnosis of stroke should be considered in all patients experiencing acute difficulty with mathematics, reading, or writing, even in the absence of other deficits.

Transcranial random noise stimulation benefits arithmetic skills.

Although arithmetic skills are crucial cognitive abilities, numeric competence impairments affect a significant portion of the young population. These problems produce a high socio-economic cost by negatively affecting scholastic and work performance. The parietal cortex is the brain area that is classically associated with numeric processing, but it is still debated whether other cortical areas are involved, and only a few studies tried to directly assess the causal link between brain and this cognitive function by using transcranial random noise stimulation, tRNS. This non-invasive electric stimulation device has been shown to enhance activity in the underlying cortex. We tested three groups of participants with equivalent arithmetic skills - an arithmetic 'screening' was administered. One group was stimulated by tRNS on the frontal lobe, another on the parietal lobe, and a third group was assigned to the placebo condition. During the stimulation, participants performed a subtraction verification task. To investigate long-term effects of tRNS, the task was repeated seven days later without stimulation. Aside previously-tested (familiar) subtractions, in the second experimental session unfamiliar subtractions were also administered. We found that, compared to placebo, parietal and frontal stimulation significantly reduced reaction times immediately, and enhanced accuracy after seven days. This benefit encompassed both familiar and unfamiliar subtractions. These results suggest that modulation of frontal and parietal cortices may ameliorate basic arithmetic skills by benefitting working memory function. This could open new avenues for neuro-restorative applications of brain stimulation.

Characteristics of number transcoding errors of Chinese- versus English-speaking Alzheimer's disease patients.

Number processing disorder is an acquired deficit in mathematical skills commonly observed in Alzheimer's disease (AD), usually as a consequence of neurological dysfunction. Common impairments include syntactic errors (800012 instead of 8012) and intrusion errors (8 thousand and 12 instead of eight thousand and twelve) in number transcoding tasks. This study aimed to understand the characterization of AD-related number processing disorder within an alphabetic language (English) and ideographical language (Chinese), and to investigate the differences between alphabetic and ideographic language processing. Chinese-speaking AD patients were hypothesized to make significantly more intrusion errors than English-speaking ones, due to the ideographical nature of both Chinese characters and Arabic numbers. A simplified number transcoding test derived from EC301 battery was administered to AD patients. Chinese-speaking AD patients made significantly more intrusion errors (p = 0.001) than English speakers. This demonstrates that number processing in an alphabetic language such as English does not function in the same manner as in Chinese. The impaired inhibition capability likely contributes to such observations due to its competitive lexical representation in brain for Chinese speakers.

The number processing and calculation system: evidence from cognitive neuropsychology.

INTRODUCTION: Cognitive neuropsychology focuses on the concepts of dissociation and double dissociation. The performance of number processing and calculation tasks by patients with acquired brain injury can be used to characterise the way in which the healthy cognitive system manipulates number symbols and quantities. The objective of this study is to determine the components of the numerical processing and calculation system. METHODS: Participants consisted of 6 patients with acquired brain injuries in different cerebral localisations. We used Batería de evaluación del procesamiento numérico y el cálculo, a battery assessing number processing and calculation. Data was analysed using the difference in proportions test. RESULTS: Quantitative numerical knowledge is independent from number transcoding, qualitative numerical knowledge, and calculation. Recodification is independent from qualitative numerical knowledge and calculation. Quantitative numerical knowledge and calculation are also independent functions. CONCLUSIONS: The number processing and calculation system comprises at least 4 components that operate independently: quantitative numerical knowledge, number transcoding, qualitative numerical knowledge, and calculation. Therefore, each one may be damaged selectively without affecting the functioning of another. According to the main models of number processing and calculation, each component has different characteristics and cerebral localisations.

Foreign accent syndrome and other neuropsychological sequelae of a parieto-occipital lesion following COVID-19 associated posterior reversible encephalopathy syndrome.

OBJECTIVE: We describe a previously fit and well 54-year-old female who acquired a range of severe and persisting neuropsychological impairments following a posterior reversible encephalopathy syndrome (PRES) complication of COVID-19. The initial presentation included aphasia, a neurogenic foreign accent syndrome (FAS) and a persisting complete cortical blindness from the underpinning parieto-occipital brain injury. METHOD: Neuropsychological single clinical case report. RESULTS: The patient retained insight and made good early progress with their adjustment to the numerous losses caused by the COVID-19 associated acquired brain injury. Comprehensive neuropsychological investigation characterised an acalculia, along with deficits in focused, sustained and divided attention impacting on verbal memory, working memory and executive functioning, amongst numerous relative strengths. CONCLUSION: Similar to PRES from other aetiologies, COVID-19 associated PRES can in some cases cause irreversible acquired brain injury. The diverse neuropsychological effects need to be comprehensively investigated and managed. This case adds to the neuropsychological literature on PRES, FAS and acquired brain injury as a rare complication of SARS-CoV-2.

The making of a syndrome: Gerstmann's patients before Gerstmann syndrome.

When Gerstmann published the case report which later became known as the first case of Gerstmann syndrome, he did not claim the discovery of a new syndrome. It was only a few years later, after reporting on another two similar cases, that he isolated the famous tetrad of symptoms (finger agnosia, right-left disorientation, agraphia and acalculia) as a meaningful cluster with both localising and functional value. In this article, we provide the translation of key-excerpts of the second of Gerstmann's reports (Gerstmann, 1927) and a synoptic description of the symptoms as reported in the three original cases, which were later identified as cases of Gerstmann syndrome. The descriptions appear highly consistent across cases. Among symptoms, finger agnosia stands out for its pervasiveness, which may explain why Gerstmann considered this as the core symptom and speculated it could subtend all symptoms. However, no common functional denominator emerges from the original descriptions.

Acalculia in Aphasia.

BACKGROUND: Patients with aphasia can present a type of acalculia referred to as aphasic acalculia. AIMS: To investigate the correlation and to test regression models for one- and two-digit calculation skills using verbal and nonverbal predictors. METHODS AND PROCEDURES: We selected an aphasia sample of 119 men and 81 women with a mean age of 57.37 years (SD = 15.56) and an average level of education of 13.52 years (SD = 4.08). Spanish versions of the Western Aphasia Battery and Boston Diagnostic Aphasia Examination, plus a Written Calculation test, were individually administered. The calculation section of the Western Aphasia Battery and the Written Calculation tests were used to pinpoint calculation difficulties. OUTCOMES AND RESULTS: Calculation difficulties were more severe in Global and Mixed non-fluent aphasia; they were very similar in Broca, Conduction, and Amnesic Aphasia. All correlations between the two calculation subtests and the other subtests of the Western Aphasia Battery were statistically significant. Calculation subtests correlated negatively with age and positively with schooling. Sex and time post-onset did not show any correlation with the calculation scores. Education, Reading, Block Design, and Raven's Colored Progressive Matrices were significant predictors of Western Aphasia Battery Calculation. Writing was the only significant predictor of the Written Calculation scores. CONCLUSIONS: Nonverbal abilities were predictors of calculation tests, whereas agraphia defects were predictors of the Written Calculation test. Therefore, calculation abilities can be regarded both as written language-dependent and verbal language-independent.

Arithmetic Word-Problem Solving as Cognitive Marker of Progression in Pre-Manifest and Manifest Huntington's Disease.

BACKGROUND: Arithmetic word-problem solving depends on the interaction of several cognitive processes that may be affected early in the disease in gene-mutation carriers for Huntington's disease (HD). OBJECTIVE: Our goal was to examine the pattern of performance of arithmetic tasks in premanifest and manifest HD, and to examine correlations between arithmetic task performance and other neuropsychological tasks. METHODS: We collected data from a multicenter cohort of 165 HD gene-mutation carriers. The sample consisted of 31 premanifest participants: 16 far-from (>12 years estimated time to diagnosis; preHD-A) and 15 close-to (≤12 years estimated time to diagnosis; preHD-B), 134 symptomatic patients (early-mild HD), and 37 healthy controls (HC). We compared performance between groups and explored the associations between arithmetic word-problem solving and neuropsychological and clinical variables. RESULTS: Total arithmetic word-problem solving scores were lower in preHD-B patients than in preHD-A (p < 0.05) patients and HC (p < 0.01). Early-mild HD patients had lower scores than preHD patients (p < 0.001) and HC (p < 0.001). Compared to HC, preHD and early-mild HD participants made more errors as trial complexity increased. Moreover, arithmetic word-problem solving scores were significantly associated with measures of global cognition (p < 0.001), frontal-executive functions (p < 0.001), attention (p < 0.001) visual working memory (p < 0.001), mental rotation (p < 0.001), and confrontation naming (p < 0.05). CONCLUSION: Arithmetic word-problem solving is affected early in the course of HD and is related to deficient processes in frontal-executive and mentalizing-related processes.

Damage to the Intraparietal Sulcus Impairs Magnitude Representations of Results of Complex Arithmetic Problems.

Past research investigating the role of the intraparietal sulcus (IPS) in numerical processes focused mainly on quantity and numerical comparisons as well on single digit arithmetic. The present study investigates the involvement of the IPS in estimating the results of multi-digit multiplication problems. For this purpose, the performance a 24-year-old female (JD) with brain damage in the left IPS was compared to an age-matched control group in the computation estimation task. When required to estimate whether the results of multi-digit multiplication problems are smaller or larger than given reference numbers, JD, in contrast to controls, did not show the common patterns of distance and size effects. Her strategy use was also atypical. Most control participants used both the approximated calculation strategy that involves rounding and calculation procedures and the sense of magnitude strategy that relies on an intuitive approximated magnitude representation of the results. In contrast, JD used only the former but not the latter strategy. Together, these findings suggest that the damage to the IPS impaired JD's representations of magnitude that play an important role in this computation estimation task.

The making of a syndrome: The English translation of Gerstmann's first report.

The label Gerstmann syndrome indicates the co-occurrence of four symptoms in persons with acquired brain lesions: finger agnosia, left-right disorientation, agraphia, and acalculia. The syndrome is often associated with a lesion affecting the posterior parietal lobe of the left cerebral hemisphere. Virtually every paper discussing this tetrad of symptoms refers back to Josef Gerstmann's (1924) first report published in German. To make it accessible to the wider community of scholars and thus enable a more in-depth appreciation of the origins of this enigmatic syndrome, here we publish, for the first time in English, a translation of Gerstmann's initial report. In this paper, the syndromal construct had not yet crystallized into its four cardinal symptoms; Gerstmann's attention was mainly focused on finger agnosia and, to a lesser extent, on left-right disorientation by virtue of their significance for the body scheme theory. Although isolated agraphia and acalculia seemed to be at least as severe as finger agnosia, Gerstmann did not consider them of consequential importance (with the exception of agraphia's localisation value). It is also worth noting that the described patient presented a picture of Gerstmann syndrome associated with other symptoms such as hemianopia, balance impairment, and light memory and reasoning disorders.

A Functional Domain Based Approach in Neurocognitive Rehabilitation with Transcranial Direct Current Stimulation: A Case Report.

Transcranial direct current stimulation (tDCS) is a novel brain stimulation technique which has kindled hope in alleviating motor, language as well as cognitive deficits in neuronal injury. Current case report describes application of tDCS in two phases using two different protocols in a patient with hypoxic injury. In the first phase anodal stimulation of dorsolateral prefrontal cortex improved the language fluency. Subsequently, after 6 months second phase application of anodal stimulation over posterior parietal region targeted arithmetic and working memory deficits. Individualising the treatment protocols of brain stimulation, based on the lesion and the functional deficits, for neuro-rehabilitation is emphasised.

The Progressive Acalculia Presentation of Parietal Variant Alzheimer's Disease.

BACKGROUND: Many patients with early-onset Alzheimer's disease (EOAD; age of onset <65 years) have non-amnestic presentations involving language (logopenic primary progressive aphasia, lvPPA), visuospatial abilities (posterior cortical atrophy, PCA), and even asymmetric symptoms consistent with corticobasal syndrome (CBS). An inferior parietal lobule variant of EOAD commonly presents with progressive difficulty with calculations. METHODS: We reviewed 276 EOAD patients for presentations with predominant acalculia. These patients were diagnosed with clinically probable Alzheimer's disease (AD) verified by positron emission tomography (PET) or cerebrospinal fluid amyloid-ß or tau biomarkers. RESULTS: We identified 18 (9M/9F) (6.5%) EOAD patients with progressive acalculia that did not meet most criteria for lvPPA, visual PCA, or CBS. Their ages of onset and presentation were 56.6 (5.0) and 59.4 (6.5), respectively. Their acalculia was consistent with a primary acalculia ("anarithmetia") not explained by language or visuospatial impairments. Many also had anomia (14/18), ideomotor apraxia (13/18), and the complete Gerstmann's syndrome (7/18). Visual analysis of their diverse magnetic resonance imaging disclosed biparietal atrophy, disproportionately worse on the left. CONCLUSIONS: Primary acalculia may be the most common manifestation of an inferior parietal presentation of EOAD affecting the left intraparietal sulcus. This parietal variant also commonly involves progressive anomia, ideomotor apraxia, and other elements of Gerstmann's syndrome. The early recognition of patients with this variant, which is distinguishable from lvPPA, visual PCA, or CBS, would be facilitated by its recognition as a unique subtype of EOAD.

Frontal Phonological Agraphia and Acalculia with Impaired Verbal Short-Term Memory due to Left Inferior Precentral Gyrus Lesion.

We report a patient with phonological agraphia (selective impairment of kana [Japanese phonetic writing] nonwords) and acalculia (mental arithmetic difficulties) with impaired verbal short-term memory after a cerebral hemorrhage in the opercular part of the left precentral gyrus (Brodmann area 6) and the adjacent postcentral gyrus. The patient showed phonemic paragraphia in five-character kana nonword writing, minimal acalculia, and reduced digit and letter span. Mental arithmetic normalized after 8 months and agraphia recovered to the normal range at 1 year after onset, in parallel with an improvement of the auditory letter span score from 4 to 6 over a period of 14 months and in the digit span score from 6 to 7 over 24 months. These results suggest a close relationship between the recovery of agraphia and acalculia and the improvement of verbal short-term memory. The present case also suggests that the opercular part of the precentral gyrus constitutes the phonological route in writing that conveys phonological information of syllable sequences, and its damage causes phonological agraphia and acalculia with reduced verbal short-term memory.

Two year outcomes of poststroke writing and reading disorders.

Poststroke language disorders are frequent and include aphasia, alexia, agraphia, and acalculia. These disorders refer to an acquired inability to read, write and calculate. In this study, we evaluated the two year outcomes of writing and reading disorders in poststroke patients, the natural course, recovery and mortality. We evaluated all the patients with stroke who were admitted to the Department of Neurology, University Clinical Centre Tuzla in period of six months, who developed poststroke alexia, agraphia, acalculia, or different combinations of these language disorders. Outcome of these patients was evaluated again after 24 months. For clinical assessment of alexia, agraphia, and acalculia we used Minnesota Test for Differential Diagnosis of Aphasia. We investigated 59 (30.5%) of 193 stroke patients with alexia, agraphia, acalculia, and combinations. Outcome of these patients after 24 months was: 37 (62.7%) died, 13 (22%) fully recovered, and 9 (15.3%) of them retained the same disorder or developed dementia or blindness. Binary logistic regression analysis showed that patients with combined language disorders had significantly higher mortality. The main factors influencing language disorders recovery in this study are initial severity of reading, writing and calculation impairment, age, neglect, and level of education.