Word-finding difficulties confound performance on verbal cognitive measures in adults with intractable left temporal lobe epilepsy

The Use of Verbal and Nonverbal Memory Tests for Alzheimer's Disease Screening in Taiwan Chinese

Patients with Alzheimer's disease typically have initial deficits in memory. Memory testing can be categorized as verbal or nonverbal by the modality of the stimuli used. We compared the discriminative validity of selected verbal and nonverbal memory tests between non-dementia and Alzheimer's disease in Taiwan. Ninety-eight patients with mild Alzheimer's disease and 269 non-dementia individuals underwent story recall test (immediate and delayed recall), and constructional praxis test (copy and delayed recall). The receiver-operating characteristic curve and area under the curve were evaluated to compare between tests. Patients with Alzheimer's disease performed poorly across all memory tests, and the receiver-operating characteristic curve analysis indicated that story recall immediate and relayed recall, and constructional praxis delayed recall had good classification accuracy with area under the curve of .90, .87 and .87 respectively. These results provide support that both verbal and nonverbal memory tests are reliable measure for screening patients with Alzheimer's disease.

Working Memory and Language Contribution to Verbal Learning and Memory in Drug-Resistant Unilateral Focal Temporal Lobe Epilepsy

We aimed to investigate the working memory (WM) and language separate contributions to verbal learning and memory in patients with unilateral drug-resistant temporal lobe epilepsy (drTLE); additionally, we explored the mediating role of WM on the relationship between the number of antiepileptic drugs (AEDs) and short-term verbal memory. We retrospectively enrolled 70 patients with left (LTLE; n = 44) and right (RTLE; n = 26) drTLE. About 40 similar (age and education) healthy controls were used to determine impairments of groups at WM, language (naming and verbal fluency), and verbal learning and memory (five trials list-learning, story memory-immediate recall). To disentangle the effect of learning from the short-term memory, we separately analyzed performances at the first trial, last trial, and delayed-recall list-learning measures, in addition to the total learning capacity (the sum of the five trials). Correlation and regression analyses were used to assess the contribution of potential predictors while controlling for main clinical and demographic variables, and ascertain the mediating role of WM. All patients were impaired at WM and story memory, whereas only LTLE showed language and verbal learning deficits. In RTLE, language was the unique predictor for the most verbal learning performances, whereas WM predicted the results at story memory. In LTLE, WM was the sole predictor for short-term verbal learning (list-learning capacity; trial 1) and mediated the interaction between AED number and the performance at these measures, whereas language predicted the delayed-recall. Finally, WM confounded the performance at short-term memory in both groups, although at different measures. WM is impaired in drTLE and contributes to verbal memory and learning deficits in addition to language, mediating the relationship between AED number and short-term verbal memory in LTLE. Clinicians should consider this overlap when interpreting poor performance at verbal learning and memory in drTLE.

Cognitive and behavioral outcome of stereotactic laser amydalohippocampotomy in a pediatric setting

We present neuropsychological and functional outcome data in a teenager undergoing stereotactic laser amygdalohippocampotomy (SLAH) who had drug-resistant mesial temporal lobe epilepsy due to left hippocampal sclerosis. Given strong baseline cognitive performance, there was concern for post-operative declines in language and verbal memory were this patient to undergo open resection. She was evaluated pre- and post-ablation with clinical and experimental neuropsychological measures including semantic memory, category-specific object/face recognition and naming, spatial learning, and socio-emotional processing. The patient became seizure-free following SLAH and experienced significant improvements in school performance and social engagement. She experienced improvement in recognition and naming of multiple object categories, memory functions, and verbal fluency. In contrast, the patient declined significantly in her ability to recognize emotional tone from facial expressions, a socio-emotional process that had been normal prior to surgery. We believe this decline was related to surgical disruption of the limbic system, an area highly involved in emotional processing, and suspect such deficits are an under-assessed and unrecognized risk for all surgeries involving the amygdalohippocampal complex and broader limbic system regions. We hope this positive SLAH outcome will serve as impetus for group level research to establish its safety and efficacy in the pediatric setting.

•

Stereotactic laser ablation can be used successfully in pediatric epilepsy.

•

At risk cognitive abilities did not decline after focal ablation in this teenager.

•

Functional improvement was observed that paralleled gains in seizure status and cognition.

•

Deficits still occurred in select areas related to focal structures ablated.

•

Socio-emotional deficits can result from surgeries restricted to the amygdalohippocampal complex.

Effects of Epilepsy on Language Functions: Scoping Review and Data Mining Findings

PURPOSE

This study involved a scoping review to identify possible gaps in the empirical description of language functioning in epilepsy in adults. With access to social network data, data mining was used to determine if individuals with epilepsy are expressing language-related concerns.

METHOD

For the scoping review, scientific databases were explored to identify pertinent articles. Findings regarding the nature of epilepsy etiologies, patient characteristics, tested language modalities, and language measures were compiled. Data mining focused on social network databases to obtain a set of relevant language-related posts.

RESULTS

The search yielded 66 articles. Epilepsy etiologies except temporal lobe epilepsy and older adults were underrepresented. Most studies utilized aphasia tests and primarily assessed single-word productions; few studies included healthy control groups. Data mining revealed several posts regarding epilepsy-related language problems, including word retrieval, reading, writing, verbal memory difficulties, and negative effects of epilepsy treatment on language.

CONCLUSION

Our findings underscore the need for future specification of the integrity of language in epilepsy, particularly with respect to discourse and high-level language abilities. Increased awareness of epilepsy-related language issues and understanding the patients' perspectives about their language concerns will allow researchers and speech-language pathologists to utilize appropriate assessments and improve quality of care.

Semantic Processing Impairment in Patients with Temporal Lobe Epilepsy

The impairment in episodic memory system is the best-known cognitive deficit in patients with temporal lobe epilepsy (TLE). Recent studies have shown evidence of semantic disorders, but they have been less studied than episodic memory. The semantic dysfunction in TLE has various cognitive manifestations, such as the presence of language disorders characterized by defects in naming, verbal fluency, or remote semantic information retrieval, which affects the ability of patients to interact with their surroundings. This paper is a review of recent research about the consequences of TLE on semantic processing, considering neuropsychological, electrophysiological, and neuroimaging findings, as well as the functional role of the hippocampus in semantic processing. The evidence from these studies shows disturbance of semantic memory in patients with TLE and supports the theory of declarative memory of the hippocampus. Functional neuroimaging studies show an inefficient compensatory functional reorganization of semantic networks and electrophysiological studies show a lack of N400 effect that could indicate that the deficit in semantic processing in patients with TLE could be due to a failure in the mechanisms of automatic access to lexicon.

The interictal language profile in adult epilepsy

OBJECTIVE

The purpose of this study was to systematically review the literature on the interictal language profile in adult patients with epilepsy.

METHODS

An extensive literature search was performed using MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, PASCAL, and PSYNDEXplus databases. Key aspects of inclusion criteria were adult patients with epilepsy, patient number >10, and in-depth qualitative investigations of a specific language modality or administration of tests of at least two different language modalities, including comprehension, naming, repetition, reading, writing, and spontaneous speech.

RESULTS

Our search strategy yielded 933 articles on epilepsy and language. Of these, 31 met final eligibility criteria. Most included articles focused on temporal lobe epilepsy; only three studies were interested in the language profile of patients with idiopathic generalized epilepsies, and one study on frontal lobe epilepsy met inclusion criteria. Study results showed a pronounced heterogeneity of language abilities in patients with epilepsy, varying from intact language profiles to impairment in several language functions. However, at least 17% of patients displayed deficits in more than one language function, with naming, reading comprehension, spontaneous speech, and discourse production being most often affected.

SIGNIFICANCE

This review underscores the need to evaluate different language functions-including spontaneous speech, discourse abilities, naming, auditory and reading comprehension, reading, writing, and repetition-individually in order to obtain a reliable profile of language functioning in patients with epilepsy. Moreover, our findings show that in contrast to the huge scientific interest of memory functions in epilepsy, the examination of language functions so far played a minor role in epilepsy research, emphasizing the need for future research activities in this field.