Components of verbal learning and hippocampal damage assessed by T2 relaxometry

2000 ◽  
Vol 6 (5) ◽  
pp. 529-538 ◽  
Author(s):  
AMANDA G. WOOD ◽  
MICHAEL M. SALING ◽  
MARIE F. O'SHEA ◽  
SAMUEL F. BERKOVIC ◽  
GRAEME D. JACKSON
Keyword(s):  
Temporal Lobe ◽  
Hippocampal Sclerosis ◽  
Verbal Learning ◽  
Relaxation Times ◽  
Hippocampal Damage ◽  
T2 Relaxation ◽  
Verbal Recall ◽  
Two Factors ◽  
Left And Right ◽  
Components Analysis

We studied a group of 31 temporal lobe epilepsy patients (25 left, 6 right) with unilateral hippocampal sclerosis evident on magnetic resonance imaging. Single slice T2 relaxation times were acquired for the left and right hippocampi. Principal components analysis of preoperative memory data resulted in two factors that reflect a distinction between arbitrary and semantic forms of verbal recall. The former component correlated with left hippocampal T2 relaxation time, while the latter component did not. This study suggests that variation in left hippocampal integrity is more related to the acquisition of arbitrary associates than semantically structured material, and reinforces the possibility that the left temporal lobe is functionally heterogeneous with respect to memory. (JINS, 2000, 6, 529–538.)

scholarly journals The effect of white matter hyperintensities on verbal memory

Neurology ◽  
2018 ◽  
Vol 90 (8) ◽  
pp. e673-e682 ◽  
Author(s):  
Walter Swardfager ◽  
Hugo Cogo-Moreira ◽  
Mario Masellis ◽  
Joel Ramirez ◽  
Nathan Herrmann ◽  
...  
Keyword(s):  
White Matter ◽  
Alzheimer Disease ◽  
Temporal Lobe ◽  
Verbal Memory ◽  
White Matter Hyperintensities ◽  
Verbal Learning ◽  
Memory Deficits ◽  
Verbal Recall ◽  
Lobe Atrophy ◽  
Proof Of Principle

ObjectiveTo determine the relationship between white matter hyperintensities (WMH) presumed to indicate disease of the cerebral small vessels, temporal lobe atrophy, and verbal memory deficits in Alzheimer disease (AD) and other dementias.MethodsWe recruited groups of participants with and without AD, including strata with extensive WMH and minimal WMH, into a cross-sectional proof-of-principle study (n = 118). A consecutive case series from a memory clinic was used as an independent validation sample (n = 702; Sunnybrook Dementia Study; NCT01800214). We assessed WMH volume and left temporal lobe atrophy (measured as the brain parenchymal fraction) using structural MRI and verbal memory using the California Verbal Learning Test. Using path modeling with an inferential bootstrapping procedure, we tested an indirect effect of WMH on verbal recall that depends sequentially on temporal lobe atrophy and verbal learning.ResultsIn both samples, WMH predicted poorer verbal recall, specifically due to temporal lobe atrophy and poorer verbal learning (proof-of-principle −1.53, 95% bootstrap confidence interval [CI] −2.45 to −0.88; and confirmation −0.66, 95% CI [−0.95 to −0.41] words). This pathway was significant in subgroups with (−0.20, 95% CI [−0.38 to −0.07] words, n = 363) and without (−0.71, 95% CI [−1.12 to −0.37] words, n = 339) AD. Via the identical pathway, WMH contributed to deficits in recognition memory (−1.82%, 95% CI [−2.64% to −1.11%]), a sensitive and specific sign of AD.ConclusionsAcross dementia syndromes, WMH contribute indirectly to verbal memory deficits considered pathognomonic of Alzheimer disease, specifically by contributing to temporal lobe atrophy.

Brain Injury With Prolonged Seizures in Children and Adults

1998 ◽  
Vol 13 (1_suppl) ◽  
pp. S3-S6 ◽  
Author(s):  
Solomon L. Moshé
Keyword(s):  
Temporal Lobe ◽  
Animal Studies ◽  
Science Studies ◽  
Hippocampal Sclerosis ◽  
Epidemiologic Studies ◽  
Late Childhood ◽  
Hippocampal Damage ◽  
Adult Rats ◽  
Spontaneous Seizures ◽  
The Brain

Some retrospective studies have suggested that there is a relationship between seizures early in life and the development of hippocampal damage (mesial temporal lobe hippocampal sclerosis) leading to intractable temporal lobe epilepsy in late childhood or adulthood. Recent prospective epidemiologic studies have not confirmed such a relationship, however, and many questions remain. Some of these questions are being addressed by animal studies. In adult rats, experimental seizures produce varying degrees of hippocampal damage and subsequent spontaneous seizures; the older the rat, the greater the hippocampal injury. The preponderance of available data indicate that such seizure-induced hippocampal damage may not occur in normally developing rats up to a certain age that may correspond to late childhood in humans. However, if the brain is already compromised, seizures early in life may produce hippocampal damage, depending on the nature of the initial lesion. Thus, the consequences of seizures appear to be age and etiology specific. Additional clinical and basic science studies are needed to clarify the neurobiology of seizure-induced hippocampal damage in children. (J Child Neurol 1998;13(Suppl 1):S3-S6).

Verbal Learning Differences in Epileptic Patients with Left and Right Temporal Lobe Foci

Epilepsia ◽  
1985 ◽  
Vol 26 (4) ◽  
pp. 340-345 ◽  
Author(s):  
Dan Mungas ◽  
Cindy Ehlers ◽  
Nancy Walton ◽  
Charlotte B. McCutchen
Keyword(s):  
Temporal Lobe ◽  
Verbal Learning ◽  
Learning Differences ◽  
Epileptic Patients ◽  
Left And Right

scholarly journals Novel approach to magnetic resonance imaging of epileptic dogs — T2 relaxometry of the brain with emphasised hippocampus

2017 ◽  
Vol 65 (2) ◽  
pp. 185-197 ◽  
Author(s):  
Borbála A. Lorincz ◽  
Agustina Anson ◽  
Péter Csébi ◽  
Gábor Bajzik ◽  
Gergely Biró ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Hippocampal Sclerosis ◽  
Relaxation Times ◽  
Visual Assessment ◽  
Resonance Imaging ◽  
T2 Relaxation ◽  
T2 Relaxometry ◽  
Individual Analysis ◽  
Skull Formation

Hippocampal sclerosis is the most common imaging finding of intractable human epilepsy, and it may play an important role in canine and feline epileptogenesis and seizure semiology, too. The magnetic resonance imaging (MRI) criteria of hippocampal sclerosis are T2 hyperintensity, shrinkage and loss of internal structure. The detection of these changes is often challenging by subjective visual assessment of qualitative magnetic resonance (MR) images. The recognition is more reliable with quantitative MR methods, such as T2 relaxometry. In the present prospective study including 31 dogs with idiopathic epilepsy and 15 control dogs showing no seizure activity, we compared the T2 relaxation times of different brain areas. Furthermore, we studied correlations between the hippocampal T2 values and age, gender and skull formation. We found higher hippocampal T2 values in the epileptic group than in the control; however, these findings were not statistically significant. No correlations were found with age, gender or skull formation. In the individual analysis six epileptic dogs presented higher hippocampal T2 relaxation times than the cut-off value. Two of these dogs were also evaluated as abnormal in the visual assessment. Individual analysis of hippocampal T2 relaxation times may be a helpful method to understand hippocampal involvement in canine epilepsy.

scholarly journals Distinctive Structural and Effective Connectivity Changes of Semantic Cognition Network across Left and Right Mesial Temporal Lobe Epilepsy Patients

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaotong Fan ◽  
Hao Yan ◽  
Yi Shan ◽  
Kun Shang ◽  
Xiaocui Wang ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Hippocampal Sclerosis ◽  
Effective Connectivity ◽  
Effective Interaction ◽  
Mesial Temporal Lobe Epilepsy ◽  
Semantic Cognition ◽  
Left And Right ◽  
Mesial Temporal Lobe

Occurrence of language impairment in mesial temporal lobe epilepsy (mTLE) patients is common and left mTLE patients always exhibit a primary problem with access to names. To explore different neuropsychological profiles between left and right mTLE patients, the study investigated both structural and effective functional connectivity changes within the semantic cognition network between these two groups and those from normal controls. We found that gray matter atrophy of left mTLE patients was more severe than that of right mTLE patients in the whole brain and especially within the semantic cognition network in their contralateral hemisphere. It suggested that seizure attacks were rather targeted than random for patients with hippocampal sclerosis (HS) in the dominant hemisphere. Functional connectivity analysis during resting state fMRI revealed that subregions of the anterior temporal lobe (ATL) in the left HS patients were no longer effectively connected. Further, we found that, unlike in right HS patients, increased causal linking between ipsilateral regions in the left HS epilepsy patients cannot make up for their decreased contralateral interaction. It suggested that weakened contralateral connection and disrupted effective interaction between subregions of the unitary, transmodal hub of the ATL may be the primary cause of anomia in the left HS patients.

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