Dataset Information

HHV-6 and hippocampal volume in patients with mesial temporal sclerosis.

ABSTRACT:

Objective

To study the effects of human herpes virus 6 (HHV-6) on the hippocampal volume in patients with mesial temporal sclerosis (MTS).

Background

HHV-6 may play an etiologic role in MTS. Previous studies found a possible association with febrile status epilepticus. Several investigators have reported a higher prevalence of HHV-6 in MTS resections compared to other epilepsy etiologies.

Design/methods

We used FreeSurfer to segment cortical structures and obtain whole hippocampal and subfield volumes in 41 patients with intractable epilepsy. In addition, an investigator blinded to other data traced hippocampi manually on each slice. The main study outcome measure was the asymmetry index (AI) between hippocampal volumes ipsilateral and contralateral to seizure foci compared between HHV-6 positive and negative patients. Viral DNA was isolated from fresh brain tissue obtained at temporal lobectomy. For 25 patients, viral detection was performed using quantitative real-time PCR specific for HHV-6A and HHV-6B. For 16 patients, viral DNA detection was performed using digital droplet PCR specific for HHV-6A and HHV-6B.

Results

Twenty-two patients were positive (14 of 25 tested with real-time PCR, and 8 of 16 with digital droplet PCR), and 19 negatives for HHV-6. HHV-6 negative patients had significantly greater AI and lower total hippocampal volume ipsilateral to seizure foci than HHV-6 positive patients. Epilepsy duration and age of onset did not affect results.

Interpretation

Our data suggest multiple potential etiologies for MTS. HHV-6 may have a less severe effect on the hippocampus than other etiologies.

SUBMITTER: Akinsoji EO

PROVIDER: S-EPMC7480901 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

HHV-6 and hippocampal volume in patients with mesial temporal sclerosis.

Akinsoji Elizabeth O EO Leibovitch Emily E Billioux B Jeanne BJ Abath Neto Osorio Lopes OL Ray-Chaudhury Abhik A Inati Sara K SK Zaghloul Kareem K Heiss John J Jacobson Steven S Theodore William H WH

Annals of clinical and translational neurology 20200817 9

<h4>Objective</h4>To study the effects of human herpes virus 6 (HHV-6) on the hippocampal volume in patients with mesial temporal sclerosis (MTS).<h4>Background</h4>HHV-6 may play an etiologic role in MTS. Previous studies found a possible association with febrile status epilepticus. Several investigators have reported a higher prevalence of HHV-6 in MTS resections compared to other epilepsy etiologies.<h4>Design/methods</h4>We used FreeSurfer to segment cortical structures and obtain whole hipp ...[more]

PMID: 33325656

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Project description:The Wada test is widely used in the presurgical evaluation of potential temporal lobectomy patients to predict postoperative memory function. Expected asymmetry (EA), defined as Wada memory lateralized to the nonsurgical hemisphere, or a higher score after injection of the surgical hemisphere would be considered favorable in terms of postoperative memory outcome. However, in some cases, nonlateralized memory (NM) results, with no appreciable asymmetry, may occur because of impaired scores after both injections, often leading to denial of surgery. The reason for such nonlateralized Wada memory in patients with intractable temporal lobe epilepsy (TLE) remains unclear. Given that quantitative morphometric magnetic resonance imaging studies in TLE patients have shown bilateral regional atrophy in temporal and extratemporal structures, we hypothesized that the volume loss in contralateral temporal structures could contribute to nonlateralized Wada memory performance. To investigate this, we examined the relationship between the volume changes of temporal structures and Wada memory scores in patients with intractable TLE with mesial temporal sclerosis (MTS) using an age- and gender-matched control group. Memory was considered nonlateralized if the absolute difference in the total correct recall scores between ipsilateral and contralateral injections was <11%. Among 21 patients, Wada memory was lateralized in 15 and nonlateralized in 6 patients, with all the nonlateralized scores being observed in left TLE. The recall scores after ipsilateral injection were significantly lower in patients with an NM profile than an EA profile (23 ± 14% vs. 59 ± 18% correct recall, p ? 0.001). However, the recall scores after contralateral injection were low but similar between the two groups (25 ± 17% vs. 25 ± 15% correct recall, p=0.97). Compared to controls, all the patients showed greater volume loss in the temporal regions. However, patients with a NM profile showed significantly more volume loss than those with a lateralized memory profile in both contralateral and ipsilateral temporal regions (p<0.05). Left hemispheric Wada memory performance correlated positively with the size of the left mesial and neocortical temporal structures (r=0.49-0.63, p=0.005-0.04). Our study suggests that volume loss in the nonsurgical temporal structures is associated with nonlateralized Wada memory results in patients with intractable TLE.

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Dataset Information

HHV-6 and hippocampal volume in patients with mesial temporal sclerosis.

Objective

Background

Design/methods

Results

Interpretation

Publications

HHV-6 and hippocampal volume in patients with mesial temporal sclerosis.

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