Cortical neuronal loss and hippocampal sclerosis are not detected by voxel-based morphometry in individual epilepsy surgery patients

The rare nevus sebaceous (NS) syndrome (NSS) includes cortical malformations and drug-resistant epilepsy. Somatic RAS-pathway genetic variants are pathogenetic in NS, but not yet described within the brain of patients with NSS. We report on a 5-year-old boy with mild psychomotor delay. A brown-yellow linear skin lesion suggestive of NS in the left temporo-occipital area was evident at birth. Epileptic spasms presented at aged six months. EEG showed continuous left temporo-occipital epileptiform abnormalities. Brain MRI revealed a similarly located diffuse cortical malformation with temporal pole volume reduction and a small hippocampus. We performed a left temporo-occipital resection with histopathological diagnosis of focal cortical dysplasia type Ia in the occipital region and hippocampal sclerosis type 1. Three years after surgery, he is seizure-and drug-free (Engel class Ia) and showed cognitive improvement. Genetic examination of brain and skin specimens revealed the c.35G > T (p.Gly12Val) KRAS somatic missense mutation. Literature review suggests epilepsy surgery in patients with NSS is highly efficacious, with 73% probability of seizure freedom. The few histological analyses reported evidenced disorganized cortex, occasionally with cytomegalic neurons. This is the first reported association of a KRAS genetic variant with cortical malformations associated with epilepsy, and suggests a possible genetic substrate for hippocampal sclerosis.

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Hippocampal sclerosis dementia: An amnesic variant of frontotemporal degeneration

Dementia & Neuropsychologia ◽

10.1590/s1980-57642013dn70100013 ◽

2013 ◽

Vol 7 (1) ◽

pp. 83-87 ◽

Cited By ~ 7

Author(s):

Chiadi U. Onyike ◽

Olga Pletnikova ◽

Kelly L. Sloane ◽

Campbell Sullivan ◽

Juan C. Troncoso ◽

...

Keyword(s):

Psychiatric Disorder ◽

Clinical Diagnosis ◽

Hippocampal Sclerosis ◽

Neuronal Loss ◽

Executive Dysfunction ◽

Convenience Sample ◽

Illness Onset ◽

Work Support ◽

Resource Center ◽

Johns Hopkins University

ABSTRACT Objective: To describe characteristics of hippocampal sclerosis dementia. Methods: Convenience sample of Hippocampal sclerosis dementia (HSD) recruited from the Johns Hopkins University Brain Resource Center. Twenty-four cases with post-mortem pathological diagnosis of hippocampal sclerosis dementia were reviewed for clinical characterization. Results: The cases showed atrophy and neuronal loss localized to the hippocampus, amygdala and entorrhinal cortex. The majority (79.2%) had amnesia at illness onset, and many (54.2%) showed abnormal conduct and psychiatric disorder. Nearly 42% presented with an amnesic state, and 37.5% presented with amnesia plus abnormal conduct and psychiatric disorder. All eventually developed a behavioral or psychiatric disorder. Disorientation, executive dysfunction, aphasia, agnosia and apraxia were uncommon at onset. Alzheimer disease (AD) was the initial clinical diagnosis in 89% and the final clinical diagnosis in 75%. Diagnosis of frontotemporal dementia (FTD) was uncommon (seen in 8%). Conclusion: HSD shows pathological characteristics of FTD and clinical features that mimic AD and overlap with FTD. The findings, placed in the context of earlier work, support the proposition that HSD belongs to the FTD family, where it may be identified as an amnesic variant.

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How Different Are the Patients With Bilateral Hippocampal Sclerosis From the Unilateral Ones Clinically?

Clinical EEG and Neuroscience ◽

10.1177/1550059416653900 ◽

2016 ◽

Vol 48 (3) ◽

pp. 209-216 ◽

Cited By ~ 4

Author(s):

Ebru Nur Vanli-Yavuz ◽

Betul Baykan ◽

Serra Sencer ◽

Altay Sencer ◽

Isin Baral-Kulaksizoglu ◽

...

Keyword(s):

Mental Retardation ◽

Status Epilepticus ◽

Epilepsy Surgery ◽

Hippocampal Sclerosis ◽

Control Group ◽

High Signal ◽

Binary Logistic Regression Analysis ◽

Laboratory Findings ◽

Patients With Epilepsy ◽

Febrile Status Epilepticus

Purpose. There is a lack of knowledge on consecutive patients with epilepsy associated with bilateral hippocampal sclerosis (BHS). We aimed to investigate the differentiating features of BHS in comparison with unilateral HS (UHS). Method. We investigated our database for patients with epilepsy fulfilling the major magnetic resonance imaging criteria for BHS; namely, presence of bilateral atrophy and high signal changes on T2 and FLAIR series in the hippocampi. UHS patients seen in past 2 years were included as the control group. Clinical, EEG, and other laboratory findings, data on treatment response and epilepsy surgery were investigated from their files. Results. A total of 124 patients (31 with BHS and 93 with UHS; 49 right-sided and 44 left-sided) were included. We found that 16.1% of the BHS and 18.3% of the UHS groups were not drug-refractory. A binary logistic regression analysis performed with significant clinical features disclosed that history of febrile status epilepticus, mental retardation, and status epilepticus were statistically more common in BHS group. Moreover, diagnosis of psychosis established by an experienced psychiatrist and slowing of the EEG background activity were both found significantly more frequent in BHS. 66.67% of the operated BHS patients showed benefit from epilepsy surgery. Conclusions. BHS is a heterogeneous group, showing significant differences such as increased frequencies of mental retardation, status epilepticus, febrile status epilepticus and psychosis, in comparison to UHS. In all, 16.1% of the BHS cases showed a benign course similar to the UHS group and some patients with drug-resistant epilepsy may show benefit from epilepsy surgery.

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Neural correlates of de novo depression following left temporal lobe epilepsy surgery: A voxel based morphometry study of pre-surgical structural MRI

Epilepsy Research ◽

10.1016/j.eplepsyres.2013.12.003 ◽

2014 ◽

Vol 108 (3) ◽

pp. 517-525 ◽

Cited By ~ 7

Author(s):

Rebecca Anne Pope ◽

Maria Centeno ◽

Dominique Flügel ◽

Mark Robert Symms ◽

Matthias Koepp ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Epilepsy Surgery ◽

De Novo ◽

Structural Mri ◽

Neural Correlates ◽

Voxel Based Morphometry ◽

Left Temporal Lobe

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Progressive neuronal loss induced by kindling: a possible mechanism for mossy fiber synaptic reorganization and hippocampal sclerosis

Brain Research ◽

10.1016/0006-8993(90)91054-k ◽

1990 ◽

Vol 527 (1) ◽

pp. 1-6 ◽

Cited By ~ 277

Author(s):

Jose´E. Cavazos ◽

Thomas P. Sutula

Keyword(s):

Mossy Fiber ◽

Hippocampal Sclerosis ◽

Neuronal Loss ◽

Synaptic Reorganization

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VISUAL FIELD DEFECTS IN SELECTIVE AMYGDALOHIPPOCAMPECTOMY FOR HIPPOCAMPAL SCLEROSIS

Neurosurgery ◽

10.1227/01.neu.0000324895.19708.68 ◽

2008 ◽

Vol 63 (3) ◽

pp. 507-515 ◽

Cited By ~ 30

Author(s):

S. Naz Yeni ◽

Necmettin Tanriover ◽

Özlem Uyanik ◽

Mustafa Onur Ulu ◽

Çiğdem Özkara ◽

...

Keyword(s):

Visual Field ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Epilepsy Surgery ◽

Hippocampal Sclerosis ◽

Visual Field Defects ◽

Selective Amygdalohippocampectomy ◽

Temporal Horn ◽

Visual Field Deficits ◽

Meyer’S Loop

ABSTRACT OBJECTIVE Meyer's loop, the most vulnerable part of the optic radiations during approaches to the temporomedial region, extends to the tip of the temporal horn and is often encountered in epilepsy surgery. The risk of damaging Meyer's loop during transsylvian selective amygdalohippocampectomy peaks while accessing the temporal horn through its roof by opening the inferior limiting sulcus of the insula. In this prospective study, we sought to evaluate and identify the incidence of visual field deficits in a homogeneous group of patients who had temporal lobe epilepsy with hippocampal sclerosis and who underwent transsylvian selective amygdalohippocampectomy. METHODS We studied 30 patients who were referred for epilepsy surgery for intractable complex partial and/or secondary generalized seizures and evaluated according to a noninvasive protocol. All patients underwent selective amygdalohippocampectomy for temporal lobe epilepsy with hippocampal sclerosis using the standard transsylvian approach. Visual field deficits were examined preoperatively in 30 patients, by either a confrontation method (n = 18) or standard Goldmann perimetry (n = 12) and postoperatively in all patients using standard Humphrey digital perimetry. RESULTS Visual field examination was normal in all patients before surgery. Humphrey perimetric measurement revealed visual field deficits in 11 patients (36.6%) after surgery. CONCLUSION We have shown that there is a considerable risk of having visual field deficits after standard transsylvian selective amygdalohippocampectomy owing to the interruption of the anterior bundle of the optic radiation fibers, which most likely occurs while opening the temporal horn through the inferior limiting sulcus of the insula.

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