Morphometric MRI features and surgical outcome in patients with epilepsy related to hippocampal sclerosis and low intellectual quotient.

OBJECTIVE: The objectives of this study were to verify in a series of patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) if those with low intellectual quotient (IQ) levels have more extended areas of atrophy compared with those with higher IQ levels and to analyze whether IQ could be a variable implicated on a surgical outcome. MATERIAL AND METHODS: Patients (n=106) with refractory MTLE-HS submitted to corticoamygdalohippocampectomy (CAH) (57 left mesial temporal lobe epilepsy (MTLE); 45 males) were enrolled. To determine if the IQ was a predictor of seizure outcome, totally seizure-free (SF) versus nonseizure-free (NSF) patients were evaluated. FreeSurfer was used for cortical thickness and volume estimation, comparing groups with lower (<80) and higher IQ (90-109) levels. RESULTS: In the whole series, 42.45% of patients were SF (Engel Class 1a; n=45), and 57.54% were NSF (n=61). Total cortical volume was significantly reduced in the group with lower IQ (p=0.01). Significant reductions in the left hemisphere included the following: rostral middle frontal (p=0.001), insula (p=0.002), superior temporal gyrus (p=0.003), thalamus (p=0.004), and precentral gyrus (p=0.02); and those in the right hemisphere included the following: rostral middle frontal (p=0.003), pars orbitalis (p=0.01), and insula (p=0.02). Cortical thickness analysis also showed reductions in the right superior parietal gyrus in patients with lower IQ. No significant relationship between IQ and seizure outcome was found. CONCLUSIONS: This is the first study of a series of patients with pure MTLE-HS, including those with low IQ and their morphometric magnetic resonance imaging (MRI) features using FreeSurfer. Although patients with lower intellectual scores presented more areas of brain atrophy, IQ was not a predictor of surgical outcome. Therefore, when evaluating seizure follow-up, low IQ in patients with MTLE-HS might not contraindicate resective surgery.

A pioneering FreeSurfer volumetric study of a series of patients with mesial temporal lobe epilepsy and hippocampal sclerosis with comorbid depression.

Depression is the most frequent psychiatric comorbidity in patients with mesial temporal lobe epilepsy (MTLE) and hippocampal sclerosis (HS). This study aimed to confirm whether patients with comorbid depression have different volumetric patterns on magnetic resonance imaging, analysing the influence of HS sides. Psychiatrists conducted semi-structured interviews with 75 patients, who were divided into non-depression group (NDG, n = 52) and depression group (DG, n = 23), and compared with 98 controls. The FreeSurfer software was used in the volumetric analysis of the estimated total intracranial volume (eTIV), bilateral cortical and subcortical regions of interest (ROIs), and for presence of left (L-, n = 41) or right (R-, n = 34) MTLE-HS. Twenty-three (30.7%) patients had depression, of whom 14 (34.1%) had l-MTLE-HS and 9 (26.5%) had R-MTLE-HS. No difference was observed between DG and NDG vs. controls in terms of eTIV and cortical ROIs, regardless of the severity of depression. In patients with l-MTLE-HS, the eTIV in the DG was reduced in comparison with that in the NDG and control group, with a small effect size. Hippocampal reduction occurred ipsilateral to HS in the l-MTLE-HS and R-MTLE-HS subgroups when DG and NDG were compared with controls, as expected according to Enhancing Neuro Imaging Genetics through Meta-Analysis (2018).

The impact of epilepsy duration in a series of patients with mesial temporal lobe epilepsy due to unilateral hippocampal sclerosis.

PURPOSE: To evaluate if the duration of epilepsy influences MRI volumes of the hippocampus, amygdala, parahippocampal gyrus, entorhinal cortex and temporal pole of both hemispheres and epileptogenic hippocampus neuronal cell density and dentate gyrus granular cells distribution in patients with refractory mesial temporal lobe epilepsy due to hippocampal sclerosis (MTLE/HS). METHODS: Seventy-seven patients with refractory MTLE/HS submitted to surgery were included. Histopathological analysis included: (1) quantitative: hippocampal subfields and total estimated hippocampal cell density (HCD), thickness of the dentate gyrus - normal, thinning or dispersion; (2) qualitative: type of HS and granule cells pathology in the dentate gyrus (normal, neuronal cell loss, dispersion and bilamination). Automated MRI-derived measurements from bilateral temporal structures (hippocampus, amygdala, parahippocampal gyrus, temporal pole, entorhinal cortex) were obtained for 58 subjects. Histopathological and imaging findings were compared with data from specimens obtained in autopsies of age-matched individuals and living controls, respectively, and the data were adjusted for the age at epilepsy onset and the frequency of focal impaired awareness seizures/month. RESULTS: Forty-two (54.5%) patients presented right HS. The greater the duration of epilepsy, the smaller the total estimated HCD (p = 0.025; r = -0.259). Patients with a normal distribution of the granular cells had a shorter epilepsy duration than those with dispersion (p = 0.018) or thinning (p = 0.031). A reduced ipsilateral hippocampal volume (r = -0.551, p = 0.017) and a smaller hippocampal asymmetry index (r = -0.414, p = 0.002) were correlated to a longer epilepsy duration. The estimated HCD was correlated to the volume of the ipsilateral hippocampus (r = 0.420, p = 0.001). CONCLUSION: Our study showed an increasing atrophy of the ipsilateral hippocampus in patients with a longer epilepsy duration. Our data suggest that this reduction in hippocampal volume is related to neuronal loss. Besides that, we also showed an increased probability of exhibiting an abnormal distribution of the granular cells in the dentate gyrus in patients with longer epilepsy duration.

Langerhans' cell histiocytosis with neurological injuries diagnosed from a single cutaneous lesion.

Histiocytoses are rare diseases caused by the proliferation of histiocytes. The pathogenesis remains unknown and the highest incidence occurs in pediatric patients. The clinical presentations can be varied, in multiple organs and systems, and the skin lesions are not always present. Evolution is unpredictable and treatment depends on the extent and severity of the disease. It is described the case of a patient with various neurological symptoms, extensively investigated, who had its was diagnosed with histiocytosis from a single skin lesion. This report highlights the importance of Dermatology in assisting the investigation of difficult cases in medical practice.

Morphometric MRI features are associated with surgical outcome in mesial temporal lobe epilepsy with hippocampal sclerosis.

PURPOSE: Corticoamygdalohippocampectomy (CAH) improves seizure control, quality of life, and decreases mortality for refractory mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). One-third of patients continue having seizures, and it is pivotal to determine structural abnormalities that might influence the postoperative outcome. Studies indicate that nonhippocampal regions may play a role in the epileptogenic network in MTLE-HS and could generate seizures postoperatively. The aim of this study is to analyze areas of atrophy, not always detected on routine MRI, comparing patients who became seizure free (SF) with those non seizure free (NSF) after CAH, in an attempt to establish possible predictors of surgical outcome. METHODS: 105 patients with refractory MTLE-HS submitted to CAH (59 left MTLE; 46 males) and 47 controls were enrolled. FreeSurfer was performed for cortical thickness and volume estimation comparing patients to controls and SF versus NSF patients. The final sample after post processing procedures resulted in 99 patients. RESULTS: Cortical thickness analyses showed reductions in left insula in NSF patients compared to those SF. Significant volume reductions in SF patients were present in bilateral thalami, hippocampi and pars opercularis, left parahippocampal gyrus and right temporal pole. In NSF patients reductions were present bilaterally in thalami, hippocampi, entorhinal cortices, superior frontal and supramarginal gyri; on the left: superior and middle temporal gyri, temporal pole, parahippocampal gyrus, pars opercularis and middle frontal gyrus; and on the right: precentral, superior, middle and inferior temporal gyri. Comparison between SF and NSF patients showed ipsilateral gray matter reductions in the right entorhinal cortex (p=0.003) and contralateral parahippocampal gyrus (p=0.05) in right MTLE-HS. Patients NSF had a longer duration of epilepsy than those SF (p=0.028). CONCLUSION: NSF patients exhibited more extensive areas of atrophy than SF ones. As entorhinal cortex and parahippocampal gyrus are reduced in NSF patients compared to those SF these structures might be implicated in the network responsible for the maintenance of postoperative seizures. Duration of epilepsy is a predictor of seizure outcome.

Hippocampal atrophy on MRI is predictive of histopathological patterns and surgical prognosis in mesial temporal lobe epilepsy with hippocampal sclerosis.

PURPOSE: To correlate hippocampal volumes obtained from brain structural imaging with histopathological patterns of hippocampal sclerosis (HS), in order to predict surgical outcome. METHODS: Patients with mesial temporal lobe epilepsy (MTLE) with HS were selected. Clinical data were assessed pre-operatively and surgical outcome in the first year post surgery. One block of mid hippocampal body was selected for HS classification according to ILAE criteria. NeuN-immunoreactive cell bodies were counted within hippocampal subfields, in four randomly visual fields, and cell densities were transformed into z-score values. FreeSurfer processing of 1.5T brain structural images was used for subcortical and cortical volumetric estimation of the ipsilateral hippocampus. Univariate analysis of variance and Pearson's correlation test were applied for statistical analyses. RESULTS: Sixty-two cases (31 female, 32 right HS) were included. ILAE type 1 HS was identified in 48 patients, type 2 in eight, type 3 in two, and four had no-HS. Better results regarding seizure control, i.e. ILAE 1, were achieved by patients with type 1 HS (58.3%). Patients with types 1 and 2 had smaller hippocampal volumes compared to those with no-HS (p<0.001 and p=0.004, respectively). Positive correlation was encountered between hippocampal volumes and CA1, CA3, CA4, and total estimated neuronal densities. CA2 was the only sector which did not correlate its neuronal density with hippocampal volume (p=0.390). CONCLUSION: This is the first study correlating hippocampal volume on MRI submitted to FreeSurfer processing with ILAE patterns of HS and neuronal loss within each hippocampal subfield, a fundamental finding to anticipate surgical prognosis for patients with drug-resistant MTLE and HS.

Langerhans' cell histiocytosis with neurological injuries diagnosed from a single cutaneous lesion

Abstract: Histiocytoses are rare diseases caused by the proliferation of histiocytes. The pathogenesis remains unknown and the highest incidence occurs in pediatric patients. The clinical presentations can be varied, in multiple organs and systems, and the skin lesions are not always present. Evolution is unpredictable and treatment depends on the extent and severity of the disease. It is described the case of a patient with various neurological symptoms, extensively investigated, who had its was diagnosed with histiocytosis from a single skin lesion. This report highlights the importance of Dermatology in assisting the investigation of difficult cases in medical practice.