磁共振表现为一侧海马硬化的颞叶癫痫手术治疗长期随访结果

目的：探讨磁共振表现为一侧海马硬化的颞叶癫痫手术治疗长期疗效。方法对25例磁共振表现为一侧海马硬化的药物难治性颞叶癫痫患者,在术中脑电监测下行裁剪式前颞叶切除术,术后长期随访,评估癫痫控制效果。结果术后疗效良好,癫痫控制效果按ILAE分类法,术后1年76％患者达1级,4％为2级,16％为3级,4％为5级;术后3年68％为1级,4％为2级,24％为3级,4％为5级;术后5年65％为1级,29％为3级,6％为5级。结论手术治疗磁共振表现为一侧海马硬化颞叶癫痫长期疗效满意,患者生活质量改善。     

Unilateral hippocampal sclerosis with contralateral temporal scalp ictal onset

PURPOSE: To investigate the clinical characteristics and surgical outcomes in patients with unilateral hippocampal sclerosis whose scalp ictal EEG recordings localize to the opposite temporal lobe. METHODS: We retrospectively reviewed the data of all adult patients who had undergone depth electrode implantation for suspected temporal lobe epilepsy (TLE) at UCLA (1993-2000) or the Montreal Neurological Institute (1991-1998) to identify patients who had (a) unilateral hippocampal atrophy, and (b) surface ictal recordings in which the majority of seizures appeared to initiate in the opposite temporal lobe, with few or none that were concordant with the hippocampal atrophy. RESULTS: Of 109 patients with suspected TLE who underwent depth electrode study at the two centers, five patients met the aforementioned criteria. Four of these five had very severe hippocampal atrophy, whereas the fifth had mild atrophy but extensive signal change on magnetic resonance imaging (MRI). Depth electrode recordings in four of the five patients yielded clear ictal onset in the mesial temporal lobe ipsilateral to the imaging abnormality (contralateral to apparent scalp ictal onset). One patient had an unusual bitemporal onset pattern, which was nonetheless suggestive of onset in the sclerotic hippocampus. No patient had intracranial ictal onset contralateral to the imaging abnormality. All patients underwent resection of the structurally abnormal temporal lobe. After follow-up of > or = 2 years, four (80%) of five patients were seizure free, while the fifth showed lesser improvement (class III). CONCLUSIONS: Some patients with severe hippocampal sclerosis (sometimes called a "burned-out hippocampus") have atypical spread of ictal discharges, resulting in apparent gross discordance between imaging and scalp ictal recordings. These patients nonetheless have excellent surgical outcomes on the whole. Whether such patients may forego intracranial recordings requires further study.     

Neuropsychological outcomes in epilepsy surgery patients with unilateral hippocampal sclerosis and good preoperative memory function

We examined postoperative changes in the memory function of 68 people with unilateral hippocampal sclerosis (HS) who underwent epilepsy surgery and had no previous clinical memory impairments. One in four with right HS (RHS) and one in five with left HS (LHS) in our sample of 323 people with unilateral HS performed within normal limits on memory tests that are sensitive to hippocampal pathology in group studies. People with intact memory function prior to surgery were significantly younger and had higher IQs than those with memory impairments. The majority of those with intact memory functions prior to surgery had significant postoperative declines on the memory measures at the 1‐year follow‐up and no longer functioned within the average range. People with RHS and left LHS were equally at risk of a postoperative decline. Postoperative deterioration was not related to seizure outcome. A higher IQ appears to protect against postoperative memory decline in this group. This finding does not support the notion that intact memory function in people with unilateral HS represents a migration of memory function to the contralateral structures, and thus protection from surgical insult. People with good preoperative memory function in the context of unilateral HS should therefore be counseled regarding the likelihood of a significant postoperative decline in memory function following a temporal lobe resection.     

Doublecortin (DCX) immunoreactivity in hippocampus of chronic refractory temporal lobe epilepsy patients with hippocampal sclerosis

IntroductionStatus epilepticus increases the production of new neurons (hippocampal neurogenesis) and promotes aberrant migration. However chronic experimental models of epilepsy and studies performed in human epilepsy showed controversial results suggesting a reduction in hippocampal neurogenesis in late stages of the disease. Doublecortin (DCX) has been validated to determine alterations in the production of new neurons in the human hippocampus.ObjectivesDetermine DCX expression in human hippocampal sclerosis (HS) from patients who underwent epilepsy surgery for refractory temporal lobe epilepsy (TLE).MethodsHippocampal sections of 9 patients with HS and TLE who underwent surgery, were processed using immunoperoxidase for DCX. Archival material from 5 normal post-mortem hippocampus were simultaneously processed.ResultsSignificantly lower staining intensity was observed in DCX-positive neurons localized in dentate gyrus (DG) and in CA1 of epileptic hippocampus; lower DCX reactive area was observed in pyramidal layers of CA1; and a reduced in the mean number of DCX-positive neurons were determined in DG compared to normal hippocampus (p < 0.05).ConclusionsThis study found a decrease in DCX expression in hippocampus of patients with HS and chronic and refractory TLE suggesting alterations in NG and hippocampal synaptogenesis with potential cognitive and emotional repercussion.     

Short-term cognitive changes after surgery in patients with unilateral mesial temporal lobe epilepsy associated with hippocampal sclerosis

We investigated the short-term postoperative cognitive function of patients with unilateral mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE/HS). Fourteen unilateral MTLE/HS patients who had undergone selective amygdalohippocampectomy (SAH) or anterior temporal lobectomy (ATL) were enrolled. Cognitive functions related to the frontal and temporal lobes were evaluated using a battery of neuropsychological tests administered before surgery and 3 months after surgery. The battery included the Verbal Fluency Test (VFT), Boston Naming Test (BNT), Stroop Color-Word Test (TST), Trail Making Test (TMT) and Wechsler Memory Scale (WMS). MTLE/HS patients demonstrated significantly improved postoperative performance on the TST regardless of the surgical method or side of resection. There was no significant difference in any of the other neuropsychological tests before and after surgery. After left-side resection, performance on the VFT and the TMT-B was worse than at baseline. After right-side resection, performance on the VFT and WMS short-term memory improved; however, these differences were not statistically significant. SAH patients exhibited improved TST performance but worse TMT-A performance; however, performance on all tests was not significantly different after surgery in ATL patients. In summary, MTLE/HS patients demonstrated improved frontal lobe-related cognitive function after surgery, but no such improvement in temporal lobe-related function was observed. Based on cognitive evaluation, right-sided MTLE/HS patients may be more appropriate surgical candidates than left-sided MTLE/HS patients. SAH may not be better than ATL in improving cognitive function. We hypothesise that postoperative cognitive changes depend on whether the excised cerebral regions are related to the neuropsychological functions examined by specific assessment instruments.     

Interictal EEG, hippocampal atrophy, and cell densities in hippocampal sclerosis and hippocampal sclerosis associated with microscopic cortical dysplasia.

The EEG characteristics of isolated hippocampal sclerosis (HS) and HS associated with other types of temporal lobe pathology are not well defined. The pathologic substrate may be an important variable in determining seizure-free outcome. The objective of this study was to define the distribution of epileptiform discharges in patients with HS and HS associated with microscopic dysplasia, and to examine their relationship with hippocampal atrophy and cell loss. Thirty-four patients (15 women and 19 men; mean age, 30.6 +/- 11.2 years), all with good outcomes after temporal lobectomy (Engel classes I and II), were included. The characteristics studied were frequency and distribution of spikes, MRI-based hippocampal volume ratios, and quantitative hippocampal cell density in various subregions. The isolated HS group showed a trend to a higher percentage of epileptiform discharges maximal at the anterior temporal electrodes (89.87 +/- 17.0%; 79.5 +/- 28.2% in the dual-pathology group). The isolated HS group had, on average, significantly more cell loss (P < 0.001). There was a significant negative correlation between the amount of cell loss in the CA1 area and both anterior temporal spikes and hippocampal ratios (P < 0.05). Isolated HS and dual pathology show minimal differences in interictal spike distribution and frequency. More widespread spike distributions in severe isolated HS compared with patients with less cell loss is probably the result of less organized limbic circuitry.     

Temporal ictal electroencephalographic frequency correlates with hippocampal atrophy and sclerosis

We studied 328 complex partial seizures (CPS) in 63 consecutive patients with temporal lobe epilepsy who underwent scalp electroencephalography/video monitoring, magnetic resonance imaging (MRI), and surgery. The initial ictal discharge (IID), defined as the first sustained electrical seizure pattern localized to the surgical site, was determined. If the IID was rhythmic waves, the median frequency was measured. To determine if IID frequency correlates with hippocampal atrophy (HA) or sclerosis (HS), hippocampal volume ratios (HVRs) were measured (n = 52) or assessed visually (n = 11) on MRI, and mesial temporal histopathology specimens (n = 22) were graded for HS. Sixteen patients (25%) had no or mild HA (HVR = 0.78-1.02), and 47 patients (75%) had moderate-to-marked unilateral (HVR = 0.33?0.76), or bilateral, HA. Theta frequency IIDs were significantly more commonly associated with moderate-to-marked HA than were delta IIDs. Theta frequency IIDs occurred in 19% of patients with mild or no HA, and 79% of patients with moderate-to-marked HA; delta IIDs occurred in 63% of patients with little to no HA, and 13% of those with moderate-to-marked HA. In addition, the median IId frequency inversely correlated with HVR and directly correlated with HS severity. In conclusion, faster frequency rhythmic IIDs during temporal lobe CPS correlate with greater degrees of ipsilateral HA on MRI, and higher grades of HS.     

Mesial temporal lobe epilepsy and hippocampal sclerosis: cognitive function assessment in Hispanic patients

PURPOSE: The goal of this study was to assess the cognitive function status in patients with mesial temporal lobe epilepsy and hippocampal sclerosis (TLE+HS) to determine their cognitive function profile and to correlate material-specific memory deficits with HS laterality diagnosed by MRI. METHODS: Seventy-one patients were assessed with a neuropsychological protocol that includes IQ, attention, handedness, verbal memory, visual memory, language, and the executive function. chi(2) and correlation tests were used. RESULTS: Memory impairment was found in 46 patients (66%): patients without any memory deficit (n=25), patients with verbal memory deficit (n=21), patients with visual memory deficit (n=17), patients with deficit for both types of memory (n=8). Correlation between MRI lesion and memory was 66%. Language was impaired in 33 patients (46%). Eighteen patients (25%) had a deficit of the executive function. CONCLUSIONS: Patients with TLE+HS presented with a deficit in material-specific episodic memory correlating in large proportion with HS lateralization. We also found language and executive function impairments.     

Three-dimensional patterns of hippocampal atrophy in mild cognitive impairment

OBJECTIVE: To measure hippocampal volumes in patients diagnosed as having subtypes of mild cognitive impairment (MCI) relative to those of elderly control subjects and those of patients with Alzheimer disease (AD) using 3-dimensional mesh reconstructions. DESIGN: A magnetic resonance imaging volumetric study of MCI subgroups (MCI, amnesic subtype [MCI-A]; and MCI, multiple cognitive domain subtype) using 3-dimensional mesh reconstructions of the structure. SETTING: Referral dementia clinic. SUBJECTS: Twenty-six subjects with MCI (MCI-A, n = 6; and MCI, multiple cognitive domain subtype, n = 20), 20 subjects with AD, and 20 controls who were equivalent in age, education, and sex distributions. MAIN OUTCOME MEASURES: Three-dimensional parametric mesh models of the hippocampus and total hippocampal volumes. RESULTS: The hippocampi of the patients with AD were significantly atrophic relative to those of the healthy controls. The MCI, multiple cognitive domain subtype, group did not differ from the controls, yet was significantly different from the MCI-A and the AD groups. The MCI-A patients had significant hippocampal atrophy compared with the controls, and did not differ significantly from the patients with AD. CONCLUSION: These data add to the growing evidence that there are multiple forms of MCI, that they have distinct neuropathological correlates, and that MCI, multiple cognitive domain subtype, is not a more advanced form of the MCI-A subtype.     

Neonatal vs. adult unilateral hippocampal lesions: differential alterations in contralateral hippocampal theta rhythm

Subcortical damage often has more severe consequences in neonates than in adults. For example, unilateral hippocampal lesions in adult rats typically lead to transient memory deficits, whereas neonatal lesions cause lasting learning impairment. We hypothesized that the defects triggered by unilateral damage may include synaptic dysfunction in the contralateral hippocampus. Consequently, we examined the hippocampal theta rhythm, an EEG pattern thought to be associated with learning. Initial comparisons between intact and lesioned rats revealed no obvious differences in basal theta rhythm properties. However, manipulations of ascending brainstem projections to hippocampus with drugs specific for serotonergic, noradrenergic and cholinergic receptors uncovered differences. Antagonism of 5-HT₃ receptors known to promote learning significantly increased theta frequency in controls and adult lesioned rats, but not after neonatal damage. In contrast, blockade of noradrenergic-α₂ receptors had no effect. Antagonism of cholinergic receptors which typically impairs learning disrupted theta and caused irregular, high-amplitude activity that was significantly more pronounced in the lesioned groups. A final approach involved pharmacological facilitation of AMPA receptor-mediated currents, using a drug which enhances memory. This treatment significantly enhanced theta frequency in controls and animals lesioned as adults. In contrast, it failed to do so in rats lesioned at birth. These observations suggest that latent dysfunction in contralateral hippocampal physiology may contribute to the lasting memory deficits seen after unilateral hippocampal lesion in neonates.     

颞叶癫(癎)后认知功能障碍与海马萎缩的相关性

目的 比较颞叶癫(癎)患者与健康者认知障碍、海马萎缩的差异,探讨颞叶癫(癎)患者认知障碍与海马萎缩的相关性.方法 随机选取颞叶癫(癎)患者49例和健康对照者20名,神经心理量表评价其认知状态并测量双侧海马体积.结果 与健康者相比,颞叶癫(癎)患者的记忆商(83.2±21.0)和智商(91.0±12.3)显著下降(t=-3.365,-4.291,P=0.001,0.000),双侧海马显著萎缩(P=0.000),不对称指数显著增高(t=3.975,P=0.000),差异有统计学意义.颞叶癫(癎)患者记忆力与癫(癎)病程显著负相关(r=-0.339,P=0-017),左右两侧海马萎缩程度与认知指数均显著负相关(左侧:r=-0.297,P=0.038;右侧:r=-0.305,P=0.033),不对称指数与认知指数显著负相关(r=-0.441,P=0.002).结论 颞叶癫(癎)患者双侧海马的萎缩程度越高、对称性越差,认知损伤也就越显著.海马体积测量可以作为颞叶癫(癎)患者智力下降的评价因子.     

Verbal retention lateralizes patients with unilateral temporal lobe epilepsy and bilateral hippocampal atrophy

PURPOSE: To examine the lateralization utility of preoperative verbal retention in patients with and without bilateral hippocampal atrophy. METHODS: The sample consisted of 74 patients with EEG-defined unilateral temporal lobe epilepsy (TLE) who had also undergone volumetric magnetic resonance imaging (MRI). Verbal retention was operationalized by the Logical Memory percentage retention subtest (LM%) of the Wechsler Memory Scale. Patients were divided into groups with (a) bilaterally normal hippocampal volumes, (b) unilateral atrophy, or (c) bilateral atrophy. Two different thresholds (empirically derived vs. normative) were used to lateralize on the basis of LM%. LM% lateralization was then examined by group using chi2, sensitivity, positive predictive values, and odds ratios. Analyses were also conducted separately in the subset of patients who were seizure free after surgery. RESULTS: Mean LM% performance was significantly lower in patients with left versus right TLE in the subset with bilateral hippocampal atrophy (p = 0.018), but not in patients with a normal MRI (p = 0.918) or unilateral atrophy (p = 0.087). The odds of a correct lateralization by LM% increased from 1.67 in patients with normal MRI to 36.11 in patients with bilateral hippocampal atrophy. The power of a right and left lateralization prediction by LM% was 100% and 75%, respectively, in patients with bilateral hippocampal atrophy. Similar results were obtained when analysis was restricted to patients who were seizure free after surgery. CONCLUSIONS: Preoperative verbal retention as measured by LM% may provide meaningful lateralization information in patients who are difficult to lateralize via MRI.     

Correlation of cognitive functions with voxel-based morphometry in patients with hippocampal sclerosis

Material-specific memory dysfunction is a feature of mesial temporal lobe epilepsy (mTLE) and has lateralizing potential. We used voxel-based morphometry (VBM) and partial regression analysis of whole-brain tissue class volumes to test if there are correlations between material-specific cognitive dysfunction and localized gray matter loss. In a cohort of 89 patients with mTLE and hippocampal sclerosis (HS), we found correlations between global gray matter and cerebrospinal fluid volume and cognitive test scores in the group with left HS. These findings, however, were poorly anatomically localized; no global changes were detected in the group with right HS. Thus, correlations between gray matter loss and cognitive dysfunction were present and suggested the involvement of widespread neural networks.     

Frontal cortex atrophy predicts cognitive impairment in multiple sclerosis

The association between regional measures of cortical atrophy and neuropsychological (NP) dysfunction was studied in 35 multiple sclerosis (MS) patients. Patients underwent neurological examination, MRI, and NP testing. Blind quantitative MRI analysis yielded total T(2) lesion area (TLA) and third ventricle width (3VW). Cortical atrophy, rated by blind visual inspection, was more extensive in superior frontal and parietal cortices than in other regions. No MRI measures were correlated with depression scores. TLA and 3VW were significantly correlated with each NP test. Cortical atrophy measures for bilateral superior frontal cortex were retained in regression models predicting impairments in verbal learning, spatial learning, attention, and conceptual reasoning. The authors conclude that cerebral atrophy predicts NP impairment while accounting for the influence of TLA or 3VW. Regions of cortex most susceptible to atrophic and cognitive changes in MS are the right and left superior frontal lobes.