Semi-quantitative analysis of hippocampal internal architecture (HIA) on MRI has been shown to be a reliable predictor of the side of seizure onset in patients with temporal lobe epilepsy (TLE). In the present study, we investigated the relationship between postoperative seizure outcome and preoperative semi-quantitative measures of HIA.We determined HIA on high in-plane resolution preoperative T2 short tau inversion recovery MR images in 79 patients with presumed unilateral mesial TLE (mTLE) due to hippocampal sclerosis (HS) who underwent amygdalohippocampectomy and postoperative follow up. HIA was investigated with respect to postoperative seizure freedom, neuronal density determined from resected hippocampal specimens, and conventionally acquired hippocampal volume.HIA ratings were significantly related to some neuropathological features of the resected hippocampus (e.g. neuronal density of selective CA regions, Wyler grades), and bilaterally with preoperative hippocampal volume. However, there were no significant differences in HIA ratings of the to-be-resected or contralateral hippocampus between patients rendered seizure free (ILAE 1) compared to those continuing to experience seizures (ILAE 2-5).This work indicates that semi-quantitative assessment of HIA on high-resolution MRI provides a surrogate marker of underlying histopathology, but cannot prospectively distinguish between patients who will continue to experience postoperative seizures and those who will be rendered seizure free. The predictive power of HIA for postoperative seizure outcome in non-lesional patients with TLE should be explored.
Objectives/Aims Patients with functional seizures (FS) can experience dissociation (depersonalisation) before their seizures. Depersonalisation encompasses a feeling of disembodiment, putatively caused by reduced afferent visceral mapping, that is, changes in interoceptive processing. The heartbeat-evoked potential (HEP) is an electroencephalographic (EEG) index of synchronised neural responses to individual heartbeats, and a marker interoceptive representation. HEP amplitude is reported to be reduced in patients with depersonalisation-derealisation disorder. The objective of this study was to assess whether alterations in interoceptive processing indexed by the HEP occur prior to FSs, and compare this with epileptic seizures (ES). Methods HEP amplitudes were calculated from EEG during video-EEG monitoring in 25 patients with FS and 19 patients with ES, and compared between interictal and preictal states. HEP amplitudes were calculated at frontal and central EEG electrodes. HEP amplitude difference was calculated as a composite measure of preictal HEP amplitude minus interictal HEP amplitude. A Receiver Operating Characteristic (ROC) curve analysis was later used to evaluate the diagnostic performance of the HEP amplitude difference measure in discriminating functional cases from epilepsy cases. Results The FS group demonstrated a significant reduction in HEP amplitude between interictal and preictal states at F8 (effect size rB=0.612, p=0.006) and C4 (rB=0.600, p=0.007). No differences in HEP amplitude were found between interictal and preictal states in the ES group. Between diagnostic groups, HEP amplitude difference was significantly different between the FS and ES group at C4 (rB=0.457, p=0.009) and F8 (rB=0.423, p=0.017). These findings were not related to heart rate, mean ECG or QRS amplitudes, which did not differ between interictal/preictal states, or groups. There was no difference in age between FS and ES groups, however there were a greater proportion of females compared to males in the FS group as compared to the ES group. Using HEP amplitude difference at frontal and central electrodes plus sex as variables, the ROC curve demonstrated an area under the curve (AUC) of 0.893, with sensitivity=0.840 and specificity=0.842 (p=0.000). Conclusions Our data support the notion that aberrant interoception underpins disembodiment prior to dissociative FS. Changes in HEP amplitude may therefore reflect a neurophysiological biomarker of FS. HEP amplitude difference between interictal and preictal states may have diagnostic utility in differentiating FS and ES.
Transverse myelitis (TM) associated with neuromyelitis optica (NMO) has many unusual characteristics compared with TM in Multiple Sclerosis (MS): long centrally located lesions that cause significant motor-sensory (including tonic spasms) and autonomic dysfunction. We wish to report a symptom not previously described in neurological literature, neuropathic post ejaculatory pain (PEP).
Methods
We will present videos of 3 male patients with AQP4-IgG +ve NMO describing post-ejaculatory pain (PEP).
Results
All patients were recovering from long thoracic TM and had autonomic dysfunction at nadir. None had preexisting urological symptoms. The pain occurred immediately after orgasm and ejaculation and was severe, brief (<1 minute) burning or searing, spreading down one leg. The pain responded to carbamazepine in one patient and subsided over few months in all. 50 MS patients with TM surveyed for PEP did not report it. PEP has hitherto been described rarely in urological diseases like ejaculatory duct stones or pelvic metastases only. We suspect that PEP in NMO-TM arises due to ephaptic cross talk between pain and autonomic fibers in the spinal cord similar to tonic spasms.
Conclusion
PEP has not been described in neurological disorders and maybe a unique feature of NMO associated myelitis.
Abstract Background Patients with chronic focal epilepsy may have atrophy of brain structures important for the generation and maintenance of seizures. However, little research has been conducted in patients with newly diagnosed focal epilepsy (NDfE), despite it being a crucial point in time for understanding the underlying biology of the disorder. We aimed to determine whether patients with NDfE show evidence of volumetric abnormalities of subcortical structures. Methods Eighty-two patients with NDfE and 40 healthy controls underwent MRI scanning using a standard clinical protocol. Volume estimation of the left and right hippocampus, thalamus, caudate nucleus, putamen and cerebral hemisphere was performed for all participants and normalised to whole brain volume. Volumes lower than two standard deviations below the control mean were considered abnormal. Volumes were analysed with respect to patient clinical characteristics, including treatment outcome 12 months after diagnosis. Results Volume of the left hippocampus ( P (FDR-corr) = 0.04) and left ( P (FDR-corr) = 0.002) and right ( P (FDR-corr) = 0.04) thalamus were significantly smaller in patients relative to controls. Relative to the normal volume limits in controls, 11% individual patients had left hippocampal atrophy, 17% had left thalamic atrophy and 9% had right thalamic atrophy. We did not find evidence of a relationship between volumes and future seizure control or with other clinical characteristics of epilepsy. Conclusions Volumetric abnormalities of structures known to be important for the generation and maintenance of focal seizures are established at the time of epilepsy diagnosis and are not necessarily a result of the chronicity of the disorder.
There are competing explanations for persistent postoperative seizures after temporal lobe surgery. One is that 1 or more particular subtypes of mesial temporal lobe epilepsy (mTLE) exist that are particularly resistant to surgery. We sought to identify a common brain structural and connectivity alteration in patients with persistent postoperative seizures using preoperative quantitative magnetic resonance imaging and diffusion tensor imaging (DTI).We performed a series of studies in 87 patients with mTLE (47 subsequently rendered seizure free, 40 who continued to experience postoperative seizures) and 80 healthy controls. We investigated the relationship between imaging variables and postoperative seizure outcome. All patients had unilateral temporal lobe seizure onset, had ipsilateral hippocampal sclerosis as the only brain lesion, and underwent amygdalohippocampectomy.Quantitative imaging factors found not to be significantly associated with persistent seizures were volumes of ipsilateral and contralateral mesial temporal lobe structures, generalized brain atrophy, and extent of resection. There were nonsignificant trends for larger amygdala and entorhinal resections to be associated with improved outcome. However, patients with persistent seizures had significant atrophy of bilateral dorsomedial and pulvinar thalamic regions, and significant alterations of DTI-derived thalamotemporal probabilistic paths bilaterally relative to those patients rendered seizure free and controls, even when corrected for extent of mesial temporal lobe resection.Patients with bihemispheric alterations of thalamotemporal structural networks may represent a subtype of mTLE that is resistant to temporal lobe surgery. Increasingly sensitive multimodal imaging techniques should endeavor to transform these group-based findings to individualize prediction of patient outcomes.
Background and purpose Patients with chronic focal epilepsy may have atrophy of brain structures important for the generation and maintenance of seizures. However, little research has been conducted in patients with newly diagnosed focal epilepsy (NDfE), despite it being a crucial point in time for understanding the underlying biology of the disorder. We aimed to determine whether patients with NDfE show evidence of volumetric abnormalities of subcortical structures. Methods Eighty‐two patients with NDfE and 40 healthy controls underwent magnetic resonance imaging scanning using a standard clinical protocol. Volume estimation of the left and right hippocampus, thalamus, caudate nucleus, putamen and cerebral hemisphere was performed for all participants and normalised to whole brain volume. Volumes lower than two standard deviations below the control mean were considered abnormal. Volumes were analysed with respect to patient clinical characteristics, including treatment outcome 12 months after diagnosis. Results Volume of the left hippocampus ( p (FDR‐corr) = 0.04) and left ( p (FDR‐corr) = 0.002) and right ( p (FDR‐corr) = 0.04) thalamus was significantly smaller in patients relative to controls. Relative to the normal volume limits in controls, 11% patients had left hippocampal atrophy, 17% had left thalamic atrophy and 9% had right thalamic atrophy. We did not find evidence of a relationship between volumes and future seizure control or with other clinical characteristics of epilepsy. Conclusions Volumetric abnormalities of structures known to be important for the generation and maintenance of focal seizures are established at the time of epilepsy diagnosis and are not necessarily a result of the chronicity of the disorder.
Background Patients with functional seizures (FS) can experience dissociation (depersonalisation) before their seizures. Depersonalisation reflects disembodiment, which may be related to changes in interoceptive processing. The heartbeat-evoked potential (HEP) is an electroencephalogram (EEG) marker of interoceptive processing. Aim To assess whether alterations in interoceptive processing indexed by HEP occur prior to FS and compare this with epileptic seizures (ES). Methods HEP amplitudes were calculated from EEG during video-EEG monitoring in 25 patients with FS and 19 patients with ES, and were compared between interictal and preictal states. HEP amplitude difference was calculated as preictal HEP amplitude minus interictal HEP amplitude. A receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance of HEP amplitude difference in discriminating FS from ES. Results The FS group demonstrated a significant reduction in HEP amplitude between interictal and preictal states at F8 (effect size rB=0.612, false discovery rate (FDR)-corrected q=0.030) and C4 (rB=0.600, FDR-corrected q=0.035). No differences in HEP amplitude were found between states in the ES group. Between diagnostic groups, HEP amplitude difference differed between the FS and ES groups at F8 (rB=0.423, FDR-corrected q=0.085) and C4 (rB=0.457, FDR-corrected q=0.085). Using HEP amplitude difference at frontal and central electrodes plus sex, we found that the ROC curve demonstrated an area under the curve of 0.893, with sensitivity=0.840 and specificity=0.842. Conclusion Our data support the notion that aberrant interoception occurs prior to FS. Changes in HEP amplitude may reflect a neurophysiological biomarker of FS and may have diagnostic utility in differentiating FS and ES.
Introduction It is unknown why over one-third of patients with mesial temporal lobe epilepsy (mTLE) and hippocampal sclerosis (HS) continue to experience seizures despite temporal lobe surgery. We investigated the relationship between hippocampal internal architecture (HIA) on preoperative MRI, and postoperative seizure outcome in patients with refractory mTLE and HS. Methods HIA was assessed on preoperative T2-STIR MR images using a published scoring system1 for 79 patients undergoing evaluation at University Hospital Bonn, Germany. Patients underwent amygdalohippocampectomy and received postoperative outcome assessment using the International League Against Epilepsy (ILAE) classification. Hippocampal volumes were obtained using 3D T1-weighted images. Quantitative histopathological assessment was performed on resected hippocampal specimens. Results No significant differences in ipsilateral or contralateral HIA ratings, or HIA score asymmetry, were found between patients rendered seizure free (ILAE I) compared to those continuing to experience postoperative seizures (ILAE II-VI). HIA significantly correlated with neuronal density in CA3 and CA4 in the pathologic hippocampus, and hippocampal volumes bilaterally. There was no significant correlation between HIA and clinical variables. Conclusion Although valuable in determining seizure laterality, HIA does not predict postoperative outcome. Acknowledgements This work was supported by a UK MRC grant awarded to SSK (Grant Number: MR/K023152/1). References:1Ver Hoef 2013
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