mesial temporal sclerosis wiki

Regardless, an aura is actually a seizure itself, and such a focal seizure may or may not progress to a focal impaired awareness seizure. [67] Other options include brain cortex responsive neural stimulators, deep brain stimulation, stereotactic radiosurgery, such as the gamma knife, and laser ablation.[68]. Mesial temporal sclerosis is the most frequent cause of drug-resistant temporal lobe epilepsy but has a satisfactory response to surgery, and is considered infrequent in children. Temporal lobe epilepsy (TLE) is a chronic disorder of the nervous system characterized by recurrent, unprovoked focal seizures that originate in the temporal lobe of the brain and last about one or two minutes. Mesial temporal sclerosis (MTS), also commonly referred to as hippocampal sclerosis, is the most common association with intractable temporal lobe epilepsy (TLE) 2,3,5. Documented by Norman Geschwind, signs include: hypergraphia (compulsion to write (or draw) excessively), hyperreligiosity (intense religious or philosophical experiences or interests), hyposexuality (reduced sexual interest or drive), circumstantiality (result of a non-linear thought pattern, talks at length about irrelevant and trivial details). Diagnosis: Mesial temporal sclerosis. It is seen in up to 65% of autopsy studies, although significantly less on imaging. TLE is initially managed medically with anti-epileptic agents. Patients with mesial temporal sclerosis usually have an early brain insult, a febrile convulsion in most cases, and a seizure free interval of variable duration. Study population An English: Mesial Temporal Sclerosis. [19], The effect of temporal lobe epilepsy on personality is a historical observation dating to the 1800s. Mesial temporal lobe epilepsy is the most common of the medically refractory chronic epilepsies. In animal models, neuronal loss occurs during seizures but in humans, neuronal loss predates the first seizure and does not necessarily continue with seizure activity. Ramachandran was able to show that patients with TLE showed enhanced emotional responses to the religious words, diminished responses to the sexually charged words, and normal responses to the neutral words. Mesial temporal sclerosis is a frequent cause of epilepsy. Because a major function of the temporal lobe is short-term memory, a focal with impaired awareness seizure, and a focal to bilateral seizure can cause amnesia for the period of the seizure, meaning that the seizure may not be remembered. [7] The arms, trunk, and legs stiffen (the tonic phase), in either a flexed or extended position, and then jerk (the clonic phase). Mesial temporal sclerosis in a cohort of children with SCN1A gene mutation. [34] However, not all patients have granule cell dispersion. [26][27][28], Dispersion of the granule cell layer in the hippocampal dentate gyrus is occasionally seen in temporal lobe epilepsy and has been linked to the downregulation of reelin, a protein that normally keeps the layer compact by containing neuronal migration. Histologically there is neuronal cell loss, gliosis and sclerosis. Rarely NITS can be detected in children during the first decade of … It has been suggested that Pope Pius IX's doctrine of the immaculate conception was influenced by his forensically-diagnosed partial epilepsy. Figure 1: A. Coronal T2 weighted, B. Coronal FLAIR. For example, if a person with complex partial seizures is driving alone, this can cause them to run into the ditch, or worse, cause an accident involving multiple people. [21], The existence of a "temporal lobe epileptic personality" and of Geschwind syndrome have been disputed and research is inconclusive. This seizure disorder can cause a variety of symptoms such as strange sensations, changes in behavior or emotions, muscle spasms, or convulsions.The seizures usually are localized in the brain, but they may spread to become generalized seizures, which involve the entire brain and may cause a sudden loss of awareness or consciousness. This is more so on the left in verbal memory loss. [76] The purported link between TLE and religiosity has inspired work by Michael Persinger and other researchers in the field of neurotheology. The etiology is uncertain, although prolonged febrile seizures and limbic encephalitis have been implicated. [2] Focal seizures account for approximately sixty percent of all adult cases. Where both sides of the brain or the whole brain are involved from the onset, these seizures are known as generalized seizures and may be tonic clonic. [46] This structure provides a filter for the excitability of neurons. ), "A proposed diagnostic scheme for people with epileptic seizures and with epilepsy: report of the ILAE Task Force on Classification and Terminology", "LGI1 mutations in autosomal dominant and sporadic lateral temporal epilepsy", "2017 Revised Classification of Seizures", "Synesthetic associations and psychosensory symptoms of temporal epilepsy", "Cortical thickness abnormalities associated with depressive symptoms in temporal lobe epilepsy", "Association of Human Herpesvirus-6B with Mesial Temporal Lobe Epilepsy", "Detection of human herpesvirus-6 in mesial temporal lobe epilepsy surgical brain resections", "Role for reelin in the development of granule cell dispersion in temporal lobe epilepsy", "Reelin deficiency and displacement of mature neurons, but not neurogenesis, underlie the formation of granule cell dispersion in the epileptic hippocampus", "Loss of hilar mossy cells in Ammon's horn sclerosis", "Reduced inhibition of dentate granule cells in a model of temporal lobe epilepsy", "Quantitative post-mortem study of the hippocampus in chronic epilepsy: seizures do not inevitably cause neuronal loss", "GABAergic mechanisms in the pathogenesis and treatment of epilepsy", "Perturbed Chloride Homeostasis and GABAergic Signaling in Human Temporal Lobe Epilepsy", "Reduced Efficacy of the KCC2 Cotransporter Promotes Epileptic Oscillations in a Subiculum Network Model", "Pyramidal cells accumulate chloride at seizure onset", "Selective Inhibition of KCC2 Leads to Hyperexcitability and Epileptiform Discharges in Hippocampal Slices and In Vivo", "Cell proliferation and granule cell dispersion in human hippocampal sclerosis", 10.1002/(sici)1096-9861(19970901)385:3<325::aid-cne1>;2-5, "Axon sprouting in a model of temporal lobe epilepsy creates a predominantly excitatory feedback circuit", "Evidence of functional mossy fiber sprouting in hippocampal formation of kainic acid-treated rats", "Kainic acid-induced recurrent mossy fiber innervation of dentate gyrus inhibitory interneurons: possible anatomical substrate of granule cell hyperinhibition in chronically epileptic rats", "Spontaneous release of neuropeptide Y tonically inhibits recurrent mossy fiber synaptic transmission in epileptic brain", "Temporal Lobe Epilepsy Workup: Approach Considerations, Computed Tomography Scanning, Magnetic Resonance Imaging", "Temporal Lobe Epilepsy; TLE medical Information Page | Patient", "Changing frontal contributions to memory before and after medial temporal lobectomy", "MR-guided stereotactic laser ablation of epileptogenic foci in children", "Spirituality aspects in patients with epilepsy", "The role of psychotic disorders in religious history considered", "Seizures among public figures: lessons learned from the epilepsy of Pope Pius IX", Reproductive endocrinology and infertility, Bachelor of Medicine, Bachelor of Surgery,, Short description is different from Wikidata, Articles with unsourced statements from December 2020, Articles with unsourced statements from September 2016, Articles with unsourced statements from February 2014, Articles needing additional medical references from August 2017, All articles needing additional references, Articles requiring reliable medical sources, Creative Commons Attribution-ShareAlike License, Lobes of the brain. Epub ahead of print. They usually begin with a focal aware seizure, then spread to a larger portion of the temporal lobe, resulting in impaired consciousness. Often mentioned, but probably one of the least specific findings, is enlargement of the temporal horn of the lateral ventricle . Sex Males = females. Mesial Temporal Sclerosis (MTS) is a term used to describe scarring in deep part of the temporal lobe of the brain. [33][34][35][36][37] The loss of the GABA-mediated inhibitory interneurons may increase the hyperexcitability of neurons of the hippocampus leading to recurrent seizures. The finding of a lesion such as hippocampal sclerosis (a scar in the hippocampus), tumour, or dysplasia, on magnetic resonance imaging (MRI) predicts the intractability of seizures. However, although the virus is found in temporal lobe tissue at surgery for TLE, it has not been recognised as a major factor in febrile seizures or TLE. Vázquez-Barrón D, Cuéllar-Herrera M, Velasco F, Velasco AL. Introduction from Dr Markus Reuber, editor-in-chief of Seizure. (1998) Personality disorders. Mesial Temporal Sclerosis Mesial temporal sclerosis, also known as hip-pocampal sclerosis, is the most common cause of temporal lobe epilepsy found at surgery. Temporal lobe epilepsy (TLE) is a chronic disorder of the nervous system characterized by recurrent, unprovoked focal seizures that originate in the temporal lobe of the brain and last about one or two minutes. The mesial temporal lobe, also known as the medial temporal lobe, is, as the name suggests, located on the medial aspect of the temporal lobe and is distinct from the rest of the lobe, which is composed of neocortex. [2] In temporal lobe epilepsy, a focal seizure usually causes abnormal sensations only. Temporal lobe in green, A sudden sense of unprovoked fear and anxiety, Auditory, visual, olfactory, gustatory, or tactile. However, it was not until 2001 that a scientifically sound study was carried out to examine the effectiveness of temporal lobectomy. It can have a number of causes such as head injury, stroke, brain infections, structural lesions in the brain, or brain tumors, or it can be of unknown onset. It is seen in up to 65% of autopsy studies, although significantly less on imaging. [citation needed], Focal impaired awareness seizures are seizures which impair consciousness to some extent:[2] they alter the person's ability to interact normally with their environment. Although the etiology of MTS remains controversial, there is now a considerable … Another treatment option is electrical stimulation of the brain through an implanted device called the vagus nerve stimulator (VNS). When there is a single identifiable electrographic focus, these patients do well with removal of that focus (i.e., temporal lobectomy), achieving up to 66% long-term seizure freedom (Tellez-Zenteno et al., 2007). Temporal lobe epilepsy is not the result of psychiatric illness or fragility of the personality. [31](p416–431)[46][50][51][52], Aberrant mossy fibre sprouting may create excitatory feedback circuits that lead to temporal lobe seizures. There are 3 specific patterns of cell loss; Cell loss might involve sectors CA1 and CA4, CA4 alone, or CA1 to CA4 . [61], Many anticonvulsant oral medications are available for the management of temporal lobe seizures. [citation needed], These seizures tend to have a warning or aura before they occur, and when they occur they generally tend to last only 1–2 minutes. The classification was based on EEG findings. PMID: 33113540. The hippocampal formation is not uniformly affected, with the dentate gyrus, and the CA1, CA4 and to a lesser degree CA3 sections of the hippocampus being primarily involved . 2. In TLE, the sprouting mossy fibres are larger than in the normal brain and their connections may be aberrant. Most patients present with complex partial temporal lobe epilepsy. Mesial temporal sclerosis is a specific pattern of hippocampal neuron cell loss. MRI is the modality of choice to evaluate the hippocampus, however dedicated TLE protocol needs to be performed if good sensitivity and specificity is to be achieved . Others have questioned the evidence for a link between temporal lobe epilepsy and religiosity. The condition called mesial temporal sclerosis is closely related to temporal lobe epilepsy, a type of partial (focal) epilepsy in which the seizure initiation point can be identified within the temporal lobe of the brain. [46][48][49], In the TLE brain, where granule cells are damaged or lost, axons, the mossy fibres, 'sprout' in order to reconnect to other granule cell dendrites. It is not uncommon for an individual to be tired or confused for up to 15 minutes after a seizure has occurred, although postictal confusion can last for hours or even days. mesial temporal sclerosis, the types of imaging tech-niques used to diagnosis this entity, and the possible significance of secondary MR findings. Loss of mossy cells lowers the threshold of action potentials of the granule cells. Date: 3 July 2007: Source: Luis Aranguren: Author: Mercurytoxic: Licensing . Aetiology Major cerebral trauma, infection, febrile illness in childhood; most patients are seizure-free after ablative surgery. Our primary outcome is time-to-seizure recurrence. Follow up of children with febrile seizures does not demonstrate signifi… mesial temporal sclerosis: A condition characterised by induration of the middle temporal lobe, associated with cortical dysplasia and intractable temporal lobe epilepsy. Mesial temporal sclerosis (MTS) is a common pathologic finding in patients with temporal lobe epilepsy. [12], Although the theory is controversial, there is a link between febrile seizures (seizures coinciding with episodes of fever in young children) and subsequent temporal lobe epilepsy, at least epidemiologically. Although the psychosocial impacts of epilepsy may be causative, there are also links in the phenomenology and neurobiology of TLE and depression. Declarative memory (memories which can be consciously recalled) is formed in the area of the hippocampus called the dentate gyrus. Simple focal seizures are the initial non-febrile seizures followed by See all (206) Mesial temporal sclerosis Etiology Controversy exists as to the causative mechanism: is mesial temporal sclerosis a result of temporal lobe epilepsy or viceversa. We evaluated the role of right and left hippocampal lesions on performance in both the retrospective and prospective PM components in patients with epilepsy secondary to mesial temporal sclerosis and correlated with performance in traditional neuropsychological tests, as well as with self-perception of memory impairment. Gadolinium is not required . Van Poppel K, Patay Z, Roberts D, Clarke DF, McGregor A, Perkins FF, Wheless JW J Child Neurol 2012 Jul;27(7):893-7. Mesial temporal sclerosis (MTS, also called hippocampal sclerosis) is the most common underlying cause of temporal lobe epilepsy (TLE). [20], Geschwind syndrome is a set of behavioural phenomena seen in some people with TLE. [citation needed], Temporal lobe epilepsy is associated with memory disorders and loss of memory. Seizure 23/6 has published Factors predicting the outcome following medical treatment of mesial temporal epilepsy with hippocampal sclerosis. It has been shown that it is theoretically possible to generate seizures in the neural networks due to down-regulation of KCC2,[41] consistent with the chloride measurements during the transition to seizure[42] and KCC2 blockade experiments. The condition called mesial temporal sclerosis is closely related to temporal lobe epilepsy, a type of partial (focal) epilepsy in which the seizure initiation point can be identified within the temporal lobe of the brain. MR spectroscopy findings typically represent neuronal dysfunction : MR perfusion demonstrates similar changes to SPECT (see below) with blood perfusion depending on when the scan is obtained. [72], TLE has been suggested as a materialistic explanation for the revelatory experiences of prominent religious figures such as Abraham, Moses, Jesus, Mohammed, Saint Paul, Joan of Arc,[73] Saint Teresa of Ávila, and Joseph Smith. This study was presented as an abstract at a neuroscience conference and referenced in Ramachandran's book, Phantoms in the Brain,[69] but it has never been published in the peer-reviewed scientific press. In interictal periods, conversely, perfusion is reduced . [53] Stimulation of aberrant mossy fibre areas increases the excitatory postsynaptic potential response. This applies worldwide. When severe and long standing, additional associated findings include : Additional 3D volumetric studies can be performed, and although time consuming to post-process may be more sensitive to subtle hippocampal volume loss. Anterior temporal lobectomy is successful in 75-90% of patients with MTS. Ramachandran presented two subjects with neutral, sexually arousing and religious words while measuring GSR. [66], Where surgery is not recommended, further management options include new (including experimental) anticonvulsants, and vagus nerve stimulation. Conversely, due to neuronal dysfunction and swelling, diffusion is restricted following a seizure, and thus values are lower . 28-year-old male with a long-standing history of seizures localizing to the inferomedial right temporal lobe on EEG. Clinical manifestations Pre-existing complex febrile convulsions are common. Mesial temporal sclerosis is the loss of neurons and scarring of the deepest portion of the temporal lobe and is associated with certain brain injuries. reduced hippocampal volume: hippocampal atrophy. This is followed by complex partial seizures with stereotypic semiology. The degree and length of postictal impairment directly correlates with the severity of the seizure type. [citation needed] The postictal state in seizures other than focal aware may last much longer than the seizure itself. [46], In TLE, granule cells are lost, the structure is no longer closely packed and there are changes in the orientation of dendrites. PATHOPHYSIOLOGY • Mesial temporal sclerosis -coined by Falconer & colleagues – by neuronal loss and gliosis involving principally the hippocampus and amygdala, or both, but occasionally extending to other mesial temporal structures or even throughout the temporal lobe, and leading to generalized atrophy and gliosis. Vagal Nerve Stimulation is a minimally invasive mesial temporal sclerosis treatment that employs an implanted stimulator to deliver electric impulses to an electrode on the vagal nerve in the neck via a lead wire implanted under the skin. [1] A focal seizure in the temporal lobe may spread to other areas in the brain when it may become a focal to bilateral seizure. Animal models and clinical studies show that memory loss correlates with temporal lobe neuronal loss in temporal lobe epilepsy. During the peri-ictal phases, perfusion is increased, not only in the mesial temporal lobe but often in large parts of temporal lobe and hemisphere. Neuronal loss on the right is more prominent in non-verbal (visuospatial memory loss). Most patients present with complex partial temporal lobe epilepsy. [citation needed]. abnormal morphology: loss of internal architecture (interdigitations of hippocampus), increased signal and or atrophy of the anterior thalamic nucleus, increased signal and/or reduction in the volume of the, dilatation of temporal horn and temporal lobe atrophy, collateral white matter and entorhinal cortex atrophy, loss of grey-white matter interface in the anterior temporal lobe, decreased NAA and decreased NAA/Cho and NAA/Cr ratios, decreased MI in ipsilateral temporal lobe, increased lipid  and lactate soon after as seizure. [10], Focal aware seizures are often called "auras" when they serve as a warning sign of a subsequent seizure. Other medical conditions with similar symptoms include panic attacks, psychosis spectrum disorders, tardive dyskinesia, and occipital lobe epilepsy. Newer drugs, such as gabapentin, topiramate, levetiracetam, lamotrigine, pregabalin, tiagabine, lacosamide, and zonisamide promise similar effectiveness, with possibly fewer side-effects. Surgery may be an option, especially when there is an observable abnormality in the brain. However, after temporal lobectomy, memory function is supported by the opposite temporal lobe; and recruitment of the frontal lobe. Associated hippocampal atrophy and gliosis is common. As a result of neuronal loss, the extracellular space is enlarged and thus diffusion of water molecules is greater on the affected side, resulting in increased values on the affected side (higher signal on ADC). ), Benson, D.F. [71] Lower education level, abnormal background EEG activity, and hippocampal sclerosis have been found to be contributing factors for religiosity in TLE. [12] The word grand mal comes from the French term, meaning major affliction. [63], Temporal lobe surgery can be complicated by decreased cognitive function. & Hermann, B.P. Mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) is considered an electroclinical syndrome, and there is a debate whether it is a unique disease or an entity with distinct subtypes. [54][55], However, aberrant mossy fiber sprouting may inhibit excitatory transmission by synapsing with basket cells which are inhibitory neurons and by releasing GABA and neuropeptide Y which are inhibitory neurotransmitters. [7], Focal seizures in the temporal lobe involve small areas of the lobe such as the amygdala and hippocampus. Furthermore, in adults 3-10% of cases of mesial temporal sclerosis demonstrate bilateral changes even though symptoms may be unilateral. Olfactory hallucinations often seem indescribable to patients beyond "pleasant" or "unpleasant". There is some period of recovery in which neurological function is altered after each of these seizure types. [1], Over forty types of epilepsy are recognized and these are divided into two main groups: focal seizures and generalized seizures. Etiology Hippocampal sclerosis. In children with newly diagnosed epilepsy, only ~ 1% have evidence of MTS on imaging . [22][23][24][25], In the mid 1980s, human herpesvirus 6 (HHV-6) was suggested as a possible causal link between febrile convulsions and mesial temporal lobe epilepsy. Also, in animal models, granule cell hyper-excitability is recorded before aberrant mossy fibre sprouting has occurred.[56][57][58][59]. Learn more from the Epilepsy Foundation. These experiences are described (in possibly unreliable accounts) as complex interactions with their visions; but lack the stereotypy, amnestic periods, and automatisms or generalized motor events, which are characteristic of TLE. Coronal volume and coronal high resolution T2WI/FLAIR are best to diagnose MTS. Automatic movements of the hands or mouth, Altered ability to respond to others, unusual speech, This page was last edited on 11 January 2021, at 00:42. [7] The newer classification uses three key features: where the seizures begin, the level of awareness during a seizure, and other features. If anything, care must be taken not to allow an enlarged horn to trick you into thinking the hippocampus is reduced in size. Age at onset Late childhood or adolescence. Thin section angled coronal sequences at right angles to the longitudinal axis of the hippocampus are required, to minimise volume averaging. Methods 2.1. These were previously known as grand mal seizures. [44][45] The granule cells of the dentate gyrus are tightly packed forming a uniform, laminated layer with no monosynaptic connections.

Lafitte's Blacksmith Shop Bar History, Home Depot Floor Installation Reviews, General Practitioner Easton, Md, Utep Athletic Director Salary, Milligan Student Handbook, Honeywell Products Catalog, Liatris Ligulistylis Missouri,


Leave a Reply

Your email address will not be published. Required fields are marked *