, 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. , In TLE, granule cells are lost, the structure is no longer closely packed and there are changes in the orientation of dendrites. Mesial temporal sclerosis is a frequent cause of epilepsy.  The postictal state in seizures other than focal aware may last much longer than the seizure itself. Other medical conditions with similar symptoms include panic attacks, psychosis spectrum disorders, tardive dyskinesia, and occipital lobe epilepsy. Rarely MTS can be detected in children during the first decade of life, but is not commonly found until adolescence. , 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. The classification was based on EEG findings.  However, as of 2017 the general classification of seizures has been revised. Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is a group of chronic disorders characterized by prominent neuronal loss and gliosis in the hippocampus and amygdala. , The existence of a "temporal lobe epileptic personality" and of Geschwind syndrome have been disputed and research is inconclusive. T2 relaxometry may also be useful in detecting cases of hippocampal sclerosis . Sex Males = females. 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. He found a constellation of symptoms that included hypergraphia, hyperreligiosity, collapse, and pedantism, now called Geschwind syndrome. Simple focal seizures are the initial non-febrile seizures followed by 2. The relationship, if any, of mesial temporal sclerosis with febrile seizures is controversial, made all the more difficult due to the relative insensitivity of imaging and the difficulty in establishing whether a particular seizure was truly febrile.  It is seen in up to 65% of autopsy studies, although significantly less on imaging. , After childhood onset, one third will "grow out" of TLE, finding a lasting remission up to an average of 20 years. Together with other mesial temporal structures, the amygdala is important in the epilep … Ramachandran presented two subjects with neutral, sexually arousing and religious words while measuring GSR. Verbal memory deficit correlates with pyramidal cell loss in TLE. Histologi-  According to the "dormant basket cell" hypothesis, mossy cells normally excite basket cells which in turn, inhibit granule cells. 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. 2020 Oct 28:1-8. doi: 10.1159/000510295. 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. Thin section angled coronal sequences at right angles to the longitudinal axis of the hippocampus are required, to minimise volume averaging. Dysphoric or euphoric feelings, fear, anger, and other emotions may also occur. 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). Mesial temporal sclerosis Etiology Controversy exists as to the causative mechanism: is mesial temporal sclerosis a result of temporal lobe epilepsy or viceversa. Pedley (Eds. 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 . This is the postictal state. Patients with temporal lobe epilepsy (TLE) due to mesial temporal sclerosis (MTS) are eligible candidates for resective epilepsy surgery. The first line of treatment is through anticonvulsants. Another treatment option is electrical stimulation of the brain through an implanted device called the vagus nerve stimulator (VNS). A focal seizure in the temporal lobe may spread to other areas in the brain when it may become a focal to bilateral seizure. , The causes of TLE include mesial temporal sclerosis, traumatic brain injury, brain infections, such as encephalitis and meningitis, hypoxic brain injury, stroke, cerebral tumours, and genetic syndromes. The diagnosis of temporal lobe epilepsy can include the following methods: Magnetic resonance imaging (MRI), CT scans, positron emission tomography (PET), EEG, and magnetoencephalography. Mesial temporal lobe epilepsy is the most common of the medically refractory chronic epilepsies. Gadolinium is not required .  The seizures of LTLE are characterized by auditory or visual features. Seizure 23/6 has published Factors predicting the outcome following medical treatment of mesial temporal epilepsy with hippocampal sclerosis. , Where surgery is not recommended, further management options include new (including experimental) anticonvulsants, and vagus nerve stimulation. 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. It has been shown that it is theoretically possible to generate seizures in the neural networks due to down-regulation of KCC2, consistent with the chloride measurements during the transition to seizure and KCC2 blockade experiments. 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. This is an example of synaptic reorganization. This is more so on the left in verbal memory loss. Anterior temporal lobectomy is successful in 75-90% of patients with MTS. , 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. Focal aware means that the level of consciousness is not altered during the seizure. The relationship, if any, of mesial temporal sclerosis with febrile seizures is controversial, made all the more difficult due to the relative insensitivity of imaging and the difficulty in establishing whether a particular seizure was truly febrile. PMID: 33113540. Public domain Public domain false false: I, the copyright holder of this work, release this work into the public domain.  This structure provides a filter for the excitability of neurons. 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. Loss of mossy cells lowers the threshold of action potentials of the granule cells. Figure 1: A. Coronal T2 weighted, B. Coronal FLAIR. PMID: 22532537. Temporal lobe in green, A sudden sense of unprovoked fear and anxiety, Auditory, visual, olfactory, gustatory, or tactile. , Granule cell dispersion is a type of developmental migration and a pathological change found in the TLE brain which was first described in 1990. This is evident in intracellular recordings. It has been suggested that Pope Pius IX's doctrine of the immaculate conception was influenced by his forensically-diagnosed partial epilepsy. Mesial temporal sclerosis (MTS, also called hippocampal sclerosis) is the most common underlying cause of temporal lobe epilepsy (TLE).  The arms, trunk, and legs stiffen (the tonic phase), in either a flexed or extended position, and then jerk (the clonic phase).  The granule cells of the dentate gyrus are tightly packed forming a uniform, laminated layer with no monosynaptic connections. Regardless, an aura is actually a seizure itself, and such a focal seizure may or may not progress to a focal impaired awareness seizure. First-aid is only required if there has been an injury or if this is the first time a person has had a seizure. 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. 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. 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. Mesial temporal sclerosis (MTS) is a common pathologic finding in patients with temporal lobe epilepsy. 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). Also, in animal models, granule cell hyper-excitability is recorded before aberrant mossy fibre sprouting has occurred.. Methods 2.1. It is seen in up to 65% of autopsy studies, although significantly less on imaging. Others have questioned the evidence for a link between temporal lobe epilepsy and religiosity. 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. Declarative memory (memories which can be consciously recalled) is formed in the area of the hippocampus called the dentate gyrus. 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). 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.  Focal seizures account for approximately sixty percent of all adult cases. Up to a third of patients with established refractory temporal lobe epilepsy have a history of seizures in childhood at the time of fever 3. Vázquez-Barrón D, Cuéllar-Herrera M, Velasco F, Velasco AL. Coronal volume and coronal high resolution T2WI/FLAIR are best to diagnose MTS. Diagnosis: Mesial temporal sclerosis. Stereotact Funct Neurosurg. Date: 3 July 2007: Source: Luis Aranguren: Author: Mercurytoxic: Licensing . , 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, Saint Teresa of Ávila, and Joseph Smith. They may include autonomic and psychic features present in focal aware seizures. They usually begin with a focal aware seizure, then spread to a larger portion of the temporal lobe, resulting in impaired consciousness. In this patient it was a left sided temporal sclerosis. , The effect of temporal lobe epilepsy on personality is a historical observation dating to the 1800s. Prevalence ~20% of patients with epilepsies; 65% of mesial TLE.  The purported link between TLE and religiosity has inspired work by Michael Persinger and other researchers in the field of neurotheology. Epub ahead of print. , Geschwind syndrome is a set of behavioural phenomena seen in some people with TLE. Van Poppel K, Patay Z, Roberts D, Clarke DF, McGregor A, Perkins FF, Wheless JW J Child Neurol 2012 Jul;27(7):893-7. , Temporal lobe surgery can be complicated by decreased cognitive function. Vilayanur S. Ramachandran explored the neural basis of the hyperreligiosity seen in TLE using the galvanic skin response (GSR), which correlates with emotional arousal, to determine whether the hyperreligiosity seen in TLE was due to an overall heightened emotional state or was specific to religious stimuli. ), "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>3.0.co;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, https://en.wikipedia.org/w/index.php?title=Temporal_lobe_epilepsy&oldid=999598843, 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. For patients with medial TLE whose seizures remain uncontrolled after trials of several types of anticonvulsants (that is, the epilepsy is intractable), surgical excision of the affected temporal lobe may be considered. 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. , The International League Against Epilepsy (ILAE) recognizes two main types of temporal lobe epilepsy: mesial temporal lobe epilepsy (MTLE), arising in the hippocampus, the parahippocampal gyrus and the amygdala which are located in the inner (medial) aspect of the temporal lobe and lateral temporal lobe epilepsy (LTLE), the rarer type, arising in the neocortex at the outer (lateral) surface of the temporal lobe. For instance, if the dendrites of granule cells reconnect, it may be in a way (through the laminar planes) that allows hyperexcitability. This is followed by complex partial seizures with stereotypic semiology. PM has not been evaluated in mesial temporal sclerosis. 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. Most patients present with complex partial temporal lobe epilepsy. This was noted in human tissue in 1974 and in animal models in 1985. The first to record and catalog the abnormal symptoms and signs of TLE was Norman Geschwind. There are 3 specific patterns of cell loss; Cell loss might involve sectors CA1 and CA4, CA4 alone, or CA1 to CA4 . Most anticonvulsants function by decreasing the excitation of neurons, for example, by blocking fast or slow sodium channels or by modulating calcium channels; or by enhancing the inhibition of neurons, for example by potentiating the effects of inhibitory neurotransmitters like GABA. TLE is diagnosed by taking a medical history, blood tests, and brain imaging. Although comparing left to right side is easiest, it must be remembered that up to 10% of cases are bilateral, and thus if symmetry is the only feature being evaluated, many cases may be misinterpreted as normal. TLE is the most common form of epilepsy with focal seizures. It has been found that GABA reversal potential is depolarising in the subpopulation of the pyramidal cells due to the lack of KCC2 co-transporter. 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. mesial temporal sclerosis, the types of imaging tech-niques used to diagnosis this entity, and the possible significance of secondary MR findings. Associated hippocampal atrophy and gliosis is common. See all (206) reduced hippocampal volume: hippocampal atrophy. Animal models and clinical studies show that memory loss correlates with temporal lobe neuronal loss in temporal lobe epilepsy.  A focal seizure in the temporal lobe may spread to other areas in the brain when it may become a focal to bilateral seizure. 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. Histologically there is neuronal cell loss, gliosis and sclerosis. In patients who are refractory to medical management temporal lobectomy or selective amygdalohippocampectomy may be performed. The ketogenic diet is also recommended for children, and some adults.  The personality changes generally vary by hemisphere. Electrical Stimulation of Subiculum for the Treatment of Refractory Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis: A 2-Year Follow-Up Study. Neurological and mental state Usually normal prior to seizure onset. 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.