the specific causes of tle in the elderly have not been clearly disclosed . with advancing age underlying coexisting factors are more likely to be identified , and the proportion of people classified as idiopathic is less when compared to the younger age groups . nonetheless , up to half of elderly patients with epilepsy go without an identified cause .   in the under 65-year age group , head trauma , brain tumors , and cns infections idiopathic tle has been reported in adults with familiar history of epilepsy ( mean age of onset : 25.5 ; range : 1145 years ) . there are however case reports of mesial temporal lobe sclerosis ( mts ) in elderly persons with new onset seizures . these accounts highlight the challenging differential diagnosis overlap with primary cognitive disorders and nonparaneoplastic limbic encephalitis . the etiology of hippocampal damage is discussed in a retrospective study of 38 patients with adult onset tle . the median age at onset was 37.8 years ( range : 21.0 to 78.7 years ) . a total of seven patients , 60 years and older , were included in this report . in all cases , the common features encompass frequent cpss ( range < 1 to 600 seizures per month ) developing over one year ( defined as the median time from the initial onset of seizures to the time of assessment ) . based on mri evidence of hippocampal atrophy , history of causative events , concomitant disease , cerebrospinal fluid results , and autoantibodies patients were classified in one of four etiologic categories ; secondary hippocampal sclerosis ( hs ) ; idiopathic hs ; definite limbic encephalitis ( le ) and mri defined possible le . two patients had experienced a severe head trauma ; two , old infarct ; one a porencephalic cyst and one neurofibromatosis type i. only two patients in this subgroup were 60 years and older . the latter reported 500 seizures per month . in the idiopathic hs group , all seven subjects had unilateral hippocampal abnormalities . definite le included nine patients with 5 ( 56% ) showing bilateral hippocampal abnormalities on mri . six of the nine patients had sequential mris with initial hippocampal swelling , followed by normalization and ultimately atrophy and high - intensity signal . four patients had positive voltage gated potassium channel antibodies ( vgkc abs ) and one anit - hu antibodies . the remaining four patients were diagnosed with rectal , small cell lung cancer ( sclc ) , testicular tumor with ma2 antibodies , and a uterine leiomyosarcoma , respectively . in this subgroup of definite le , three patients were 60 years and older . vgkc abs , rectal cancer , and small cell lung cancer were documented in one patient each . finally , 11 patients were classified as mri defined possible le based on repeated mris with initial hippocampal swelling , normalization and atrophy , and absence of malignancy or antibodies ( one exception with atypical anti - hu antibodies ) . two patients , 60 years and older , were included , both with unilateral hippocampal involvement . this report delineates idiopathic and secondary hs as well as paraneoplastic and non - paraneoplastic le as causative factors of late onset tle emphasizing bilateral hs in the latter two subgroups , however , not infrequent with secondary hs . memory impairment was more common with bilateral hs and in all cases frequent cpss developed over a relatively short period of time . the few elderly subjects included in this series appear to follow these general premises . a potential etiologic factor of tle in the elderly is represented in generalized convulsive status epilepticus ( gcse ) recognized to occur more often in the elderly with an estimated incidence of 86 per 100000 [ 12 , 13 ] . a complication of gcse is subsequent damage to the hippocampus [ 14 , 15 ] . mortality after gcse is significant . survivors would be at risk of subsequent partial seizures originating after hippocampal damage . the clinical features of various partial seizure types have been recently reported comparing patients 55 years of age and older ( mean 65.2  8.53 ) to a group between 18 and 45 years of age ( mean 33.6  6.75 ) ; each group encompassed 55 consecutive subjects . partial seizures with loss of awareness and lack of prominent automatisms were classified as dialeptic seizures and in the older group accounted for 60% of all focal seizures and 52% of the younger patients . partial seizures with prominent mouth and/or hand automatisms happened in 18% of the older patients while in 14% of the younger group . the authors did not specifically report on the localization of the origin of these seizures . in this series not surprisingly , the older group had a later age at seizure onset ( 53.6  20.23  yrs versus 23.4  12.12  yrs ) , seizure - free period greater than 1 year ( 20% versus 8% ) , and cerebral vascular disease as a risk factor ( 20% versus 6% ) . the younger group reported more than one seizure per month ( 54% versus 28% ) and a history of febrile seizures ( 20% versus 6% ) . for the older and younger age groups , risk factors included trauma 30% in each group , cns infection in 6% and 4% and cns tumor in 8% and 6% . among the 28 patients that had no recollection of their seizures , 17 ( 61% ) were from the older age group . in total , 9 subjects ( 18% ) , all of the older age group , reported subtle perception of transient confusion ( p = 0.002 ) . the total number of subjects with aura ( defined as partial seizures without loss of awareness ) was less common in the older age group ( 54% versus 76%  p = 0.03 ) . no significant differences could be demonstrated in the comparison of symptoms consisting of auras ( psychic , autonomic , abdominal , visual , somatosensory or gustatory , auditory , olfactory , and vertigo ) or generalized tonic clonic seizures ( gtcss ) occurrence . approximately one - third of patients in each group had a normal eeg , while 26% of the older group and 20% of the younger group had nonspecific finding . focal epileptiform discharges were shown in 42% of the older and 23% of the younger subjects . video - eeg monitoring was limited to a total of 9 patients yielding an additional 10% of older and 8% of younger patients with focal epileptiform and/or focal seizures . in patients with epilepsy , transient epileptic amnesia is an emerging concept described in middle - aged and older people with an evident response to antiepileptic drug treatment ( aed ) . a characteristic feature is prolonged periods of ante- and retrograde memory impairment with a mean duration between 30 and 60 minutes and subsequent amnesia that occurs upon awakening . transient amnesia may be the sole clinical manifestation in approximately one - third of patients . repetitive questioning is present in up to half of patients requiring differentiation from transient global amnesia . interictal epileptiform abnormalities may be demonstrated in one - third of patients and ictal electrophysiological correlates have been recorded uni o bilaterally in the temporal lobes . brain imaging is usually clear , or lesions involve the temporal lobe [ 18 , 19 ] . the diagnosis of tle in the elderly poses a challenge ( see table 1 ) . memory lapses , brief gaps in the flow of conversation , and blank stare and confusion may be the only clinical manifestations . clinical features resemble tia , delirium , congestive heart failure , cardiac arrhythmia , orthostatic hypotension , vasodepressor episodes , metabolic dysfunction with hypoglycemia , hyponatremia , sepsis , or drug toxicity . a small number of randomized controlled trials ( rcts ) have been conducted in elderly patients testing the efficacy of aeds . studies do not specifically address tle but serve to evaluate efficacy and safety issues of aeds in the setting of epilepsy in the elderly . recently , a group of 77 people with a mean age of 68 years and partial onset seizures were randomized in a pilot study to topiramate ( tpm ) 50  mg or 200  mg doses as add - on or monotherapy . seizure freedom was similar with the lower and higher doses ( 52% and 58% , resp . ) as well as seizure frequency ( 0.26/month and 0.33/month , resp . ) . more than 60% in both study groups complained of adverse side effects with somnolence , dizziness , and headache being the most common . one randomized controlled trial ( rct ) tested carbamazepine ( cbz ) versus lamotrigine ( lmt ) in a total of 64 subjects ( mean age : 67 years ) with partial seizures ( simple or complex ) with or without secondary generalization presenting on average between 8 and 12 months after stroke . stroke was classified as cortical in 64% of patients allocated to lmt and 66.7% of the cbz group . subcortical strokes were diagnosed in 36% and 33.3% , respectively , in these study groups . subjects allocated to cbz reported significantly more adverse effects than lmt leading to study withdrawal ( 31% versus 3% , p = 0.02 ) . on completion of the first year , 72% of patients on lmt and 44% on cbz were seizure - free ( p = 0.05 ) . a total of 590 elderly patients ( mean age : 72 years ) with newly diagnosed epilepsy with any seizure type were randomly allocated to gabapentin ( gbp ) , lmt , or cbz . in total , the etiology was similar among groups with an approximate one - third due to cerebral infarction . the localization of the origin of cpss was not accounted for . a mild cognitive impairment or memory problems were present in 35% and 25% of patients , respectively . at 12 months lmt was significantly best retained than cbz ( p < 0.0001 ) or gbp ( p = 0.015 ) . at one year , seizure freedom was not significantly different between groups ( lmt 51.4% , gbp 47.4% , and cbz 64.3% ) . the time to first , second , fifth , and tenth seizure in the first year was also similar and no significant statistical differences were demonstrated between groups . of the seven patients requiring hospital admission due to hypersensitivity reactions , one was due to lmt and six to cbz . a total of 150 elderly people ( mean age : 77 years ) with any seizure type resulting from idiopathic , symptomatic , or cryptogenic epilepsies were included and randomized in a 2  :  1 ratio to either lmt or cbz . cerebral infarction was disclosed in 30% of the lmt group and 38% in the cbz group . in 79% the daily lmt median dose was 100  mg ( range : 75300  mg ) , and in 82% the daily cbz median dose was 400  mg ( range : 200800  mg ) . seizure freedom during the 16 weeks of the study period was significantly different favoring lmt over cbz ( 39% versus 21% , p = 0.027 ) . seizure outcome in 16 patients 50 years and older ( mean 55.5  yrs , range 5072 ) was compared to 184 younger patients ( mean : 32.9  yrs , range : 1649 ) undergoing anterior temporal lobectomy ( atl ) . all patients had pathologically confirmed unilateral hs and mri lacked evidence of any other pathology . following atl older patients were less often seizure - free than the younger patients ( 56% versus 79% , p = 0.041 ) . postsurgical complications were more frequent in the older patients ( 25% versus 4.4% , p = 0.009 ) .   boling et al . the mean age at surgery was 54 years and followed for up to 64 months . seizure freedom was reached by 61% , and 72% were able to reduce or stop their antiepileptic drugs . this older set of patients underwent multiple comparisons with subjects grouped in decades from ages 10 to 49 years . in the four resulting groups sirven et al . reviewed a total of 30 patients aged 50 years and older ( mean 54.2  4.7 ) and compared them to 340 subjects younger than 50 years ( mean 32.8  7.7 ) . these groups were followed for 4.0  2.7 years and 5.0  2.9 years , respectively . seizure freedom was 52% in the older group and 75% in the younger group ( p = 0.008 ) . a discriminant function analysis disclosed that age at surgery and duration of epilepsy explained the largest fraction of variance . the authors consider that results could have been impacted by the fact that surgery in the older group was performed in their early 50 's with only 5 patients 59 years and older . in this retrospective analysis , as population grows , an increment is expected in the number of subjects 65 years and older identified with tle . countries with a longer life expectancy are going to be impacted to a greater extent . more often than not a coexisting significant medical condition may be revealed as well as acute or chronic brain involvement . clinical diagnosis is elusive with subtle presenting features such as recurrent memory lapses or periods of confusion . nevertheless , the typical signs of cpss are likely . the undisputable advantage of video - eeg monitoring recognized in the investigation of people with epilepsy is clearly applicable to elderly populations [ 2022 , 38 , 39 ] .
the incidence of epilepsy has bimodal distribution peaking at the extremes of life . 
 incidence is greater in younger and older age groups ( hauser et al . , 1993 , sidenvall et al . , 1993 , forsgren et al . , 1996 , and olafsson et al . , 2005 
 ) . as the world population ages more elders with epilepsy will be identified . in the high - income countries with longer life expectancy 
 , the number of elders with epilepsy will be even higher . 
 cpss account for 40% of all seizure types in the elderly ( hauser et al . , 1992 ) 
 ; however , the proportion with temporal lobe epilepsy ( tle ) is uncertain .