Temporal lobe pathology The mesial temporal structures play a critical role in the learning and consolidation of new material. In patients with hippocampal sclerosis (one of the most common pathologies seen in focal tem- poral lobe epilepsies) the extent of hippocampal vol ume loss in the dominant hemisphere, quanti \201 ed using magnetic resonance imag- ing vol umetry, correlates with scores on tests of verbal learning and recall. These correlations h ave been corroborated with postopera- tive cell counting studies that have found signi \201 cant correlations between the neuronal densities in resected hippocampal specimens and preoperative scores on verbal memory tests. See Baxendale for a review ( 13 ). Whilst the role of the hippocampi in memory function has long been recognized, Saling has recently pre sented a persuasive argument that the perirhinal cortex is also a key node in a more extens ive memory network ( 14 ). Frontal lobe pathology Whilst people with frontal lobe epilepsy (FLE) may achieve comparabl e scores on formal tests of learning and recall to their counterparts with a temporal focus , their performance is often qualitatively very different. Frontal lesions are associated w ith dif- \201 culties in placing past events in order, or within the correct time frame. Confabulation and intrusions may be prominent, when recall of the original material is weak . Thus the FLE patient may be able to provide a fulsome (albeit inaccurate) recount of a st ory they have just heard, in stark contrast to TLE patients, who are often unable to provid e much detail and who are generally very aware of their poor recall. Recall is not always d isrupted in FLE. In some cases, recognition memory can be impaired in the context of intact recall abilities. This may be due to interference from distraction items in recognition me mory tests. Dif \201 culties in recalling the source of new information (the where, when, and how you learned something new) are also associated with frontal lobe disturbance. The material-speci \201 c model of memory function has been a dominant concept in the neur opsychological understanding of memory function for over 50 years ( 15 ). Based on postoper ative studies of early epilepsy surgery patients, this model postulates that verbal memory functions are associated with the dominant medial structures whilst non-verbal memory funct ions are associated with non-dominant mesial structures. However, this model has recently b een challenged on both theoretical and clinical grounds following critical re-evaluations o f the classic literature often cited in support of the model ( 14 , 15 ). The verbal versus non-verbal specialisms of the mesial temporal structures where they do exist, are just tha t \200\224 specialisms, they do not represent exclusive functions. Thus is it Cahn-Weiner et al. ( 18 ) compared the memory and executive functions of FLE and TLE patien ts on cognitively-based daily living tasks. They expected the TLE patients to be more impai red on memory tasks, whilst the FLE patients would be more impaired on tests that employed executive function. However, they did not \201 nd this double dissociation, but rather bo th groups were signi \201 cantly CHAPTER 36 epilepsy: cognition and memory in adults 369 Adapted from Baxendale et al (2010) (20) 45 Males RHS 40 Females RHS Males LHS Females LHS 35 n o i t a u p o p 30 l l a m r o n n 25 i k n a r 20 e l i t n e c r e P 15 10 5 0 Naming Verbal learning Verbal retention Visual learning Verbal IQ Visual retention Performance IQ Fig. 36.1 Mean scores of patients with unilateral hippocampal sclerosis (n = 417) on standa rdized neuropsychological tests of intellect, learning, memory, and language, plotted again st the percentile rank of healthy controls. Adapted from Baxendale et al. ( 20 ). recognition ( 19 ). However, gender may play a role in mediating the effects of underlying pathology on cognitive function, and females with left-sided hippocampal sclerosis may be p articularly vulnerable to more widespread cognitive dysfunction beyond the memory domain ( 20 ). impaired on the memory tasks whilst their executive function scores fell within normal limi ts. Language problems were also found in both groups. The authors concluded that a wide ran ge of cognitive problems were found in both groups, despite the appar- ent focal nature of their pathology. Etiology Whilst the focus of much early research was on the effects of the location of the underlying lesion in epilepsy, clinicians and researchers have recently begun to appreciate that the nature of the lesion may play just as important a role in shaping the characteris - tics and extent of any associated neuropsychological de \201 cit. Very early development al lesions, such as dysembroplastic neuroepithe- lial tumors (DNET), and other forms of cor tical dysplasia may be associated with relatively little cognitive disturbance as cognitive functions are reorganized during subsequent cognitive develop- ment. However, fast-growing tumors that occur in an adult brain that has developed normally can have a devastating imp act on neigh- bouring cortical functions. Thus similar-sized lesions, in the same location, can have a very different impact on cognitive function in different patients dependent on the etiology of the pathology. Fluid factors Seizure control can have a signi \201 cant impact on cognitive func- tion. C lusters of seizures may lead to temporarily reduced memory function and a reduced attention span. The proximity of a seizure to a neuropsychological assessment may have a signi \201 cant impact on the results. Nocturnal seizures disrupt sleep patterns, which can decrease cognitive ef \201 ciency the following day. Interictal subclinical electro- encephalogram (EEG) disturbances can signi \201 cantly interfere with normal brain function. Disruptions in cognitive processing cons e- quent on these otherwise subclinical abnormalities are sometimes detected when neuropsyc hological testing is conducted during a routine EEG recording. Low mood and anxiety (common comorbidities in epilepsy) are associated with reduced learnin g capacity and increased dif \201 culties in recall. Mood disturbance is also a signi \201 cant factor in self-reported memory function. Salas-Puig et al. ( 1 ) examined the con tribution of clinical and demographic factors to scores on a memory complaint questionnaire . They found that measures of anxiety and depression explained over a third of the variance in the self-perception of In the general population, women generally have better verbal abilities than men and this p attern appears to hold for women with epilepsy, whose verbal memory de \201 cits may not b e as marked as those observed in matched male groups. Female epilepsy patients also have a gender advantage over males in delayed facial oxford textbook of epilepsy and epileptic seizures 370 postoperative seizures on memory function is complex following surgery ( 32 \200\22336 ), t here are some patients who suffer the \200\230double whammy \200\231 of a signi \201 cant postoperative deterioration of memory functions and ongoing seizures following surgery. Th e lifetime risk of developing an amnesic syndrome is increased following surgery if the con tralateral hippocampal structures become damaged fol- lowing an episode of status or a seve re cluster of seizures. This is not just a theoretical risk; a number of such case studies have been reported in the literature ( 37 \200\22339 ). memory disturbance. Independent of formal neuropsychological test results, patients \200 \231 perceptions of cognitive dif \201 culties are also sig- ni \201 cantly correlated wi th measures of quality of life in epilepsy ( 21 ). Developmental course of epilepsy Whilst cognitive dif \201 culties may be present early on and may even predate the diagnosis of epilepsy ( 22 ), repeated seizures can also lead to a stepwise deterioration in memory function for some patients across the adult lifespan. Ce ll death following status epi- lepticus can lead to an irrevocable decline in cognitive fun ction. Repeated head injuries sustained as the result of frequent drop attacks can also lea d to a stepwise pattern of cognitive deteriora- tion. Although frequent partial seizures do not appear to accelerate normal age-related decline in memory function, the same cannot be said for generalized convulsions. Frequent generalized convul- sions have been associated with accelerated deterioration in memory function in some patients ( 23 ). Helmsteadter et al. ( 24 ) report that memory functions may never fully develop in adults who develop epile psy in childhood. Whilst the gradient of normal age-related decline in cognitive function m ay be similar to that observed in the normal population, people with epilepsy may start thi s decline from a lower level than their healthy peers This lower starting level means that they will become impaired at an earlier age. Gender and side of pathology may also in \202 uence long-term trajec- tories of cognitive decline ( 20 ). Social and psychological impact Cognitive dif \201 culties in epilepsy can have a signi \201 cant impact on the quality of life of those affected. It can be dif \201 cult for fri ends, family, and colleagues to understand the nature of a poor memory and this can lead to frustration and interpersonal con \202 ict. In the workplace, cognitive failures can be m istaken for carelessness or a lack of ability. This can limit the economic opportunities op en to people with epilepsy. Baxendale et al. ( 40 ) found that it was the extent of memory dif \201 culties, rather than a diagnosis of epilepsy or overall level of intellectual fun ction, that had the greatest associa- tion with low socioeconomic status in people with epi lepsy. The embarrassment of being unable to recall a friend \200\231s name can be acute. In person al relationships, failure to recall important events or facts can be misinterpreted as disi nterest. As a result, many people with memory dif \201 culties \201 nd their social circ le grad- ually shrinking over the years. Within the family, familiarity with an individual \200\231s memory dif \201 culties can lead to gradual exclusion from joint decisions as re latives become impatient with the need for constant repetition. Treatments Many of the treatments that are effective in controlling seizures also have side effects that affect cognition. Different cognitive pro- \201 les are associated with eac h antiepileptic medication. Most GABA (gamma-aminobutyric acid) inhibitory agents are assoc iated with mental slowing ( 25 ). As a general rule of thumb, cognitive prob- lems usually increase with the dose and number of different medi- cations taken. Antiepileptic drug toxi city can result in very marked cognitive decline in a poorly monitored patient. Although co gni- tive side effects are generally thought to be less pronounced with the newer antiepile ptic medications, caution should be exercised in the introduction of some of these. Topiram ate can result in mark- edly reduced verbal \202 uency and processing ( 26 , 27 ). Althou gh some have found that the cognitive side effects can be reduced following gradual titrati on ( 28 ), others have suggested that the presence of word \201 nding dif \201 culties a ppears to be a phenomenon independent from titration schedule and is a side effect that occ urs in a subgroup of patients with a speci \201 c biological vulnerability ( 29 ). Fortuna tely, the cognitive dif \201 culties associated with topiramate appear to be reversed foll owing discontinuation of the drug ( 30 ). Neuropsychological rehabilitation A neuropsychological assessment forms the basis for all r ehabilita- tion efforts for cognitive problems in epilepsy. Approaches to cogni- tive rehab ilitation fall into three main categories. The \201 rst are strategy based. For memory di f \201 culties these may include teaching the patient strategies that help them to process new information in greater depth, in a variety of ways. Mnemonic strategies may be useful for people with epilepsy but generalization of this technique to everyday situations outsid e the clinic is usually modest or even absent. Success is largely dependent on small, indiv idualized, concrete goals ( 41 ). Another common strategy is the method of loci, where list s of items are recalled via visual imagery, the more bizarre imagery the better. Schefft et al. ( 42 ) reported some improvements in formal memory test scores in patients with epilep sy who were taught to use a self- generated encoding procedure. The patients with a left te mporal sei- zure onset (who had the poorest memory performance in a didactic control condit ion) bene \201 ted the most from the self-generation con- dition. It remains unknown wheth er these improvements last. In postoperative patients it appears that patients who have und ergone a left temporal lobectomy and who are in the greatest need of rehabili- tation bene \201 t less from rehabilitation strategies than those with more residual function remainin g following surgery ( 43 ). Memory strate- gies can be very time consuming to master and re quire a high level of motivation from the patient for any real level of success. Wider cog- nitive de \201 cits may mean it is not easy for some to employ visual imagery. As a resul t, many patients \201 nd these methods dif \201 cult to adopt and apply effectively in t heir everyday lives. Although epilepsy surgery can be associated with postoperative decline in memory function, individual postoperative trajectories can differ signi \201 cantly. Whilst approximately o ne-third of patients may experience a signi \201 cant decline in memory function following a unilateral temporal lobe resection, memory functions for the majority may remain unchang ed and can actually improve in approximately 20 % of some surgical series ( 31 ). Postopera tive change is governed by a variety of pre-, peri-, and postoperative factors. Preoperativ e risk factors for postoperative decline in memory function include good preoperative funct ion and surgery on the language dominant hemisphere. Although the role of CHAPTER 36 epilepsy: cognition and memory in adults 371 The second rehabilitation approach involves environmental adaptations. These can range from simple techniques to ease the nuisance of everyday memory dif \201 culties to more comple x inter- ventions to reduce the impact of impulsive or disinhibited behav- iours associated with frontal lobe dysfunction. These adaptations range from the use of diaries, calendars, \200\230Post-it \200\231 notes, and tele- phone pads to structural changes within the wor kplace to allow behavioral prompts from handheld devices, computer systems, and even collea gues, where appropriate. These environmental adaptations often involve the development of r outines that need to become second nature to ensure success. 10. Hesdorffer DC , Hauser WA , Olafsson E , Ludvigsson P , Kjartansson O . Depression and suicide attempt as risk factors for incident unprovoked seizures . Ann Neurol 2006 ; 59 ( 1 ): 35 \200\223 41 . 11. Hesdorffer DC , Ludvigsson P , Hauser WA , Olafsson E , Kjartansson O . Co-occurrence of major depression or suicide attempt with migraine with aura and risk for u nprovoked seizure . Epilepsy Res 2007 ; 75 ( 2 \200\2233 ): 220 \200\223 3 . 12. Taylor J , Kolamunnage-Dona R , Marson AG , Smith PE , Aldenkamp AP , Baker GA . Patients with epilepsy: cognitively compromised before the start of antiepi leptic drug treatment? Epilepsia 2010 ; 51 ( 1 ): 48 \200\223 56 . 13. Baxendale SA . The hippocampus: functional and structural correlations . Seizure 1995 ; 4 ( 2 ): 105 \200\223 17 . 14. Saling MM . Verbal memory in mesial temporal lobe epilepsy: beyond The planning of these strategies relies heavily on \201 nding the appropriate external pr ompt to shore up the failing internal cogni- tive functions. Each neuropsychological rehabi litation package will be unique to the individual and will be drawn up on the basis of the results from a detailed clinical interview and a formal neuropsy- chological assessment. Re latives and work colleagues may also need to be actively involved in some rehabilitation st rategies, particularly where frontal lobe functions are compromised. material speci \201 city . Brain 2009 ; 132 (Pt 3 ): 570 \200\223 82 . 15. Baxendale S , Thompson P . Beyond localization: the role of traditional neuropsychological tests in an age of imaging . Epilepsia 2010 ; 51 ( 11 ): 2225 \200\223 30 . 16. Hermann B , Seidenberg M , Lee EJ , Chan F , Rutecki P . Cognitive phenotypes in temporal lobe epilepsy . J Int Neuropsychol Soc 2007 ; 13 ( 1 ): 12 \200\223 20 . 17. Dabbs K , Jones J , Seidenberg M , Hermann B . Neuroanatomical correlates of cognitive phenotypes in temporal lobe epilepsy . Epilepsy Behav 2009 ; 15 ( 4 ): 445 \200\223 51 . Acceptance of cognitive dif \201 culties as an integral part of having epilepsy is a funda mental adjustment that many patients with epi- lepsy must make. Many have never been explic itly told this and they continue to strive for a remedy many years after diagnosis. Many of the factors that underpin cognitive dif \201 culties in epilepsy are \201 xed and canno t be changed. Memory functions will not get better, although neuropsychological rehabilitat ion can help to develop ways around the nuisance of frequent memory failures. An early expl anation that cognitive dif \201 culties are an integral part of the condition can help the long-term adjustment to living with epilepsy. The third approach to neuropsychological reh abilitation may employ a cognitive behavioral or psychotherapeutic approach to help the pat ient work through the issues of loss that are inevitably associated with the development of this acceptance. 18. Cahn-Weiner DA , Wittenberg D , McDonald C . Everyday cognition in temporal lobe and frontal lobe epilepsy . Epileptic Disord 2009 ; 11 ( 3 ): 222 \200\223 7 . 19. Bengner T , Fortmeier C , Malina T , Lindenau M , Voges B , Goebell E , et al . Sex dif ferences in face recognition memory in patients with temporal lobe epilepsy, patients with generalized epilepsy, and healthy controls . Epilepsy Behav 2006 ; 9 ( 4 ): 593 \200\223 6 00 . 20. Baxendale S , Heaney D , Thompson PJ , Duncan JS . Cognitive consequences of childhood-onset temporal lobe epilepsy across the adult lifespan . Neurolog y 2010 ; 75 ( 8 ): 705 \200\223 11 . 21. Baker GA , Taylor J , Hermann B . How can cognitive status predispose to psychological impairment? Epilepsy Behav 2009 ; 15(Suppl 1) : S31 \200\223S 35 . 22. Baker GA , Taylor J , Aldenkamp AP . Newly diagnosed epilepsy: Cognitive outcome after 12 months . Epilepsia 2011 ; 52(6):1084 \200\22391 . References 23. Thompson PJ , Duncan JS . Cognitive decline in severe intractable epilepsy . Epilepsia 2005 ; 46 ( 11 ): 1780 \200\223 7 . 1. Salas-Puig J , Gil-Nagel A , Serratosa JM , Sanchez-Alvarez JC , Elices E , Villanueva V , et al . Self-reported memory problems in everyday activities in patients wit h epilepsy treated with antiepileptic drugs . Epilepsy Behav 2009 ; 14 ( 4 ): 622 \200\223 7 . 24. Helmstaedter C , Elger CE . Chronic temporal lobe epilepsy: a neurodevelopmental or progressively dementing disease? Brain 2009 ; 132 (Pt 10 ): 2822 \200\223 30 . 2. Baxendale S , Thompson P . De \201 ning meaningful postoperative change in epilepsy sur gery patients: measuring the unmeasurable? Epilepsy Behav 2005 ; 6 ( 2 ): 207 \200\223 11 . 25. Cavanna AE , Ali F , Rickards HE , McCorry D . Behavioral and cognitive effects of anti-epileptic drugs . Discov Med 2010 ; 9 ( 45 ): 138 \200\223 44 . 26. Gomer B , Wagner K , Frings L , Saar J , Carius A , Harle M , et al . The in \202 uence of antie pileptic drugs on cognition: a comparison of levetiracetam with topiramate . Epilepsy Behav 2007 ; 10 ( 3 ): 486 \200\223 94 . 3. Rayner G , Wrench JM , Wilson SJ . Differential contributions of objective memory and mood to subjective memory complaints in refractory focal epilepsy . Ep ilepsy Behav 2010 ; 19 ( 3 ): 359 \200\223 64 . 4. Hall KE , Isaac CL , Harris P . Memory complaints in epilepsy: an 27. Blum D , Meador K , Biton V , Fakhoury T , Shneker B , Chung S , et al . Cognitive effects of lamotrigine compared with topiramate in patients with epilepsy . Neuro logy 2006 ; 67 ( 3 ): 400 \200\223 6 . accurate re \202 ection of memory impairment or an indicator of poor adjustment? A review of the literature . Clin Psychol Rev 2009 ; 29 ( 4 ): 354 \200\223 67 . 28. Aldenkamp AP , De KM , Reijs R . Newer antiepileptic drugs and cognitive issues . Epilepsia 2003 ; 44( Suppl 4) : 21 \200\223 9 . 5. Zeman A , Butler C . Transient epileptic amnesia . Curr Opin Neurol 29. Mula M , Trimble MR , Thompson P , Sander JW . Topiramate and word- \201 nding dif \201 culties in patients with epilepsy . Neurology 2003 ; 60 ( 7 ): 1104 \200\223 7 . 2010 ; 23 ( 6 ): 610 \200\2231 6 . 6. Butler CR , Zeman AZ . Recent insights into the impairment of memory in epilepsy: transient epileptic amnesia, accelerated long-term forgetting and remote memor y impairment . Brain 2008 ; 13 (Pt 9 ): 2243 \200\223 63 . 30. Kockelmann E , Elger CE , Helmstaedter C . Signi \201 cant improvement in frontal lobe associated neuropsychological functions after withdrawal of topiramate in epilepsy patient s . Epilepsy Res 2003 ; 54 ( 2 \200\2233 ): 171 \200\223 8 . 7. Hermann B , Lang \201 tt J . Forgetting to remember in epilepsy: a family 31. Baxendale S , Thompson PJ , Duncan JS . Improvements in memory function following anter ior temporal lobe resection for epilepsy . Neurology 2008 ; 71 ( 17 ): 1319 \200\223 25 . affair? Neurology 2010 ; 75 ( 24 ): 2144 \200\223 55 . 8. Davies R , Baxendale S , Thompson P , Duncan JS . Epilepsy surgery for people with a low IQ . Seizure 2009 ; 18 ( 2 ): 150 \200\223 2 . 32. Alpherts WC , Vermeulen J , van Rijen PC , da Silva FH , van Veelen CW . Verbal memory decline after temporal epilepsy surgery?: A 6-year multiple assessments follow-up study . N eurology 2006 ; 67 ( 4 ): 626 \200\223 31 . 9. Hesdorffer DC , Hauser WA , Annegers JF , Cascino G . Major depression is a risk factor for seizures in older adults . Ann Neurol 2000 ; 47 ( 2 ): 246 \200\223 9 . oxford textbook of epilepsy and epileptic seizures 372 38. Oxbury S , Oxbury J , Renowden S , Squier W , Carpenter K . Severe amnesia: an usual la te complication after temporal lobectomy . Neuropsychologia 1997 ; 35 ( 7 ): 975 \200\223 88 . 33. Alpherts WC , Vermeulen J , Hendriks MP , Franken ML , van Rijen PC , Lopes da Silva FH , et al . Long-term effects of temporal lobectomy on intelligence . Neuro logy 2004 ; 62 ( 4 ): 607 \200\223 11 . 39. Loring DW , Hermann BP , Meador KJ , Lee GP , Gallagher BB , King 34. Andersson-Roswall L , Engman E , Samuelsson H , Malmgren K . DW , et al . Amnesia after unilateral temporal lobectomy: a case report . Epilepsia 1994 ; 35 ( 4 ): 757 \200\223 63 . Cognitive outcome 10 years after temporal lobe epilepsy surgery: a prospective controlled s tudy . Neurology 2010 ; 74 ( 24 ): 1977 \200\223 85 . 35. Engman E , Andersson-Roswall L , Samuelsson H , Malmgren K . Serial cognitive change patterns across time after temporal lo be resection for epilepsy . Epilepsy Behav 2006 ; 8 ( 4 ): 765 \200\223 72 . 40. Baxendale S , Heaney D . Socioeconomic status, cognition, and hippocampal sclerosis . E pilepsy Behav 2011 ; 20 ( 1 ): 64 \200\223 7 . 41. Ponds RW , Hendriks M . Cognitive rehabilitation of memory problems in patients with epilepsy . Seizure 2006 ; 15 ( 4 ): 267 \200\223 73 . 36. Helmstaedter C , Kurthen M , Lux S , Reuber M , Elger CE . Chronic epilepsy and cognition: a longitudinal study in temporal lobe epilepsy . Ann Neurol 2003 ; 54 ( 4 ): 425 \200\223 32 . 42. Schefft BK , Dulay MF , Fargo JD , Sza \202 arski JP , Yeh HS , Privitera MD . The use of self-generation procedures facilitates verbal memory in individuals with seizure disord ers . Epilepsy Behav 2008 ; 13 ( 1 ): 162 \200\223 8 . 43. Helmstaedter C , Loer B , Wohlf ahrt R , Hammen A , Saar J , Steinhoff BJ , 37. Dietl T , Urbach H , Helmstaedter C , Staedtgen M , Szentkuti A , Grunwald T , et al . Persistent severe amnesia due to seizure recurrence after unilateral t emporal lobectomy . Epilepsy Behav 2004 ; 5 ( 3 ): 394 \200\223 400 . et al . The effects of cognitive rehabilitation on memory outcome after temporal lobe epile psy surgery . Epilepsy Behav 2008 ; 12 ( 3 ): 402 \200\223 9 . CHAPTER 37 Legal Aspects of Epilepsy and Epilepsy and Driving Morris Odell Legal aspects of epilepsy Epilepsy has always occupied a distinctive place among the variou s medical conditions that come to medico-legal attention, possibly because of its sometimes spectacular manifestations of paroxysmal disability, and misconceptions regarding automati c or violent behavior occurring during or after a seizure. Automatism is sometimes claimed as a defense for criminal actions occurring while a person is suffering a seizure. The word \200\230automatism \200\231 has a particular meaning in law, which is not necessarily the same as its pure clinical usage to describe unconscious behavior; however, a detailed disc ussion of the resulting legal issues is beyond the scope of this chapter ( 1 , 2 ). Potenti ally dangerous or criminal behavior may be exhibited by patients with epilepsy but may not necessarily be associated with epilepsy per se. Violent and aggressive behav- iour may be i nterictal and unrelated to a seizure although underly- ing psychiatric conditions or brain injury may be common to both. True ictal violence may be attributed to automatisms associat ed with complex partial seizures, myoclonic seizures, and similar types of epilepsy but thi s occurs without purpose or conscious control. Actions may appear to be destructive, violen t, or aggressive but they are not directed and are not modi \201 ed to suit the circumstan ces. In the postictal state a person may be psychotic, delirious, disorien- tated, and conf used. Actions may seem purposeful but they are based on an altered sensorium with impaired cognition and deci- sion-making ability. An example of this might be resisting or lash- ing out at someone trying to restrain or assist the delirious person. In cases where epileptic automatism is claimed as a defense it is necessary to prove the person was actually having a seizure and was ictal or postictal at the time of the incident. The seizure must occur s uddenly and there must be demonstrable impaired consciousness. Alternatively it should be d emonstrated that the behavior in ques- tion was characteristic of a typical seizure for tha t person. Video electroencephalogram (EEG) monitoring may be required and detailed neurolog ical and forensic psychiatric assessment is always advisable ( 3 ). It is uncommon for crim inal activity to be caused by epileptic seizures. In one British study, epilepsy was cited in only 7.3 % of criminal cases found \200\230not guilty by reason of insanity \200\231 be tween 1975 and 2001. In the majority of these cases there were associated factors such as i ntoxications and psychiatric comorbidi- ties that could not be excluded as contributing fac tors ( 4 ). Epilepsy and driving Epilepsy is probably the most common neurological disorder seen in the general community and all general practitioners and neu- rologists will have patients with a history of seizures and who are taking anticonvulsant medication. Epilepsy has the poten tial to cause a wide range of episodic disability from minor disturbances of perception or movement to complete loss of consciousness and this may result in adverse events associated with complex or dan- gerous activities including driving. Behavior and events associ- ated with seizures or postictal states may be of major medico-legal signi \201 cance. Even tho ugh drug treatment of epilepsy has the poten- tial to produce side effects that affect beha vior or driving ability, in practice it is the risk of a seizure that is the de \201 ning criterion for holding a license ( 5 ). Despite this, the relative risk of crashes attrib- u ted to \201 tting drivers is low ( 6 ), possibly because of medical man- agement of epile ptic patients and consequent advice regarding licensing. However, one study in a country wi th no regulations regarding \201 tness to drive of epilepsy patients but a low population density found similar low risk, with the overall relative risk for \200\230traf \201 c v iolations \200\231 being only 1.95 (6, 7). The relative risk of a crash in drivers with kno wn epilepsy is usually quoted as less than 2 which must be put into the context of, for ins tance, the much higher relative risk associated with alcohol and drug use, and the increase d crash risk of healthy drivers between the ages of 18 and 25 compared to middle-aged exper ienced drivers. Many other medical conditions are related to similar degrees of crash risk as epilepsy, but this is not always recognized in a consistent manner in various \201 tne ss to drive regulations. There are also signi \201 cant dif- ferences in crash risk betwee n drivers with epilepsy under treat- ment or advice (who have a very low relative risk) and the epilepsy population as a whole where the risk of a crash is increased by 40 \200\22310 0 % ( 8 ). This probably represents the difference in severity of the condition between epi lepsy patients who can obtain a license and those who cannot satisfy the authorities that t hey are \201 t to drive ( 9 ). As epilepsy is a condition that relies on historical detai ls for clinical decision-making, it is perhaps not surprising that there is a perception th at many drivers with epilepsy do not tell their doctors the truth ( 10 ). Social and work p ressures are often cited as reasons why poorly controlled patients continue to drive ( 11 , 12 ). oxford textbook of epilepsy and epileptic seizures 374 Sudden loss of consciousness during an epileptic \201 t is obviously incompatible with ma intaining control of a motor vehicle although a more or less universal \201 nding is that crash frequency in drivers with epilepsy is only 50 \200\22360 % of seizure frequency whil e driving. This probably re \202 ects the inclusion of seizures without loss of con- sciou sness in studies, or the perception of an imminent seizure allowing the driver to pull over . It may also represent interictal events which have a minor and subtle effect on conscious ness and performance ( 13 ). However, it may also be a fortuitous \201 nding due more to luck and the real risk is potentially much higher ( 14 ). The types of crashes have also be en reported to be different from \200\230gen- eral \200\231 crashes in being more commonly in open areas rather than built-up areas, against an immovable object rather than a vehicl e, and causing less severe injuries ( 15 ). inform a doctor or to drive against medical advice. A number of legal cases have explored t his issue with varying outcomes, not always consistent with each other ( 19 ). Another important medico-legal issue is the estimation of risk of seizure recurrence in pat ients who have ceased anticonvulsant medication. There are many variables here, including t he type of epilepsy and the indications for ceasing treatment ( 20 ). Patients with general ized tonic \200\223clonic seizures and those on multiple drug therapy present the greatest risk of seizure recurrence. Studies have shown variable periods of increased risk in patien ts withdrawn from medication with increased risk in some cases persisting for long periods. Patients recommenced on treatment after a recurrent seizure have an increased risk over th e next 12 months compared to patients started on treatment, probably re \202 ecting the in creased severity of epilepsy which has recurred after treatment withdrawal ( 21 ). However, there are unpredictable variables introduced because of uncertainties in following-up pati ents remaining on treatment. The most signi \201 cant factor in assessing risk is the time since the last seizure rather than the time off medication. There are many different types of epilepsies which may differ in some respects in their pot ential effect on licensing policy although they have a common thread of paroxysmal gross im pairment sepa- rated by periods of relative normality. Complex partial and gener- alized to nic \200\223clonic seizures (primary or secondary) are the types most commonly associated w ith crashes ( 14 ). These are completely incapacitating during the ictal phase and are asso ciated with a vari- able postictal period where the driver may remain incapacitated despite a partial return of consciousness. Involuntary motor move- ments during partial seizures h ave also been noted to contribute to crashes. Other forms are less commonly causes of crash es, with simple partial or uncomplicated myoclonic seizures where con- sciousness is preser ved being rarely involved. Psychogenic pseudo- seizures rarely occur in dangerous situation s and should not affect driving; however, it is not always possible to be sure whether the events really are psychogenic unless they can be captured during EEG monitoring ( 16 ). Lic ensing guidelines for patients with epi- lepsy therefore may require identi \201 cation of a speci \201 c epilepsy syn- drome and monitoring of treatment. Because the oversight of epilepsy by clinicians rests largely on evidence from the patient regarding the frequency o f seizures, it is important for doctors to assess the reliability of the history. Informati on from family mem- bers can be helpful in this regard. It is important to differentiate be tween the risk of having a seizure (whether behind the wheel or not) and the risk of having a crash. This is especially problematic as most licensing guidelines specify a \201 xed \201 t-free period and record- ing of this historical data is likely to be adversely affe cted by bias in histories given to clinicians ( 17 ). Objective evidence of seizure fre- qu ency and type may come from police reports, hospital records, or observations made during a dmissions for monitoring. Clinical evidence of brain imaging or EEG may be helpful in estab lishing a diagnosis and serum drug levels may be helpful in monitoring treatment. Video EEG monitoring extended over a period of a day or more is a useful aid to assessment in cases where the extent of seizure control is doubtful ( 18 ). Therapeutic measures in epilepsy cases may also have a bearing on \201 tness to drive eve n though seizures are controlled. Visual \201 eld defects resulting from epilepsy surgery or treatment with certain drugs such as vigabatrin may be severe enough to render a person un \201 t to drive ( 22 ). Many anticonvulsant drugs have undesirable side effects such a s sedation, confusion, incoordination, or other psychomotor effects that can affect driving ability. In most cases these are either transient, due to wrong dosing or may be avoided w ith a change of medication. It is important to keep these effects in mind when treating pat ients with epilepsy. Reporting of drivers with epilepsy or any other medical condi- tion to the driver licensing authority (Driver and Vehicle Licensing Agency in the UK) is a source of anxiety for many doctors. In some jurisdictions reporting is compulsory, which makes the decision easy, but there may be an adverse impact on the doctor \200\223patient relationship and the reliabili ty of the history of seizure control. This aspect of licensing policy involves a breach of con \201 dentiality and raises ethical and medico-legal questions which have been debated vociferously in the literature ( 23 \200\22325 ). In some jurisdic- tions doctors are prote cted from litigation by the driver if it can be shown that they acted in good faith when re porting. Regardless of whether reporting is compulsory, it is always good practice to dis- cuss the situation fully with the patient and attempt to explain the reasons why they shoul d not be driving. Doctors who deal with epileptic patients need to be familiar with local \201 tness to drive requirements ( 26 ) and should be proactive in counseling the patient regarding driving ( 27 ). Medical notes are documents which may be examined in court and th erefore all aspects of these discus- sions and decisions should be meticulously recorded. Medical standards for drivers with epilepsy are concerned with When a person is actually suffering a seizure, they are uncon- scious and technically incap able of controlling a motor vehicle. This has implications for criminal proceedings where i t is neces- sary to prove intent or negligence for certain acts such as culpable driving, v ehicular homicide, or similar offenses. If a person is inca- pacitated by a seizure or a po stictal state it can be argued that they were not actually in control of the vehicle or res ponsible for their actions. The question of automatism may also arise. Arguments can be mad e that negligence extends to driving with untreated or inadequately treated epilepsy or aft er a negligent decision not to the following aspects: \227\206 The existence of a prescribed seizure-free period. Periods vary with different ju risdictions and the evidence base for them may not be strong ( 28 ); however, as a general rule, the risk of a recur- rence is reduced as the seizure-free period increases ( 29 ) . \227\206 The type of seizures being experienced. In some jurisdictions a distinction is ma de regarding \200\230safe \200\231 seizures such as purely sen- sory phenomena or those oc curring in or from sleep which by their nature are not likely to disturb driving. The recur rence rate Table 37.1 Private licensing guidelines for drivers with epilepsy ( 31 ) Disorder Canada Australia UK USA New Zealand Sweden CMA (2006) Austroads (2006 and 2012) Drivers Medical Group, Swansea (2008) Utah Driver License Division (2006) Land Transportation Safety Authority (2002) Swedish National Road Administration (1999) Auras and minor epilepsy (absences) May drive if: \227\206 seizure pattern has been Not addressed If patient suffered an attack whilst awake \200\224 must desist from driving for minimum 1 year from date of attack before license may be issued. 3-year license issue is dependent o n patient being treatment compliant and if driving is unlikely to cause danger to the publi c. 70 license restored if seizure free for minimum 7 years (with medication if necessary) An unrestricted license may be issued if seizure or episode free for 5 years, without medic ation. OR seizure free for 3 \200\22312 months without medication or with medication but no side effects. Reviews are required 6-monthly, yearly, or 2-yearly. Speed, area, and time o f day restriction apply, depending on the length of time without seizures. 6-monthly review required Regarded as a partial epilepsy attack and treat as uncontrolled epilepsy. May resume drivin g after 1 year free of any epileptic seizures. Upon specialist advice this period may be re duced if further seizures are unlikely Not addressed stable for at least 12 months \227\206 no generalized seizures \227\206 neurologist gives approval \227\206 no impairm ent of cognition or consciousness \227\206 no head or eye deviation with seizures First, isolated epileptic seizure (prior to epilepsy diagnosis) Desist from driving for 3 months. Neurological assessment including EEG (awake and asleep) and appropriate imaging preferable