Basilar migraine may also be mistaken for epilepsy. In this form of migraine neurological s ymptoms suggest primary involvement of the brain stem. Basilar migraine can cause loss of c onsciousness preceded by vertigo, tinnitus, hypo-acusis, and bilateral visual symptoms ( 11 4 ). However, attacks of basilar migraine tend to develop more slowly than epileptic seizur es and last longer. The symptoms listed here may also be associated with other brainstem si gns unlikely in epileptic seizures (such as ataxia or diplopia). Clinical cases in which ep ileptic seizures seem to develop out of typical migraines also exist ( \200\230migralepsy \200\231). The etiology of myoclonus tends to be easier to determine if it occurs as one part of a syn drome than if myoclonus appears in isolation. CHAPTER 8 differential diagnosis of epilepsy 91 Transient global amnesia The syndrome of transient global amnesia (TGA) is de \201 ned by a sudden onset of an anterograde and retrograde amnesia lasting up to 24 hours. The memory impairment consists of a profound reduction of anterograde and a milder reduction of retrog rade epi- sodic memory, including executive functions and recognition (for references see ( 115 ). Typically patients recover (although they do not tend to retrieve memories of the p eriod of amnesia) and a recent meta-analysis including 25 studies could not \201 nd long- term differences in cognitive performance between patients and healthy controls ( 116 ). Mo st attacks occur in people aged 50 \200\22370 years and occurrence below the age of 40 is r are, as is recurrence. There is, however, some evidence of association between younger pati ents and history of migraine and a case series of \201 ve patients with TGA who had previ ously successfully undergone temporal lobe resec- tion for epilepsy suggests that epilepsy surgery in the temporal lobes may increase the vulnerability for TGA ( 117 ). of consciousness (including symptomatic GTCS), odd behavior, speech dif \201 culties, and incoordination. There are several other endocrine disorders, which can cause episodic symptoms such as \202 ushing, tachycardia, tremor, and anx- iety and which may be mistaken for simple partia l seizures espe- cially of temporal lobe origin ( 83 ). These include carcinoid syndrome, s ystemic mast cell disease, phaeochromocytoma, med- ullary carcinoma of the thyroid, pancrea tic islet-cell tumors, renal cell carcinoma \200\224 or even menopausal hypo-oestrogenaemi a. In children and adolescents, hypocalcaemia may also induce symp- toms that mimic seizure s, typically tonic or focal seizures; unfortu- nately, hypocalcaemia may also cause genuine epileptic seizures, although this is typically in young infants. Common differential diagnoses in children Many of the conditions seen in adults and describ ed in this chapter also occur in children and particularly children over 10 years of age. C ardiac arrhythmias resulting in drop attacks tend to occur in older children ( > 12 years o f age) and TIAs are extremely uncom- mon. PNES is less commonly seen in children and is rar e under 9 years of age. The most common \200\230seizure \200\231 type in PNES is tonic \200\223 clonic-like followed by atonic-like seizures (drop or \200\230swoon \200\231-type seizures). Paroxysmal movement disorders, including simple or complex motor tics and stere otypies are relatively common and are often misdiagnosed as focal or myoclonic seizures. Pa rasomnias are a common phenomenon in children, and particularly arising from NREM-sleep res ulting in night terrors or rhythmic body- rocking or head-banging behaviors. Self-grati \201 cation is a common and normal behavior in infants and young children and may per- sist well into late childhood, although by this stage children are much more self-conscious and it is unlikely to be witnessed. However, the behavior may continue to be manifest in publi c places in children with learning difficulties or autism. Self- grati \201 cation is more likely to be seen when the child is bored or relaxed; speci \201 c situations include in a busy classroom or when watching television. Children can either assume dystonic or tonic postures with crossing of their legs or, less frequently, clonic move- ments of their legs usually in association with rhythmic rocking of the body and facial \202 ushing. They may also appear to be \200\230absent \200\231 and unresponsive although they can usually be d istracted out of them, but usually only temporarily. Predictably, these characteris- tic fe atures may lead to a diagnosis of absence, complex partial sei- zure, or, rarely, tonic sei zures. Precipitating factors described for TGA include physical exer- tion, emotional or psycholog ical stress, pain, medical procedures, and sexual intercourse. The diagnosis is primarily c linical, using the following criteria ( 118 ): 1 ) anterograde amnesia witnessed by an obse rver; 2 ) no clouding of consciousness or loss of personal identity; 3 ) cognitive impairme nt limited to amnesia; 4 ) no focal neurological or epileptic signs; 5) no recent history o f head trauma or seizures; and 5 ) resolution of symptoms within 24 hours. The exact pathop hysiology of TGA is not clear although a number of neuroimaging studies have shown mesiotem poral abnormalities (for references see ( 119 )). The main differential diagnostic problem in relation to epilepsy concerns transient epilept ic amnesia \200\224 TEA. This is a recently delineated neurological condition occurring in middle age and presenting with amnesic attacks ( 120 ). Butler described a series of 50 pa tients with TEA with detailed clinical and EEG data ( 121 ). They found that their patients with TEA had a mean onset of 62 years, similar to TGA. The amnesic episodes were rather mo re fre- quent (median 12/year) and shorter than TGA, although in general longer than epilep tic seizures (median duration 30 \200\22360 minutes), and transient amnesia was the most pr ominent feature of the epi- sodes. The amnesic attacks were characterized by mixed antero- grade and retrograde amnesia, sometimes with repetitive questioning. Epileptiform activity on EEG was present in 37 % of the patients and some patients had features indicative of foc al epi- lepsy, e.g. olfactory hallucinations, oral automatisms, or brief peri- ods of unres ponsiveness. However, epilepsy was the initial specialist diagnosis in only 12 of 50 cases. Forty of the 50 patients described persistent memory dif \201 culties. Importantly, attac ks ceased on anti- convulsant medication in 44 of 47 treated patients. Attacks com- monly o ccurred on waking, a helpful diagnostic clue. Less common differential diagnoses in children There is a wide range of other maturational (and therefore normal) phenomena but also a number of uncommon or rare non-physio- logical conditions that may be misdiagnosed as epilepsy, and usu- ally as myoclonic, tonic, or comp lex partial seizures (see Fig. 8.1 ). Fabricated or \201 ctitious illness (also known as M nchhausen syn- drome by proxy ( 124 , 125 )) is a relatively uncommon but almost certain ly under-recognized phenomenon and represents a form of child abuse or \200\230non-acciden tal injury \200\231. Syncope and seizures are the most common presentation of this conditio n. The parent, most often (but not invariably) the mother, fabricates a history that her ch ild is experiencing seizures. Less commonly, this fabrication is more sinister in that the parent is actively doing something to the Metabolic and endocrine disorders The metabolic or endocrine problem most likely to cause c onfu- sion with epilepsy is hypoglycaemia. Episodic hypoglycaemia suf- \201 cient to caus e neurological symptoms is most likely to occur in patients with diabetes mellitus (due to overmedication), alcohol- ism, or sepsis ( 122 ). However, it is particularly likely to cau se diag- nostic confusion in patients with insulinomas who develop hypoglycaemic attacks wi thout identi \201 able precipitants ( 123 ). Autonomic symptoms of hypoglycaemia such as h unger, palpita- tions, tremor, or sweating can help with the diagnosis but may be less prom inent than neurological symptoms confusion, impairment oxford textbook of epilepsy and epileptic seizures 92 child which induces a \200\230seizure \200\231. This may be by suffocation (caus- ing an a noxic seizure), giving the child salt (causing a hypernatrae- mic seizure), or by overdosin g the child with antiepileptic medication that has been erroneously prescribed for the chil d \200\231s \200\230epilepsy \200\231. In addition, antiepileptic medication may cause sid e effects including ataxia or dyskinesia which may in turn be misdi- agnosed as another typ e of seizure or an underlying neurodegen- erative disorder leading to spiraling inappropria te investigation and overtreatment. A number of features should raise concern that the chil d \200\231s paroxysmal episodes are likely to be fabricated: 11 . Angus-Leppan H . Diagnosing epilepsy in neurology clinics: A prospective study . Seizure 2008 ; 17 ( 5 ): 431 \200\223 6 . 12 . Kotsopoulos IA , de Krom MC , Kessels FG , Lodder J , Troost J , Twellaar M , et al . The diagnosis of epileptic and non-epileptic seizures . Epilepsy Res 2 003 ; 57 ( 1 ): 59 \200\223 67 . 13 . Smith D , Defalla BA , Chadwick DW . The misdiagnosis of epilepsy and the management o f refractory epilepsy in a specialist clinic . Q J Med 1999 ; 92 ( 1 ): 15 \200\223 23 . 14 . Plug L , Reuber M . Making the diagnosis in patients with blackouts: it \200\231s all in the history . Pract Neurol 2009 ; 9 ( 1 ): 4 \200\223 15 . 15 . Hoefnagels WAJ , Padberg GW , Overweg J , Roos RAC , van Dijk JG . Syncope or seizure? the diagnostic value of the EEG and hyperventilation test in transient loss of consciousness . J Neurol, Neurosurg, Psychiatry 1991 ; 54 ( 11 ): 953 \200\223 6 . \227\206 The history of the events is \200\224 and remains persistently \200\224 vague. \227\206 The person who has witnessed the events seems to be only the mother (or involved parent), despite the fact that the episodes are reported to occur every week or every day. 16 . Hoefnagels WAJ , Padberg GW , Overweg J , von der Velde EA , Roos RAC . Transient loss of consciousness: the value of the history for distinguishing sei zure from syncope . J Neurol 1991 ; 238 : 39 \200\223 43 . \227\206 The history is convincing of epilepsy but repeated EEGs are normal. 17 . Sheldon R , Rose S , Ritchie D , Conolly SJ , Koshman ML , Lee MA, et al . Historical criteria that distinguish syncope from seizures . J Am Coll Cardiol 2002 ; 40 ( 1 ): 142 \200\223 8 . \227\206 The episodes continue on appropriate antiepileptic medication despite the fact th at the child is considered to have a benign epi- lepsy syndrome. 18 . Alboni P , Brignole M , Menozzi C , Raviele A , Del Rosso A , Dinelli M , et al . Diag nostic value of history in patients with syncope with or without heart disease . J Am Coll Cardiol 2001 ; 37 ( 7 ): 1921 \200\223 8 . 19 . Syed TU, LaFrance WC Jr, Kahriman ES, Hasa n SN, Rajasekaran V, Gulati D, et al . Can semiology predict psychogenic nonepileptic seizu res . Ann Neurol 2011 ; 69 ( 6 ): 997 \200\223 1004 . \227\206 The parent provides a number of excuses for not being able to video a typical epi sode despite their very frequent occurrence (excuses include: \200\230I didn \200\231t hav e time to video them \200\231; \200\230I was too upset \200\231; \200\230She [the daughte r] didn \200\231t want me to video her \200\231; \200\230She [the daughter] was too embarr assed \200\231). 20 . Frucht MM , Quigg M , Schwaner C , Fountain NB . Distribution of seizure precipitants among epilepsy syndromes . Epilepsia 2000 ; 41 ( 12 ): 1534 \200\223 9 . \227\206 The parent often has a history of either mental health or chronic, 21 . Pavlova MK , Shea SA , Scheer FA , Brom \201 eld EB . Is there a circadian variation of epileptiform abnormalities in idiopathic generalized epilepsy? Epilepsy Behav 2009 ; 16 ( 3 ): 461 \200\223 7 . non-speci \201 c illnesses. References 22 . Xue LY , Ritaccio AL . Re \202 ex seizures and re \202 ex epilepsy . Am J Electroneurodiagnostic Technol 2006 ; 46 ( 1 ): 39 \200\223 48 . 1 . Beach R , Reading R . The importance of acknowledging clinical 23 . Benbadis SR . A spell in the epilepsy clinic and a history of \200\230chronic pain \200\231 or \200\230 \201 bromyalgia \200\231 independently predict a diagnosis of psycho genic seizures . Epilepsy Behav 2005 ; 6 ( 2 ): 264 \200\223 5 . uncertainty in the diagnosis of epilepsy and non-epileptic events . Arch Dis Child 2005 ; 9 0 ( 12 ): 1219 \200\223 22 . 2 . Scheepers B , Clough P , Pickles C . The misdiagnosis of epilepsy: 24 . Reuber M , Enright SM , Goulding PJ . Postoperative pseudostatus: not everything that shakes is epilepsy . Anesthesia 2000 ; 55 ( 1 ): 74 \200\223 8 . 25 . Colman N , Nahm K , van Dijk JG , Reitsma JB , Wieling W , Kaufmann \201 ndings of a population study . Seizure 1998 ; 7 ( 5 ): 403 \200\223 6 . 3 . Leach JP , Lauder R , Nicolson A , Smith DF . Epilepsy in the UK: misdiagnosis, mistrea tment and undertreatment . Seizure 2005 ; 14 ( 7 ): 514 \200\223 20 . H . Diagnostic value of history taking in re \202 ex syncope . Clin Autonomic Res 2004 ; 1 4 (Suppl 1 ): 1/37 \200\223 1/44 . 4 . Stroink H , van Donselaar CA , Geerts AT , Peters AC , Brouwer OF , 26 . Krediet CTP , Jardine DL , Cortelli P , Visman AGR , Wieling W . Vasovagal syncope int errupting sleep? Heart 2004 ; 90 : e25 . 27 . Benbadis SR , Lancman ME , King LM , Swanson SJ . Preictal van Nieuwenhuizen O , et al . Interrater agreement of the diagnosis and classi \201 cation of a \201 rst seizure in childhood. The Dutch Study of Epilepsy in Childhood . J Neurol Neurosurg Psychiatry 2004 ; 75 ( 2 ): 241 \200\223 5 . pseudosleep: a new \201 nding in psychogenic seizures . Neurology 1996 ; 47 ( 1 ): 63 \200\223 7 . 5 . Uldall P , Alving J , Hansen LK , Kibaek M , Buchholt J . The 28 . Duncan R , Oto M , Russel AJ , Conway P . Pseudosleep events in misdiagnosis of epilepsy in children admitted to a tertiary epilepsy center with paroxysmal events . Arch Dis Child 2006 ; 91 ( 3 ): 219 \200\223 21 . 6 . Benbadis SR, LaFrance WC J r, Papandonatos GD, Korabathina K, Lin K, Kraemer HC, et al . Interrater reliability of EEG -video monitoring . Neurology 2009 ; 73 ( 11 ): 843 \200\223 6 . patients with psychogenic non-epileptic seizures: prevalence and associations . J Neurol Ne urosurg Psychiatry 2004 ; 75 ( 7 ): 1009 \200\223 12 . 29 . Reuber M, Jamnadas-Khoda J, Br oadhurst M, Grunewald R, Howell S, Koepp , M, et al . Psychogenic non-epileptic seizures: seizure manifestations reported by p atients and witnesses . Epilepsia 2011; 52(11):2028 \200\22335 . 7 . Jacoby A , Baker GA , Steen N , Potts P , Chadwick DW . The clinical course of epilepsy and its psychosocial correlates: \201 ndings from a U.K. Community stu dy . Epilepsia 1996 ; 37 ( 2 ): 148 \200\223 61 . 30 . Schwabe M , Reuber M , Schoendienst M , Guelich E . Listening to people with seizures: how can Conversation Analysis help in the differential diagnosis of seizure disorders . Co mmun Med 2008 ; 5 ( 1 ): 59 \200\223 72 . 8 . van Donselaar CA , Geerts AT , Meulstee J , Habbema JD , Staal A . Reliability of the d iagnosis of a \201 rst seizure . Neurology 1989 ; 39 ( 2 Pt 1 ): 267 \200\223 71 . 31 . Luther JS , McNamara JO , Carwile S , Miller P , Hope V. 9 . Zaidi A , Clough P , Cooper P , Scheepers B , Fitzpatrick AP . Misdiagnosis of epilepsy : Many seizure-like attacks have a cardiovascular cause . J Am Coll Cardiol 2000 ; 36 ( 1 ) : 181 \200\223 4 . 10 . Reuber M , Baker GA , Gill R , Smith DF , Chadwick D . Failure to Pseudoepileptic seizures: methods and video analysis to aid diagnosis . AnnNeurol 1982 ; 12 ( 5 ): 458 \200\223 62 . 32 . Meierkord H , Will B , Fish D , Shorvon S . The clinical features and prognosis of pseudoseizures diagnosed using video-EEG telemetry . Neurology 1991 ; 41 ( 10 ): 1643 \200\223 6 . recognize psychogenic nonepileptic seizures may cause death . Neurology 2004 ; 62 ( 5 ): 83 4 \200\223 5 . CHAPTER 8 differential diagnosis of epilepsy 93 58 . Reuber M , Monzoni C , Sharrack B , Plug L . Using Conversation Analysis to distinguis h between epilepsy and non-epileptic seizures: a prospective blinded multirater study . Epi lepsy Behav 2009 ; 16 ( 1 ): 139 \200\223 44 . 33 . Goldstein LH , Mellers JD . Ictal symptoms of anxiety, avoidance behavior, and dissociation in patients with dissociative seizures . J Neurol Neurosurg Psyc hiatry 2006 ; 77 ( 5 ): 616 \200\223 21 . 34 . Vinton A , Carino J , Vogrin S , Macgregor L , Kilpatrick C , Matkovic Z , et al . \200\230 Convulsive \200\231 nonepileptic seizures have a characteristic pattern of rhythmi c artifact distinguishing them from epileptic seizures . Epilepsia 2004 ; 45 ( 11 ): 1344 \200\223 50 . 59 . Reuber M , Elger CE . Psychogenic nonepileptic seizures: review and update . Epilepsy Behav 2003 ; 4 ( 3 ): 205 \200\223 16 . 60 . Syed TU , Arozullah AM , Suciu GP , Toub J , Kim H , Dougherty ML , et al . Do observe r and self-reports of ictal eye closure predict psychogenic nonepileptic seizures? Epilepsi a 2008 ; 49 ( 5 ): 898 \200\223 904 . 61 . Bowman ES , Markand ON . Psychodynamics and psy chiatric diagnoses 35 . Lempert T , Bauer M , Schmidt D . Syncope: a videometric analysis of 56 episodes of transient cerebral hypoxia . Ann Neurol 1994 ; 36 : 233 \200\223 7 . of pseudoseizure subjects . Am J Psychiatry 1996 ; 153 ( 1 ): 57 \200\223 63 . 62 . Gracie J , Newton JL , Norton M , Baker C , Freeston M . The role of 36 . James MR , Marshall H , Carew-McColl M . Pulse oximetry during apparent tonic-clonic s eizures . Lancet 1991 ; 337 ( 8738 ): 394 \200\223 5 . 37 . Gates JR , Ramani V , Whalen S , Loewenson R . Ictal characteristics of psychological factors in response to treatment in neurocardiogenic (vasovagal) syncope . Eu ropace 2006 ; 8 ( 8 ): 636 \200\223 43 . pseudoseizures . Arch Neurol 1985 ; 42 ( 12 ): 1183 \200\223 7 . 63 . Jones JE , Hermann BP , Barry JJ , Gilliam F , Kanner AM , Meador KJ . 38 . Selai CE , Elstner K , Trimble MR . Quality of life pre and post epilepsy Clinical assessment of Axis I psychiatric morbidity in chronic epilepsy: a multicenter inve stigation . J Neuropsychiatry Clin Neurosci 2005 ; 17 ( 2 ): 172 \200\223 9 . surgery . Epilepsy Res 2000 ; 38 ( 1 ): 67 \200\223 74 . 39 . Dworetzky BA , Bubrick EJ , Sza \202 arski JP . Nonepileptic psychogenic status: mark edly prolonged psychogenic nonepileptic seizures . Epilepsy Behav 2010 ; 19 ( 1 ): 65 \200 \223 8 . 64 . Reuber M , Fern andez G , Bauer J , Singh DD , Elger CE . Interictal EEG abnormalities in patients with psychogenic non-epileptic seizures . Epilepsia 2002 ; 43 : 1013 \200\223 20 . 40 . Reuber M . Psychogenic nonepileptic seizures \200\224 a comprehensive review . Adv Clin Neurosci 2003 ; 13 : 175 \200\223 204 . 65 . Ganesan K , Appleton R , Tedman B . EEG departments in Great Britain: a survey of prac tice . Seizure 2006 ; 15 ( 5 ): 307 \200\223 12 . 41 . Groppel G , Kapitany T , Baumgartner C . Cluster analysis of clinical seizure semiology of psychogenic nonepileptic seizures . Epilepsia 2000 ; 41 ( 5 ): 610 \200\223 4 . 66 . Tan M , Appleton R , Tedman B . Pediatric EEGs: what NICE didn \200\231t say . Arch Dis Child 2008 ; 93 ( 5 ): 366 \200\223 8 . 42 . Benbadis SR , Chichkova R . Psychogenic pseudosyncope: 67 . Reuber M , Fern andez G , Helmstaedter C , Qurishi A , Elger CE . Evidence of brain ab normality in patients with psychogenic nonepileptic seizures . Epilepsy Behav 2002 ; 3 : 24 6 \200\223 8 . an underestimated and provable diagnosis . Epilepsy Behav 2006 ; 9 ( 1 ): 106 \200\223 10 . 43 . Gulick TA , Spinks IP , King DW . Pseudoseizures: ictal phenomena . 68 . Marsh E , O \200\231Callaghan P , Smith P . The humble electrocardiogram . Neurology 1982 ; 32 ( 1 ): 24 \200\223 30 . Pract Neurol 2008 ; 8 ( 1 ): 46 \200\223 59 . 44 . Leis AA , Ross MA . Psychogenic seizures . Neurology 1992 ; 69 . Sarasin FP , Louis-Simonet M , Carballo D , Slama S , Rajeswaran A , 42 ( 5 ): 1128 \200\223 9 . Metzger JT , et al . Prospective evaluation of patients with syncope: a population-based st udy . Am J Med 2001 ; 111 ( 3 ): 177 \200\223 84 . 70 . Benbadis SR , O \200\231Neill E , Tatum WO , Heriaud L . Outcome of 45 . Leis AA , Ross MA , Summers AK . Psychogenic seizures: ictal characteristics and diagnostic pitfalls . Neurology 1992 ; 42 ( 1 ): 95 \200\223 9 . 46 . Geyer JD , Payne TA , Drury I . The value of pelvic thrusting in the prolonged video-EEG monitoring at a typical referral epilepsy center . Epilepsia 2004 ; 45 ( 9 ): 1150 \200\223 3 . diagnosis of seizures and pseudoseizures . Neurology 2000 ; 54 ( 1 ): 227 \200\223 9 . 47 . Groppel G , Pataraia E , Olbrich A , Bacher J , Leutmezer F , Aull S , et al . Clinica l symptoms in psychogenic seizures . Wien Klin Wochenschr 1999 ; 111 ( 12 ): 469 \200\223 75 . 71 . Krahn AD , Klein GJ , Yee R , Skanes AC . The use of monitoring strategies in patients with unexplained syncope \200\224 role of the external and implantable loop re corder . Clin Auton Res 2004 ; 14 (Suppl. 1 ): 55 \200\223 61 . 72 . Samuel M , Duncan JS . Use of the hand held video camcorder in the 48 . Chung SG , P; Kirlin , KA . Ictal eye closure is a reliable indicator for psychogenic nonepileptic seizures . Neurology 2006 ; 66 : 1730 \200\223 1 . evaluation of seizures . J Neurol Neurosurg Psychiatry 1994 ; 57 ( 11 ): 1417 \200\223 8 . 49 . DeToledo JC , Ramsay RE . Patterns of involvement of facial muscles during epileptic a nd nonepileptic events: review of 654 events . Neurology 1996 ; 47 ( 3 ): 621 \200\223 5 . 73 . McGonigal A , Oto M , Russel AJ , Greene J , Duncan R . Outpatient video EEG recording in the diagnosis of non-epileptic seizures: a randomized controlled trial of simple sugges tion techniques . J Neurol Neurosurg Psychiatry 2002 ; 72 ( 4 ): 549 \200\223 51 . 50 . Fluegel D , Bauer J , Kaeseborn U , Burr W , Elger CE . Closed eyes during a seizure indicate psychogenic etiology: a study with suggestive seizure provocation . J Epilepsy 1996 ; 9 : 165 \200\223 9 . 74 . Grubb BP , Gerard G , Wolfe DA , Samoil D , Davenport CW , Homan RW , et al . Syncope and seizures of psychogenic origin: identi \201 cation with head- upright tilt table testi ng . Clin Cardiol 1992 ; 15 ( 11 ): 839 \200\223 42 . 75 . Brignole M , Alboni P , Benditt DG , Bergfeldt L , Blanc JJ , Thomsen PE , 51 . Bergen D , Ristanovic R . Weeping as a common element of pseudoseizures . Arch Neurol 1993 ; 50 ( 10 ): 1059 \200\223 60 . 52 . Walczak TS , Bogolioubov A . Weeping during psyc hogenic et al . Guidelines on management (diagnosis and treatment) of syncope-update 2004. Executiv e Summary . Eur Heart J 2004 ; 25 ( 22 ): 2054 \200\223 72 . nonepileptic seizures . Epilepsia 1996 ; 37 : 208 \200\223 10 . 53 . Ettinger AB , Weisbrot DM , Nolan E , Devinsky O . Postictal symptoms help distinguish patients with epileptic seizures from those with non- epileptic seizures . Seizure 1999 ; 8 ( 3 ): 149 \200\223 51 . 76 . Hainsworth R . Pathophysiology of syncope . Clin Auton Res 2004 ; 14 (Suppl. 1 ): I/18 \200\223 I/24 . 54 . Peguero E , Abou-Khalil B , Fakhoury T , Mathews G . Self-injury and incontinence in p sychogenic seizures . Epilepsia 1995 ; 36 ( 6 ): 586 \200\223 91 . 77 . Ammirati F , Colivicchi F , Santini M . Diagnosing syncope in clinical practice. Implementation of a simpli \201 ed diagnostic algorithm in a multicentre prospec tive trial \200\224 the OESIL 2 study (Osservatorio Epidemiologico della Sincope nel Lazio ) . Eur Heart J 2000 ; 21 ( 11 ): 935 \200\223 40 . 55 . Williams C , House AO . Heavy hospital case notes: a simple case \201 nding method f or psychiatric problems . Ir J Psychol Med 1999 ; 16 : 123 \200\223 6 . 56 . Schwabe M , Howell SJ , Reuber M . Differential diagnosis of seizure disorders: a conv ersation analytic approach . Soc Sci Med 2007 ; 65 ( 4 ): 712 \200\223 24 . 78 . Blanc JJ , L \200\231Her C , Touiza A , Garo B , L \200\231Her E , Mansourati J . Prospective evaluation and outcome of patients admitted for syncope over a 1 year period . Eur Heart J 2002 ; 23 ( 10 ): 815 \200\223 20 . 57 . Plug L , Sharrack B , Reuber M . Conversation analysis can help in the 79 . Kenny RA , Richardson DA , Steen N , Bexton RS , Shaw FE , Bond J . Carotid sinus synd rome: a modi \201 able risk factor for nonaccidental falls in older adults (SAFE PACE) . J Am Coll Cardiol 2001 ; 38 ( 5 ): 1491 \200\223 6 . distinction of epileptic and non-epileptic seizure disorders: a case comparison . Seizure 2 009 ; 18 : 43 \200\223 50 . oxford textbook of epilepsy and epileptic seizures 94 102 . Fahn S . Overview, history, and classi \201 cation of myoclonus . Adv Neurol 80 . Mathias CJ . Role of autonomic evaluation in the diagnosis and 2002 ; 89 : 13 \200\223 7 . management of syncope . Clin Auton Res 2004 ; 14 (Suppl 1 ): 45 \200\223 54 . 81 . Reuber M . Psychogenic nonepileptic seizures: answers and questions . 103 . Kojovic M , Cordivari C , Bhatia K . Myoclonic disorders: a practical Epilepsy Behav 2008 ; 12 : 622 \200\223 35 . approach for diagnosis and treatment . Ther Adv Neurol Disord 2011 ; 4 ( 1 ): 47 \200\223 62 . 82 . American Psychiatric Association . Diagnostic and Statistical Manual of Mental Disorders . Washington, DC : APA , 1994 . 104 . Caviness JN , Alving LI , Maraganore DM , Black RA , McDonnell SK , Rocca WA . The in cidence and prevalence of myoclonus in Olmsted County, Minnesota . Mayo Clin Proc 1999 ; 74 ( 6 ): 565 \200\223 9 . 83 . Brick JF , Crosby TW . Hot \202 ash epilepsy . South Med J 1988 ; 81 ( 1 ): 98 . 84 . World Health Organization . The ICD-10 Classi \201 cation of Mental and Behavioral Disor ders: Clinical Descriptions and Diagnostic Guidelines . Geneva : WHO , 1992 . 105 . Shibasaki H . Electrophysiological studies of myoclonus . Muscle Nerve 2000 ; 23 ( 3 ): 321 \200\223 35 . 85 . Reuber M . The etiology of psychogenic non-epileptic seizures: toward 106 . Caviness JN , Brown P . Myoclonus: current concepts and recent a biopsychosocial model . Neurol Clin 2009 ; 27 ( 4 ): 909 \200\223 24 . advances . Lancet Neurol 2004 ; 3 ( 10 ): 598 \200\223 607 . 86 . Reuber M , Zeidler M , Chataway J , Sadler M . Munchausen syndrome 107 . Fisher CM . Concerning recurrent transient cerebral ischemic attacks . by phone . Lancet 2000 ; 365 : 1358 . Can Med Assoc J 1962 ; 86 : 1091 \200\223 9 . 87 . Devinsky O , Putnam F , Grafman J , Brom \201 eld E , Theodore WH . 108 . Persoon S , Kappelle LJ , Klijn CJ . Limb-shaking transient ischaemic attacks in pati ents with internal carotid artery occlusion: a case- control study . Brain 2010 ; 133 (Pt 3 ): 915 \200\223 22 . Dissociative states and epilepsy . Neurology 1989 ; 39 ( 6 ): 835 \200\223 40 . 88 . Bowma n ES , Coons PM . The differential diagnosis of epilepsy, pseudoseizures, dissociative identity disorder, and dissociative disorder not otherwise spe ci \201 ed . Bull Menninger Clin 2000 ; 64 ( 2 ): 164 \200\223 80 . 89 . Mace \201 eld G , Burke D . Paraesthesiae and tetany induced by voluntary hyperventilation. Increased exci tability of human cutaneous and motor axons . Brain 1991 ; 114 (Pt 1B ): 527 \200\223 40 . 109 . Schulz UG , Rothwell PM . Transient ischaemic attacks mimicking focal motor seizures . Postgrad Med J 2002 ; 78 ( 918 ): 246 \200\223 7 . 110 . Panayiotopoulos CP . Elementary visual hallucinations, blindness, and headache in idiopathic occipital epilepsy: differentiation from migraine . J Neurol Neurosu rg Psychiatry 1999 ; 66 ( 4 ): 536 \200\223 40 . 111 . Panayiotopoulos CP . Elementary vis ual hallucinations in migraine 90 . van Dixhoorn JD , H.J . Ef \201 cacy of the Nijmegen Questionnaire in recognition of the hyperventilation syndrome . J Psychosom Res 1985 ; 29 ( 2 ): 199 \200 \223 206 . and epilepsy . J Neurol Neurosurg Psychiatry 1994 ; 57 ( 11 ): 1371 \200\223 4 . 112 . Blume WT , Wiebe S , Tapsell LM . Occipital epilepsy: lateral versus 91 . Provini F , Plazzi G , Tinuper P , Vandi S , Lugaresi E , Montagna P . mesial . Brain 2005 ; 128 (Pt 5 ): 1209 \200\223 25 . Nocturnal frontal lobe epilepsy. A clinical and polygraphic overview of 100 consecutive cas es . Brain 1999 ; 122 (Pt 6 ): 1017 \200\223 31 . 113 . Bien CG , Benninger FO , Urbach H , Schramm J , Kurthen M , Elger CE . Localizing value of epileptic visual auras . Brain 2000 ; 123 (Pt 2 ): 244 \200 \223 53 . 92 . Zucconi M , Ferini-Strambi L . NREM parasomnias: arousal disorders and differentiation from nocturnal frontal lobe epilepsy . Clin Neurophysiol 2000 ; 111(Sup pl 2) : S129 \200\223 35 . 114 . Kirchmann M , Thomsen LL , Olesen J . Basilar-type migraine: clinical, epidemiologic, and genetic features . Neurology 2006 ; 66 ( 6 ): 880 \200\223 6 . 93 . Derry CP , Duncan JS , Berkovic SF . Paroxysmal motor disorders of sleep: the clinical spectrum and differentiation from epilepsy . Epilepsia 2006 ; 47 ( 11 ): 1775 \200\223 91 . 115 . Bartsch T , Deuschl G . Transient global amnesia: functional anatomy and clinical implications . Lancet Neurol 2010 ; 9 ( 2 ): 205 \200\223 14 . 94 . Derry CP , Davey M , Johns M , Kron K , Glencross D , Marini C , et al . 116 . Jager T , Bazner H , Kliegel M , Szabo K , Hennerici MG . The transience and nature o f cognitive impairments in transient global amnesia: a meta-analysis . J Clin Exp Neuropsyc hol 2009 ; 31 ( 1 ): 8 \200\223 19 . Distinguishing sleep disorders from seizures: diagnosing bumps in the night . Arch Neurol 2 006 ; 63 ( 5 ): 705 \200\223 9 . 95 . Derry CP , Harvey AS , Walker MC , Duncan JS , Berkovic SF . NREM 117 . Dupont S , Samson S , Baulac M . Is anterior temporal lobectomy a arousal parasomnias and their distinction from nocturnal frontal lobe epilepsy: a video EEG analysis . Sleep 2009 ; 32 ( 12 ): 1637 \200\223 44 . precipitating factor for transient global amnesia? J Neurol Neurosurg Psychiatry 2008 ; 79 ( 3 ): 309 \200\223 11 . 96 . Tassinari CA , Cantalupo G , Hogl B , Cortelli P , Tassi L , Francione S , 118 . Hodges JR , Warlow CP . Syndromes of transient amnesia: towards a et al . Neuroethological approach to frontolimbic epileptic seizures and parasomnias: The s ame central pattern generators for the same behaviors . Rev Neurol (Paris) 2009 ; 165 ( 10 ): 762 \200\223 8 . classi \201 cation. A study of 153 cases . J Neurol Neurosurg Psychiatry 1990 ; 53 ( 10 ): 834 \200\223 43 . 119 . Shekhar R . Transient global amnesia \200\224 a review . Int J Clin Pract 2008 ; 97 . Bisulli F , Vignatelli L , Naldi I , Licchetta L , Provini F , Plazzi G , et al . 62 ( 6 ): 939 \200\223 42 . Increased frequency of arousal parasomnias in families with nocturnal frontal lobe epilepsy : a common mechanism? Epilepsia 2010 ; 51 ( 9 ): 1852 \200\223 60 . 120 . Kapur N . Transient epileptic amnesia \200\224 a clinical update and a reformulation . J Neurol Neurosurg Psychiatry 1993 ; 56 ( 11 ): 1184 \200\223 90 . 98 . Billiard M . Diagnosis of narcolepsy and idiopathic hypersomnia. 121 . Butler CR , Graham KS , Hodges JR , Kapur N , Wardlaw JM , Zeman AZ . The syndrome of transient epileptic amnesia . Ann Neurol 2007 ; 61 ( 6 ): 587 \200\223 98 . An update based on the International classi \201 cation of sleep disorders, 2nd edition . Sleep Med Rev 2007 ; 11 ( 5 ): 377 \200\223 88 . 99 . Overeem S , van Nues SJ , van der Zande WL , Donjacour CE , van Mierlo P , Lammers GJ . The clinical features of cataplexy: a questionnaire study in narcolepsy patients with and without hypocretin-1 de \201 ciency . Sleep Med 2011 ; 12 ( 1 ): 12 \200\223 8 . 122 . Malouf R , Brust JC . Hypoglycemia: causes, neurological manifestations, and outcome . Ann Neurol 1985 ; 17 ( 5 ): 421 \200\223 30 . 123 . Dizon AM , Kowalyk S , Hoogwerf BJ . Neuroglycopenic and other symptoms in patients w ith insulinomas . Am J Med 1999 ; 106 ( 3 ): 307 \200\223 10 . 100 . Unterberger I , Trinka E . Diagnosis and treatment of paroxysmal dyskinesias revisited . Ther Adv Neurol Disord 2008 ; 1 ( 2 ): 4 \200\223 11 . 101 . Bruno MK , Hallett M , Gwinn-Hardy K , Sorensen B , Considine E , Tucker S , et al . Clinical ev aluation of idiopathic paroxysmal kinesigenic dyskinesia: new diagnostic criteria . Neurolo gy 2004 ; 63 ( 12 ): 2280 \200\223 7 . 124 . Martinovic Z . Fictitious epilepsy in Munchausen syndrome by proxy: family psychodynamics . Seizure 1995 ; 4 ( 2 ): 129 \200\223 34 . 125 . Meadow R . Fictiti ous epilepsy . Lancet 1984 ; 1 : 25 \200\223 8 . CHAPTER 9 The Electroencephalogram in the Investigation of Epilepsy Stephan U. Schuele , Adriana C. B ermeo , and Samden D. Lhatoo History of the electroencephalogram Typical for revolutionary innovations, the electroencep halogram (EEG) conquered the medical world within a decade. In 1929, Hans Berger reported o n the \201 rst recordings of the human EEG ( 1 ). His discovery became widely accepted th rough the corroborating studies of Adrian and Matthews published 5 years later ( 2 ). In 19 35, Foerster and Altenburger performed the \201 rst intraopera- tive electrocortigogram ( ECoG) from the human brain and by 1939, Pen \201 eld reported the \201 rst case of invas ive monitoring for epilepsy surgery ( 3 ). diameters, MRI compatible platinum electrodes, ampli \201 ers allow- ing 256 and more chan nel inputs, and sampling rates of 1 kHz and more are now widely available for the invasive recording of epilepsy patients. In the pre-digital era, simultanous recording and correlation of EEG and video was a major challenge. The \201 rst closed-circuit tele- vision (CCTV) for simultanous recording of E EG and video was reported in 1966 and similar analog recording systems were used for the ne xt three decades ( 9 ). Since the 1990s, digital recording equipment has almost completely replaced analog systems. Long-term monitoring is becoming increasingly available not only a s a tool for presurgical evaluation, but also as the diagnostic method of choice for patien ts with treatment resistant seizures ( 10 ). In the last few years, central servers and rem ote access within and from outside the hospital has permitted an increasing number of inten sive care units to offer continuous EEG monitoring for (subclinical) seizure detection and management, further expand- ing the role of EEG in neurological practice. The early years of clinical EEG were dominated by two schools, one led by Frederick A. Gibb s and his wife Erna L. Gibbs in Boston, US, the other by Herbert H. Jasper in Montreal, Can ada. Gibbs and Gibbs had the concept of epilepsy as a \200\230dysrhythmia \200\231 of the brain. They postulated that epilepsies could be classi \201 ed based on pathog- nomonic in terictal EEG \201 ndings. They deserve credit for describ- ing the classical 3Hz spike an d wave pattern seen with absence epilepsy but also erroneously assumed that rhythmic midtem poral theta known as \200\230psychomotor variant \200\231 is predictive of psychomotor epi lepsy ( 4 ). Gibbs and Gibbs emphasized the use of the ear refer- ence which is well suited to visualize the typical aspects of general- ized 3 Hz spike and wave discharges but also led them to mislocalize patients with temporal lobe epilepsy due to the proximity of the ab normal activity to the ear reference. Jasper and colleagues pre- ferred the use of a bipola r montage which is more sensitive for focal epileptiform discharges. The Montreal school pi oneered the localization of interictal and ictal activity for surgical evaluation in collab oration with Wilder Pen \201 eld ( 5 , 6 ). Physiological basis of the EEG The main generators of the scalp EEG are excitatory and inhi bitory postsynaptic potentials. EEG surface activity depends on the sum- mation of the loca l \201 eld potentials which is enhanced in perpen- dicular oriented apical dendrites of p yramidal neurons close to the surface. In addition to orientation and location, the size of the neuronal population necessary to show synchronized activity is estimated at 6 cm 2 or more to become visible on the surface EEG ( 11 , 12 ) (Fig. 9.1 ). The cellular correlate of interictal epileptiform activity is a par- oxysmal depolarization shift (PDS) which results in the initiation of a high-frequency burst of action potentials followed by a pro- longed hyperpolarization. The cardinal features of interictal epi- lept iform abnormalities visible on surface EEG mimic the cellular processes and consist of a pa roxysmal interruption of the existing background activity, an initial sharp wave (80 \200 \223200 ms duration) or spike (40 \200\22380 ms) de \202 ection corresponding to a summati on of postsynaptic potentials. This is followed by a prominent slow wave, which re \202 ec ts the cellular hyperpolarization. The transition from single PDS generating interictal spi kes to a full electrographic In the pre-magnetic resonance imaging (MRI) era, epilepsy sur- gery almost always required an invasive evaluation which was ini- tially limited to intraoperative recordings using sub dural electrodes. In the late 1960s, the \201 rst implantable subdural strip electrodes w ere introduced in North America allowing seizure recording out- side the operating room ( 7 ). At the same time in France, Tailarach and Bancaud introduced a stereotactic method to a ccurately place intracerebral depth electrodes, which could be left in place for sev- eral days and allowed a systematic exploration of seizure onset and propagation ( 8 ). Over the subsequent half a century, these tech- niques have further evolved and thinner electrode pl ates and depth oxford textbook of epilepsy and epileptic seizures 96 \227\206 As con \201 rmatory testing for patients with a clinical exam apnea I + + test consistent with \200\230brain death \200\231. \210\222 \210\222 + + Inpatient continuous (video) EEG monitoring: + + II,III + + \227\206 Epilepsy monitoring unit (usually associated with medication \210\222 \210\222 tapering) \210\222 \210\222 \226 Diagnostic evaluation of patients with intractable seizures for IV more than 1 year. \210\222 \210\222 + + \226 Rapid treatment changes in patients with poorly controlled + + seizures. V + + + + \226 Presurgical evaluation of potential surgical candidates (non- invasive and invasive). VI Intensive care unit: \226 Detection of subclinical seizures in patient with altered mental A B status: Fig. 9.1 Generation of extracellular voltage \201 elds from graded synaptic activity. A) Excitatory postsynaptic potential (EPSP) at the apical dendrite is associated with a \202 ow of positive ions into the cell (an active current sink) and an extracellular negative \201 eld. A passive current source at the level of the cell body and basal dendrites is as sociated with an extracellular positive \201 eld. B) EPSP on the proximal apical dendrite at the level of cortical layer IV is associated with an active current sink and an extrace llular negative \201 eld. A passive current source at the distal apical dendrite in layer s II and III is associated with an extracellular positive \201 eld. With permission from Ebersole , 2003 ( 13 ). after convulsive status epilepticus. after an acute brain insult (trauma, hemorrhage, anoxic injury). \226 Monitoring of patients in burst suppression. \227\206 Procedures: \226 Carotid endarterectomy, aneurysm surgery, balloon occlusion. \226 Wada test.