The clinical forms and causes of epilepsy

ILAE classification of seizure type, 4 ILAE classification of the epilepsies and epilepsy syndromes, 11 Classification of partial seizures by anatomical site of seizure onset, 13 The age-related epilepsy syndromes, 17 The causes of epilepsy, 26 Epilepsy due to genetic or developmental causes, 26

Epilepsy surgery

Epilepsy surgery is defined as surgery carried out specifically to control epileptic seizures. This will include operations on tumours and vascular lesions where epilepsy is the primary indication for surgery. There is clearly an overlap with lesional surgery carried out for other primary reasons, if the lesion is causing epilepsy, and even if the operation influences the epilepsy, such operations are not generally included in epilepsy surgery statistics. The distinction though is not always...

Gaucher disease

Gaucher disease (glucocerebrosidase deficiency glucosylce-ramidase deficiency) is caused by deficient activity of the lysosomal enzyme glucosylceramidase and the resultant accumulation of its undegraded substrate, glucosylceramide and other glycolipids. In the central nervous system gluco-sylceramide originates from the turnover of membrane gangliosides. There is a wide phenotypic range, and the condition is usually divided into five subtypes. The frequency is about 1 case per 50,000-100,000...

Primary reading epilepsy

This is a specific rare epilepsy syndrome in which clonic jerking of the jaw or peri-oral muscles, which can evolve to a generalized convulsion, is precipitated by reading. The age of onset is usually 12-25 years. The condition has various forms. In some patients, the attacks occur only after prolonged reading. In individual cases, different aspects of reading seem to act as precipitating factors content, comprehension, context. Reading difficult or unfamiliar passages, music, nonsense passages...

The ketogenic diet

The ketogenic diet is a high-fat and low-carbohydrate diet which was introduced into epilepsy therapy in the 1920s, and which in recent times has been the subject of a resurgence of interest. Its use is confined to the treatment of severe childhood epilepsy that has proved resistant to more conventional therapy. It has no role in adult epilepsy, where its use has proved difficult and dangerous. The diet is high in fat and low in carbohydrate, with adequate protein, and provides nutrition with 1...

Chronic psychosis

A grumbling interictal psychosis, with occasional exacerbation, is often seen in patients with severe epilepsy. Psychotic features may be quite mild, and complicated by irritability, anxiety, paranoia and dysphoria. In most cases antipsy-chotic medication is required. Sulpiride is a good drug for mild psychosis, and its additional anxiolytic effects can be helpful. During acute exacerbations of psychotic behaviour, risperidone, olanzapine or quetiapine may become necessary. Sometimes...

Autonomic status epilepticus

This is a form of SE which occurs typically in Panyiotopoulos syndrome. The exact prevalence of this syndrome is unclear, and estimates have ranged from 0 to 6 of all children with epilepsy. The seizures consist of episodes of nausea, retching and vomiting, and deviation of the eyes. There may or may not be altered awareness. Other autonomic features occur including incontinence of urine, pallor, hyperventilation and headache. The EEG shows occipital spiking or runs of 3 Hz spike-wave and there...

Other benign focal epilepsies

Epilepsy with occipital calcifications is an occipital epilepsy syndrome in which there is more severe epilepsy and a poorer outcome. Almost all cases are associated with coeliac disease, which may be demonstrable only on jejunal biopsy. Other rarer but interesting childhood benign focal syndromes have been described, sometimes in a handful of families only, and include benign partial epilepsy in infancy, idiopathic photosensitive occipital lobe epilepsy, idiopathic frontal lobe epilepsy,...

Early onset benign occipital epilepsy synonym Panayiotopoulos syndrome

This is another syndrome with age of onset between 1 and 14 years (mean 4-5 years). Estimates of prevalence have ranged from 0 to 0.6 of all children with epilepsy, and in one study it accounted for 28 of all benign focal epilepsies of childhood. Panayiotopoulos considers the condition to be due to diffuse maturation-related epileptogenicity activating emetic centres and the hypothalamus. The clinical presentation is distinctive. In the core syndrome, seizures take the form of eye deviation,...

Alcohol and toxininduced seizures

Alcohol abuse is a potent cause of acute symptomatic seizures, and indeed of epilepsy, in many societies. There are various mechanisms. Binge drinking can result in acute cerebral toxicity and seizures. Alcohol withdrawal in an alcohol-dependent person carries an even greater risk of seizures. Withdrawal seizures are typically tonic-clonic in form, occurring 12-24 hours after withdrawal, and are associated with photosensitivity. Seizures can also be caused by the metabolic disturbances...

Special diets and nutritional supplements

The ketogenic diet is widely accepted now as main-line therapy for a few children with severe epilepsy (see p. 96). However, other diets are also used widely as complementary therapies. The Atkins diet (60 fat, 30 protein and 10 carbohydrate) has gained favour, no doubt because of its superficial resemblance to the ketogenic diet (typically 80 fat, 15 protein and 5 carbohydrate). In a small open study of six children and adults, 50 became seizurefree. The best results were seen in those who...

Use in myoclonus

Piracetam is useful in cortical myoclonus of various types and causes. The drug has been shown to be effective in post-anoxic action myoclonus, some cases of progressive myoclonic epilepsy, myoclonus due to carbon monoxide poisoning, some cases of primary generalized epilepsy with myoclonus, post-electrocution myoclonus, myoclonus in Huntington disease, and in other symptomatic metabolic disorders e.g. sialidosis . Initial case reports and then case series were followed by a well-conducted...

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Phenytoin Dose Concentration

Figure 3.8 The principal pathways of metabolism of phenytoin, and the involvement of CYP2C9 and CYP2C19. Figure 3.9 Relationship between serum phenytoin concentration and daily dose in five patients. Each point represents the mean SD ofthree to eight measurements of serum phenytoin concentration at steady state. The curves were fitted by computer using the Michaelis-Menten equation. Figure 3.9 Relationship between serum phenytoin concentration and daily dose in five patients. Each point...

Postictal psychosis

This typically occurs, with a brief delay, after an exacerbation of seizures. Benzodiazepines are effective in controlling the psychosis in many cases, and it is possible that the psychotic manifestations relate to ongoing seizure activity in effect status in limbic structures. During the psychotic episode, lorazepam is the drug of choice, and is sometimes sufficient alone. In other cases, antipsychotic drugs are needed. Patients with postictal psychosis can show violent, aggressive or...

Tuberculoma

Tuberculosis remains a major problem in developing countries and the incidence is also rising in industrialized countries with increasing migration and the spread of the human immunodeficiency virus HIV . The most common form of tuberculosis is pulmonary infection, and the incidence of intracranial tuberculoma tuberculous abscess has decreased, particularly in Western countries, owing to the BCG vaccination programme. In the early 20th century tuberculomas accounted for about one-third of all...

Drug excretion

Most drugs and their metabolites are excreted via the kidney. Nearly all the various processes of renal excretion are mediated by concentration-dependent passive transfer, although acidic molecules, including the glucuronide conjugates, are also actively pumped into the proximal renal tubules. The more polar the molecule the less resorption occurs in the distal tubule. Severe renal disease affects this process and can result in impaired excretion and greater drug accumulation. Mild renal...

Febrile seizures

Febrile seizures are defined as epileptic events that occur in the context of an acute rise in body temperature, usually in children between 3 months and 5 years of age, in whom there is no evidence of intracranial infection or other defined intracranial cause Table 1.17 . They are common. About 2-5 of children 7 in Japan and up to 14 in the Mariana Islands will have at least one attack, and it has been estimated that between 19 and 41 per 1000 infants with fever will convulse. The first...

Hippocampal sclerosis

Hippocampal sclerosis is the most common cause of temporal lobe epilepsy. It is found in over one-third of cases of people with refractory focal epilepsy attending hospital clinics in whom there is no other structural lesion, but is less frequent in population-based cohorts and in patients with mild epilepsy. Hippocampal sclerosis typically causes complex partial seizures, and the clinical features and symptom complex associated with the syndrome of mesial temporal lobe epilepsy are described...

Landau Kleffner syndrome and ESES

The clinical feature of these conditions are considered on p. 25. In the Landau-Kleffner syndrome control of seizures is often possible with rather modest antiepileptic treatment. However, the EEG abnormalities may not disappear and the aphasia may not improve. If one accepts that the speech disturbance was caused by the EEG disturbance, then aggressive antiepileptic therapy to suppress the EEG disturbance is a logical approach even in the absence of overt seizures. All antiepileptic drugs have...

Treatment of different seizure types in idiopathic generalized epilepsy

Treatment varies to some extent with the type of seizure, but some broad-spectrum drugs are available that treat all types. Generalized tonic-clonic seizures in idiopathic generalized epilepsy As most antiepileptic clinical trials have been seizure-rather than syndrome-orientated, it is at present unclear whether the generalized tonic-clonic seizures of idiopathic generalized epilepsy respond to a different antiepileptic drug profile than the generalized tonic-clonic seizures in other types of...

Dentatorubropallidoluysian atrophy DRPLA

Dentato-rubro-pallido-luysian atrophy is inherited in an autosomal dominant fashion. It occurs with markedly varying frequency around the world, being particularly common in Japan a frequency of 0.2-0.7 per 100,000 persons and in northern Europe. It is a triplet repeat disorder involving the DRPLA gene, which is of uncertain function. The normal repeat number is between 6 and 35 and the condition is present with full penetrance when the repeat number is greater than 48. DRPLA is a slowly...

Pharmacokinetics

Phenobarbital has a bioavailability of 80-100 in adults after oral or intramuscular administration. Peak plasma concentrations occur 1-3 hours after oral administration, but can be significantly delayed in patients with poor circulation or reduced gastrointestinal motility. After intramuscular administration, peak serum concentrations occur within 4 hours, and peak plasma concentrations are similar to those after oral administration Figure 3.6 . Absorption is slowed by the presence of food, but...

Phase 2 phase of decompensation

The status epilepticus may then enter a second late phase in which cerebral protective measures progressively fail. The main systemic characteristics of this phase are a fall in systemic blood pressure and progressive hypoxia. Hypotension is due to seizure-related autonomic and cardio-respiratory changes and drug treatment, and in the later stages can be severe and intractable. At a critical stage cerebral autoregulation begins to fail and the control of blood flow then becomes dependent on...

Other IGE variants with myoclonus

Other types of myoclonic IGE subtypes are less well defined, and their nosological position less clear-cut. Myoclonic absences occur at a younger age, have a male predominance, an EEG initially at least indistinguishable from that of typical absence epilepsy, are associated with intellectual disturbance, and are much more resistant to drug therapy other seizure types evolve in two-thirds of cases. Eyelid myoclonia with or without absence is a photosensitive IGE variant characterized by very...

Alternative psychosis and forced normalization

In some patients periods of seizure control and normalized EEG appear to be associated with the development of psychoses, which is reversed when seizures recur the phenomenon as applied to EEG is sometimes known as 'forced normalization' . However, the opposite pattern is also observed, and the true status of forced normalization is rather contentious. The exact mechanism of this pattern is unclear. Antipsychotics, antidepressants and anxiolytic drugs, as appropriate, can be used to treat these...

Cerebral infections

Infections Brales

In general, surgical therapy for chronic post-meningitic or post-encephalitic epilepsy carries a poor outcome for seizure control. Even if an apparently single lesion is uncovered on imaging for example, apparently unilateral hippocampal atrophy following herpes simplex encepahlitis there is usually more subtle widespread diffuse damage in other areas of the brain, and localized resection will fail to control seizures. This may be because the boundaries of the destructive process in...

Clinical use in epilepsy

Clobazam should be considered as adjunctive therapy whenever treatment with a single first-line antiepileptic drug has proved ineffective. In my own practice, clobazam is often the first adjunctive drug to be tried. It is effective in a wide range of epilepsies, although perhaps best in those with partial seizures alone. It can be used in patients with Lennox-Gastaut and other primarily and secondarily generalized epilepsies. It is effective in a broad spectrum of other types of epilepsy and...

Seizure Precipitants

One of the worst aspects of having epilepsy is the lack of predictability of seizures. For many people, the fact that a seizure can occur without warning on a more or less random fashion is far more problematic than the actual seizure itself. If there were sufficient advanced notice of seizures, the negative impact of epilepsy would be greatly reduced. Why seizures occur when they do is one of the major unanswered research questions in epilepsy. Of some interest is the tantalizing demonstration...

Phase II decompensation

During this phase, the greatly increased cerebral metabolic demands cannot be fully met, resulting in hypoxia and altered cerebral and systemic metabolic patterns. Autonomic changes persist and cardio-respiratory functions may progressively fail to maintain homoeostasis. Autonomic and cardiovascular changes Failure of cerebral autoregulation thus cerebral blood flow becomes dependent on systemic blood pressure Rise in intracranial pressure and cerebral oedema Consumptive coagulopathy, DIC,...

Intracranial ictal EEG

Temporal Seizure Eeg

In some centres, intracranial depth EEG recordings used to be carried out in all patients with temporal lobe epilepsy being evaluated for epilepsy surgery Figure 5.6 . With the advent of MRI this practice seems now to be obsolete in most cases indeed in our unit it is applied in less than 5 of cases. Depth EEG does record from otherwise functionally inaccessible cortex, but the EEG data come from only a small area around the electrode lt 1 cm core , and unless the electrodes are placed...

Posttraumatic epilepsy

Head trauma is an important cause of epilepsy. Estimates of frequency of injury and of the risk of post-traumatic epilepsy have varied widely in different studies, partly owing to different definitions and changes in diagnosis and management. The figures given below are best-guess estimates based on modern practice. It is customary to draw a distinction between open head injury, where the dura is breached, and closed head injury, where there is no dural breach. Post-traumatic seizures are...

Adverse effects

Phenytoin is one of the oldest drugs in the pharmacopoeia although outflanked by phenobarbital in venerability and the most studied. There is therefore a large body of information about adverse effects. It is salutary to contemplate how long some, even common, side-effects took to be recognized. Many patients, however, taking phenytoin suffer no or only minimal side-effects even after decades of therapy an important point to emphasize when discussing the pros and cons of therapy. Phenytoin...

Multiple Subpial Transection

Multiple Subpial Transection

This operation is also referred to as the Morrell procedure. Parallel rows of 4-5 mm deep cortical incisions are ploughed perpendicular to the cortical surface. This is done on the theoretical basis that the transections sever horizontal cortical connections and thus disrupt the lateral recruitment of neurones, which is essential for the production of synchronized epileptic discharges Figure 5.23 . At the same time normal function is preserved, as this is supported largely by vertically...

Focal cortical dysplasia

This is a common form of dysplasia, important to identify because of its potential for surgical therapy. The term encompasses a variety of subtypes, with different histolo-gical appearances due, possibly, to formation at different stages of embryogenesis. In some the cortical lamination is normal but in others there may be associated widespread macrogyria and polymicrogyria. Focal dysplasia can occur in any part of the cortex, and vary greatly in size. There are often widespread minor...

Surgical treatment of epilepsy due to cortical dysplasia

Eeg Findings Post Ictal Psychosis

Cortical dysplasia is an important cause of medically intractable seizures. MRI scanning detects brain malformations in 5-10 of patients with refractory epilepsy and up to 15 of children with refractory epilepsy and learning disability. These figures are, however, likely to underestimate the true incidence, as histologically proven dysplasia is sometimes found on examination of tissue removed at surgery in patients with refractory epilepsy and normal conventional MRI. 'MRI-negative' cases...

West syndrome

West syndrome Table 1.18 is a severe epileptic encephalopathy, with an incidence of 1-2 per 4000 live births, and a family history in 7-17 . The condition is defined by the occurrence of a typical form of epileptic seizure infantile spasm and EEG hypsarrhythmia . The infantile spasms take the form of sudden, generally bilateral and symmetrical contractions of the muscles of the neck, trunk or limbs. The spasms grow in frequency as the condition evolves, and at its peak, seizures occur hundreds...

Lafora body disease

Lafora body disease, an autosomal recessive condition mostly reported from southern Europe, is characterized the presence of Lafora bodies, which are periodic acid-Schiff PAS positive intracellular polyglucosan inclusions found in neurones, sweat glands and a variety of other sites. The age of onset is between 6 and 19 years usually 12-17 years , although many patients have a history of isolated febrile or non-febrile seizures earlier in childhood, and the disease presents with progressive...

Epilepsy arising in the lateral temporal neocortex

There is considerable overlap between the clinical and EEG features of mesial and lateral temporal lobe epilepsy, due presumably to rapid spread and dissemination of discharges between these two anatomical areas. However, differences Table 1.10 Complex partial seizures of lateral temporal lobe origin. Features overlap with those of complex partial seizures of mesial temporal origin Table 1.9 with the following differences in emphasis Motor arrest and absence less prominent Aura more likely to...

Atypical absence seizures

Atypical absence seizures, like typical absence seizures, take the form of loss of awareness absence and hypo-motor behaviour. They differ from typical absences in clinical form, EEG, aetiology and clinical context Table 1.5 . Their duration is longer, loss of awareness is often incomplete Typical absence seizure Complex partial seizure Underlying focal anatomical lesion Duration of attack Other clinical features Ictal and interictal EEG Photosensitivity Childhood or early adult Idiopathic...

Frequency and population features of epilepsy

Its incidence is in the region of 80 cases per 100,000 persons per year, with different studies showing rates varying between 50 and 120 per 100,000 per year. Its point prevalence is about 4-10 cases per 1000 persons. The prevalence is higher in underdeveloped countries, perhaps due to poorer perinatal care and standards of nutrition and public hygiene, and the greater risk of brain injury, cerebral infection or other symptomatic cerebral conditions. The...

Partial seizures Simple partial seizures

Simple partial seizures are defined as partial seizures in which consciousness is not impaired. They are due to focal cerebral disease. Any cortical region may be affected, the most common sites being the frontal and temporal lobes. The symptoms are useful in predicting the anatomical localization of the seizures. The form of the seizures usually has no pathological specificity, and can occur at any age. Most simple partial seizures last only a few seconds. Their clinical form depends on the...

Urea cycle disorders

Various autosomal recessive disorders of urea cycle enzymes occur, with a prevalence of about 1 in 30,000 live births, resulting in abnormalities of protein breakdown and consequential hyperammonaemia. There are five urea cycle enzymes and one co-factor, and defects in each are described. The severity of the conditions vary, with some rapidly fatal. Ornithine transcabamylase OTC deficiency is the most common deficiency, with a frequency of about 1 in 80,000 live births. It is an X-linked trait,...

Ictal scalp EEG and videoEEG telemetry

The ictal scalp EEG recording of a complex partial seizure remains a fundamental part of the pre-surgical evaluation but see p. 242 . Long recordings are usually performed with concurrent video video-EEG telemetry . To catch seizures, recordings may need to be continued for days or even weeks. In unilateral hippocampal sclerosis, a clear-cut ictal unilateral temporal sphenoidal rhythmic discharge of 5 Hz or faster within the first 30 seconds of the ictal recording occurs in about 50-60 of...

Vagus Nerve Stimulation

Multiple Subpial Transection

In 1997 vagus nerve stimulation was approved by the US FDA for use as adjunctive therapy for adults and adolescents over 12 years of age whose partial-onset seizures are refractory to antiepileptic medications. Vagus nerve stimulation was then also approved in European Union countries Figure 5.23 Technique of multiple subpial transection. a After a tiny incision is created in the pia, a hook is inserted down one gyral edge. b It is then swept across the full width of the gyrus. c The hook is...

Lennox Gastaut syndrome

This term denotes an ill-defined age-specific epileptic encephalopathy with a wide range of causes Table 1.20 . Epileptic encephalopathy 1-5 of all childhood epilepsies Age of onset 1-7 years 40 cryptogenic, 60 symptomatic identifiable underlying cause Learning disability, sometimes severe Multiple seizure types atypical absence, tonic, atonic, tonic-clonic, myoclonic Episodes of non-convulsive status epilepticus common 75 of patients Seizures precipitated by sedation and lack of stimulation...

Midazolam

Midazolam is another benzodiazepine, and it can be used in a the premonitory stage or stage of early status epilepticus or b as an anaesthetic in the stage of refractory status epilepticus. It is a water-soluble compound whose ring structure closes when in contact with serum to convert it into a highly lipophilic structure. Its solubility in water provides one major advantage over diazepam, that is, it can be rapidly absorbed by intramuscular IM injection or by intra-nasal or buccal...

Different surgical approaches to temporal lobe surgery

Approaches The Temporal Lobe

Because of the rate of complications, operative techniques have been modified to try to avoid some of the adverse Figure 5.8 A standard temporal lobectomy. Transverse plane showing the habitual extent of temporal resections cortical and limbic in the dominant hemisphere. AG, amygdala CX, neocortex HP, hippocampus PH, parahippocampus grey line, extent of resection. Figure 5.8 A standard temporal lobectomy. Transverse plane showing the habitual extent of temporal resections cortical and limbic in...

Visual stimuli photosensitivity and photosensitive epilepsy

The most common reflex epilepsies are those induced by visual stimuli. Flashing lights, bright lights, moving visual patterns e.g. escalators , eye closure, moving from dark into bright light, and viewing specific objects or colours have all been reported to induce seizures. Photosensitive epilepsy is a form of simple reflex epilepsy. The term should be confined to those individuals who show unequivocal EEG evidence of photosensitivity, and differentiated from other, usually more complex, cases...

Porphyria

Porphyria is a term used to describe a range of at least eight different diseases in which the hepatic production of haem is disordered. There is a marked geographical variation, and the highest frequency is in South Africa, where a founder effect has been traced to a Dutch orphan immigrant in 1688. Acute intermittent porphyria AIP is an autosomal dominant condition due to mutations in the porphobi-linogen deaminase gene. Symptoms the acute attack occur only intermittently, and are precipitated...

Agyria pachygyriaband spectrum lissencephaly pachygyria agyria and subcortical band heterotopia

These are descriptive terms denoting abnormalities of cortical gyration, and are grouped together as they show an interconnected genetic basis. In all the gyration is simplified and the cortex is thickened. Lissencephaly literally, smooth brain is the most severe form, in which gyration is grossly diminished or even absent. Subcortical band heterotopia subcortical laminar heterotopia, band heterotopia or double cortex syndrome denotes the presence of a band of grey matter sandwiched by white...

Epilepsia partialis continua

Epilepsia partialis continua EPC can be defined as spontaneous regular or irregular clonic twitching of cerebral cortical origin, sometimes aggravated by action or sensory stimuli, confined to one part of the body, and continuing for hours, days or weeks. It is a remarkable condition, with highly characteristic features, and has a number of underlying causes Table 4.7 . The clonic jerks in EPC can affect any group of muscles. In some individuals they are confined to a single muscle or muscle...

Clorazepate

Clorazepate is a benzodiazepine used in adjunctive treatment of seizure disorders, anxiety and alcohol withdrawal. It is a prodrug which is rapidly converted to nordiazepam, the major active metabolite produced by diazepam. Ninety per cent of clorazepate is converted in the stomach to nordiaze-pam in less than 10 minutes. Clorazepate is 100 bioavailable by the intramuscular route, and conversion to nordiazepam occurs more slowly in the blood. Clorazepate and nordiazepam are 97-98 protein bound....

Childhood epilepsy with occipital paroxysms benign occipital epilepsy Gastaut typeidiopathic childhood occipital

This is a well-defined syndrome, with mean age of onset of 6 years, in which seizures occur with prominent visual symptomatology, including hemianopia and amaurosis, abstract and complex structured visual hallucinations, eye deviation and prominent postictal headaches with nausea and vomiting. There may be secondary generalization. The EEG shows prominent occipital epileptiform spike-wave activity which appears after eye closure and is suppressed by eye opening. The condition has an excellent...

Interictal scalp EEG

In the presence of a neocortical lesion EEG often is unhelpful. The spatial distribution of an EEG focus coincides with lesion localization in less than one-third of patients, and can 11 44 00 11 44 01 11 44 02 11 44 03 11 44 04 11 44 05 11 44 06 11 44 07 11 44 08 11 44 09 11 44 00 11 44 01 11 44 02 11 44 03 11 44 04 11 44 05 11 44 06 11 44 07 11 44 08 11 44 09 indeed be widely discrepant Figures 5.13 and 5.14 . This is due to the rapid and wide propagation of seizure discharges in neocortical...

Acute Symptomatic Seizures

This unsatisfactory term is reserved for seizures that start in close temporal association to a sudden acute precipitant, in people who had not had prior seizures. If the epilepsy can be attributed to a pre-existing non-acute or static cause, it is referred to as remote symptomatic epilepsy, but clearly there is a grey area in which the distinction between acute and remote symptomatic epilepsies is rather arbitrary. The boundary is similarly blurred in some cases of reflex epilepsy or cases in...

Dravet syndrome severe myoclonic epilepsy of infancy [SMEI polymorphic epilepsy of infancy

Dravet syndrome is a severe form of epilepsy, developing in early life and with a poor prognosis. The frequency is about 1 in 20,000-40,000 live births. Twenty-five per cent of children affected have a family history of epilepsy, and interestingly many but not all cases have mutations in the SCNIA gene, the same gene that causes the more benign GEFS , and indeed there are families in which both phenotypes co-exist. Furthermore, in spite of the frequency of a family history, curiously, the...

Epilepsy arising in the frontal lobe

Seizures of frontal lobe origin can take the form of complex partial seizures, simple partial seizures, and secondarily generalized attacks. About 30 of complex partial seizures arise in the frontal lobe. The clinical and EEG features of the complex partial seizures overlap with those of temporal lobe origin, not Table 1.11 Clinical features of complex partial seizures of frontal lobe origin which help differentiation from seizures of temporal lobe origin. Frequent attacks with clustering Brief...

Drug treatment of complex partial status epilepticus

How aggressively complex partial status epilepticus needs to be treated is a matter of some controversy. It is the author's view that in most cases there is little risk of cerebral damage due to the seizures, and for this reason intravenous therapy is not needed unless the condition is particularly severe or resistant. Others disagree and treat complex partial status using similar protocols to that described above for tonic-clonic status. There is, however, no good evidence that aggressive...

Ilae Classification Of Seizure Type

Epilepsy is a variable condition, and it is therefore appropriate to devise a system of classification. The International League Against Epilepsy ILAE has been engaged on this task for over 40 years, proposing and then revising various systems. The classification most widely accepted is a classification of seizure type i.e. of the phenomenology of seizures rather than of epilepsies . Such a classification could be based on various criteria, for instance the cerebral region in which the seizure...

Meningitis and encephalitis

The risk of chronic epilepsy following encephalitis or meningitis is almost sevenfold greater than that in the population in general. The increased risk is highest during the first 5 years after infection, but remains elevated for up to 15 years. The risk is much higher after encephalitis relative risk RR 16.2 than bacterial meningitis RR 4.2 or aseptic meningitis RR 2.3 . The presence of early seizures i.e. during the acute phase of the infection greatly influences the risk of subsequent...

Epilepsy arising in the parietal and occipital lobes

Focal seizures arise from foci in these locations less commonly than from frontal, central or temporal lobe regions. The typical manifestations of the seizures are subjective sensory and visual disturbances Table 1.13 . Additional features are common owing to spread to adjacent cortical regions. Parietal lobe seizures typically comprise sensory manifestations. These may be tingling or a feeling of electricity which can be confined or march in a Jacksonian manner. Sensations of sinking, choking...

Benign epilepsy with centrotemporal spikes BECTS

In this common childhood epilepsy syndrome p. 20 , therapy is gratifyingly straightforward and indeed drug treatment is not necessary in all cases. If attacks are infrequent or mild, regular therapy seems inappropriate, especially as some children have only a few attacks before the epilepsy remits. Tonic-clonic seizures carry greater risks than the partial attacks and may tip the balance towards therapy. The partial seizures, when frightening and distressing, can warrant treatment, even if they...

Articles in scientific journals

Adab N, Kini U, Vinten J, Ayres J, et al. 2004. The longer term outcome of children born to mothers with epilepsy. J Neurol Neurosurg Psychiatry, 75 1575-83. Adab N, Tudur SC, Vinten J, Williamson P, and Winterbottom J. 2004. Common antiepileptic drugs in pregnancy in women with epilepsy. Cochrane Database Syst Rev, 3 CD004848. American Academy of Pediatrics. Committee on Quality Improvement, Subcommittee on Febrile Seizures. 1999. Practice parameter long-term treatment of the child with simple...

Other vascular disorders

Cortical venous infarcts are particularly epileptogenic, at least in the acute phase, and may underlie a significant proportion of apparently spontaneous epileptic seizures complicating other medical conditions and pregnancy. Seizures also occur with cerebrovascular lesions secondary to rheumatic heart disease, endocarditis, mitral valve prolapse, cardiac tumours and cardiac arrhythmia, or after carotid endarterectomy. Infarction is also an important cause of seizures in neonatal epilepsy....

Progressive myoclonic epilepsy PME

This is a rather specific phenotype, which can be caused by a variety of genetically determined neurological disorders Table 1.26 . In most parts of the world there are six common underlying conditions mitochondrial disorders, Unverricht-Lundborg disease, dentato-rubro-pallido-luysian atrophy DRPLA , Lafora body disease, neuronal ceroid lipofuscinosis, and sialidosis. The term progressive myoclonic epilepsy should be confined to those cases where the predominant clinical symptom is myoclonus....

Piracetam

Piracetam is a drug with an unusual clinical history Table 3.32 . It was developed in 1967 by the research laboratory of UCB-Pharma in Belgium and deployed in clinical practice as a 'memory enhancing drug'. Its efficacy in this role has been highly contentious and the drug has not been licensed for this indication, either in the USA or the UK, although it is widely used in other, particularly developing countries the manufacturers report over a million prescriptions . Recent controlled trials...

Inflammatory and immunological diseases of the nervous system

Epilepsy can be a complication of many inflammatory and immunological diseases affecting the central nervous system. The mechanisms of seizures can be due to the direct effect of immunological processes for instance in Rasmussen's encephalitis or an indirect effect due to vascular disease and cerebral infarction for instance in the cerebral vascul-itides . In many conditions the mechanisms are unknown. Seizures are the most common neurological complication of the inflammatory bowel diseases...

Precautions needed with parenteral benzodiazepines

Although benzodiazepines are the drugs of first choice for emergency therapy, they do carry a risk of respiratory depression, hypotension and cardio-respiratory collapse. In a well-controlled study in anaesthetic practice, for example, diazepam 10 mg was given intravenously to 15 patients and resulted in a drop in blood pressure of 10 mmHg or more in eight patients, a mean 28 decrease in ventilation, and a 23 decrease in tidal volume. The effects on cardiorespiratory function are as great or...

Nitrazepam

Nitrazepam is a benzodiazepine derivative with a nitro group at the 7 position of the benzodiazepine ring. Oral bioavailability is about 78 . Peak concentrations are reached in about 1.5 hours. Nitrazepam is 85-88 protein bound. The volume of distribution is 2.4 l kg, and is higher in the elderly. The plasma half-life is about 27 hours, but the drug is rapidly taken up into the CSF and brain tissue and the CSF elimination half-life is 68 hours. Nitrazepam is metabolized in the liver by...

Postvaccination encephalopathy

The possible role of vaccination particularly pertussis vaccination in causing a childhood encephalopathy and subsequent epilepsy and learning disability has been the subject of intense study, with contradictory claims. The UK National Childhood Encephalopathy Study found that children hospitalized with seizures and encephalopathy were more likely to have received diphtheria-tetanus-pertussis DTP vaccination in the previous 7 days than control children. However, the potential methodological...

The Reflex Epilepsies

The term reflex epilepsy is used to describe cases in which seizures are evoked consistently by a specific environmental trigger. In some cases the stimulus can be highly specific and in others less so. The term is not usually applied to patients whose seizures are precipitated by internal influences such as menstruation, nor to situations where the precipitating factors are vague or ill-defined e.g. fatigue, stress , nor to patients with existing epilepsy where seizures are more likely to...

Typical absence status epilepticus petit mal status

This occurs only in patients with idiopathic generalized epilepsy, usually as part of the subcategory childhood absence epilepsy, in which a history of absence status occurs in about 3 -9 . The attacks can recur, and can last for hours or occasionally days. The episodes are typically precipitated by factors such as menstruation, withdrawal of medication, hypoglycaemia, hyperventilation, flashing or bright lights, sleep deprivation, fatigue, stress, or grief. The principle clinical feature is...

Paraldehyde

Paraldehyde still has a minor role in premonitory stage given rectally, as an alternative to the benzodiazepines in situations where facilities for resuscitation are not available. Paraldehyde is rapidly and completely absorbed after IM injection or rectally. The risk of drug accumulation, hypotension or cardio-respiratory arrest is small, and seizures do not often recur after control has been obtained. Paraldehyde has been used for many years in status, and although there is wide experience in...

Myoclonic status epilepticus in coma

Myoclonic status epilepticus in coma is a well-recognized complication of the cerebral anoxia resulting from cardiorespiratory arrest typically after a myocardial infarction or cardiac surgery . It is characterized by spontaneous and stimulus-sensitive myoclonus usually occurring within 24 hours of the coma. To what extent this is really an 'epileptic' state, or is simply a sign of a severely damaged brain, is arguable. The patients generally have burst suppression on their EEGs, are deeply...

Cortical mapping

Depth Electrodes

Cortical mapping of functionally important cortex is a vital function where neurosurgical procedures are planned in sensory, motor or speech areas, and is required to identify eloquent areas and thus avoid post-surgical neurological deficit. Techniques vary but all include the placement of grids over the proposed resection site, and the observation of the clinical effects of electrical stimulation of each cortical contact. Ictal and interictal EEG can be recorded at the same time. Mapping is...

Emergency antiepileptic drug therapy

This is needed in convulsive attacks if the convulsions persist for more than 10 minutes, recur rapidly or last longer than is customary for the individual patient. It is usual to give a fast-acting benzodiazepine. The traditional choice is diazepam, administered either intravenously or rectally. Intravenous diazepam is given in its undiluted form at a rate not exceeding 2-5 mg min, using the Diazemuls formulation. Because of the high lipid solubility of diazepam, injections given at a faster...

Rasmussens encephalitis

This is a rare progressive neurological disorder, of unknown cause, in which severe epilepsy co-exists with slowly pro gressive atrophy of one cerebral hemisphere. The condition usually begins in late childhood, but can start in adults and also in young children. Pathologically, there is severe atrophy of one hemisphere with histological evidence of perivascular lymphocytic infiltration, neuronal loss and microglial nodule formation. The pathological changes are strikingly unilateral, and where...

Landau Kleffner syndrome

The Landau-Kleffner syndrome is a childhood epileptic encephalopathy in which persisting aphasia develops in association with severe EEG abnormalities and epilepsy Table 1.23 . It is an uncommon condition with a male predominance and usually without a family history. Onset occurs at between 18 months and 13 years, in most cases between 4 and 7 years. The aetiology and pathogenesis of the syndrome, if indeed these are unitary, are unknown. The condition develops in children who were previously...

Epilepsy arising in the central perirolandic region

The primary manifestations are motor or sensory Table 1.12 . The motor features can take the form of jerking, dystonic spasm, posturing or occasionally paralysis, Table 1.12 Partial seizures of central origin. Often no loss of consciousness simple partial seizure Contralateral clonic jerking which may or may not march Contralateral tonic spasm Posturing, which is often bilateral, and version of head and eyes Speech arrest and involvement of bulbar musculature producing anarthria or choking,...

Sialidosis

Sialidosis is less common than the other causes of progressive myoclonic epilepsy. There are at least two variants. All cases are inherited in an autosomal recessive manner. Type I sialidosis cherry-red spot myoclonus syndrome is due to N-acetyl neuraminidase deficiency, which results in defective cleavage, and thus accumulation, of oligosaccha-rides, typically with inclusion bodies with vacuolation. It has a juvenile or adult onset and is characterized by action myoclonus and an intention...

Hypothalamic hamartoma and gelastic epilepsy

The hypothalamic hamartoma is a particular form of hamartoma. These are benign tumours, usually small and sometimes confined to the tuber cinerium. They are present in young children, and characteristically present with gelastic seizures, learning disability, behavioural disturbance, and later with precocious puberty. They are diagnosed by MRI scanning, but the lesions can be very subtle, especially if small, without mass effect, and isodense on both T1 and T2 sequences. Gelastic seizures are...

Febrile seizures temporal lobe epilepsy and hippocampal sclerosis

A research area of great current importance, and intensive investigation, is the study of the undoubtedly strong genetic influences on febrile seizures and thus on hippocampal sclerosis and temporal lobe epilepsy TLE . Various strands of evid-ence exits. Families are reported with inherited TLE mesial and lateral TLE and also epilepsy with variable EEG foci . Four foci have to date been found in linkage studies of febrile seizures. In cohort studies, polymorphisms in the interleukin-1p gene...

Generalised epilepsy with febrile seizures plus GEFS

This is a very heterogeneous form of epilepsy, inherited in an autosomal dominant fashion, with age-specific manifestations and variable penetrance about 60 in the original families . Febrile seizures are the most common feature, and seizures precipitated by fever tend to occur throughout childhood. Afebrile seizures of varying types, generalised tonic-clonic, myoclonic, atypical absence, and less commonly focal seizures, develop later in childhood. Status epilepticus can occur. The severity...

Benign partial epilepsy with centrotemporal spikes

Benign partial epilepsy with centro-temporal spikes BECTS also known as rolandic epilepsy or benign epilepsy with rolandic spikes is the most common 'idiopathic' epilepsy syndrome, accounting for perhaps 15 of all epilepsies Table 1.16 . The peak age of onset is 5-8 years and over 80 of cases have onset between 4 and 10 years. It is likely that the condition is the result of an age-related genetically determined neuronal hyperexcitability in the rolandic area, resulting in characteristic giant...

Autosomal dominant nocturnal frontal lobe epilepsy ADNFLE

This was the first 'pure epilepsy' in which the causal gene was found. Various mutations in the a4 and P2 subunits of the nicotinic acetylcholine receptor have been identified in families with this interesting condition. Typically, the condition is inherited in an autosomal dominant fashion with 75 penetrance. The patients suffer from purely nocturnal frontal lobe seizures sometimes many each night without daytime seizures and without other symptoms. The seizures are brief, lasting less than 1...

Magnetic resonance imaging MRI

MRI is undertaken in all patients undergoing evaluation for epilepsy surgery. Indeed, it is now the primary screening test for entry into a programme of pre-surgical evaluation. The imaging must be of an appropriate quality and tailored to the visualization of mesial temporal pathologies. Substandard MRI, for instance with wide inter-slice intervals or sequences with poor grey white differentiation, frequently fails to detect hippocampal sclerosis, which is then shown on better targeted...

Syndrome of electrical status epilepticus during slow wave sleep ESES

ESES continuous spike-wave of slow sleep CWES Table 1.22 refers to an epileptic encephalopathy characterized by the presence of generalized 1-3 Hz spike-wave discharges occupying 85 or more of the EEG of non-REM sleep. Of children with epilepsy, 0.5 show this EEG pattern. The condition is diagnosed during childhood 1-14 years with a peak age of onset between 3 and 5 years. About 30 of children showing this pattern have identifiable brain pathology such as previous meningitis or brain anoxia,...