Epilepsy Due to Structural or Metabolic Conditions or Diseases (ICD-11: 8A60)

Introduction

Epilepsy due to structural or metabolic conditions or diseases represents a fundamental category within the classification of epilepsies, distinguished by its clearly identifiable etiology. Unlike epilepsies of unknown origin or purely genetic, this classification encompasses cases where there is a demonstrable underlying condition that substantially increases the risk of development of recurrent epileptic seizures.

This category has significant clinical importance, as it represents a considerable proportion of epilepsy cases seen in specialized neurological services. Correct identification of the structural or metabolic etiology not only guides antiepileptic treatment, but also directs specific interventions for the underlying condition, potentially modifying long-term prognosis.

From a public health perspective, properly understanding and coding these cases allows better resource planning, development of appropriate investigation protocols, and allocation of specialized treatments. Structural or metabolic epilepsy frequently requires a multidisciplinary approach, involving neurologists, neurosurgeons, endocrinologists, and other specialists, depending on the underlying condition.

Accurate coding using the code 8A60 is critical for various aspects of medical practice: it ensures adequate reimbursement in health systems, facilitates epidemiological research, allows international comparisons of clinical data, and ensures that patients receive the appropriate level of investigation and follow-up. The transition from ICD-10 to ICD-11 brought greater specificity and clarity in the classification of these epilepsies, reflecting significant advances in the understanding of their causes and mechanisms.

Correct ICD-11 Code

Code: 8A60

Description: Epilepsy due to structural or metabolic conditions or diseases

Parent category: Epilepsy or seizures

Official definition: Epilepsy that occurs in relation to another distinct structural or metabolic condition or disease, which has been demonstrated to be substantially associated with an increased risk of epilepsy development.

This code is applied when there is clear evidence, usually through neuroimaging, metabolic studies, or other complementary examinations, of a structural brain condition or metabolic alteration that precedes and underlies the development of seizures. The causal or associative relationship between the identified condition and epilepsy must be established based on consolidated medical knowledge.

Code 8A60 serves as the main category, possessing specific subcategories that detail the exact nature of the underlying structural or metabolic condition. This hierarchical structure allows for both generic and specific coding, depending on the level of available information and the need for specificity in clinical documentation.

The use of this code presupposes that epilepsy is not the primary manifestation of a specific genetic syndrome, nor that seizures are provoked exclusively by acute reversible factors. The diagnosis requires demonstration of recurrent unprovoked seizures in the context of chronic or persistent structural or metabolic alteration.

When to Use This Code

Code 8A60 should be applied in specific clinical scenarios where there is clear evidence of structural or metabolic condition associated with epilepsy:

Scenario 1: Chronic Post-Traumatic Epilepsy Patient with history of severe traumatic brain injury two years ago, presenting with brain magnetic resonance imaging showing encephalomalacia in the left temporal lobe and surrounding gliosis. Developed recurrent focal seizures with impaired consciousness, unrelated to acute precipitating factors. Chronic post-traumatic epilepsy, when associated with demonstrable structural changes, fits perfectly into this category.

Scenario 2: Epilepsy Secondary to Cerebrovascular Accident Individual who suffered extensive ischemic cerebrovascular accident in the territory of the right middle cerebral artery, with sequela of established infarction visible on neuroimaging. Six months after the acute event, recurrent focal motor seizures began involving the left hemibody. The chronic vascular structural lesion constitutes a clearly identifiable epileptogenic substrate.

Scenario 3: Focal Cortical Dysplasia Child with refractory focal seizures since five years of age, whose investigation with high-resolution magnetic resonance imaging demonstrated focal cortical dysplasia in the right frontal lobe. The cortical developmental malformation represents a congenital structural condition associated with substantially elevated risk of epilepsy, justifying this code.

Scenario 4: Epilepsy Associated with Tuberous Sclerosis Patient with confirmed diagnosis of tuberous sclerosis, presenting with multiple cortical tubers and subependymal nodules on neuroimaging, developing multifocal focal epilepsy. Although tuberous sclerosis has a genetic basis, epilepsy results from the characteristic brain structural lesions of the disease, fitting into this category when structural manifestations predominate.

Scenario 5: Epilepsy in Context of Previous Encephalitis Adult with history of severe viral encephalitis three years ago, which progressed to bilateral hippocampal atrophy and signal changes on magnetic resonance imaging. Presents with recurrent temporal focal seizures, characterizing epilepsy secondary to residual structural changes from the infectious process.

Scenario 6: Epilepsy Associated with Low-Grade Brain Tumor Patient with slow-growing brain tumor (such as low-grade astrocytoma) located in the temporal region, whose initial clinical manifestation was the development of focal epileptic seizures. The tumor structural lesion constitutes a clearly identifiable substrate for epilepsy.

Essential criteria for use of this code include: documentation of recurrent unprovoked epileptic seizures, identification of structural or metabolic condition through appropriate complementary examinations, and plausible temporal and pathophysiological relationship between the identified condition and the development of epilepsy.

When NOT to Use This Code

There are specific situations where code 8A60 is not appropriate and should be replaced by other more precise classifications:

Acute Provoked Seizures: When seizures occur exclusively in the context of acute reversible insult (severe hypoglycemia, acute electrolyte disturbance, intoxication, substance withdrawal), code 8A63 (Seizure due to acute cause) should be used. The fundamental difference is that in 8A60 there is a chronic or permanent condition, whereas in 8A63 the precipitating factor is transitory and potentially reversible.

Genetic Epilepsy Syndromes: Epilepsies where the primary manifestation is genetically determined, even if secondary structural alterations may exist, should be coded as 8A61 (Genetic or presumed genetic syndromes expressed primarily as epilepsy). Examples include juvenile myoclonic epilepsy, childhood absence epilepsy, and Dravet syndrome when the genetic component is the primary defining characteristic.

Epileptic Encephalopathies: When there is cognitive or behavioral deterioration related to epileptic activity itself, not merely to the underlying condition, and this deterioration is disproportionate to what would be expected from the underlying etiology, the appropriate code is 8A62 (Epileptic encephalopathies). The crucial distinction is that in epileptic encephalopathies, the epileptic activity itself contributes significantly to progressive neurological impairment.

Single or Isolated Seizures: The diagnosis of epilepsy requires recurrence of unprovoked seizures. A single seizure, even in the context of structural lesion, does not constitute epilepsy and should be coded appropriately as a single seizure.

Transient Neonatal Seizures: Seizures occurring exclusively in the neonatal period, related to transient metabolic or structural conditions of this period, without subsequent recurrence, should not be classified as chronic epilepsy.

Appropriate differentiation requires careful analysis of clinical history, temporal pattern of seizures, complementary investigation findings, and understanding of underlying pathophysiology. Detailed documentation is essential to justify the choice of appropriate code.

Step-by-Step Coding Process

Step 1: Assess Diagnostic Criteria

The first essential step is to confirm that the patient meets criteria for epilepsy diagnosis. This requires documentation of at least two unprovoked seizures occurring with an interval greater than 24 hours, or one unprovoked seizure with a risk of recurrence greater than 60% over the next 10 years based on clinical and complementary findings.

Diagnostic confirmation should include detailed clinical history, characterizing seizure semiology, frequency, precipitating or aggravating factors, and functional impact. Observer testimonies are valuable for seizures with impaired consciousness. Electroencephalogram should be performed to document epileptiform activity and characterize the type of epilepsy (focal versus generalized).

High-quality structural neuroimaging is fundamental. Brain magnetic resonance imaging with protocols specific for epilepsy is the examination of choice, allowing identification of subtle structural lesions. Computed tomography may be used when magnetic resonance imaging is contraindicated, although with lower sensitivity for cortical lesions.

Metabolic investigations may be necessary depending on clinical presentation, including glucose levels, electrolytes, hepatic and renal function, and specialized metabolic studies when indicated.

Step 2: Verify Specifiers

After confirming the diagnosis of epilepsy, the underlying structural or metabolic condition should be appropriately characterized. The specific nature of the lesion or alteration should be documented with maximum possible detail, using subcategories of code 8A60 when applicable.

The severity of epilepsy should be evaluated considering seizure frequency, response to antiepileptic treatment, impact on quality of life and functionality. Drug-resistant epilepsies, defined as failure to achieve adequate control with two appropriate antiepileptic medications in monotherapy or combination, require specific documentation.

Lateralization and localization of focal seizures should be specified when determined through clinical semiology, electroencephalographic findings, and neuroimaging. This information is particularly relevant for potentially surgical cases.

Associated comorbidities, both neurological and systemic, should be documented, as they frequently influence management and prognosis.

Step 3: Differentiate from Other Codes

Differentiation from 8A61 (Genetic or presumed genetic syndromes): The fundamental distinction lies in primary etiology. In 8A60, epilepsy results from an acquired or congenital structural or metabolic condition that is not primarily genetic. In 8A61, the basis is a specific genetic mutation or epileptic syndrome with a strong hereditary component, even though secondary structural alterations may be present. Examples of 8A61 include juvenile myoclonic epilepsy, Dravet syndrome with confirmed SCN1A mutation, and childhood absence epilepsy.

Differentiation from 8A62 (Epileptic encephalopathies): The differentiating criterion is whether the epileptic activity itself contributes to cognitive or behavioral deterioration beyond what is expected from the underlying condition. In epileptic encephalopathies, there is regression or developmental stagnation directly attributable to epileptic activity, not merely to the underlying structural lesion. West syndrome, Lennox-Gastaut syndrome, and Landau-Kleffner syndrome are examples of epileptic encephalopathies.

Differentiation from 8A63 (Seizure due to acute cause): Temporality is crucial. 8A63 applies to seizures provoked by reversible acute insults (hypoglycemia, electrolyte disturbance, intoxication, withdrawal, acute trauma). In 8A60, the underlying condition is chronic or permanent, and seizures are recurrent independent of acute factors. A single seizure during severe hypoglycemia would be 8A63; recurrent seizures in a patient with sequela of old stroke would be 8A60.

Step 4: Required Documentation

Checklist of mandatory information for adequate coding:

Detailed description of epileptic seizure semiology
Frequency and temporal pattern of seizures
Date of epilepsy onset and initial seizures
Electroencephalogram results with description of epileptiform findings
Complete structural neuroimaging report (magnetic resonance imaging or computed tomography)
Specific description of the identified structural or metabolic condition
Temporal relationship between the underlying condition and seizure onset
Antiepileptic medications used and therapeutic response
Relevant neurological and systemic comorbidities
Impact on functionality and quality of life

The medical record should clearly establish the connection between the identified structural or metabolic condition and the development of epilepsy, based on established pathophysiological knowledge and clinical plausibility.

Complete Practical Example

Clinical Case

A 34-year-old male patient presents to the neurology service with a history of three episodes over the last six months characterized by ascending epigastric sensation followed by behavioral arrest, fixed gaze, oromandibuler automatisms and manipulation of objects with the right hand, lasting approximately 90 seconds each episode, followed by post-ictal confusion for 5-10 minutes. There is no history of febrile seizures in childhood.

Past medical history reveals a motorcycle accident four years ago, with severe traumatic brain injury, Glasgow 7 on admission, requiring intensive care unit hospitalization for two weeks. Initial computed tomography showed left temporal hemorrhagic contusion. Neurological recovery was satisfactory, with sequela of anosmia. There were no epileptic seizures in the immediate post-traumatic period.

Current neurological examination is normal except for confirmed anosmia. General physical examination without abnormalities.

Electroencephalogram demonstrates focal epileptiform activity in the left anterior temporal region, with sharp waves and spikes, occasionally with propagation to the ipsilateral frontobasal region. Background activity preserved.

Brain magnetic resonance imaging with epilepsy protocol reveals an area of encephalomalacia in the left temporal pole and anterior portion of the left superior temporal gyrus, with localized volumetric retraction and signal alteration on T2/FLAIR, consistent with sequela of old hemorrhagic contusion. Left hippocampus shows preserved volume without signs of sclerosis. No other structural lesions.

Step-by-Step Coding

Criteria Analysis:

Confirmation of Epilepsy: Patient presents three unprovoked seizures with consistent characteristics (focal seizures with impaired consciousness, semiology suggestive of mesial temporal origin), meeting epilepsy criterion.
Identification of Structural Condition: Magnetic resonance imaging demonstrates chronic structural lesion (left temporal encephalomalacia) secondary to previous traumatic brain injury.
Appropriate Temporal Relationship: Four-year interval between trauma and seizure onset is consistent with late post-traumatic epilepsy, a well-established pattern in medical literature.
Anatomical Correlation: The location of the structural lesion (left temporal) correlates with seizure semiology and electroencephalographic findings, reinforcing causal relationship.
Exclusion of Other Etiologies: There is no evidence of genetic epilepsy syndrome, epileptic encephalopathy, or reversible acute precipitating factor.

Code Selected: 8A60 - Epilepsy due to structural or metabolic conditions or diseases

Complete Justification:

This case exemplifies perfectly the application of code 8A60. Epilepsy developed in direct relation to a clearly identifiable structural condition (post-traumatic encephalomalacia), demonstrated through high-quality neuroimaging. Severe traumatic brain injury is a well-established risk factor for epilepsy development, particularly when associated with permanent structural lesions.

The four-year latency between trauma and seizure onset is characteristic of late post-traumatic epilepsy, distinguishing itself from acute symptomatic seizures that would occur in the first week post-trauma. The structural lesion provides permanent epileptogenic substrate, justifying classification as chronic structural epilepsy.

Complementary Codes:

In addition to the main code 8A60, the underlying condition should be coded:

Sequela of traumatic brain injury (appropriate code from the injury category)

Additional coding for prescribed antiepileptic medication and therapeutic response may be relevant for complete documentation and longitudinal follow-up.

Related Codes and Differentiation

Within the Same Category

8A61: Genetic or presumed genetic syndromes expressed primarily as epilepsy

The fundamental differentiation between 8A60 and 8A61 lies in the primary etiology of epilepsy. Code 8A61 is used when epilepsy results primarily from a determined or strongly suspected genetic basis, manifesting as a specific epileptic syndrome with characteristic clinical and electroencephalographic pattern.

When to use 8A61 versus 8A60: Use 8A61 for idiopathic generalized epilepsies (juvenile myoclonic epilepsy, childhood absence epilepsy, generalized epilepsy with generalized tonic-clonic seizures), benign familial focal epilepsies, and epileptic syndromes with identified genetic mutation as the primary defining characteristic. Use 8A60 when epilepsy results from acquired structural lesion or cortical developmental malformation where the structural component predominates over any genetic predisposition.

Main difference: 8A61 emphasizes primary genetic mechanism; 8A60 emphasizes identifiable structural or metabolic substrate as the cause of epilepsy.

8A62: Epileptic encephalopathies

Epileptic encephalopathies represent conditions where epileptic activity itself contributes to progressive cognitive and behavioral deterioration, in addition to any impairment caused by the underlying etiology.

When to use 8A62 versus 8A60: Code 8A62 is appropriate when there is regression or stagnation of neuropsychomotor development directly attributable to epileptic activity, often associated with specific electroencephalographic patterns (such as hypsarrhythmia in West syndrome or generalized slow spike-and-wave discharges in Lennox-Gastaut syndrome). Use 8A60 when epilepsy occurs in the context of structural lesion, but cognitive impairment is stable and attributable to the underlying lesion, not to epileptic activity per se.

Main difference: 8A62 implies deterioration caused by epileptic activity; 8A60 implies epilepsy secondary to structural condition without seizures themselves causing significant additional deterioration.

8A63: Epileptic seizure due to acute cause

This code applies to seizures provoked by reversible acute factors, not constituting epilepsy proper.

When to use 8A63 versus 8A60: Use 8A63 for seizures occurring exclusively during or immediately after acute insult (hypoglycemia, hyponatremia, intoxication, alcohol withdrawal, acute head trauma in the first week, acute cerebrovascular accident). Use 8A60 for recurrent unprovoked seizures in the context of established chronic or structural condition.

Main difference: 8A63 indicates reversible acute precipitating factor; 8A60 indicates chronic or permanent underlying condition.

Differential Diagnoses

Conditions that may be confused with structural epilepsy include psychogenic non-epileptic seizures, syncope, sleep disorders (such as parasomnias), migraine with aura, and transient global amnesia episodes. Differentiation requires careful clinical evaluation, often with prolonged video-electroencephalographic monitoring for event capture and clinical-electrographic correlation.

Differences with ICD-10

In ICD-10, epilepsy was classified primarily by seizure semiology (codes G40.0 to G40.9), with less emphasis on etiology. Epilepsies secondary to structural conditions were often coded as "symptomatic epilepsy" within subcategories based on seizure type.

The closest code in ICD-10 would be G40.1 (Focal symptomatic epilepsy related to localized lesions) or G40.2 (Generalized symptomatic epilepsy), depending on clinical presentation.

Main changes in ICD-11:

ICD-11 adopts a more explicit etiological approach, prioritizing the underlying cause of epilepsy over seizure semiology. Code 8A60 specifically groups epilepsies with identifiable structural or metabolic etiology, regardless of seizure type.

This change reflects evolution in the pathophysiological understanding of epilepsies and aligns with contemporary classifications from the International League Against Epilepsy (ILAE). The hierarchical structure of ICD-11 allows greater specificity through subcategories, detailing the exact nature of the structural or metabolic condition.

Practical impact:

The transition requires that healthcare professionals prioritize adequate etiological investigation, not just semiological characterization of seizures. Electronic documentation systems must be adapted to capture information about underlying structural or metabolic conditions. Investigation protocols may need revision to ensure adequate neuroimaging and appropriate complementary studies.

For purposes of continuity of epidemiological and administrative data, correspondence tables between ICD-10 and ICD-11 are essential, although the correlation is not always direct due to conceptual differences between the classifications.

Frequently Asked Questions

1. How is the diagnosis of structural or metabolic epilepsy made?

The diagnosis requires three essential components: confirmation of epilepsy through clinical history of recurrent unprovoked seizures, identification of structural or metabolic condition through appropriate complementary tests (mainly high-quality neuroimaging), and establishment of a plausible relationship between the identified condition and epilepsy. Electroencephalogram documents epileptiform activity and characterizes the type of epilepsy. Brain magnetic resonance imaging with specific protocols for epilepsy is fundamental for identifying structural lesions. Metabolic investigations are necessary when there is suspicion of underlying metabolic disorder.

2. Is treatment available in public health systems?

First-line antiepileptic medications are generally available in public health systems in most countries, although availability of newer medications may vary. Treatment of structural or metabolic epilepsy involves not only seizure control with antiepileptic medication, but also management of the underlying condition when possible. Evaluation for surgical treatment in refractory cases may be accessible through specialized epilepsy centers linked to public health systems, although access may vary geographically.

3. How long does treatment last?

Structural or metabolic epilepsy generally requires prolonged treatment, often for life, especially when the underlying structural condition is permanent. The decision to discontinue antiepileptic medication is individualized, considering factors such as duration of seizure-free period (generally minimum of 2-5 years), type of epilepsy, neuroimaging and electroencephalogram findings, and patient preferences. In some specific cases, such as epilepsy secondary to surgically resectable structural lesion, cure may be possible with complete removal of the epileptogenic lesion.

4. Can this code be used in medical certificates?

Yes, code 8A60 can and should be used in official medical documentation, including certificates, reports, and prescriptions, when appropriate. Proper coding is important for justifying need for treatment, work absence when necessary, and access to benefits or accommodations. Depending on the context, it may be appropriate to also include specific code of the underlying structural or metabolic condition. Medical confidentiality considerations should be respected, providing necessary information without excessive detail in documents that will be widely shared.

5. Is structural epilepsy always refractory to drug treatment?

Not necessarily. Although structural epilepsies present higher rates of refractoriness than idiopathic epilepsies, many patients achieve adequate seizure control with appropriate antiepileptic medication. Treatment response depends on various factors, including type and extent of the structural lesion, location, age of seizure onset, and optimization of drug treatment. Approximately one-third of patients with structural epilepsy may become refractory, defined as failure of control with two appropriate medications, but this means that two-thirds respond adequately to treatment.

6. Can children with structural epilepsy attend regular school?

In most cases, yes. The ability to attend regular school depends not so much on the epilepsy itself, but on seizure control, presence of cognitive or behavioral comorbidities, and availability of adequate support. Children with well-controlled epilepsy and preserved cognitive development can generally participate fully in regular school activities. Adaptations may be necessary in some cases, such as seizure action plan at school, modifications of physical activities as needed, and additional educational support when there is cognitive impairment associated with the underlying structural lesion.

7. What is the difference between structural and symptomatic epilepsy?

The term "symptomatic epilepsy" was used in previous classifications to describe epilepsies with known cause, being gradually replaced by more specific terminology. "Structural epilepsy" in the current classification refers specifically to cases where there is identifiable brain structural lesion on neuroimaging. The term "structural or metabolic" in code 8A60 is more comprehensive, including both anatomical alterations and metabolic disorders that increase seizure risk. The terminological evolution reflects greater diagnostic precision provided by advances in neuroimaging and pathophysiological understanding.

8. Is it necessary to repeat neuroimaging tests periodically?

The need for follow-up neuroimaging depends on the nature of the underlying structural condition. Static lesions (such as sequelae of old stroke, cortical developmental malformations) generally do not require routine test repetition, except if there is change in clinical pattern. Potentially progressive lesions (such as tumors, vascular malformations) require periodic monitoring according to specific protocol for the condition. Significant change in seizure pattern, development of new neurological symptoms, or suspicion of complications may justify neuroimaging repetition even in lesions considered static.

Conclusion:

Proper coding of epilepsy due to structural or metabolic conditions using ICD-11 code 8A60 requires clear understanding of diagnostic criteria, appropriate investigation to identify the underlying condition, and careful differentiation from other categories of epilepsy. The etiological approach of ICD-11 reflects scientific advances and provides greater precision in classification, with important implications for treatment, prognosis, and research. Complete and accurate documentation benefits patients through optimized management and facilitates effective communication among health professionals, administrative systems, and researchers.

External References

This article was prepared based on reliable scientific sources:

References verified on 2026-02-03

Epilepsy due to structural or metabolic conditions or diseases

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