Autosomal dominant epilepsy with auditory features

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Autosomal dominant epilepsy with auditory features (ADEAF) is an uncommon form of epilepsy that runs in families. People with this condition typically hear sounds (auditory features), such as buzzing, humming, or ringing, during seizures. Some people hear more complex sounds, like specific voices or music, or changes in the volume of sounds. Some people with ADEAF suddenly become unable to understand language before losing consciousness during a seizure. This inability to understand speech is known as receptive aphasia. Less commonly, seizures may cause visual hallucinations, a disturbance in the sense of smell, a feeling of dizziness or spinning (vertigo), or other symptoms that affect the senses.

ADEAF is called a focal epilepsy because the seizures start in one part of the brain, rather than involving the entire brain from the beginning. Most people with ADEAF have focal aware seizures, which do not cause a loss of consciousness. These seizures are thought to begin in a part of the brain called the lateral temporal lobe. In some people, seizure activity may spread from the lateral temporal lobe to affect other regions of the brain. If seizure activity spreads to the entire brain, it causes a loss of consciousness, muscle stiffening, and rhythmic jerking. Episodes that begin as focal seizures and spread throughout the brain are known as secondarily generalized seizures.

Seizures associated with ADEAF usually begin in adolescence or young adulthood. They may be triggered by specific sounds, such as a ringing telephone or speech, but in most cases the seizures do not have any recognized triggers. In most affected people, seizures are infrequent and effectively controlled with medication.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Variants (also called mutations) in the LGI1 gene or RELN gene are the most common cause of ADEAF. Variants in other genes have been identified in small numbers of affected families, and the genetic cause in many families is unknown.

The LGI1 gene provides instructions for making a protein called Lgi1 or epitempin, which is found primarily in nerve cells (neurons) in the brain. Although the precise role of epitempin remains uncertain, researchers suggest it may play a role at the junction of neurons (synapses) where cell-to-cell communication takes place.

The RELN gene provides instructions for making a protein called reelin. Reelin is produced in the brain both during brain development and after birth. It appears to play several roles at synapses, including controlling communication between neurons.

Variants in the LGI1 or RELN gene may impair the formation or function of synapses. Abnormal communication between neurons can lead to seizure activity in the brain.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to raise the risk of developing epilepsy. About two-thirds of people who inherit an LGI gene variant will develop seizures. Some people who have the altered gene never develop the condition, which is known as reduced penetrance. The likelihood of developing seizures in people with a variant in RELN or other associated genes is unknown. Most people with ADEAF have one affected parent and other relatives with the condition.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

ADEAF appears to be uncommon, although its prevalence is unknown.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Auditory hallucinations · Very frequent (99-80%)

Perception of sounds without auditory stimulus.

EEG with focal epileptiform discharges · Very frequent (99-80%)

EEG discharges recorded in particular areas of a localized (focal) abnormality in cerebral electrical activity recorded along the scalp by electroencephalography (EEG).

Focal-onset seizure · Very frequent (99-80%)

A focal-onset seizure is a type of seizure originating within networks limited to one hemisphere. They may be discretely localized or more widely distributed, and may originate in subcortical structures.

Aphasia · Frequent (79-30%)

An acquired language impairment of some or all of the abilities to produce or comprehend speech and to read or write.

Interictal epileptiform activity · Frequent (79-30%)

Epileptiform activity refers to distinctive EEG waves or complexes distinguished from background activity found in in a proportion of human subjects with epilepsy, but which can also be found in subjects without seizures. Interictal epileptiform activity refers to such activity that occurs in the absence of a clinical or subclinical seizure.

Abnormal autonomic nervous system physiology · Occasional (29-5%)

A functional abnormality of the autonomic nervous system.

Focal autonomic seizure · Occasional (29-5%)

An autonomic seizure is a type of focal non-motor seizure characterized by alteration of autonomic nervous system function as the initial semiological feature.

Focal aware seizure · Occasional (29-5%)

A type of focal-onset seizure in which awareness is preserved. Awareness during a seizure is defined as the patient being fully aware of themself and their environment throughout the seizure, even if immobile.

Other findings in the same source

From: Orphanet

Additional reported features include Nocturnal seizures (Occasional (29-5%)); Visual hallucinations (Occasional (29-5%)); Atypical behavior (Very rare (<4-1%)); Bilateral tonic-clonic seizure (Very rare (<4-1%)); Bilateral tonic-clonic seizure with focal onset (Very rare (<4-1%)); Depression (Very rare (<4-1%)); Generalized-onset seizure (Very rare (<4-1%)); Impulsivity (Very rare (<4-1%)); Migraine (Very rare (<4-1%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Autosomal dominant epilepsy with auditory features is Neurology, with a neurologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which nervous-system findings help explain the symptoms?
• Would an assessment of walking, communication or daily function be helpful?
• Are rehabilitation or other specialist services relevant?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Autosomal dominant epilepsy with auditory features. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.