Acquired epileptic aphasia is a rare childhood disorder, which occurs due to developmental regression. It is an age-related neurological disorder which is also known as aphasia with a convulsive disorder, or infantile acquired aphasia. Acquired epileptic aphasia is a progressive condition that mainly occurs in children of about 6 years of age and is characterized by gradual loss of expressive and receptive language ability. Most children affected by Acquired epileptic aphasia also experience epileptic seizures at night due to paroxysmal electroencephalographic changes. This syndrome was first discovered by Dr. William M. Landau and Dr. Frank R. Kleffner in 1957 among 6 children and therefore the condition is named after the discoverer as Landau-Kleffner Syndrome or LKS.
What is Acquired Epileptic Aphasia?
Acquired epileptic aphasia occurs in the pediatric population and it is a neurological disorder that mainly affects the temporal-parietal regions of the brain. This syndrome is generally characterized by the rapid or gradual loss of the perceptive language ability and unresponsiveness to sounds. This is followed by the abnormal electrical waves in the brain as noted on encephalogram and onset of epileptic seizures. Due to the progression of this syndrome, the child stops responding to non-verbal sounds associated with behavioral changes.
Symptoms of Acquired Epileptic Aphasia
Acquired epileptic aphasia predominantly occurs in a child between 3 to 7 years of age. However, the onset of the disease can typically happen between 18 months to 13 years of age. The common clinical signs to identify Acquired epileptic aphasia are mentioned as follows:
- Linguistic abnormalities with Bilateral Perisylvian Polymicrogyria.
- Paroxysmal electroencephalographic alteration in EEG.
- Abrupt or gradual development of verbal auditory agnosia.
- Language deterioration in pediatric patients usually occurs over a span of weeks or months.
- Acquired epileptic aphasia may progress to total loss of the ability to speak, i.e., mutism.
- Trouble in understanding and expression of language and thus the child can start communicating through sign language or gestures.
- Infrequent nocturnal epileptic seizures.
- Seizures normally appear between 4 to 10 years of age and gradually disappear with the onset of adulthood.
- Short-term memory is impaired in children with Acquired epileptic aphasia.
- Behavioral changes that are seen include hyperactivity, rage or aggressiveness, decreased attention span, depression and anxiety.
- Intelligence level or IQ is usually unaffected.
- Children with Acquired epileptic aphasia may become developmentally backward or autistic.
- Behavioral and cognitive problems generally affect the parts of the brain that is responsible for controlling speech and comprehension, electrographic seizures, and also for controlling the electrographic status epilepticus of sleep or ESES.
Epidemiology of Acquired Epileptic Aphasia
The prevalence rate of Acquired epileptic aphasia is not much as only 1 or 2 cases are reported annually in some specialized centers. Males are more prone to develop Acquired epileptic aphasia than females with a ratio of 2:1. The peak age for the development of acquired epileptic aphasia is 6 years, but the onset can be seen from 18 months of age to 15 years. The predominant time period is 2 years to 8 years.
Worldwide, 200 or more cases of acquired epileptic aphasia are mentioned in the medical literature. In between 1957 and 1990, about 81 cases were reported, with the rate of diagnosis as 100 cases in every 10 years.
Causes of Acquired Epileptic Aphasia
The actual cause of the occurrence of acquired epileptic aphasia is still unknown and not well-defined. The probable cause of Acquired epileptic aphasia may include demyelinating disease, low-grade brain tumors, neurocysticercosis, central nervous system vasculitis, closed-head injury, unilateral brain lesions, any sorts of infection or inflammatory illnesses, encephalopathic ailments, and autoimmune diseases. Epileptic discharges or seizures are thought to be due to underlying disturbance in cerebral integration or may be because of incapability in processing complex auditory or speech signals. An electroencephalographic abnormality in aphasia is quite common and can occur due to a head injury and astrocytoma in the left temporal lobe.
Genetic disposition can also cause acquired epileptic aphasia. A mutation in genes like GRIN2A gene (16p13.2) and other associated genes, such as BSN, NID2, RELN, and EPHB2 can also cause acquired epileptic aphasia syndrome in infants. Studies have revealed that in some patients acquired epileptic aphasia syndrome occurs because of immunosuppression.
Risk Factors for Acquired Epileptic Aphasia
There are no particular risk factors for acquired epileptic aphasia. If a child manifests any of the above-mentioned symptoms, then it is advised to visit a healthcare provider for early detection and management of the cause. The possible risk factors are as follows:
- Head trauma.
- Presence of neurological deficits, such as signs of increased intracranial pressure due to the underlying structural lesion and hemiparesis.
- Other neurodegenerative diseases.
Treatment of Acquired Epileptic Aphasia
- Drugs for Managing Acquired Epileptic Aphasia: These include –
- Anticonvulsant medications are helpful.
- At the initial stage, medicines like diazepam and valproic acid are often used. Other anti-epileptic drugs or intravenous immunoglobulin or IVIG therapy can also be used to treat Acquired epileptic aphasia.
- Various corticosteroids including oral prednisone, intravenous pulse corticosteroids in high dosage and adrenocorticotrophic hormone are also quite effective in treating.
- Acquired epileptic aphasia.
- Oxcarbazepine, carbamazepine, phenobarbital, and phenytoin are usually avoided as it can cause an increase of epileptic discharges.
- Behavioral Intervention and Speech Therapy for Children with Acquired Epileptic Aphasia:
- Acquired epileptic aphasia patients usually need special education including speech therapy. Speech therapy involves sign language; an aphasic multimodal sensory approach, such as pictures, a communication board, printed word, vocabulary therapy, computers, and a number of behavioral and classroom interventions.
- Psychotherapy may also be helpful for Acquired epileptic aphasia patients.
- A ketogenic diet is advised.
- Followup with an audiologist is always recommended and some type of special education can be necessary.
- Surgical Procedure for Patient with Acquired Epileptic Aphasia: Multiple subpial transection or MST has been used in order to prevent the spread of the epileptic activity. This treatment is responded in pediatric patients who have not responded well to various medical therapies, but has shown improvement in cognitive behavior and language skills.
Prognosis of Acquired Epileptic Aphasia
The prognosis of Acquired epileptic aphasia usually varies in children, but it is quite good in case of seizures. In the case of returning to the pre-disease state, the prognosis is unpredictable. EEG abnormalities and seizures generally relapse and remit by 15 years of age. The prognosis for Acquired epileptic aphasia improves when speech therapy starts early. By the starting of the adolescence years or puberty, seizures usually disappear. Neuropsychological disturbances also improve gradually. Even, short-term remissions are also quite uncommon in acquired epileptic aphasia, but can cause difficulties in different therapeutic modalities. The prognosis for language problem is poorer as language problem usually continues until adulthood and it may take days or years to recover. Only 10% to 20% of patients recover completely. Others develop further complications.
Diagnosis of Acquired Epileptic Aphasia
The common procedure for diagnosis involved in the detection of the acquired epileptic aphasia syndrome includes the following:
- Magnetic Resonance Imaging or MRI: This test demonstrates abnormalities in the dominant temporal lobe, brain tumors, cerebrovascular thromboembolism, neurodegenerative disorders, central nervous system infections, and demyelination. Even, cerebrospinal fluid analysis and quantitative proton magnetic resonance spectroscopy or MRS, are some of the diagnostic techniques used for the diagnosis of acquired epileptic aphasia.
- Electroencephalograms: Abnormal electrical brain activity in both the right and left hemispheres of the brain are common in acquired epileptic aphasia. However, abnormalities in the EEG test have shown language deterioration. EEG findings include posterior temporal, bilateral centrotemporal, and parieto-occipital spikes at the time of wakefulness that is much intense at the time of non-rapid eye movement sleep resulting in electrical status epilepticus in sleep. The pattern of ESES in acquired epileptic aphasia can be either bilateral or unilateral. The most effective way to confirm acquired epileptic aphasia is shown by overnight sleep EEGs with EEGs in every stage of sleep. Interictal EEG reveals posterior temporal peak with slow-wave foci that are often considered bisynchronous and multifocal.
- Positron Emission Tomography: In one or both temporal lobes, Fluorodeoxyglucose Positron Emission Tomography or FDG-PET imaging shows reduced metabolism. Single-photon emission computed tomography or SPECT of the brain shows reduced perfusion of the left temporal lobe. Hypermetabolism is also observed in patients with acquired epileptic aphasia.
- Genetic Tests to Detect Acquired Epileptic Aphasia: Genetic tests for the mutation in GRIN2A gene are also available at certain medical centers.
Differential Diagnosis for Acquired Epileptic Aphasia
This includes any epileptic seizures including sleep potentiation of epileptic actions, such as continuous waves or spikes during sleep, Gastaut, Panayiotopoulos, and other types of rolandic epilepsy and benign infanthood occipital epilepsy. It is important to diagnose autism or a hearing defect which may present as the last sign of acquired epileptic aphasia syndrome.
Unfortunately, a pediatric population with acquired epileptic aphasia is often misdiagnosed as autism, peripheral auditory problem, emotional, behavioral, or cognitive disorder, etc awareness should be created about the signs and symptoms of acquired epileptic aphasia. If symptoms such as inattentiveness to sound, partial epileptic seizures followed by staring, and language regression develop, a physician should be consulted immediately. However, proper medicines and therapies can help in gradual management of the symptoms of Acquired epileptic aphasia.