[3][4] Landau–Kleffner syndrome is characterized by the sudden or gradual development of aphasia (the inability to understand or express language) and an abnormal electroencephalogram (EEG).

This is demonstrated in patients in multiple ways including the inability to recognize familiar noises and the impairment of the ability to lateralize or localize sound.

Generally, earlier manifestation of the disease correlates with poorer language recovery, and with the appearance of night seizures that last for longer than 36 months.

Occasionally, the condition may be induced secondary to other diagnoses, such as low-grade brain tumors, closed-head injuries, neurocysticercosis, and demyelinating disease.

In LKS, fluorodeoxyglucose (FDG) and positron emission tomography (PET) scanning can show decreased metabolism in one or both temporal lobes – hypermetabolism has been seen in patients with acquired epileptic aphasia.

[6] The table below demonstrates the extensive and differential diagnosis of acquired epileptic aphasia along with Cognitive and Behavioral Regression:[6] Note: EEG = electroencephalographic; ESES = electrical status epilepticus of sleep; RL = receptive language; S = sociability Treatment for LKS usually consists of medications, such as anticonvulsants[8] and corticosteroids[9] (e.g., prednisone),[10] and speech therapy, which should be started early.

Some patients improve with the use of corticosteroids or adrenocorticotropin hormone (ACTH) which lead researches to believe that inflammation and vasospasm may play a role in some cases of acquired epileptic aphasia.

The cortex is sliced in parallel lines to the midtemporal gyrus and perisylvian area to attenuate the spread of the epileptiform activity without causing cortical dysfunction.

There is a study by Morrell et al. in which results were reported for 14 patients with acquired epileptic aphasia who underwent multiple subpial transections.

[12] Another study by Sawhney et al. reported improvement in all three of their patients with acquired epileptic aphasia who underwent the same procedure.

Typically, a care team for children with LKS consists of a neurologist, a neuropsychologist, and a speech pathologist or audiologist.

Short-term remissions are not uncommon in LKS but they create difficulties in evaluating a patient's response to various therapeutic modalities.

The following table demonstrate the Long-Term Follow-up of Acquired Epileptic Aphasia across many different instrumental studies:.

The Duran et al. study is one of few that features long-term follow up reports of LKS and utilizes EEG testing, MRIs, the Vineland Adaptive Behavior Scales, the Connor's Rating Scales-revised, and a Short-Form Health Survey to analyze its patients.