The use of electroencephalography (EEG) can exclude temporal status epilepticus from consideration. EEGs are normal in about 70% of KLS patients, but background slowing may sometimes be detected. In addition, low-frequency high-amplitude waves can be observed during waking hours.Initially, KLS appears similar to bipolar depression. Patients with frontal-lobe syndromes and Klüver–Bucy syndrome also display similar symptoms, but these conditions can be differentiated by the presence of brain lesions. KLS should also be distinguished from very rare cases of menstruation-caused hypersomnia. Prevention
Lithium is the only drug that appears to have a preventive effect. In two studies of more than 100 patients, lithium helped prevent recurrence of symptoms in 20% to 40% of cases. The recommended blood level of lithium for KLS patients is 0.8–1.2 mEq/ml. It is not known if other mood stabilizers have an effect on the condition. Anti-depressants do not prevent recurrence. Treatment
Several drug therapies have been used on patients with KLS, but none of them have been subject to randomized controlled trials. A 2016 Cochrane Review concluded that "No evidence indicates that pharmacological treatment for Kleine–Levin syndrome is effective and safe".In several cases, stimulants, including modafinil, have been reported to have a limited effect on patients, often alleviating sleepiness. They can cause behavioral problems, but they may pose fewer issues if used in older patients with mild symptoms. In some case reports, lithium has been reported to decrease the length of episodes and the severity of their symptoms and to increase the time between episodes.
Esophageal dysphagia is a form of dysphagia where the underlying cause arises from the body of the esophagus, lower esophageal sphincter, or cardia of the stomach, usually due to mechanical causes or motility problems. Signs and symptoms
Patients usually complain of dysphagia (the feeling of food getting stuck several seconds after swallowing), and will point to the suprasternal notch or behind the sternum as the site of obstruction. Causes
If there is dysphagia to both solids and liquids, then it is most likely a motility problem. If there is dysphagia initially to solids but progresses to also involve liquids, then it is most likely a mechanical obstruction. Once a distinction has been made between a motility problem and a mechanical obstruction, it is important to note whether the dysphagia is intermittent or progressive. An intermittent motility dysphagia likely can be diffuse esophageal spasm (DES) or nonspecific esophageal motility disorder (NEMD). Progressive motility dysphagia disorders include scleroderma or achalasia with chronic heartburn, regurgitation, respiratory problems, or weight loss. Intermittent mechanical dysphagia is likely to be an esophageal ring. Progressive mechanical dysphagia is most likely due to peptic stricture or esophageal cancer.Schematically the above can be presented as a tree diagram:

Differential diagnosis
Esophageal stricture, or narrowing of the esophagus, is usually a complication of acid reflux, most commonly due to gastroesophageal reflux disease (GERD). These patients are usually older and have had GERD for a long time.