normal, and there is dissociation between subj ective and objective sleepiness, as measured
by the mean sleep latency during the MSLT.
Conversion disorder (functional neurological symptom disorder). Atypical features,
such as long-lasting cataplexy or unusual tr iggers, may be present in conversion disorder
(functional neurological symptom disorder).  Individuals may report sleeping and dream-
ing, yet the MSLT does not show the characteristic sleep-onset REM period. Full-blown,
long-lasting pseudocataplexy may occur during consultation, allowing the examining
physician enough time to verify reflexes, which remain intact. 
Attention-deficit/hyperactivity disord er or other behavioral problems. In children and
adolescents, sleepiness can ca use behavioral problems, including aggressiveness and in-
attention, leading to a misdiagnosis of attention-deficit/hype ractivity disorder.
Seizures. In young children, cataplexy can be misd iagnosed as seizures. Seizures are not
commonly triggered by emotions, and when they are, the trigger is not usually laughing or
joking. During a seizure, individuals are more  likely to hurt themselves when falling. Sei-
zures characterized by isolated atonia are rare ly seen in isolation of other seizures, and
they also have signatures on  the electroencephalogram. 
Chorea and movement disorders. In young children, cataplexy can be misdiagnosed as
chorea or pediatric autoimmune neuropsychiatric disorders associated with streptococcal
infections, especially in the co ntext of a strep throat infectio n and high antistreptolysin O
antibody levels. Some children may have an overlapping movement d isorder close to on-
set of the cataplexy.