Dyskinesia following modafinil administration in a patient with autism spectrum disorder and narcolepsy: a case report.

A 24-year-old woman with autism and a sleep disorder called narcolepsy developed involuntary muscle movements (dyskinesia) after taking modafinil, a medication used to help with daytime sleepiness. She had previously taken another medication called aripiprazole for autism symptoms. The doctors believe the combination of having autism, previous medication use, and modafinil may have caused these movement problems. This is the first reported case of this side effect in someone with autism.

This case report describes a 24-year-old Japanese woman with autism spectrum disorder (ASD) and narcolepsy who developed dyskinesia after modafinil treatment. The patient had previously been treated with aripiprazole for ASD symptoms, which was discontinued weeks before starting modafinil. Dyskinesia emerged two weeks after the modafinil dose was increased from 100mg to 200mg daily. The authors hypothesize that the dyskinesia resulted from dysregulated striatal dopamine release associated with ASD, combined with residual dopamine D2 receptor blockade from prior aripiprazole use, triggered by modafinil.

This appears to be the first reported case of modafinil-induced dyskinesia in an individual with ASD.

Clinicians should exercise caution when prescribing modafinil to autistic individuals, particularly those with prior antipsychotic exposure. Close monitoring for movement disorders is recommended, especially after dose increases. This case highlights potential unique medication sensitivities in the autism population.

Single case report limits generalizability. Causal relationship between modafinil and dyskinesia cannot be definitively established. Mechanisms proposed are hypothetical. No control group or systematic investigation of contributing factors.

In our clinical practice, we encountered a patient with autism spectrum disorder (ASD) and comorbid narcolepsy who developed dyskinesia following the administration of modafinil for excessive daytime sleepiness. Modafinil is widely prescribed as a wakefulness-promoting agent for the treatment of narcolepsy. Although dyskinesia has been reported as a potential adverse effect of modafinil, to our knowledge, no cases have been described in individuals with ASD. We hypothesized that modafinil contributed to the development of dyskinesia in this patient and conducted a literature review to explore the possible underlying mechanisms.

A 24-year-old Japanese woman with ASD was diagnosed with narcolepsy type 2. She had previously been treated with aripiprazole for ASD-related symptoms, but it had been discontinued more than two weeks before the sleep study. Modafinil was initiated at 100 mg/day and increased to 200 mg/day after three weeks because of insufficient efficacy. Two weeks after the dose increase, dyskinesia developed.

A literature review was performed to identify potential mechanisms. Dyskinesia may have resulted from dysregulated striatal dopamine release associated with ASD and residual dopamine D2 receptor blockade from prior aripiprazole use, triggered by modafinil. Dopaminergic agents in individuals with ASD may induce dyskinesia, particularly following dose escalation, underscoring the need for clinical vigilance.