18F-FDG Brain PET Findings in Narcolepsy Type 2

Area of Science:

• Neurology
• Sleep Medicine
• Diagnostic Imaging

Background:

• Narcolepsy type 2 is a chronic neurological disorder characterized by excessive daytime sleepiness.
• Adolescent-onset narcolepsy can present with atypical symptoms, including social withdrawal and anhedonia.
• Brain imaging and advanced sleep studies are crucial for diagnosing narcolepsy, especially in complex cases.

Purpose of the Study:

• To present a case of narcolepsy type 2 in an adolescent male with an unusual presentation.
• To illustrate the diagnostic process involving neuroimaging and polysomnography.
• To highlight the importance of considering narcolepsy in adolescents with prolonged unexplained sleepiness and behavioral changes.

Main Methods:

• Clinical presentation and medical history review.
• Electroencephalography (EEG) and Magnetic Resonance Imaging (MRI).
• 18F-FDG brain Positron Emission Tomography (PET) scan and cerebrospinal fluid (CSF) analysis.
• Outpatient sleep study including polysomnography and multiple sleep latency test (MSLT).

Main Results:

• The patient exhibited severe hypometabolism in the brainstem on 18F-FDG PET.
• MSLT revealed reduced mean sleep latency with sleep-onset REM periods.
• CSF analysis ruled out infectious and autoimmune causes.
• MRI showed a small pituitary gland and a developmental venous anomaly.

Conclusions:

• The diagnostic findings were consistent with narcolepsy type 2.
• This case underscores the utility of advanced neuroimaging and sleep studies in diagnosing narcolepsy.
• Early diagnosis and management are essential for improving quality of life in adolescents with narcolepsy.