Differential Diagnoses for Hypersomnia
Single Most Likely Diagnosis
- Idiopathic Hypersomnia: This condition is characterized by excessive daytime sleepiness and prolonged nighttime sleep, without any identifiable cause. It is a primary hypersomnia disorder, meaning it is not caused by another medical condition, medication, or substance.
Other Likely Diagnoses
- Obstructive Sleep Apnea (OSA): A common sleep disorder that causes pauses in breathing during sleep, leading to fragmented sleep and excessive daytime sleepiness.
- Narcolepsy: A neurological disorder that affects the brain's ability to regulate sleep-wake cycles, causing excessive daytime sleepiness, cataplexy, and other symptoms.
- Sleep Deprivation: Insufficient sleep or disrupted sleep patterns can cause excessive daytime sleepiness and hypersomnia.
- Hypothyroidism: An underactive thyroid gland can cause fatigue, sleepiness, and hypersomnia due to the decreased production of thyroid hormones.
Do Not Miss Diagnoses
- Brain Tumors or Cysts: Rarely, brain tumors or cysts can cause hypersomnia by compressing or damaging brain structures that regulate sleep and wakefulness.
- Prion Diseases (e.g., Fatal Familial Insomnia): A group of rare, degenerative brain disorders that can cause progressive insomnia, followed by excessive daytime sleepiness and eventually complete inability to sleep.
- Encephalitis or Meningitis: Infections that cause inflammation of the brain or meninges can lead to hypersomnia, among other symptoms.
- Sleep-Related Medication Side Effects: Certain medications, such as sedatives or antidepressants, can cause excessive daytime sleepiness and hypersomnia as a side effect.
Rare Diagnoses
- Kleine-Levin Syndrome: A rare sleep disorder characterized by recurring episodes of excessive daytime sleepiness, often accompanied by automatic behavior, confusion, and other symptoms.
- Sleep-Related Eating Disorder: A rare condition where individuals eat excessively during the night, often without remembering the episodes.
- Hypersomnia Associated with Neurodegenerative Diseases (e.g., Parkinson's Disease, Multiple Sclerosis): Certain neurodegenerative diseases can cause hypersomnia as a symptom, often due to the degeneration of brain structures that regulate sleep and wakefulness.
- Genetic Disorders (e.g., Myotonic Dystrophy): Some genetic disorders can cause hypersomnia as a symptom, often due to the underlying genetic mutation affecting brain function and sleep regulation.