Hypersomnia is a condition of excessive daytime sleepiness or prolonged nighttime sleepiness with extended periods of non-REM sleep. Typical symptoms include disorientation, stupor, and sluggishness on waking. Other symptoms may include anxiety, increased irritation, restless leg syndrome, periodic limb movement disorder, decreased energy, restlessness, slow thinking, slow speech, loss of appetite, hallucinations, and memory difficulty.
Hypersomnia may be caused by another sleep disorder (such as narcolepsy or sleep apnea), dysfunction of the autonomic nervous system, hypothyroidism, low tyrosine levels or as a reaction to drugs or alcohol. Symptoms of hypersomnia typically emerge in adolescence and may occur in recurrent cycles.
Three Subgroups of Hypersomnia
Subgroup I: These patients have a positive family history, and associated clinical symptoms suggest dysfunction of the autonomic nervous system. These symptoms include headache, syncope, orthostatic hypotension, and peripheral vasoconstriction (cold hands and feet).
Subgroup II: This group includes patients who had a viral infection associated with neurologic symptoms, such as Guillain-Barré syndrome, infectious mononucleosis, or atypical viral pneumonia. Even after their infectious disease resolves, these patients continue to require significantly more nocturnal sleep and continue to feel very tired. Although initially these patients are fatigued, subsequently, they have difficulty differentiating fatigue from sleepiness. To fight tiredness, these patients nap and eventually present with complaints of excessive daytime sleepiness. Analysis of cerebral spinal fluid demonstrates moderate lymphocytosis (30-50 cells/mL3 or 30-50 X 10-6/L with mild-to-moderate elevation in protein).
Subgroup III: These patients do not have a positive family or viral infection history, and the cause of the disorder truly is idiopathic. Idiopathic disorders include those caused by low tyrosine levels, which may result in hypothyroidism.
The amino acid tyrosine combines with iodine to form thyroid hormone. Low tyrosine levels, which can be caused by metabolic disturbances, stress, and nutrient deficiencies, can cause hypothyroidism and they can also contribute to hypersomnia. A typical protocol for treating hypersomnia consists of stimulant drugs and tyrosine supplements. Many doctors also treat hypothyroidism with replacement hormone and tyrosine. Tyrosine increases the production of both dopamine and adrenaline as well as thyroid hormone if tyrosine deficiency is present. Tyrosine should be taken on an empty stomach. Unless blood tests are used and show a deficiency requiring larger amounts, the usual dose is 1,000 mg daily.
What's important to note is that even a mild tyrosine deficiency can exacerbate symptoms in patients with hypothyroidism.