Thyrotoxic periodic paralysis
Alternative names:
periodic paralysis - thyrotoxic
Symptoms:
- weakness/paralysis
- shoulders and hips are the most common location
- arms and legs may possibly be involved
- intermittent occurrences
- most commonly occurring upon awakening
- triggered by rest after exercise
- triggered by heavy, high carbohydrate, high salt meals
- lasting for up to several days
- spontaneous recovery of normal strength between attacks
- vision changes (rare)
- swallowing difficulty (rare)
- speech difficulty (rare)
- difficulty breathing (rare)
- person is alert during attacks
Symptoms of hyperthyroidism:
Signs and tests:
The health care provider may suspect thyrotoxic periodic paralysis based on a family history of the disorder, the episodic nature of symptoms, low potassium levels during attacks, abnormal thyroid hormone levels, and elimination of other disorders associated with low potassium as the cause of symptoms.
Between attacks, examination is normal, or there may be signs of hyperthyroidism, such as a palpably enlarged thyroid. During an attack, reflexes may be decreased or absent. Weakness is constant rather than spastic (spasmodic) and is greater in proximal muscle groups (near the body, such as the shoulders or hips) than in distal groups (away from the body, such as the arms or legs). The health care provider may attempt to trigger an attack by administering insulin and glucose (which reduces potassium levels) or thyroid hormone.
Hyperthyroidism is confirmed by abnormal results of: - TSH levels
- T3
- T3 resin uptake
- T4
- Serum potassium is low during attacks but is normal between attacks, confirming the diagnosis.
- An ECG may be abnormal during attacks.
- An EMG is normal between attacks; during an attack EMG is abnormal, showing electrical silence.
- A muscle biopsy may occasionally show abnormalities.
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