Thanks Dolores for the further information.
Following possibilities should be considered for these shivers;
1) Electrolyte abnormalities; estimation of calcium, magnesium, sodium, potassium need to be performed.
2) Abnormal thyroid function tests.
3) Dystonia / dyskinesia
4) Tics and stereotypies.
5) Mild grade infection.
An examination by a neurologist and investigations like MRI may be needed apart from the blood work, if these recur or persist.
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