[Hypokalemic thyrotoxic periodic paralysis (HTPP). Rare differential diagnosis in case of acute tetraparesis in Europe].
BACKGROUND
Differential diagnosis of acute tetraparesis includes paraplegia caused by trauma, ischemia, inflammation or tumor, Guillain-Barré syndrome, periodic paralysis, myasthenia gravis, and dissociative paralysis.


METHODS
The case of a 45-year-old man is reported who noticed weakness of both legs after heavy labor. In the evening he was unable to climb stairs, at night he noticed additional weakness in both arms and dyspnea. After transfer to the authors' department profound tetraparesis, tachycardia and slight dyspnea were found on examination. Cranial nerve examination was unremarkable. Deep tendon reflexes, however, were only slightly diminished. Laboratory work-up revealed hypokalemia (potassium 1.9 mmol/l) and hyperthyreosis. Elevated TRAK and TPO antibodies as well as sonography and scintigraphy of the thyroid gland gave evidence of Graves' disease. After intravenous administration of potassium tetraparesis resolved completely.


CONCLUSIONS
Hypokalemic thyrotoxic periodic paralysis (HTPP), a subtype of hypokalemic paralysis, is unusual in Caucasians. In Asian men the disease is more common. The underlying mechanism is an extra-intracellular shift of potassium in the voluntary muscle cells. In contrast to hereditary autosomal dominant paralyses, a genetic defect is not known. Usually, symptoms of hyperthyreosis in HTPP are mild which can hamper the correct diagnosis.
Gaul
Charly
C
Klinik und Poliklinik für Neurologie, Martin-Luther-Universität, Halle-Wittenberg. Charly.Gaul@gmx.de
Leonhardt
Georg
G
Spens
Antje
A
Schneyer
Ulrich
U
Zierz
Stephan
S
D000208:Acute Disease; D003937:Diagnosis, Differential; D005060:Europe; D006801:Humans; D020514:Hypokalemic Periodic Paralysis / Q000150:complications / Q000175:diagnosis*; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000008:administration & dosage; D011782:Quadriplegia / Q000175:diagnosis* / Q000188:drug therapy; D013971:Thyrotoxicosis / Q000150:complications / Q000175:diagnosis*
D011188:Potassium