Improvement of Cerebral Hypoperfusion with Levothyroxine Therapy in Hashimoto's Encephalopathy Demonstrated by (99m)Tc-HMPAO-SPECT.
BACKGROUND
Hashimoto's encephalopathy (HE) is a rare immune-mediated encephalopathy associated with autoimmune Hashimoto's thyroiditis.


OBJECTIVE
We report on a patient with HE and significant clinical improvement correlating with an increase in cerebral blood flow demonstrated by hexamethylpropyleneamine oxime (HMPAO) single-photon emission computed tomography (SPECT). HMPAO-SPECT was performed with 740 MBq of technetium-99m-HMPAO. To demonstrate the improvement in regional cerebral blood flow, individual regions of interest were drawn around visually diminished HMPAO uptake, the lesion to reference region ratio was calculated and transverse section images and semi-quantitative measurements were performed.


RESULTS
We show a 5-year follow-up with significant clinical improvement, a 10-fold reduction in autoantibodies to thyroid peroxidase and an approximately 20% improvement in cerebral blood flow with HMPAO-SPECT.


CONCLUSIONS
Adequate levothyroxine treatment achieving and maintaining euthyroidism should be considered as therapy to lower autoantibodies and improve clinical outcome in patients with Hashimoto's thyroiditis and encephalopathy.
Practice for General Internal Medicine, Bruck/Mur, Medical University of Graz, Austria.
Wolfgang J
WJ
Schnedl
Department of Nuclear Medicine, Wilhelminenspital, Vienna, Medical University of Graz, Austria.
Siroos
S
Mirzaei
Institute of Pathophysiology, Centre for Molecular Medicine, Medical University of Graz, Austria.
Sandra J
SJ
Wallner-Liebmann
Institute of Physiological Chemistry, Centre of Physiological Medicine, Medical University of Graz, Austria.
Erwin
E
Tafeit
Clinical Institute of Medical and Chemical Laboratory Diagnosis, Medical University of Graz, Austria.
Harald
H
Mangge
Department of Internal Medicine, Medical University of Graz, Graz, Austria.
Robert
R
Krause
Department of Radiology, Medical University of Graz, Graz, Austria.
Rainer W
RW
Lipp
Hashimoto's encephalopathy; Hashimoto's thyroiditis; Hexa­methyl­pro­pylene­amine oxime single-photon emission computed tomography; Hypothyroidism; Levothyroxine