Ken Shibano

Thyrotoxicosis Presenting as Unilateral Drop Foot

Neuromuscular disorders associated with hyperthyroidism have several variations in their clinical phenotype, such as ophthalmopathy, periodic paralysis, and thyrotoxic myopathy. We herein report an unusual case of thyrotoxic myopathy presenting as unilateral drop foot. Histopathological examinations of the left tibialis anterior muscle showed marked variation in the fiber size, mild inflammatory cell infiltration, and necrotic and regenerated muscle fibers with predominantly type 1 fiber atrophy. Medical treatment with propylthiouracil resulted in complete improvement of the left drop foot. This case expands the phenotype of thyrotoxicosis and suggests that thyrotoxicosis be considered as a possible cause of unilateral drop foot.

Amyloid myopathy with external ophthalmoparesis

JO N 3 13 8 examination of the specimens obtained by fine needle aspiration of the gland revealed no malignancies. On neurological examination, the eye movements were severely restricted in all directions with mild bilateral ptosis (Fig. 1 a). He also had difficulty in opening the mouth, and his tongue was enlarged, hard, rimmed by indentations caused by the teeth, and having neither the capacity for movement nor fasciculation (Fig. 1 c). The proximal muscles were moderately weak and wasting, without hypertrophy. His serum analyses showed κ-type BenceJones protein (κ-BJP), IgG, IgA and IgM decrement and normal CK. Other laboratory results, including thyroid function tests, anti-thyroid antibodies and anti-acetylcholine receptor antibody, were unremarkable. A CT scan of the orbital structures revealed bilateral lacrimal grand swelling with calcification (Fig. 2 a). An MRI of the orbits also demonstrated an enlargement of all extraocular muscles (Fig. 2 b). Within days after admission, he developed progressive paralytic ileus. He then developed pulmonary edema and cardiac failure, which required intubation and mechanical ventilation. He died 36 days after admission. An autopsy was performed. The histological examination revealed various amounts of an amorphous eosinophilic material deposited in the interstitial tissue of the submaxillary gland, tongue (Fig. 2 c), lungs, pericardium, iliopsoas muscles (Fig. 2 e) and colon. Positive staining with Congo red revealed the eosinophilic material to be an amyloid deposition (Fig. 2 d and f). The tongue and iliopsoas muscle fibers showed marked atrophy under the thick perimysium and endomysium deposited by the eosinophilic material (Fig. 2 c and e). Amyloid Akihiko Hoshi Masahiro Ebitani Gaku Tanaka Kouichirou Nakamura Ken Shibano Nozomu Matsuda Masafumi Abe Yoshikazu Ugawa