Dysphagia caused by Graves thyrotoxicosis
A Abbara, N Chhina, J Joharatnam, JF Todd, G Williams
A 77 year old man with a background of Crohns disease requiring ileostomy, pernicious anaemia and hypertension, presented with a 4month history of dysphagia to solids, hoarseness of voice, anorexia and marked weight loss of 30kg. He was initially referred to gastroenterology, who performed an endoscopy which was normal.
Subsequently he was referred to the ENT and speech and language therapy departments. A video fluoroscopy confirmed severe oropharyngeal dysphagia with effortful initiation and reduced hyolaryngeal elevation, resulting in decreased airway protection and aspiration. Thyroid ultrasound, CT neck/thorax and whole body FDG PET scans were all normal.
Thereafter he was referred to neurology, who noted marked generalised wasting, although no fatigability, a weak cough, but a preserved gag reflex. An anti-mACh antibody was negative and nerve conduction studies and EMG were unremarkable.
At this time at around 6 months after presentation, he was also noted to be in atrial fibrillation and his blood tests revealed that he had Graves Thyrotoxicosis : TSH <0.05 (NR 0-4.3mU/l) , fT4 42.5 (NR 9-26pmol/l) and fT3 18.5 (NR 2.5-5.7pmol/l), TSH receptor Antibody 7 (NR 0-0.4u/ml), TPO antibody 148 (NR 0-75u/ml).
He was commenced on anti-thyroid medications and anticoagulation with warfarin for cardiovascular risk. Within 6 weeks, his appetite had normalised, his swallowing and voice had virtually normalised and he had gained 8kg in weight.
Discussion:Thyrotoxicosis may commonly result in skeletal proximal myopathy, however rarely it may cause marked wasting of the bulbar muscles resulting in dysphagia, dysphonia and dysarthria. The incidence of bulbar muscle involvement in thyrotoxicosis is not clear, however may range from 16-80% of patients. (1,3)
Most patients have antecedent generalised skeletal muscle wasting, although rarely dysphagia may occur in the absence of chronic generalised thyroid myopathy. (2) Oropharyngeal dysphagia is more commonly encountered than oesophageal dysmotility. (3) The dysphagia usually resolves within 14weeks as the patient is rendered euthyroid with antithyroid medication and a quicker response may be elicited with the addition of B-blockade. (3)
This case highlights the need to consider thyrotoxicosis in patients with new onset dysphagia and marked weight loss in order to avoid unacceptable delays in diagnosis and therapy.
(1) Ramsay ID. Lancet. 1966 Oct 29;2(7470):931-4.
(2) Noto H et al. Intern Med. 2000 Jun;39(6):472-3.
(3) Wei-Yih Chiu et al. Dysphagia Volume 19, Number 2, 120-124.