Acute Thyrotoxic Bulbar Myopathy with Encephalopathic Behaviour: An Uncommon Complication of Hyperthyroidism

Abstract

Objective. Acute thyrotoxic bulbar palsy is rare, severe, and rapidly progressive. We describe a case of thyrotoxicosis with bulbar palsy, encephalopathy, and pyramidal tract dysfunction. Case Report. 64-year-old white male with toxic multinodular goiter presented with rapid atrial fibrillation. He had mild tremor, normal cranial nerve examination, 4/5 strength in all extremities, normal reflexes, and down going plantars. TSH was low at 0.09 (normal: 0.34–5.6 uIU/mL), and free T4 was high at 5.22 (normal: 0.47–1.41 ng/dL). Despite optimal AV nodal blockade, he had persistent rapid atrial fibrillation. He later developed cervical dystonia, rigidity, clonus, dysarthria, dysphagia, vocal cord palsy, and absent gag reflex. Thyroid storm was suspected. Neuroimaging and cerebrospinal fluid cultures were nondiagnostic. Acetylcholine receptor antibodies were negative. Swallow ability was impaired with heavy secretions. Remarkable improvement in symptoms was noted after initiation of treatment for thyroid storm. Conclusion. Pyramidal tract symptoms and bulbar palsy may occur with thyrotoxicosis. Cranial nerve involvement and encephalopathy raise a question of primary brain mechanism causing bulbar palsy. This is reversible with prompt treatment of thyroid storm.

Massive barium sulfate aspiration during upper gastrointestinal contrast material study in an elderly patient with dysphagia

“…While an enlarging cervical or retrosternal goiter may cause direct impingement of the esophagus, muscle weakness from thyrotoxicosis can cause bulbar muscle wasting, resulting in oropharyngeal or esophageal dysmotility [4,5]. It is usually associated with thyroid crises or chronic thyrotoxic myopathy and acute bulbar palsy, abrupt in onset and fatal, is a rare pattern [5,6].…”

“…On the other hand, there are different comorbid disease associations with dysphagia based on age, and their prevalence varies among age groups [6]. In particular, the prevalence of dysphagia associated with esophageal malignancy ranges from 53-93% with the average age of 63-65 years [10].…”

Thyrotoxic myopathy: research status, diagnosis, and treatment

“…The clinical manifestation is rapidly advanced to severe muscle weakness. In general, flaccid paralysis occurs in a few days, which primarily weakens the pharyngeal muscles and then induces chewing difficulties, dysphagia, dysphonia, weakness of limbs, and even lethargy and coma [27]. Moreover, it can be manifested as bulbar paralysis with binocular diplopia and hyperreflexia [28].…”

Endocrine Myopathies: Clinical Review

“…Younger patients generally have sympatho-adrenergic symptoms and thyrotoxic myopathy is a rare clinical finding such as rhadbomyolysis and hypokalemic periodic paralysis [36]. Chronic thyrotoxicosis may affect bulbar muscles and can be fatal [37,38]. Bulbar myopathy develops in 16.4 percent of patients with chronic thyrotoxic myopathy [37].…”

“…Chronic thyrotoxicosis may affect bulbar muscles and can be fatal [37,38]. Bulbar myopathy develops in 16.4 percent of patients with chronic thyrotoxic myopathy [37]. Other clinical fatal syndrome is Tyhrotoxic Periodic Paralysis [TPP] [39].…”