Uncommon presentation of a common disorder.

Area of Science:

• Endocrinology
• Neurology
• Internal Medicine

Background:

• Stiff person syndrome (SPS) is a rare autoimmune neurological disorder characterized by fluctuating muscle rigidity and spasms.
• Hypothyroidism, a common endocrine disorder, can present with various neuromuscular symptoms, including myopathy.

Observation:

• A young male presented with severe generalized muscle stiffness, impacting daily activities and causing recurrent falls, mimicking SPS.
• Physical examination revealed calf muscle hypertrophy and generalized muscle tautness.
• Investigations uncovered severe hypothyroidism with elevated thyroid antibodies.

Findings:

• The patient's clinical presentation, initially suggestive of SPS, was ultimately attributed to severe hypothyroidism.
• Myopathy is a recognized, though less common, manifestation of hypothyroidism.
• Thyroid antibodies indicated an autoimmune component contributing to the thyroid dysfunction.

Implications:

• This case underscores the importance of considering hypothyroidism in the differential diagnosis of conditions resembling SPS.
• Early identification and treatment of hypothyroidism are crucial for complete resolution of neuromuscular symptoms.
• Raising awareness among clinicians can prevent misdiagnosis and ensure timely, effective management of hypothyroid myopathy.