27th December 2023

Investigations

Blood pressure, blood glucose, urine analysis and erythrocyte sedimentation rate should be performed in cases where a microvascular pathology is suspected. Where thyroid or myasthenia causes are suspected, thyroid function tests, anti-acetylcholine receptor antibodies and single fibre electromyography (EMG) of the orbicularis muscles should be considered. The ice test is a simple bedside investigation which is highly sensitive and specific to myasthenia. The test is interpreted as positive when a ptotic lid is improved after ice application for 2-5 minutes. Acute CT or MRI scans should be obtained when the onset of diplopia is acute and/or present with neurological signs or papilloedema.