Differential Diagnosis for Unilateral Ptosis with Acute Onset
Single Most Likely Diagnosis
- Third Cranial Nerve (Oculomotor Nerve) Palsy: This is often the first consideration for acute onset unilateral ptosis due to its common involvement in conditions such as aneurysms, diabetes, and stroke, which can cause sudden weakness or paralysis of the muscles it innervates, including the levator palpebrae superioris.
Other Likely Diagnoses
- Horner Syndrome: Characterized by ptosis, miosis, and anhidrosis, it results from disruption of the sympathetic nerves supplying the eye. It can be caused by various conditions, including stroke, carotid artery dissection, and tumors.
- Myasthenia Gravis: An autoimmune disease that can cause fluctuating muscle weakness, including the muscles controlling eyelid movement, leading to ptosis. The weakness often worsens with use and improves with rest.
- Orbital or Periorbital Trauma: Direct injury to the orbit or surrounding tissues can cause ptosis due to swelling, hematoma, or direct damage to the levator palpebrae superioris muscle or its innervation.
Do Not Miss Diagnoses
- Cavernous Sinus Thrombosis or Aneurysm: Although less common, these conditions can present with acute ptosis and are medical emergencies due to their potential for severe complications, including blindness, stroke, and death.
- Giant Cell Arteritis: This condition can cause sudden onset of ptosis, especially in older adults, and is associated with other symptoms like headache, jaw claudication, and visual disturbances. Prompt diagnosis and treatment are crucial to prevent blindness.
- Stroke or Transient Ischemic Attack (TIA): While often associated with more widespread neurological deficits, stroke or TIA can occasionally present with isolated third nerve palsy or other focal signs, including ptosis.
Rare Diagnoses
- Botulism: A rare but potentially life-threatening condition caused by the toxin of Clostridium botulinum, which can lead to bilateral ptosis, though unilateral cases can occur. It's characterized by descending flaccid paralysis.
- Lymphoma or Other Orbital Tumors: Although rare, these can cause unilateral ptosis by infiltrating or compressing the orbital tissues or nerves.
- Mitochondrial Myopathies: A group of rare genetic disorders that affect muscle and nerve function, which can include ptosis as part of their clinical presentation.