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Ptosis

Medicine > Neurosciences

Differential Diagnosis Schema 🧠

Neurogenic Causes

  • Third nerve palsy: Typically associated with diplopia and a “down and out” eye position; may be caused by aneurysm, diabetes, or head trauma.
  • Horner’s syndrome: Ptosis, miosis, and anhidrosis on the affected side; caused by disruption of the sympathetic pathway, possibly due to a lung apex tumor (Pancoast tumor) or carotid artery dissection.
  • Myasthenia gravis: Fluctuating ptosis that worsens with fatigue and improves with rest; may be associated with diplopia.
  • Multiple sclerosis: Demyelination can cause a variety of ocular motor disturbances, including ptosis.
  • Guillain-Barré syndrome: Rarely, this can present with bilateral ptosis due to cranial nerve involvement.
  • Congenital ptosis: Present from birth due to abnormal development of the levator palpebrae superioris muscle or its innervation.

Myogenic Causes

  • Myasthenia gravis: Most common myogenic cause, characterized by fatigable muscle weakness.
  • Oculopharyngeal muscular dystrophy: Late-onset progressive ptosis and dysphagia.
  • Mitochondrial myopathies: Can present with ptosis, ophthalmoplegia, and other systemic manifestations.
  • Chronic progressive external ophthalmoplegia (CPEO): Ptosis and limited eye movements due to mitochondrial DNA mutations.
  • Congenital myopathies: Such as nemaline myopathy, can cause ptosis as part of generalized muscle weakness.
  • Blepharophimosis syndrome: Congenital condition with ptosis, epicanthus inversus, and telecanthus.
  • Myotonic dystrophy: Ptosis may be accompanied by muscle wasting, cataracts, and myotonia.
  • Facioscapulohumeral muscular dystrophy: Ptosis may occur alongside facial and shoulder girdle muscle weakness.

Mechanical Causes

  • Dermatochalasis: Excess skin in the upper eyelid, often seen in elderly patients, can cause a mechanical ptosis.
  • Eyelid tumors: Tumors or lesions on the eyelid, such as chalazion, can weigh down the eyelid and cause ptosis.
  • Trauma: Eyelid or orbital trauma can damage the levator muscle or its aponeurosis, leading to ptosis.
  • Post-surgical: Ptosis may occur after surgeries involving the eyelid or orbit, such as cataract surgery or blepharoplasty.
  • Contact lens use: Long-term use of hard contact lenses can cause mechanical stretching of the eyelid.
  • Eyelid edema: From conditions like angioedema or severe allergies, can cause temporary mechanical ptosis.
  • Blepharoptosis from scarring: Secondary to inflammatory conditions such as Stevens-Johnson syndrome or ocular cicatricial pemphigoid.

Key Points in History 🥼

Symptom Characteristics

  • Onset: Sudden onset suggests a neurological cause (e.g., third nerve palsy), while gradual onset may indicate a myogenic or mechanical cause.
  • Duration: Chronic ptosis is often associated with conditions like myasthenia gravis or congenital ptosis.
  • Fatigability: Ptosis that worsens with fatigue and improves with rest is highly suggestive of myasthenia gravis.
  • Laterality: Unilateral ptosis may indicate a localized issue such as a third nerve palsy or eyelid tumor, while bilateral ptosis often points to a systemic cause like myasthenia gravis.
  • Associated diplopia: The presence of double vision alongside ptosis suggests an ocular motor nerve palsy or myasthenia gravis.
  • Pain: Painful ptosis may indicate an underlying inflammatory or neoplastic process.
  • History of trauma: Recent trauma may point towards a mechanical cause of ptosis.
  • Variability: Fluctuating symptoms throughout the day are typical of myasthenia gravis.
  • Visual symptoms: Blurred vision, eye strain, or headaches can accompany ptosis, particularly in conditions like myasthenia gravis.
  • Previous ocular surgery: Past surgeries, particularly involving the eyelids or orbit, may lead to ptosis.
  • Medication use: Use of medications like corticosteroids or botulinum toxin can sometimes contribute to ptosis.
  • Systemic symptoms: Associated symptoms such as generalized muscle weakness, fatigue, or respiratory difficulties may point to systemic myopathies.
  • Family history: Genetic conditions such as oculopharyngeal muscular dystrophy or mitochondrial disorders may have a family history.

Background

  • Medical history: Chronic illnesses such as diabetes, hypertension, or thyroid disease may predispose to conditions like third nerve palsy or myasthenia gravis.
  • Surgical history: Prior eye surgeries or trauma may have implications for the development of ptosis.
  • Family history: A family history of ptosis or muscular dystrophies can suggest a genetic predisposition.
  • Social history: Occupational or lifestyle factors that could contribute to the mechanical causes of ptosis, such as prolonged contact lens use.
  • Medication history: Detailed medication review is important, especially for drugs known to cause ptosis.
  • Allergy history: Particularly in patients with eyelid edema related to allergic reactions.
  • Neurological history: History of migraines, seizures, or previous neurological conditions may be relevant.
  • Recent infections: Recent upper respiratory or systemic infections can precipitate conditions like Guillain-Barré syndrome.
  • Immunization status: Particularly relevant in the context of Guillain-Barré syndrome, where vaccination history may be important.

Possible Investigations 🌡️

Laboratory Tests

  • Acetylcholine receptor antibodies: Highly suggestive of myasthenia gravis if positive.
  • Thyroid function tests: To rule out thyroid-related eye disease, particularly Graves’ ophthalmopathy.
  • Fasting blood glucose and HbA1c: To check for diabetes, which may predispose to cranial nerve palsies.
  • Full blood count (FBC): To assess for underlying infection or hematological conditions.
  • Autoimmune screen: Including ANA, ANCA, and other markers if an autoimmune process is suspected.
  • Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP): To assess for inflammation or vasculitis.
  • CK (Creatine kinase) levels: Elevated in myopathies such as muscular dystrophy.
  • Electrolyte levels: To check for abnormalities that might suggest a metabolic cause.
  • Viral serology: For recent infections that could precipitate conditions like Guillain-Barré syndrome.
  • Liver function tests: Particularly if systemic or metabolic causes are suspected.
  • Genetic testing: May be indicated in cases of suspected inherited myopathies or congenital conditions.
  • Plasma lactate and pyruvate: To assess for mitochondrial disorders in the appropriate clinical context.
  • Urine catecholamines: If a paraneoplastic syndrome or neuroblastoma is suspected in children.
  • Muscle biopsy: In selected cases of myopathy or mitochondrial disease, for definitive diagnosis.
  • Antibodies for Lambert-Eaton syndrome: In cases where myasthenia gravis tests are negative, but suspicion remains high.

Imaging and Other Tests

  • MRI brain and orbits: To assess for structural lesions, demyelination, or space-occupying lesions affecting cranial nerves or ocular muscles.
  • CT scan of the orbits: Useful for detecting orbital masses, trauma, or inflammatory processes.
  • CT angiography: To evaluate for aneurysms, carotid artery dissection, or other vascular causes of third nerve palsy.
  • Electromyography (EMG): To assess for neuromuscular junction disorders such as myasthenia gravis.
  • Tensilon test (edrophonium test): Historically used for diagnosing myasthenia gravis, though less common now.
  • Visual field testing: To assess for visual field defects associated with neurological causes.
  • Ultrasound of the eyelid: To assess for masses or structural abnormalities causing mechanical ptosis.
  • Blood pressure monitoring: Important in cases of suspected hypertensive crisis leading to vascular causes of ptosis.
  • Lumbar puncture: If an inflammatory or infectious cause is suspected in the central nervous system.
  • Neurophysiological studies: Including repetitive nerve stimulation, for myasthenia gravis or Lambert-Eaton syndrome.
  • Orbitotomy: In cases where a biopsy of an orbital mass is required for diagnosis.
  • Chest X-ray or CT chest: If a Pancoast tumor or other thoracic cause of Horner’s syndrome is suspected.
  • Genetic counseling: For patients with hereditary causes of ptosis, such as oculopharyngeal muscular dystrophy.
  • Consultation with neurology or ophthalmology: Often necessary for complex cases of ptosis.
  • Slit-lamp examination: To assess for anterior segment pathology, which may contribute to ptosis.

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Neurosciences