Trochlear nerve palsy causes

Question 1

Definition

Answer 1

Lesion of the 4th cranial nerve

Trochlear nerve lesions in isolation are rare

Can cause vertical diplopia (double vision when looking down)

Question 2

Causes

Answer 2

Idiopathic:
– most idiopathic cases are believed to be congenital
—- Bagheri et al presumed 76.7% of cases we’re thought to be congenital

Trauma:
– frequent cause of bilateral trochlear nerve palsy
—- Bagheri et al presumed 16.4% of cases

Rare causes:
- meningioma
- Lyme disease
- Guillain-Barré syndrome
- Pseudotumor cerebri

• lack of blood flow caused by DM or Hypertension
• aneurysm

Dosunmu et al:
Congenital (49%)

Hypertension (18%)

Trauma (18%)

Hypertension with DM (5%)

post-neurosurgery (3%)

Intracranial neoplasms (1%)

Diabetes (1%)

Herpes zoster (1%)

Idiopathic (4%)