Complete third nerve palsy: Only presenting sign of extradural hematoma in an awake patient

Sir,

Complete third nerve palsy due to extradural hematoma in an awake patient is a contrasting clinical feature and an extremely rare clinical entity.

A 28-year-female presented with a sudden-onset, painless, complete left third nerve palsy. She had a fall in the bathroom four weeks ago. At the time of the fall, she was pregnant and was asymptomatic. Two weeks after the fall, she had an uneventful normal vaginal delivery. One week post partum, she developed diplopia and noticed drooping of the left eyelid, which was painless. She consulted an ophthalmologist who asked for a magnetic resonance imaging (MRI) of the brain and referred the patient to the neurosurgery department.

She had no headache. She was fully conscious and well oriented to time, place, and person. The left pupil was 5 mm in size and not reacting to light. The right was 3 mm in size and briskly reacting to the light. External ocular movement examination revealed left medial rectus palsy [Figure 1]. Fundoscopic examination revealed no abnormality. No other positive finding was observed. MRI of the brain revealed a 7.5 × 3.5 × 6 cm-sized extradural hematoma in the left temporal region, which was iso to hyperintense on T1- and hyperintense on T2-weighted images with effacement of the nearby temporal lobe. Clot age of about 7 to 10 days was confirmed on MRI findings [Figure 2].

Figure 1.

Preoperative clinical photograph showing (a) left-sided ptosis, (b) restricted adduction movement of left eyeball, and (c) normal abduction movement of left eyeball suggestive of left-sided isolated third nerve palsy

Figure 2.

Magnetic resonance (MR) image of brain showing extradural hematoma in the left temporal fossa significantly compressing the ipsilateral temporal lobe. Hematoma showed central hypointensity and peripheral hyperintensity on T1-weighted images and homogeneous hyperintensity on T2-weighted images

She underwent left temporal craniotomy. About 150 mL of solid/liquid blood was drained out. No source of bleeding was found. Diplopia improved postoperatively. At the end of two weeks, near-complete improvement in ptosis and significant improvement in adduction was achieved [Figure 3]. Pupillary size became normal at six weeks.

Figure 3.

Postoperative clinical photograph showing (a) near-complete improvement of ptosis, (b) improved adduction movement of left eyeball, and (c) normal adduction movement of left eyeball

Traumatic expanding subdural hematomas may present with third nerve involvement and are usually accompanied by additional neurological dysfunction. In an awake patient, complete third nerve paralysis due to intracranial hematomas is rare, and all of them have been associated with subdural hematoma.[1,2] Ramirez et al. have reported a case of second, third, and fourth cranial nerve paresis as the only evidence of a recurrent epidural hematoma.[3] Only one case of complete third nerve paralysis and epidural hematoma in an awake patient without any other neurological signs or symptoms has been reported.[4]

Epidural hematomas occur rapidly and are usually stable, attaining maximum size within minutes of injury. We believe that isolated complete third nerve palsy without any other signs or symptoms in our patient was due to the slowly developing extradural hematoma of venous origin displacing the temporal lobe and causing compression of the third nerve.

Dilated, sluggish, or fixed pupil (s), bilateral or ipsilateral to the injury occur due to increased intracranial pressure (ICP) or transtentorial herniation. Raised ICP can also have other signs like hypertension, bradycardia, and bradypnea. Transtentorial herniation has the triad of coma, fixed and dilated pupil (s), and decerebrate posturing. In our patient, fundoscopic examination was normal, ruling out raised ICP. Also, transtentorial herniation would have presented with other neurological symptoms, which were absent in our patient. Epidural hematoma accompanied by oculomotor nerve palsy may also occur due to sphenoid sinusitis.[5,6] Stretching of the ipsilateral third nerve initially causes compression of pupilloconstrictor fibers with subsequent paralytic mydriasis. As the uncal herniation progresses, ptosis and weakness of the medial rectus muscle follows sequentially.

Patients presenting with isolated third nerve palsy must undergo brain imaging to rule out extradural hematoma. Physicians must be aware of this unusual and treatable cause of isolated third nerve paralysis, as early intervention in such cases results in complete recovery.