Pituitary Apoplexy Presenting with Isolated Third Nerve Palsy: A Rare Case Report

Abstract

A 46-year-old female came to neurosurgery outpatient department with sudden onset of drooping of RE upper eyelid and restriction of movements in adduction, depression and elevation in right eye. Patient was a known case of diabetes mellitus whose blood sugar levels were deranged. On examination, patient was diagnosed pituitary macroadenoma. Patient was treated for her uncontrolled diabetes mellitus following which she had underwent transsphenoidal pituitary macroadenoma removal. On treatment, patient’s ptosis had subsided and restriction of movement has resolved.

Introduction

Acquired oculomotor nerve palsies can occur due to numerous factors such as vascular disease, trauma, aneurysm or intracranial tumours [1]. Most common cause of sudden onset of oculomotor nerve palsy is posterior communicating artery aneurysm. Other differentials include intracranial hemorrhage, bacterial meningitis, subarachnoid hemorrhage, cavernous sinus thrombosis, midbrain infarction etc. Isolated oculomotor nerve palsy due to Pituitary Apoplexy is extremely rare. Pituitary apoplexy is a rare clinical syndrome secondary to abrupt hemorrhage or infarction, complicates 2%–12% of pituitary adenomas, especially nonfunctioning tumors, which results in a rapid rise in intrasellar pressure which compresses on adjacent cranial nerves resulting in cranial nerve palsy. Pituitary apoplexy can present with sudden onset headache, visual impairment, ophthalmoplegia, altered mental status and hormonal dysfunction and is an medical and surgical emergency. Pituitary adenomas make up 12–15% of symptomatic intracranial neoplasms [2]. Cranial nerve (CN) palsies occur as a result of compression caused by the direct extension of a tumor out of the sella and into the adjacent cavernous sinuses. Patients with pituitary macroadenomas may present to an eye clinic with symptoms related to mass effect on surrounding structures, which can include headache, bitemporal visual defects, and ocular motor deficits, drooping of lids, double vision, restriction of movements, headache etc. In the rare case report, pituitary apoplexy as a cause of isolated complete oculomotor nerve palsy has been reported (Figs. 1 and 2).

Fig.1.

Preoperative image showing affected extraocular movements

Fig.2.

Preoperative CT scan of brain axial and sagittal sections showing pituitary macroadenoma

Case presentation

A 46-year-old female patient presented to opd with complaints of RE drooping of upper eyelid since 15 days associated with headache. On presentation, In RE patient’s vision was 6/36— > 6/6 (−1.00DS) and Near vision was N12—> N6 (with an add of + 1.50DS). In LE, vision was 6/36— > 6/6 (−1.00DS) and Near vision was N12—> N6 (with an add of + 1.50DS). Anterior segment examination was done on slit lamp biomicroscopy in both eyes and was normal. There was partial pupillary involvement noted. No relative afferent pupillary defect was noted. Fundus examination revealed normal optic disc, macula was normal and general fundus was within normal limits in both eyes. Colour vision was tested on Ishihara plates and was normal in both eyes. On ocular examination RE revealed restriction of movements in adduction, depression and elevation. There was complete ptosis in Right eye. In LE, the extraocular movements were full, free, painless. There was no ptosis noted. There was no facial asymmetry or abnormal head posture noted. Patient did not have features of acromegaly or any menstrual irregulatities. Hormone profile reports were within normal limit (Figs. 3, 4, and 5).

Fig.3.

Preoperative MRI scan of brain axial sections showing hyperintense sellar lesion with hypointensities within suggestive of pituitary macroadenoma with haemorrhagic foci’s

Fig.4.

Preoperative MRI scan of brain coronal sections showing hyperintense sellar lesion

Fig.5.

Preoperative MRI scan of brain sagittal sections showing hyperintense sellar lesion

Investigations

On confrontation test, visual fields were restricted. Automated perimetry performed using the 30–2 Swedish Interactive Thresholding Algorithm revealed bitemporal hemianopia. CT BRAIN was done which revealed: A well-defined heterogeneously enhancing hypodense mass lesion in the sellar region. Pituitary gland is not seen separately from the lesion suggestive of pituitary macroadenoma.

MRI Brain with contrast imaging confirmed the CT scan of Brain findings (Figs. 6, 7, and 8).

Fig.6.

A Tumour bulge seen after dural opening. B Tumour excision been done using ring curette. C Visible tumour after being biopsied. D Visible diaphragm after tumour excision

Fig.7.

Postoperative CT scan of brain showing complete excision of the sellar lesion

Fig.8.

Image showing patient’s ptosis has resolved and restriction of extraocular movements has subsided in post operative period

Treatment

Patient underwent emergency surgical intervention. Patient underwent endoscopic transnasal transsphenoidal pituitary macroadenoma excision. Surgery was uneventful. Complete tumour removal was achieved.

Result

On follow up, patient ‘s ptosis has resolved and restriction of extraocular movements has subsided.

Discussion

Authors report an unusual presentation as the patient has a third cranial nerve palsy which was secondary to the pituitary macroadenoma. Ocular nerve palsy is reported in only 5–17 percent of such tumours, although several nerves are usually affected in the advanced stages of the disease. Isolated ocular nerve palsy is even less common; although rare, third nerve palsy may be the presenting manifestation of pituitary adenoma [3]. In such cases, usually the restriction of movements would be attributed to uncontrolled diabetes, but a careful and vigilant examination reveals that the eye involvement is due to the tumor itself. Lau et al. reported a case of a pituitary adenoma presenting with complete, bilateral oculomotor nerve palsiesw ith minimal loss of visual fields and intact abducens and trochlear nerves [4]. In that case visual acuity in both eyes was 6/18, which persisted even after the surgical excision of the tumour. Ocular motor palsy due to pituitary adenoma was reported to occur in only 5–17% of cases. Several published studies had suggested various mechanisms for the pathophysiology of such palsies, including either indirect compression on the ocular cranial nerves by compressing the cavernous sinus or direct compression through cavernous sinus invasion.

Varma et al. reported a case with acute, partial pupil involving third nerve paresis without affecting vision or other cranial nerves [5].

In our case, patient blood sugar levels were optimized, patient underwent Endoscopic Transnasal Transsphenoidal pituitary macroadenoma excision. Post operative period was uneventful and Patient recovered after surgery. On discharge, there was no restriction of movements and complete resolution of ptosis.

Hence thorough and detailed evaluation and appropriate management is the need of the hour in cases of ocular motor nerve palsies. The eye could be a gateway to many underlying undiscovered systemic illnesses and has to be evaluated with utmost importance, which could benefit the patient.

Ophthalmic manifestation in pituitary apoplexy can be due to the sellar expansion of lesion in the lateral and superior direction. Multiple cranial nerves palsies (3^rd,4^th,6^th) occur from lateral expansion of the pituitary tumour, while superior expansion result in dysfunction of optic nerve and optic chiasma.

3rd Cranial nerve is more susceptible to laterally transmitted pressure by expanding the pituitary mass. Because of its anatomical location, there Is slow onset of palsy due to either gradual compression of nerve on the sinus wall or direct infiltration of nerve by pituitary tumour. Sudden onset due to hemorrhage or infraction in pre-existing pituitary mass is due to compromise of vascular supply of nerve due to compression of vasa nervosum. The most common cause of sudden onset of 3rd nerve palsy is the posterior communicating artery aneurysm.

In the rare event of an otherwise neurologically intact patient presenting with isolated oculomotor nerve palsy, the diagnostic radar should include rare surgical emergencies like pituitary apoplexy. These lesions put time limits on management and should be addressed at the earliest in terms of both diagnosis and treatment.

The differential diagnosis includes intracranial hemorrhage, bacterial meningitis, cavernous sinus thrombosis, and mid brain infarction.

The definitive treatment for pituitary apoplexy early surgical decompression which relieves pressure on the sellar and suprasellar structure.

Conclusion

Pituitary apoplexy should be considered early in the differential diagnosis of sudden onset isolated complete 3rd nerve palsy. Despite its disastrous pathology, there have been cases where affected patients present with isolated visual disturbances or with no symptoms at all as seen in our case as the patient presented with isolated 3^rd cranial nerve palsy. It is therefore important to have early suspicion of pituitary apoplexy in stable patients with eye complaints as early detection and management are life-saving and significantly improve neuro-ophthalmic outcome.