Fascicular multiple ocular motor nerve paresis as first presentation of anaplastic astrocytoma.

A case of spontaneous, painless partial III (pupil-sparing) and IV fascicular nerve paresis as the first presentation of anaplastic astrocytoma is reported. The other ocular, neurological and systemic examination was within normal limits. The literature and possible anatomical location of this atypical presentation is reviewed.

Astrocytoma is a common brain tumor. We report an atypical presentation of anaplastic astrocytoma, which presented with fascicular III (pupil-sparing) and IV cranial nerve paresis.

Case Report

A 40-year-old Caucasian gentleman visited our hospital with complaints of sudden onset of diplopia of two weeks duration. The night before the onset he was at a dance party where he consumed alcohol and cocaine. The dance consisted of violent head banging movement. The diplopia was worse on moving the eye either in vertical or horizontal gaze. He visited the eye casualty the next day and was advised a magnetic resonance imaging (MRI) scan. He instead went for a holiday and came to our institution two weeks later. There was no associated history of decreased vision, eye pain, headache, flashes, floaters, headache, nausea and signs and symptoms of raised intracranial pressure. There was no associated significant past ocular and medical history. His personal history included consumption of a bottle of wine daily since 20 years and occasional cocaine use since three to four years.

Examination revealed visual acuity of 20/20 in each eye with normal anterior segment and fundus in both eyes. Neuro-ophthalmic and orthoptic assessment confirmed pupil-sparing IIIrd and IVth nerve paresis of the left eye [Fig. 1] and Hess Chart performed on the patient is shown in Fig 2,Fig 3. Systemic and other neurological examination was unremarkable.

Figure 1

Showing eye in the primary position of gaze after the left eye pupil has been dilated using mydriatics

Figure 2

Hess chart of left eye

Figure 3

Hess chart of right eye

All the blood investigation were within normal limits. Urgent MRI reported an area of increased signal intensity in the brainstem mainly in the left side with mass effect [Fig. 4]. There was also a small area of low density within it more superiorly. Magnetic resonance angiography revealed an area of high signal intensity in the vicinity of the posterior communicating region on the left side [Fig. 5]. This represented a vascular event probably due to a small bleed arising from the vertebral basilar region. No communicating artery aneurysm could be detected.

Figure 4

MRI showing increased signal intensity in the brain stem mainly in left side with mass effect, in the box area

Figure 5

MRA area of high signal intensity in the vicinity of the posterior communicating region on the left side as shown in boxed area

Urgent referral to a neurologist was made and MRI stereotactic stealth biopsy was performed. A diagnosis of Grade 3 anaplastic astrocytoma was made. No ocular surgery or for tumor was done. His symptoms and general health had deteriorated in the first week in the interim when we first saw him till he was seen in peripheral hospital. His ocular symptoms started to improve four weeks from then significantly, that there was no diplopia in primary gaze. He was followed in the ophthalmology department in a tertiary hospital eight weeks later and then at six months and was subsequently discharged with complete recovery of eye movements. Subsequently, he was doing well and was discharged and is being currently followed by an oncologist/radiotherapist.

Discussion

This patient presented with intracerebral hemorrhage in a distribution commonly seen with hypertensive vasculopathy.1,2

Astrocytoma is the most common glial tumor but is more commonly located in the cerebrum, leptomeninges, spinal cord and usually present with other associated focal neurological signs and symptoms. This case represents a rare manifestation of the tumor with only fascicular III and IV nerve paresis.

An important cause of spontaneous (non-traumatic) intracranial hemorrhage not due to cerebral aneurysm, vascular malformation or hypertensive cerebrovascular disease is brain tumor which has been reported to represent 0.9 to 11% of spontaneous intracranial hemorrhage according to various studies.3

Hemorrhage due to tumor is significantly more common in younger patients with the exception of pituitary adenoma. Wakai et al. in their study reported that 42.2% patients showed no evidence of clinical symptoms related to bleeding, 33.3% had preceding history related to brain tumors and in 24.4% the apoplectic syndrome was the initial presentation and out of them only four were astrocytoma.4 Kothbauer in their autopsy series of 430 spontaneous cerebral hematomas found that 21 out of 44 tumor-associated hematomas were anaplastic gliomas, 17 associated with metastatic tumors, two with oligodendrogliomas, two malignant lymphomas and one meningioma.5 In another series of 235 surgically verified brain tumors by Bromowicz, eight had hemorrhage into the tumor and out of them three had anaplastic astrocytoma.6

The anatomical elucidation of this infrequent palsy is difficult but the possible mechanism here is astrocytoma and associated hemorrhage which was located in the oculomotor nerve fascicle, where the pupillary efferent fibers are anatomically separate from the fibers to the extraocular muscle and also the trochlear nerve fascicle as they transverse the brainstem.

Therefore, screening for mass lesions using neuro-imaging, preferably MRI, is indicated in patients with the presentation of pupil-sparing third and other nerve paresis where diagnosis of hypertensive or ischemic vasculopathy is often made, as timely intervention may carry a favorable prognosis.