Transient ischemic attack presenting in an elderly patient with transient ophthalmic manifestations.

Transient ischemic attack (TIA) is a transient neurological deficit of cerebrovascular origin without infarction which may last only for a short period and can have varying presentations. We report a case of 58-year-old male with presenting features of sudden onset transient vertical diplopia and transient rotatory nystagmus which self-resolved within 12 h. Patient had no history of any systemic illness. On investigating, hematological investigations and neuroimaging could not explain these sudden and transient findings. A TIA could possibly explain these sudden and transient ocular findings in our patient. This case report aims to highlight the importance of TIA for ophthalmologists. We must not ignore these findings as these could be warning signs of an impending stroke which may or may not be detected on neuroimaging. Thus, early recognition, primary prevention strategies, and timely intervention are needed.

Introduction

Transient ischemic attack (TIA) is classically defined as a neurological deficit lasting <24 h due to focal ischemia in the brain or retina.[1] Recently, TIA has been defined as a brief episode of neurological dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting <1 h, and without any evidence of acute infarction.[2] TIA although appearing to be a benign event can be a precursor of impending stroke. The 90-day risk of stroke after a TIA has been estimated to be approximately 10%, with one-half of strokes occurring within the first 2 days of the attack.[3] TIA has always been a challenge to diagnose as most of the signs and symptoms disappear by the time patient visits the clinician. Many a times, the diagnosis is based solely on clinical history. A TIA can be misdiagnosed as migraine, seizure, peripheral neuropathy, or anxiety.[3] Therefore, all patients with symptoms of TIA should undergo complete evaluation-complete blood count, lipid profile, prothrombin time, international normalized ratio, partial thromboplastin time, electrolyte and glucose levels, computed tomographic scanning and magnetic resonance imaging (MRI) of the head.[3] We hereby, report a case of a 58-year-old male patient presenting with transient ocular findings disappearing within next 12 h which could possibly be due to TIA which was not picked up on MRI and still remains a diagnosis of exclusion stressing the importance of targeted education on the warning signs of stroke for ophthalmologists.

Case Report

A 58-year-old male patient presented in the ophthalmology outpatient department of secondary health center with complaints of sudden onset double vision, rotation, and spinning of images with a decrease of vision since morning. There was no history of trauma, vomiting, unconsciousness, seizures, deafness, and tinnitus. No history of any previous similar episode was present. There was no history of eye pain, numbness/weakness of extremities or weakness of one side of the body. There was no history of any other systemic disease.

On ocular examination, patient had a best-corrected visual acuity (BCVA) of 20/100 in both eyes, exodeviation of thirty prism diopters and hyperdeviation of sixty prism diopters in the left eye [Figure 1]. Diplopia had both vertical and torsional component and was maximum in dextrodepression. Torsional nystagmus was also present. Pupillary responses, intraocular pressure, and rest of the anterior segment examination were within normal limits. Posterior segment examination was normal except for the mild extorsion in the left fundus. Fundus photograph of the patient could not be taken due to nonavailability of fundus camera in our set up. As the finding of the patient was sudden in onset, taking into account the age and presentation of the patient, neurological and cardiology consultation was done and contrast enhanced MRI of head and orbit (t1-, t2-, and diffusion-weighted) was advised along with hematological investigations.

Figure 1

Left eye of the patient showing exodeviation and hyperdeviation

On the same day, 6 h later, the patient reported with all investigations and resolution of all ocular signs and symptoms except for mild (<10°) of exodeviation in the left eye [Figure 2]. Both torsional nystagmus and vertical diplopia had disappeared, and his BCVA improved to 20/20. MRI revealed an old lacunar infarct in the right caudate nucleus with chronic white matter ischemic changes [Figure 3]. Diffusion-weighted MRI [Figure 4] showed no abnormality. These MRI findings could not explain the transient ocular findings of our case. Even though, neurological as well as hematological examination of the patient was within normal limits, but due to the high index of suspicion of TIA, the patient was started on prophylactic antiplatelet and hypolipidemic drugs by the neurologist and reviewed after a week. In the follow-up visits till 6 months, the patient had no complaints and was asymptomatic.

Figure 2

Left eye of the patient showing mild exodeviation

Figure 3

Magnetic resonance imaging brain of the patient showing old lacunar infarct in right caudate nucleus (red arrow)

Figure 4

Normal diffusion-weighted magnetic resonance imaging of the patient

Discussion

As ophthalmologists, we often face difficulties in making the diagnosis, deciding imaging modality, and treating TIA effectively. TIA may present with neurological symptoms such as hemiparesis or quadriparesis, cranial nerve deficits, respiratory difficulty, altered sensorium, vertigo, and ataxia.[4] Nystagmus, vertigo, and diplopia have mostly been described as features of posterior cerebral circulation stroke.[56] Many times elderly patients present to ophthalmologists with such symptoms which are judged to be of insufficient magnitude for a clinical diagnosis and these patients are deferred without any intervention. A complete medical history emphasizing on symptoms of TIA and risk factors for stroke[7] should be obtained in every case of suspected TIA. A detailed neurologic examination,[8] cognitive and language function, facial and limb strength, deep tendon reflexes and coordination to serve as a baseline examination if the neurologic status worsens is a must.

In our case, patient presented with ocular findings of transient nystagmus and vertical diplopia which disappeared within 12 h. With all neuroimaging coming out to be normal, no other ocular cause could explain these findings. Only possible explanation of this event could have been a TIA which was neither picked up on t1- and t2-weighted MRI nor diffusion-weighted MRI. The patient was timely referred to the neurologist and started on treatment. Moreover, all transient findings were only limited to ocular features with no other systemic involvement which is not a very common presentation of TIA.

Diffusion-weighted MRI is highly sensitive and specific[910] for early detection of size, number, and location of the lesion as well as the vascular territory involved which helps in guiding long-term therapy.[11] Diffusion-weighted images showed an index lesion not visualized on conventional MR images in 13% of patients, but this percentage increased to 25% when MR imaging was performed within the first 2 days after symptom onset.[12] However, further studies are required to establish the clinical and prognostic significance of TIA-related diffusion-weighted imaging abnormalities.

We hereby suggest that one needs to keep a high index of suspicion in subtle neurological findings. TIA can have varying presentations, and it still remains a diagnosis of exclusion. TIA needs early diagnosis, but the modality for early diagnosis still needs to be investigated. As ophthalmologists, we should identify these warning neurological signs and accordingly investigate and refer the patient for timely management.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.