DELAYED DIAGNOSIS OF AVM PRESENTING WITH STROKE AND SEIZURES IN A YOUNG NIGERIAN: A CASE REPORT.

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A.I. Makanjuola¹ , P. Bolaji¹ , C. Onyejelam² , G.I. Ogbole² , and R.O. Akinyemi^1,3

1. Neurology Unit, Department of Medicine, University College Hospital, Ibadan, Nigeria. 
2. Department of Radiology, University College Hospital, Ibadan, Nigeria.
3. Neuroscience and Ageing Research Unit, Institute for Advanced Medical Research and Training, College of Medicine, University of Ibadan.

Abstract

Background: Brain arteriovenous malformations (BAVM) are a cause of intracerebral haemorrhage (ICH) and seizures especially in young patients. ICH due to BAVMs seem to have relatively better neurologic outcomes compared to other causes of spontaneous ICH as patients often recover fully. In this report we highlight a case of delayed diagnosis of BAVM in a young man who presented with seizures and stroke. 

Case summary: A 36-year-old man was referred on account of focal, secondarily generalized tonic clonic convulsions. He had suffered a right ICH 3 years before the index presentation. His general physical and neurologic examination were normal. Electroencephalography revealed right sided focal epileptiform discharges and brain MRI revealed a right parieto-occipital AVM. The seizures were controlled with carbamazepine and he was referred for neurosurgical evaluation. 

Conclusion: BAVMs are an important cause of intracerebral haemorrhage and attendant neurologic morbidity especially in young individuals. Neuroimaging plays a central role in BAVM diagnosis and MRI is of great value where facilities and expertise for conventional angiography do not exist. In some instances, delayed presentation of BAVM cases may be due to relatively better neurologic outcomes in BAVM-related ICH.

Introduction

Arteriovenous Malformations (AVMs) are vascular anomalies that consist of tangles of arterioles in direct connection with venules, without intervening capillaries. Although they can occur in any part of the body, including the central nervous system, brain AVMs (BAVMs) are of concern because of their potential for devastating neurologic sequelae. BAVMs may occur in isolation or as part of vascular disorders such as Osler-Weber-Rendu syndrome, Sturge-Weber syndrome, or moyamoya disease.^1,2 

BAVMs occur relatively rarely and are responsible for about 2% of all strokes.^1,3 The prevalence of BAVMs has been estimated at 15-18 per 100, 000 adults.⁴ In a systematic review – based on data from ⁴ multi-centre studies conducted in New York, Northern California, Scotland, and Sweden – Abecassis et al. reported a BAVM incidence of 1.12–1.42 per 100, 000 person years.⁵ There is no robust data regarding epidemiology of BAVM in Nigeria. Over a 5-year period culminating in 1967 at the University College Hospital (UCH), Ibadan, only 19 cases of intracranial vascular malformations were reported. Three of the 19 cases were isolated BAVMs, while 2 patients had BAVMs as part of Sturge-Weber syndrome.⁶ Adeyinka et al. in 2005 reported a case of BAVM diagnosed by brain computerized tomography (CT) scan and conventional angiography.⁷ Furthermore, in a retrospective review of 62 three-dimensional CT angiography procedures performed at Ibadan over a near 2-year period, five intracranial AVMs were detected.⁸ More recently, Adekanmi et al found that between 2011 and 2018, approximately 20% of patients with CT-angiographyconfirmed intracranial vascular lesions at UCH, Ibadan had BAVMs.⁹

BAVMs usually come to clinical attention because of intracerebral haemorrhage (ICH), seizures, headache, or other focal neurologic deficits. Focal neurologic deficits may occur in the absence of ICH, and may be due to mass effect by large BAVMs, or ischaemia of adjacent areas resulting from vascular steal phenomenon.¹

In this report, we present the case of a young Nigerian man who presented with seizures, in whom a diagnosis of BAVM was confirmed, and salient anatomic details delineated with brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA).

CASE SUMMARY 

A 36-year-old man was referred to the neurology clinic with a 2-year history of recurrent convulsions. Seizures were described as initially focal with versive features which then progressed to bilateral tonic clonic seizures. Seizures became more frequent in the month preceding his presentation. All episodes of seizures occurred during sleep. The seizures were associated with tongue biting, sphincteric incontinence, postictal sleep and occasional headaches. However, there was no preceding aura. There was no history of visual impairment or childhood history of head trauma or seizures. He was neither hypertensive nor diabetic and had no known family history of epilepsy. He neither smoked cigarettes, used illicit drugs, nor drank alcohol.

He had been admitted 3 years prior to the index presentation because of a stroke with right hemispheric intracerebral hemorrhage confirmed on computed tomography (CT) scan. The CT images from that admission were however not available for review. Following the stroke, he recovered with no residual neurological deficit.

On examination, he was not pale and there were no telangiectasias. He was conscious and alert, cognition was not impaired, and visual field examination was normal. Cranial nerve, motor, and sensory examination, including higher cortical sensation were normal.

Routine electroencephalography (EEG) was performed using a 16-channel EB Neuro S.p.A. Neurotravel LIGHT machine (Florence, Italy) with electrodes placed according to the 10-20 international system, and hyperventilation performed as activation maneuver. The EEG showed a normal background with focal epileptiform discharges preponderant in the right temporo-parieto-occipital region (Figure 1).