Unilateral anterior choroidal artery infarction presenting with a temporary stupor

Abstract

A 73-year-old woman presented with a temporary stupor and right hemiplegia. Brain magnetic resonance imaging revealed acute infarction of the anterior choroidal artery. The clinical features associated with acute anterior choroidal artery infarction typically include hemiparesis, hemihypesthesia, and hemianopsia. However, our patient presented with a temporary stupor, which is a rare manifestation of anterior choroidal artery infarction.

Introduction

Acute cerebral infarction is one of the most common diseases in clinical practice. The lesion sites related to acute cerebral infarction that result in disorders of consciousness (DoC) are primarily located within the cerebral hemispheres, brainstem, and thalamus. ¹ The incidence of anterior choroidal artery (AChA) infarction is relatively low, typically manifesting as hemiplegia, dysarthria, and hemisensory disturbances. ² There have been no reports on AChA infarction causing DoC. This report described the case of a patient who experienced unilateral AChA infarction accompanied with a temporary stupor and analyzed the underlying causes.

Case presentation

A 73-year-old woman collapsed suddenly 1.5 h prior to her arrival at the emergency department. Neurological examination revealed a lethargic state and weakness on the right side of her body. The National Institute of Health Stroke Scale (NIHSS) score ³ was 13 points (2 = arousable only to painful stimulation, 1 = ask patient’s age and the current month (one correct), 4 = cannot move the right arm at all, 4 = cannot move the right leg at all, and 2 = severe dysarthria). Emergency head CT demonstrated multiple low-density shadows in the bilateral basal ganglia and right corona radiata. After discussing treatment options with her son, consent was obtained for intravenous thrombolytic therapy using recombinant tissue plasminogen activator. After thrombolysis, the NIHSS score improved to 8 points (1 = arousable to minor stimulation, 3 = no antigravity effort of the right arm, but even minimal movement counts present, 3 = no antigravity effort of the right leg, but even minimal movement counts present, 1 = mild dysarthria). She had been diagnosed with hypertension for 3 years but did not receive any medication treatment. The personal and family histories were unremarkable.

The patient presented to the emergency department in a state of constant drowsiness, and head CT showed no new bleeding or infarction. After completing relevant tests to rule out potential causes of consciousness impairment, such as metabolic encephalopathy, hypoxia, and ion imbalance, no abnormalities were identified. Diffusion-weighted imaging demonstrated acute infarction in the left temporal lobe and basal ganglia regions supplied by the AChA (Figure 1). Magnetic resonance angiography and digital subtraction angiography indicated approximately 80% stenosis of the left middle cerebral artery (Figure 2). Following interventions to improve circulation along with antiplatelet and antihypertensive treatments, she regained consciousness after 3 days (NIHSS: 7 points). At discharge, she was alert but exhibited right limb muscle strength of 3 (NIHSS: 4 points), leading to subsequent transfer to the rehabilitation hospital. Remarkably, she was able to stand independently after 3 months. The reporting of this study conforms to the Case Report (CARE) guidelines, ⁴ and informed consent for publication was obtained from the patient.

Figure 1.

Brain MRI revealed diffusion restriction in the posterior limb of the internal capsule and medial temporal lobe (the left side illustrates areas supplied by the intracranial arteries, whereas the right side depicts the affected regions). MRI: magnetic resonance imaging.

Figure 2.

(a) Brain MRA showed the sparse left middle cerebral artery and its distal branches and (b) DSA showed the right anterior choroidal artery (red arrow). MRA: magnetic resonance angiography; DSA: digital subtraction angiography.

Discussion

The AChA is an important branch of the internal carotid artery, mainly supplying the posterior limbs of the internal capsule, lateral geniculate body, medial temporal lobe, cerebral peduncle, and hippocampus. ⁵ Due to its lengthy course characterized by numerous bends and small diameter, infarction in this territory often manifests as hemiparesis, hemihypesthesia, and hemianopsia—a clinical presentation referred to as the “AChA syndrome.” ⁶ Additionally, advanced neurological dysfunction may present with symptoms such as thalamic aphasia, lateral spatial neglect, and articulation disorders. ⁷ Notably, decreased levels of consciousness can occur due to bilateral acute infarctions within the AChA territory. ⁸ We report the case of a patient who experienced unilateral AChA infarction with subsequent improvement in her level of consciousness after 3 days.

DoC are characterized by alterations in arousal and/or awareness. Common causes of DoC include cardiac arrest, traumatic brain injury, intracerebral hemorrhage, and ischemic stroke. ⁹ Extensive pontine infarction and hemispheric infarction can result in DoC due to their impact on vital centers in the brain responsible for respiration and heartbeat. ¹⁰

In this case, our patient experienced AChA infarction, which presented with not only typical symptoms but also a temporary stupor. The underlying mechanisms involve the body receiving appropriate stimuli from the external environment and generating neural impulses. The neural impulses are transmitted to the cortex via a specific upward projection system originating from the brainstem, reaching areas connected to the reticular formation within the brainstem. ¹¹ Activation of the ascending reticular activating system located in these regions facilitates excitation that is relayed to the nonspecific nucleus of the thalamus before diffusing into the cortex, thereby maintaining awakeness. ¹² When lesions affect any component of this pathway, it may result in DoC or coma (Figure 3).

Figure 3.

The ascending reticular activating system.