An In-Depth Analysis of Medullary Strokes at a Tertiary Care Stroke Center: Incidence, Clinical and Radiological Characteristics, Etiology, Treatment, and Prognosis.

Abstract

Introduction Medullary infarctions (MI) are a rare medical entity that is classified mainly as the more commonly lateral medullary infarcts (LMI) and the less common medial medullary infarcts (MMI). Lateral medullary syndrome, also known as Wallenberg syndrome, results when the medulla oblongata is affected and predominantly occurs secondary to atherosclerotic occlusion of the vertebrobasilar arteries. Previous studies have focused more on the anatomical, clinical, and topographical aspects of medullary infarcts. We describe the incidence of their presentation, radiological findings, etiology, treatment, and outcome at our comprehensive stroke center. Material and method This is a retrospective cohort study of 108 medullary stroke patients with confirmed clinical and radiological diagnoses of MI at Hamad General Hospital, Doha, between January 1, 2018 and December 31, 2020. We evaluated the electronic medical records of all stroke patients. Result During the selected period, a total of 2,912 ischemic strokes were reported. Of these, 843 (28.8%) were posterior circulation strokes. Only 108 (3.7%) patients had medullary strokes. Commonly encountered neurological features were dizziness (94.4%), limb ataxia (84.3%), dysarthria (44.4%), ipsilateral facial sensory loss (32.4%), headache (32.4%), contralateral limb sensory loss (25%), ipsilateral hemiparesis (24%), dysphagia (19.4%), and hiccups (13%). Most strokes reported were either minor (73% with National Institutes of Health Stroke Scale [NIHSS] 1-4) or moderate (26% with NIHSS 5-15). LMIs (87.9%) were the most common, followed by medial paramedian MI (10%). Twenty-five percent had extramedullary involvement, predominantly of the cerebellum (17.6%). Out of the total number of patients, 44 (40.7%) had large vessel atherosclerotic disease, followed by 41 (37.6%) whose stroke was due to small vessel disease, 15 (13.8 %) due to undetermined etiology, and 6 (5.5%) due to arterial dissection. Twenty-eight patients (25.4%) underwent 48-hour Holter monitoring, which detected atrial fibrillation in two patients (1.85%). The majority of patients (98.2%, or 106 patients) received antiplatelet therapy, while 68.5% (74 patients) received single antiplatelet therapy (SAPT), and 29.6% (32 patients) received dual antiplatelet therapy (DAPT). Noteworthy is that only 2.7% (three patients) received thrombolysis as an acute reperfusion therapy. Forty-seven percent (51 patients) were discharged home (mRS 0-2), and 51.9% (56 patients) were transferred to rehabilitation facilities. Follow-up assessments were performed at the stroke clinic for 57.4% (62) of the patients. The assessments found that 46 of the follow-up patients were functionally independent at that time (mRS 0-2). Conclusion This is the first large local study of medullary strokes to determine their frequency, presentation, etiology, treatment, and clinical outcome. Medullary strokes represent 3.7% of total ischemic strokes at our comprehensive stroke center. MI is rare and could present with a variety of neurological and non-specific symptoms that mimic common benign conditions. Prompt and early recognition with a high index of suspicion, the use of posterior NIHSS (POST-NIHSS), and urgent MRI-diffusion-weighted imaging (DWI) of the brain in acute settings can improve early diagnosis and the rate of reperfusion therapy. Further studies are needed to enable the early recognition and treatment of medullary infarcts.