From the Guidelines
Medial medullary syndrome, also known as Dejerine syndrome, results from a lesion in the medial part of the medulla oblongata, typically due to occlusion of the anterior spinal artery or vertebral artery, and is characterized by a classic triad of symptoms including contralateral hemiparesis, contralateral loss of position and vibration sensation, and ipsilateral tongue weakness and deviation toward the side of the lesion. The lesion specifically affects the pyramid (corticospinal tract), medial lemniscus, and hypoglossal nucleus or its fibers 1. Patients typically present with weakness of the arm and leg on one side of the body, difficulty with coordinated movements, impaired position and vibration sense, and tongue weakness causing speech and swallowing difficulties.
Key Symptoms and Signs
- Contralateral hemiparesis (weakness on the opposite side of the body) due to damage to the pyramidal tract
- Contralateral loss of position and vibration sensation due to damage to the medial lemniscus
- Ipsilateral tongue weakness and deviation toward the side of the lesion due to hypoglossal nerve damage
- Difficulty with coordinated movements
- Impaired position and vibration sense
- Tongue weakness causing speech and swallowing difficulties
Treatment and Prognosis
Treatment focuses on managing the underlying cause, usually ischemic stroke, with standard stroke protocols including possible thrombolysis if diagnosed early, antiplatelet or anticoagulation therapy, blood pressure management, and rehabilitation 1. Prognosis varies depending on the extent of the lesion and how quickly treatment is initiated, with some patients experiencing significant recovery while others have persistent neurological deficits. Early diagnosis and treatment are crucial to improve outcomes and reduce morbidity and mortality. A thorough neurologic examination evaluating for associated signs can localize a process to the brainstem, and imaging protocols can then be tailored to evaluate the suspected region of anatomy affected 1.
From the Research
Lesion of Medial Medullary Syndrome
The medial medullary syndrome is a rare condition characterized by a specific set of symptoms, including:
- Ipsilateral hypoglossal nerve palsy
- Contralateral hemiparesis
- Loss of deep sensation 2 It is often associated with hypertension and atherosclerosis, and has a higher incidence of bilateral involvement and a worse prognosis compared to the lateral medullary syndrome 3.
Clinical Features
The clinical features of medial medullary syndrome can vary, but common symptoms include:
- Unilateral sensorimotor stroke
- Pure motor stroke
- Tingling sensation with decreased vibration and position sense
- Lingual paresis
- Respiratory difficulties (rare) 4 In some cases, patients may present with atypical findings, such as contralateral face hypalgesia 5.
Lesion Location
The lesion location in medial medullary syndrome is typically in the upper medulla, involving the:
- Medullary pyramid
- Ventromedial portion of the inferior olivary nucleus
- Medial lemniscus
- Hypoglossal nerve 3, 4 The site of the lesion may help predict the arteries involved, with vertebral artery disease being a common cause 4.
Diagnosis and Prognosis
Diagnosis of medial medullary syndrome can be challenging, and imaging examinations such as MRI may not always show abnormalities on the day of onset 6. The prognosis is generally good, although residual hemiparesis may remain in patients with initially severe hemiparesis 4. In some cases, the prognosis may be poorer, particularly with more dorsal lesion locations 6.