### Date : 2024-12-27 22:20 ### Topic : Wallenberg Syndrome (Lateral Medullary Syndrome) #neurology ---- ### **Wallenberg Syndrome (Lateral Medullary Syndrome)** **Wallenberg syndrome**, also known as **lateral medullary syndrome**, is a **neurological condition** caused by **ischemic stroke** in the **lateral part of the medulla oblongata** in the brainstem. This syndrome results from the occlusion or damage of the **posterior inferior cerebellar artery (PICA)** or one of its branches, which supplies blood to the **medulla** and parts of the **cerebellum**. ### **Causes**: - The most common cause of Wallenberg syndrome is a **stroke** in the **lateral medulla**, often due to a blockage of the **posterior inferior cerebellar artery (PICA)**. - Other potential causes include **vertebral artery occlusion**, **atherosclerosis**, **embolism**, or even **tumors** affecting the brainstem. ### **Pathophysiology**: - The **medulla oblongata** contains important centers for functions such as **cardiovascular control**, **breathing**, **swallowing**, and **sensory pathways**. - The **PICA** supplies blood to the lateral parts of the **medulla**, and when it is blocked, it can result in ischemia and damage to the **brainstem** and its surrounding structures. - The **symptoms** of Wallenberg syndrome arise from the damage to these neural pathways, which disrupts normal motor and sensory functions. --- ### **Clinical Features** (Signs and Symptoms): Symptoms of Wallenberg syndrome are often **contralateral** (on the opposite side of the body) or **ipsilateral** (on the same side) to the lesion, depending on the pathways affected: 1. **Ipsilateral (Same Side) Symptoms**: - **Ataxia**: **Uncoordinated movement** on the side of the lesion due to involvement of the **cerebellum**. - **Dysphagia** and **Dysarthria**: Difficulty swallowing and speaking due to **cranial nerve involvement** (especially **nucleus ambiguus** affecting the **vagus nerve [CN X]**). - **Horner's Syndrome**: This includes **ptosis (drooping eyelid)**, **miosis (constricted pupil)**, and **anhidrosis (lack of sweating)** on the side of the lesion, caused by disruption of the **sympathetic fibers** that innervate the eye. - **Loss of Pain and Temperature Sensation**: There is a loss of **pain and temperature sensation** on the **ipsilateral side of the face** (due to damage to the **trigeminal nerve (CN V)** fibers). 2. **Contralateral (Opposite Side) Symptoms**: - **Loss of Pain and Temperature Sensation**: There is a loss of **pain and temperature sensation** on the **contralateral body** (due to damage to the **spinothalamic tract** in the medulla, which carries these sensations from the body). 3. **Other Symptoms**: - **Vertigo**: Due to involvement of the **vestibular nuclei**. This may be accompanied by **nausea**, **vomiting**, and **nystagmus** (abnormal eye movements). - **Ipsilateral weakness or paralysis**: This may result from involvement of the **corticospinal tract**. --- ### **Key Features of Wallenberg Syndrome**: - **Ipsilateral Horner’s Syndrome** (due to disruption of sympathetic fibers) - **Ataxia** and **dysmetria** (due to cerebellar involvement) - **Dysphagia** and **dysarthria** (due to involvement of cranial nerves) - **Contralateral loss of pain and temperature sensation** (due to damage to the spinothalamic tract) - **Ipsilateral loss of pain and temperature sensation in the face** (due to damage to the trigeminal nerve pathway) --- ### **Diagnosis**: 1. **Clinical Examination**: - A thorough clinical examination often reveals the hallmark signs of Wallenberg syndrome, including **ipsilateral cranial nerve involvement** (such as **dysphagia**, **hoarseness**, and **Horner’s syndrome**) and **contralateral sensory loss**. 2. **Imaging**: - **MRI (Magnetic Resonance Imaging)**: The primary imaging modality used to diagnose Wallenberg syndrome. It will show **ischemic changes** in the **lateral medulla**, specifically in the region supplied by the **PICA**. - **CT Scan**: A **CT scan** may be used in acute settings to rule out hemorrhage, but MRI is more sensitive for detecting **ischemic strokes**. 3. **Angiography**: - **Cerebral angiography** may be used to assess the **PICA** or other arteries for occlusion or stenosis in cases where the stroke cause is unclear. --- ### **Treatment**: 1. **Acute Stroke Management**: - Immediate treatment of Wallenberg syndrome involves managing the underlying cause of the stroke (e.g., **thrombolysis** for ischemic stroke or **antiplatelet therapy**). - **Antiplatelet medications** (e.g., **aspirin** or **clopidogrel**) may be used if the stroke is ischemic and related to atherosclerosis. - In cases where **vertebrobasilar insufficiency** or **vertebral artery dissection** is suspected, appropriate vascular management, such as **anticoagulation** or **angioplasty**, may be considered. 2. **Symptom Management**: - **Physical therapy** to improve coordination and strength in cases of **ataxia**. - **Speech therapy** to assist with **swallowing** and **speech difficulties**. - **Vestibular rehabilitation** for managing **vertigo** and balance problems. 3. **Long-term Management**: - Individuals may need **long-term therapy** to manage symptoms like **dysphagia**, **dysarthria**, and **coordination issues**. - **Cognitive and emotional support** may be required for stroke survivors coping with the psychological impact of the condition. --- ### **Prognosis**: - **Prognosis** depends on the severity of the stroke, the size of the affected area, and how quickly treatment is administered. - Some people with Wallenberg syndrome can recover significantly with **rehabilitation** and support, while others may experience **chronic deficits**, including **difficulty swallowing**, **balance problems**, and **sensory loss**. - **Long-term recovery** may involve a combination of **therapy** and **medications** to manage the sequelae. --- ### **Conclusion**: **Wallenberg syndrome** (lateral medullary syndrome) is caused by a **stroke** affecting the **lateral part of the medulla** and is associated with a range of neurological symptoms due to the involvement of various brainstem nuclei and pathways. Early diagnosis with **MRI** and timely management of the underlying cause, as well as symptom management and rehabilitation, are key to improving outcomes for individuals with this condition. ### Reference: - ### Connected Documents: -