Wallenberg Syndrome


Article Author:
Forshing Lui
Prasanna Tadi


Article Editor:
Arayamparambil Anilkumar


Editors In Chief:
David Wood
Andrew Wilt
Mary Cataletto


Managing Editors:
Avais Raja
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Khalid Alsayouri
Trevor Nezwek
Radia Jamil
Patrick Le
Anoosh Zafar Gondal
Saad Nazir
William Gossman
Hassam Zulfiqar
Steve Bhimji
John Shell
Matthew Varacallo
Heba Mahdy
Ahmad Malik
Sarosh Vaqar
Mark Pellegrini
James Hughes
Beata Beatty
Nazia Sadiq
Hajira Basit
Phillip Hynes
Tehmina Warsi


Updated:
6/4/2019 7:05:58 PM

Introduction

Wallenberg syndrome is also known as lateral medullary syndrome or the posterior inferior cerebellar artery syndrome. Wallenberg described the first case in 1895. This neurological disorder is associated with a variety of symptoms that occur as a result of damage to the lateral segment of the medulla posterior to the inferior olivary nucleus. It is the most typical posterior circulation ischemic stroke syndrome in clinical practice. [1]

Etiology

Wallenberg syndrome is caused most commonly by atherothrombotic occlusion of the vertebral artery, followed most frequently by the posterior inferior cerebellar artery, and least often, the medullary arteries. Hypertension is the commonest risk factor followed by smoking and diabetes. Cerebral embolism is a less frequent cause of the infarction. The other important cause to remember is vertebral artery dissection which may have risk factors including neck manipulation or injury, Marfan syndrome, Ehlers Danlos syndrome, and fibromuscular dysplasia. Vertebral artery dissection is the commonest cause of Wallenberg syndrome in younger patients.[2][3]

Epidemiology

Wallenberg syndrome is the most prevalent posterior ischemic stroke syndrome. There are nearly 800,000 patients who suffer from an acute stroke each year in the United States. Of these, 83% are ischemic strokes. Twenty percent of the ischemic strokes occur in the posterior circulation. If clinicians assume that about half of these suffer from Wallenberg syndrome, it can be estimated that there are more than 60,000 new cases of Wallenberg syndrome each year in the United States. There is a predominance of men in their sixth decade. Large artery atherothrombotic causes account for about 75% of the cases followed by cardioembolism in 17% and vertebral dissection in 8%.

Pathophysiology

The primary pathology of Wallenberg syndrome is occlusion of the posterior inferior cerebellar artery (PICA) or one of its branches[4]. The syndrome can also be due to occlusion of the vertebral artery, or the inferior, middle, or superior medullary vessels. Anatomically the infarcted area in Wallenberg syndrome is supplied by the posterior inferior cerebellar artery (PICA). It turns out occlusion of the PICA accounts for only a small number of cases. The majority (80%) are caused by occlusion of the vertebral artery which gives rise to the PICA and the anterior spinal artery before it joins with the opposite vertebral artery to form the basilar artery. The commonest mechanism of occlusion of the vertebral artery or PICA is atherothrombosis.[5]

History and Physical

A typical patient with Wallenberg syndrome is an elderly patient with vascular risk factors. Like any acute stroke syndrome, the onset is acute. The most common symptoms of onset are dizziness with vertigo, loss of balance with gait instability, hoarseness of voice and difficulty swallowing. The symptoms often progressed over several hours to sometimes a couple of days. [5]

Usually, there is no weakness associated with this syndrome and so this condition is often misdiagnosed or missed. A careful neurological examination is key to the diagnosis.  A complete Wallenberg syndrome is not common, yet partial syndromes are good enough for the diagnosis most of the time. The important points in clinical diagnosis are a combination of crossed hemiparesis or hemianesthesia to indicate a brainstem lesion and the involvement of structures in the posterolateral medulla to localize where in the brainstem.

Different combinations of the following deficits may all be found in Wallenberg syndrome:

On the side of lesion:

  • Vertigo with nystagmus (inferior vestibular nucleus and pathways). The nystagmus is typically central beating to the direction of gaze. Nausea and vomiting, and sometimes hiccup are associated with vertigo. Hiccup can often be intractable.
  • Dysphonia, dysarthria, and dysphagia (different nuclei and fibers of the IX and X nerves), often with ipsilateral loss of gag reflex
  • Horner syndrome (sympathetic fibers)
  • Ipsilateral ataxia with a tendency to fall to the ipsilateral side (inferior cerebellar hemisphere, spinocerebellar fibers, and inferior cerebellar peduncle)
  • Pain and numbness with impaired facial sensation on the face (descending trigeminal tract)
  • Impaired taste sensation (involvement of nucleus tractus solitarius)

On the contralateral side:

  • Impaired pain and temperature sensation in the arms and legs (spinothalamic tract)
  • It is important to note that there is no or only minimal weakness of the contralateral side (corticospinal fibers are ventral in location)

It is clinically interesting to note that more rostral lesions tend to be more ventrally located. These patients present with more dysphagia and dysphonia due to the involvement of the nucleus ambiguus. More caudal lesions involve more dorsolateral structures. These patients present with vertigo, ataxia, nausea/vomiting, and Horner syndrome.

Evaluation

The clinical differential diagnoses include:

  1. Other causes of vertigo especially peripheral vertigo such as acute labyrinthitis: the patient may be younger without many vascular risk factors. The nystagmus is peripheral and unidirectional or rotary. There may be associated tinnitus without other brainstem signs. Head thrust test will be positive which if present, is most helpful in differentiating a central cause such as Wallenberg syndrome from a peripheral cause.[6][7]
  2. Hemorrhagic stroke: much less common and headache is much more prominent.
  3. Acute demyelination in multiple sclerosis: patients are generally much younger, more likely female and known history of demyelinating disease
  4. Acute relapse/attack of neuromyelitis optica with the involvement of the area postrema. Patients are most likely young adult female and the signs may suggest more than one central nervous system (CNS) lesion.

The diagnosis is usually made or suspected from a clinical exam and history of presentation. MRI with diffusion-weighted imaging is the best diagnostic test to confirm the infarct in the inferior cerebellar area or lateral medulla.[8] Up to 30% of patients with nondisabling stroke do not have a lesion on DWI-MRI brain. These patients are DWI-negative stroke patients and secondary prevention should be started to prevent future strokes. [9]

A CT angiogram or MR angiogram is very helpful in identifying the site of vascular occlusion and rule out uncommon causes such as vertebral artery dissection[10].

An ECG is helpful in excluding any underlying atrial fibrillation or unexpected acute coronary syndrome.

Checking the serum electrolytes is important.

Patient with dysphagia or dysarthria needs to be assessed by the speech pathologist because any food or medicine can be given orally.

Treatment / Management

Similar to the management of any acute ischemic stroke, remember "TIME IS BRAIN." Rapid evaluation is essential to an orderly approach(algorithm) developed within each hospital or stroke center. Management in certified stroke centers has shown to improve overall patient outcome. Treatment aims at reducing the size of infarction and preventing any medical complication with the final target of improving patient outcome and prognosis. [5]

The management steps include:

  1. Intravenous (IV) thrombolysis with IV TPA within 3 or 4.5 hours of onset of the ischemic stroke with slightly different exclusion criteria. Overall IV thrombolysis, whether within 3 or 4.5 hours, improve functional stroke outcome by 30%. There have been studies showing that the window for posterior circulation strokes may be longer than 4.5 hours.[11]
  2. Endovascular revascularization: the newer devices have been shown to improve outcome with the number needed to treat to be as low as 3. These are indicated mainly for large vessel intracranial occlusion which carries very poor prognosis without revascularization.
  3. General medical therapy: Patient is best monitored in the intensive care unit (ICU) for 24 hours after IV thrombolysis. Otherwise, it will be best to manage the patients in dedicated stroke beds or units.
  • IV fluid: avoid hypotonic solution to reduce risks of cerebral edema. Normal saline generally is the best.
  • Blood pressure management: cerebral autoregulation is impaired in the infarcted areas of the brain. Blood pressure very often comes down gradually without any drug treatment. In general, BP does not need to be lowered unless the patient receives IV thrombolysis or when it is over 220/120.
  • Speech therapy assessment: very important to prevent aspiration.
  • Deep vein thrombosis prophylaxis: with sequential pressure devices and low dose heparin or low molecular weight heparin.
  • Blood sugar: best to keep the patient normoglycemic.
  • Fever: the source of fever needs to be identified and treated. A simple antipyretic with acetaminophen is helpful.
  • Antithrombotics: numerous more recent clinical trials failed to show any benefit or anticoagulants in acute stroke even in atrial fibrillation. Antithrombotic therapy with aspirin does improve the outcome.
  • Early physical therapy and occupational therapy with a good plan for rehabilitation.

Secondary stroke prevention will be decided soon. This will again include a multimodality approach:

  1. Carotid endarterectomy for significant large vessel extracranial stenosis
  2. Oral anticoagulation for cardioembolic strokes
  3. Antiplatelets such as aspirin, clopidogrel, or Aggrenox (ASA/Dipyridamole) for other forms of stroke
  4. Statin
  5. Smoking cessation
  6. Good control of diabetes
  7. Good blood pressure control
  8. Healthy diet and lifestyle with regular exercises

This multimodal approach can reduce the risk of subsequent stroke by 80%.

Prognosis

Overall Wallenberg syndrome has a better functional outcome than most other stroke syndromes. Most patients can return to satisfactory activities of daily living. The commonest sequel is gait instability.

Pearls and Other Issues

Hypertension is the commonest risk factor. Atherothrombosis of the vertebral artery is the most frequent underlying vascular cause. Vertebral artery dissection needs to be considered in younger patients especially with a history of trauma, neck manipulation, or underlying collagen disorders such as Marfan syndrome. Head thrust (head impulse) test in the emergency department can differentiate peripheral vertigo due to acute labyrinthitis from central cause due to Wallenberg syndrome.[12] The outlook for patients with Wallenberg syndrome depends on the size of the infarct, but in general, most patients have a better outcome compared with other ischemic stroke syndromes with the exception of some lacunar syndromes. Gait instability or ataxia are the most typical sequelae. Sometime hiccup can be intractable.

Enhancing Healthcare Team Outcomes

Treatment of Wallenberg Syndrome requires a rapid response and coordinated team approach involving clinicians, nurses, and pharmacists to provide the patient with the best possible outcome. [Level V]


Interested in Participating?

We are looking for contributors to author, edit, and peer review our vast library of review articles and multiple choice questions. In as little as 2-3 hours you can make a significant contribution to your specialty. In return for a small amount of your time, you will receive free access to all content and you will be published as an author or editor in eBooks, apps, online CME/CE activities, and an online Learning Management System for students, teachers, and program directors that allows access to review materials in over 500 specialties.

Improve Content - Become an Author or Editor

This is an academic project designed to provide inexpensive peer-reviewed Apps, eBooks, and very soon an online CME/CE system to help students identify weaknesses and improve knowledge. We would like you to consider being an author or editor. Please click here to learn more. Thank you for you for your interest, the StatPearls Publishing Editorial Team.

Wallenberg Syndrome - Questions

Take a quiz of the questions on this article.

Take Quiz
A 55-year-old man with diabetes mellitus, hypertension, and chronic renal failure presents to the emergency department with acute onset of ataxia, dizziness worsened with motion, right facial numbness, and left arm and leg numbness. Which of the following arteries is most likely occluded to cause this clinical problem?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 65-year-old right-handed man with a history of hypertension and diabetes presented with sudden onset of vertigo, slurring of speech and difficulty swallowing. Examination revealed a left Horner syndrome, nystagmus beating to the direction of gaze, palate deviated to his right side, and impaired left facial sensation. Which of the following is the most likely etiology of his clinical picture?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 65-year-old female is a chronic heavy smoker and has poorly controlled hypertension. She presented with sudden onset of vertigo, unsteadiness of gait and numbness affecting her left face and right arm. What is the least likely finding in this patient?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 61-year-old male with a history of chronic smoking, diabetes, hypertension, and chronic atrial fibrillation presents with acute onset of vertigo, dysarthria, dysphagia, sensory abnormalities on the face, and on the opposite trunk and extremities. Neurological exam reveals loss of pain and temperature on the same side of the face with decreased pain and temperature sensation and on the opposite side of trunk and extremities. MRI showed an occlusion of his right posterior inferior cerebellar artery. The patient improved well during hospitalization. What is the most important treatment for secondary prevention in this patient that has the greatest impact on his subsequent risk of stroke?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Which cranial artery obstruction most likely will result in Wallenberg syndrome?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Occlusion of which vessel can cause lateral medullary syndrome?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A patient presented to the emergency department with a sudden onset of headache after he has ingested some pills given to him by his friend in a party. Physical examination showed that he has left sided ptosis with a smaller pupil compared with his right side. He has left sided past-pointing and dysdiadochokinesia. He has an upgoing plantar response on his right side. He has impaired pain and temperature sensation on his left face and right arm and leg. His urine toxicology screen showed the presence of methamphetamine and the MRI showed an infarct affecting his left posterolateral medulla. Which of the following clinical features is most diagnostic of his vascular syndrome?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up

Wallenberg Syndrome - References

References

Spectrum of the posterior inferior cerebellar artery territory infarcts. Clinical-diffusion-weighted imaging correlates., Kumral E,Kisabay A,Ataç C,Calli C,Yunten N,, Cerebrovascular diseases (Basel, Switzerland), 2005     [PubMed]
Hong YH,Zhou LX,Yao M,Zhu YC,Cui LY,Ni J,Peng B, Lesion Topography and Its Correlation With Etiology in Medullary Infarction: Analysis From a Multi-Center Stroke Study in China. Frontiers in neurology. 2018;     [PubMed]
Ogawa K,Suzuki Y,Oishi M,Kamei S, Clinical study of 46 patients with lateral medullary infarction. Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association. 2015 May     [PubMed]
Inamasu J,Nakae S,Kato Y,Hirose Y, Clinical Characteristics of Cerebellar Infarction Due to Arterial Dissection. Asian journal of neurosurgery. 2018 Oct-Dec     [PubMed]
Park MG,Choi JH,Yang TI,Oh SJ,Baik SK,Park KP, Spontaneous isolated posterior inferior cerebellar artery dissection: rare but underdiagnosed cause of ischemic stroke. Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association. 2014 Aug     [PubMed]
Kim JS,Caplan LR, Clinical Stroke Syndromes. Frontiers of neurology and neuroscience. 2016     [PubMed]
Saber Tehrani AS,DeSanto JR,Kattah JC, Neuroimaging "HINTS" of the Lateral Medullary Syndrome. Journal of neuro-ophthalmology : the official journal of the North American Neuro-Ophthalmology Society. 2017 Dec     [PubMed]
Chen K,Schneider AL,Llinas RH,Marsh EB, Keep it simple: vascular risk factors and focal exam findings correctly identify posterior circulation ischemia in "dizzy" patients. BMC emergency medicine. 2016 Sep 13     [PubMed]
De Cocker LJ,Lövblad KO,Hendrikse J, MRI of Cerebellar Infarction. European neurology. 2017     [PubMed]
Salerno A,Cotter BV,Winters ME, The Use of Tissue Plasminogen Activator in the Treatment of Wallenberg Syndrome Caused by Vertebral Artery Dissection. The Journal of emergency medicine. 2017 May     [PubMed]
Guler A,Karbek Akarca F,Eraslan C,Tarhan C,Bilgen C,Kirazli T,Celebisoy N, Clinical and video head impulse test in the diagnosis of posterior circulation stroke presenting as acute vestibular syndrome in the emergency department. Journal of vestibular research : equilibrium & orientation. 2017     [PubMed]
Makin SD,Doubal FN,Dennis MS,Wardlaw JM, Clinically Confirmed Stroke With Negative Diffusion-Weighted Imaging Magnetic Resonance Imaging: Longitudinal Study of Clinical Outcomes, Stroke Recurrence, and Systematic Review. Stroke. 2015 Nov;     [PubMed]

Disclaimer

The intent of StatPearls is to provide practice questions and explanations to assist you in identifying and resolving knowledge deficits. These questions and explanations are not intended to be a source of the knowledge base of all of medicine, nor is it intended to be a board or certification review of Pediatric. The authors or editors do not warrant the information is complete or accurate. The reader is encouraged to verify each answer and explanation in several references. All drug indications and dosages should be verified before administration.

StatPearls offers the most comprehensive database of free multiple-choice questions with explanations and short review chapters ever developed. This system helps physicians, medical students, dentists, nurses, pharmacists, and allied health professionals identify education deficits and learn new concepts. StatPearls is not a board or certification review system for Pediatric, it is a learning system that you can use to help improve your knowledge base of medicine for life-long learning. StatPearls will help you identify your weaknesses so that when you are ready to study for a board or certification exam in Pediatric, you will already be prepared.

Our content is updated continuously through a multi-step peer review process that will help you be prepared and review for a thorough knowledge of Pediatric. When it is time for the Pediatric board and certification exam, you will already be ready. Besides online study quizzes, we also publish our peer-reviewed content in eBooks and mobile Apps. We also offer inexpensive CME/CE, so our content can be used to attain education credits while you study Pediatric.