Lateral medullary syndrome is a

neurological disorder Neurological disorders represent a complex array of medical conditions that fundamentally disrupt the functioning of the nervous system. These disorders affect the brain, spinal cord, and nerve networks, presenting unique diagnosis, treatment, and ...

causing a range of symptoms due to

ischemia Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems ...

in the lateral part of the

medulla oblongata The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...

in the

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is conti ...

. The ischemia is a result of a blockage most commonly in the

vertebral artery The vertebral arteries are major artery, arteries of the neck. Typically, the vertebral arteries originate from the subclavian arteries. Each vessel courses superiorly along each side of the neck, merging within the skull to form the single, m ...

or the

posterior inferior cerebellar artery The posterior inferior cerebellar artery (PICA) is the largest branch of the vertebral artery. It is one of the three main arteries that supply blood to the cerebellum, a part of the brain. Blockage of the posterior inferior cerebellar artery can ...

. Lateral medullary syndrome is also called Wallenberg's syndrome, posterior inferior cerebellar artery (PICA) syndrome and vertebral artery syndrome.

Signs and symptoms

This syndrome is characterized by sensory deficits that affect the trunk and extremities contralaterally (opposite to the lesion), and sensory deficits of the face and cranial nerves ipsilaterally (same side as the lesion). Specifically a loss of pain and temperature sensation if the lateral

spinothalamic tract The spinothalamic tract is a nerve tract in the anterolateral system in the spinal cord. This tract is an ascending sensory pathway to the thalamus. From the ventral posterolateral nucleus in the thalamus, sensory information is relayed upwar ...

is involved. The cross body finding is a highly suggestive symptom from which the diagnosis may be considered (however, this a symptom common to all brainstem pathology). Patients often have difficulty walking or maintaining balance (

ataxia Ataxia (from Greek α- negative prefix+ -τάξις rder= "lack of order") is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in e ...

), or difficulty in differentiating the temperature of an object based on which side of the body the object of varying temperature is touching. Some patients may walk with a slant or experience skew deviation and illusions of room tilt. The

nystagmus Nystagmus is a condition of involuntary (or voluntary, in some cases) Eye movement (sensory), eye movement. People can be born with it but more commonly acquire it in infancy or later in life. In many cases it may result in visual impairment, re ...

is commonly associated with

vertigo Vertigo is a condition in which a person has the sensation that they are moving, or that objects around them are moving, when they are not. Often it feels like a spinning or swaying movement. It may be associated with nausea, vomiting, perspira ...

spells. These vertigo spells can result in falling, caused from the involvement of the region of Deiters' nucleus. Common symptoms of lateral medullary syndrome may include difficulty swallowing, or

dysphagia Dysphagia is difficulty in swallowing. Although classified under " symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right. It may be a sensation that suggests difficulty in the passage of solids or l ...

. This can be caused by the involvement of the nucleus , as it supplies the

vagus The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fiber ...

and

glossopharyngeal The glossopharyngeal nerve (), also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper Medulla oblongata, medulla, just anterior (closer to the nose) to t ...

nerves. Slurred speech (

dysarthria Dysarthria is a speech sound disorder resulting from neurological injury of the motor component of the motor–speech system and is characterized by poor articulation of phonemes. It is a condition in which problems effectively occur with the ...

), and disordered vocal quality (

dysphonia A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice can be associated with a feeling of unease or scratchiness in the ...

) are also common. The damage to the cerebellum or the

inferior cerebellar peduncle The inferior cerebellar peduncle is formed by fibers of the restiform body that join with fibers from the much smaller juxtarestiform body. The inferior cerebellar peduncle is the smallest of the three cerebellar peduncles. The upper part of t ...

can cause

. Damage to the hypothalamospinal fibers disrupts sympathetic nervous system relay and produces symptoms that are similar to the symptoms caused by

Horner's syndrome Horner's syndrome, also known as oculosympathetic paresis, is a combination of symptoms that arises when a group of nerves known as the sympathetic trunk is damaged. The signs and symptoms occur on the same side (ipsilateral) as it is a lesion ...

– such as

miosis Miosis, or myosis (), is excessive constriction of the pupil.Farlex medical dictionary
citing: ...

, anhidrosis and partial ptosis. Palatal myoclonus, the twitching of the muscles of the mouth, may be observed due to disruption of the central tegmental tract. Other symptoms include hoarseness, nausea, vomiting, a decrease in sweating, problems with body temperature sensation, dizziness, difficulty walking, and difficulty maintaining balance. Lateral medullary syndrome can also cause

bradycardia Bradycardia, also called bradyarrhythmia, is a resting heart rate under 60 beats per minute (BPM). While bradycardia can result from various pathological processes, it is commonly a physiological response to cardiovascular conditioning or due ...

, a slow heart rate, and increases or decreases in the patient's average blood pressure.

Based on location

Cause

It is the clinical manifestation resulting from occlusion of the

(PICA) or one of its branches or of the

, in which the lateral part of the

infarcts, resulting in a typical pattern. The most commonly affected artery is PICA, specifically the lateral medullary segment.

Diagnosis

Since lateral medullary syndrome is often caused by a stroke, diagnosis is time dependent. Diagnosis is usually done by assessing vestibular-related symptoms in order to determine where in the medulla that the infarction has occurred. Head Impulsive Nystagmus Test of Skew (HINTS) examination of oculomotor function is often performed, along with computed tomography (CT) or magnetic resonance imaging (MRI) to assist in stroke detection. Standard stroke assessment must be done to rule out a

concussion A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include headache, dizziness, difficulty with thinking and concentration, sleep disturbances, a brief ...

or other

head trauma A head injury is any injury that results in trauma to the skull or brain. The terms ''traumatic brain injury'' and ''head injury'' are often used interchangeably in the medical literature. Because head injuries cover such a broad scope of inj ...

Treatment

Treatment for lateral medullary syndrome is dependent on how quickly it is identified. Treatment for lateral medullary syndrome involves focusing on relief of symptoms and active rehabilitation to help patients return to their daily activities. Many patients undergo

speech therapy Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...

. Depressed mood and withdrawal from society can be seen in patients following the initial onslaught of symptoms. In more severe cases, a

feeding tube A feeding tube is a medical device used to provide nutrition to people who cannot obtain nutrition by mouth, are unable to swallow safely, or need nutritional supplementation. The state of being fed by a feeding tube is called gavage, enteral f ...

may need to be inserted through the mouth or a

gastrostomy A gastrostomy is the creation of an artificial external opening into the stomach for nutritional support or gastric decompression. Typically this would include an incision in the patient's epigastrium as part of a formal operation. When originall ...

may be necessary if swallowing is impaired. In some cases, medication may be used to reduce or eliminate residual pain. Some studies have reported success in mitigating the chronic

neuropathic Peripheral neuropathy, often shortened to neuropathy, refers to damage or disease affecting the nerves. Damage to nerves may impair sensation, movement, gland function, and/or organ function depending on which nerve fibers are affected. Neuropa ...

pain associated with the syndrome with anti-

epileptic Epilepsy is a group of non-communicable neurological disorders characterized by a tendency for recurrent, unprovoked seizures. A seizure is a sudden burst of abnormal electrical activity in the brain that can cause a variety of symptoms, rang ...

s such as

gabapentin Gabapentin, sold under the brand name Neurontin among others, is an anticonvulsant medication primarily used to treat neuropathic pain and also for partial seizures of epilepsy. It is a commonly used medication for the treatment of neuropath ...

. Long-term treatment generally involves the use of antiplatelets like

aspirin Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...

clopidogrel Clopidogrel, sold under the brand name Plavix among others, is an antiplatelet drug, antiplatelet medication used to reduce the risk of Cardiovascular disease, heart disease and stroke in those at high risk. It is also used together with aspi ...

and

statin Statins (or HMG-CoA reductase inhibitors) are a class of medications that lower cholesterol. They are prescribed typically to people who are at high risk of cardiovascular disease. Low-density lipoprotein (LDL) carriers of cholesterol play ...

regimen for the rest of their lives in order to minimize the risk of another stroke.

Warfarin Warfarin, sold under the brand name Coumadin among others. It is used as an anticoagulant, anticoagulant medication. It is commonly used to prevent deep vein thrombosis and pulmonary embolism, and to protect against stroke in people who ha ...

is used if

atrial fibrillation Atrial fibrillation (AF, AFib or A-fib) is an Heart arrhythmia, abnormal heart rhythm (arrhythmia) characterized by fibrillation, rapid and irregular beating of the Atrium (heart), atrial chambers of the heart. It often begins as short periods ...

is present. Other medications may be necessary in order to suppress high blood pressure and risk factors associated with strokes. A blood thinner may be prescribed to a patient in order to break up the infarction and reestablish blood flow and to try to prevent future infarctions. One of the most unusual and difficult to treat symptoms that occur due to Wallenberg syndrome are interminable, violent

hiccup A hiccup (scientific name singultus, from Latin for "sob, hiccup"; also spelled hiccough) is an spasm, involuntary contraction (myoclonic jerk) of the diaphragm (anatomy), diaphragm that may repeat several times per minute. The hiccup is an in ...

s. The hiccups can be so severe that patients often struggle to eat, sleep and carry on conversations. Depending on the severity of the blockage caused by the

stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...

, the hiccups can last for weeks. Unfortunately, there are very few successful medications available to remediate the inconvenience of constant hiccups. For dysphagia symptoms, repetitive

transcranial magnetic stimulation Transcranial magnetic stimulation (TMS) is a noninvasive neurostimulation technique in which a changing magnetic field is used to induce an electric current in a targeted area of the brain through electromagnetic induction. A device called a st ...

has been shown to assist in rehabilitation. Overall, traditional stroke assessment and outcomes are used to treat patients, since lateral medullary syndrome is often caused by a stroke in the lateral medulla.

Prognosis

The outlook for someone with lateral medullary syndrome depends upon the size and location of the area of the brain stem damaged by the stroke. Some individuals may see a decrease in their symptoms within weeks or months, while others may be left with significant neurological disabilities for years after the initial symptoms appear. However, more than 85% of patients have seen minimal symptoms present at six months from the time of the original stroke, and have been able to independently accomplish average daily activities within a year.

Epidemiology

Lateral medullary syndrome is the most common form of posterior ischemic stroke syndrome. It is estimated that there are around 600,000 new cases of this syndrome in the United States alone. Those at the overall highest risk for lateral medullary syndrome are men at an average age of 55.06. Having a history of hypertension, diabetes and smoking all increase the risk of large artery

atherosclerosis Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. This is a chronic inflammatory disease involving many different cell types and is driven by eleva ...

. Large artery atherosclerosis is thought to be the greatest risk factor for lateral medullary syndrome due to the deposits of cholesterol, fatty substances, cellular waste products, calcium and fibrin. Otherwise known as plaque build up in the arteries.

History

The earliest description of lateral medullary syndrome was first written by Gaspard Vieusseux at the Medical and Chirurgical Society of London describing the symptoms observed at the time. Adolf Wallenberg further reinforced these signs after completing his first case report in 1895. He was able to make an accurate localization of the lesion and soon after proved it following a postmortem examination. Wallenberg accomplished three more published articles about lateral medullary syndrome.

Adolf Wallenberg

Adolf Wallenberg was a renowned

neurologist Neurology (from , "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the brain, the ...

and

neuroanatomist Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defin ...

most widely known for his clinical descriptions of Lateral Medullary Syndrome. He completed his doctorate at

Leipzig University Leipzig University (), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 December 1409 by Frederick I, Electo ...

in 1886. By 1928 he had spent 2 years (1886-1888) as an assistant at the city hospital in Danzig, 21 years (1907-1928) as the director of internal and psychiatric departments and 18 years (1910-1928) as a titular professor. In 1929, Wallenberg received the Erb Commemorative Medal for his work in the field of anatomy, physiology and pathology of the nervous system. Wallenberg's first patient in 1885 was a 38-year-old male with symptoms of vertigo,

numbness Hypoesthesia or numbness is a common side effect of various medical conditions that manifests as a reduced sense of touch or sensation, or a partial loss of sensitivity to Sensory receptor, sensory stimuli. In everyday speech this is generally r ...

, loss of pain and temperature sensitivity, paralysis of multiple locations, ataxia and more. His background in neuroanatomy helped him in correctly locating the patient's lesion to the lateral medulla and connected it to a blockage of the ipsilateral posterior inferior cerebral artery. After the death of his patient in 1899, he was able to prove his findings after a postmortem examination. He continued his work with many patients and by 1922 he had reported his 15th patient with clinicopathological correlations. In 1938, Adolf Wallenberg was forced to end his career as a physician by the German occupation. When the Nazis came to power, he was stripped of his research laboratory and forced to stop working because he was Jewish. He emigrated to Great Britain in 1938, then relocated to the United States in 1943.

References

External links

MRI of Lateral Medullary Infarction (Wallenberg)
MedPix Images {{DEFAULTSORT:Lateral Medullary Syndrome Types of stroke Syndromes affecting the nervous system