Lateral medullary syndrome | |
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Other names | Wallenberg syndrome, posterior inferior cerebellar artery syndrome |
Medulla oblongata, shown by a transverse section passing through the middle of the olive. (Lateral medullary syndrome can affect structures in upper left: #9=vagus nerve, #10=acoustic nucleus, #12=nucleus gracilis, #13=nucleus cuneatus, #14=head of posterior column and lower sensory root of trigeminal nerve and #19=Ligula.) | |
Specialty | Neurology |
Lateral medullary syndrome is a neurological disorder causing a range of symptoms due to ischemia in the lateral part of the medulla oblongata in the brainstem. The ischemia is a result of a blockage most commonly in the vertebral artery or the posterior inferior cerebellar artery. [1] Lateral medullary syndrome is also called Wallenberg's syndrome, posterior inferior cerebellar artery (PICA) syndrome and vertebral artery syndrome. [2]
This section needs additional citations for verification .(November 2024) |
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 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).[ citation needed ]
Patients often have difficulty walking or maintaining balance (ataxia), or difficulty in differentiating the temperature of an object based on which side of the body the object of varying temperature is touching. [2] Some patients may walk with a slant or experience skew deviation and illusions of room tilt. The nystagmus is commonly associated with vertigo spells. These vertigo spells can result in falling, caused from the involvement of the region of Deiters' nucleus.[ citation needed ]
Common symptoms of lateral medullary syndrome may include difficulty swallowing, or dysphagia. This can be caused by the involvement of the nucleus ambiguus, as it supplies the vagus and glossopharyngeal nerves. Slurred speech (dysarthria), and disordered vocal quality (dysphonia) are also common. The damage to the cerebellum or the inferior cerebellar peduncle can cause ataxia. Damage to the hypothalamospinal fibers disrupts sympathetic nervous system relay and produces symptoms that are similar to the symptoms caused by Horner's syndrome – such as miosis, anhidrosis and partial ptosis.[ citation needed ]
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, a slow heart rate, and increases or decreases in the patient's average blood pressure. [2]
Dysfunction | Effects |
Vestibular nuclei | Vestibular system: Vomiting, vertigo, nystagmus |
Inferior cerebellar peduncle | Ipsilateral cerebellar signs including ataxia, dysmetria (past pointing), dysdiadochokinesia |
Central tegmental tract | Palatal myoclonus |
Lateral spinothalamic tract | Contralateral deficits in pain and temperature sensation from body (limbs and torso) |
Spinal trigeminal nucleus & tract | Ipsilateral deficits in pain and temperature sensation from face |
Nucleus ambiguus - (which affects vagus nerve and glossopharyngeal nerve) - localizing lesion (all other deficits are present in lateral pontine syndrome as well) | Ipsilateral laryngeal, pharyngeal, and palatal hemiparalysis: dysphagia, hoarseness, absent gag reflex (efferent limb—CN X) |
Descending sympathetic fibers | Ipsilateral Horner's syndrome (ptosis, miosis, & anhidrosis) |
It is the clinical manifestation resulting from occlusion of the posterior inferior cerebellar artery (PICA) or one of its branches or of the vertebral artery, in which the lateral part of the medulla oblongata infarcts, resulting in a typical pattern. The most commonly affected artery is PICA, specifically the lateral medullary segment.
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 or other head trauma. [2]
Treatment for lateral medullary syndrome is dependent on how quickly it is identified. [2] 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. Depressed mood and withdrawal from society can be seen in patients following the initial onslaught of symptoms.[ citation needed ]
In more severe cases, a feeding tube may need to be inserted through the mouth or a gastrostomy 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 pain associated with the syndrome with anti-epileptics such as gabapentin. Long-term treatment generally involves the use of antiplatelets like aspirin or clopidogrel and statin regimen for the rest of their lives in order to minimize the risk of another stroke. [2] Warfarin is used if atrial fibrillation 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. [3]
One of the most unusual and difficult to treat symptoms that occur due to Wallenberg syndrome are interminable, violent hiccups. 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, the hiccups can last for weeks. Unfortunately, there are very few successful medications available to remediate the inconvenience of constant hiccups.[ citation needed ]
For dysphagia symptoms, repetitive transcranial magnetic stimulation 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. [3]
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. [2] 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. [4] 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. [3]
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. [5] [ outdated statistic ] 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. [3] 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. [6]
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. [7]
Adolf Wallenberg was a renowned neurologist and neuroanatomist most widely known for his clinical descriptions of Lateral Medullary Syndrome. He completed his doctorate at Leipzig University 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. [8]
Wallenberg's first patient in 1885 was a 38-year-old male with symptoms of vertigo, numbness, 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. [8] 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.[ citation needed ]
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 (involuntary) functions, ranging from vomiting to sneezing. The medulla contains the cardiovascular center, the respiratory center, vomiting and vasomotor centers, responsible for the autonomic functions of breathing, heart rate and blood pressure as well as the sleep–wake cycle. "Medulla" is from Latin, ‘pith or marrow’. And "oblongata" is from Latin, ‘lengthened or longish or elongated'.
The brainstem 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 continuous with the thalamus of the diencephalon through the tentorial notch, and sometimes the diencephalon is included in the brainstem.
Medial medullary syndrome, also known as inferior alternating syndrome, hypoglossal alternating hemiplegia, lower alternating hemiplegia, or Dejerine syndrome, is a type of alternating hemiplegia characterized by a set of clinical features resulting from occlusion of the anterior spinal artery. This results in the infarction of medial part of the medulla oblongata.
Adolf Wallenberg was a German internist and neurologist.
In human anatomy, the anterior spinal artery is the artery that supplies the anterior portion of the spinal cord. It arises from branches of the vertebral arteries and courses along the anterior aspect of the spinal cord. It is reinforced by several contributory arteries, especially the artery of Adamkiewicz.
The posterior cerebral artery (PCA) is one of a pair of cerebral arteries that supply oxygenated blood to the occipital lobe, part of the back of the human brain. The two arteries originate from the distal end of the basilar artery, where it bifurcates into the left and right posterior cerebral arteries. These anastomose with the middle cerebral arteries and internal carotid arteries via the posterior communicating arteries.
Vertebrobasilar insufficiency (VBI) describes a temporary set of symptoms due to decreased blood flow (ischemia) in the posterior circulation of the brain. The posterior circulation supplies the medulla, pons, midbrain, cerebellum and supplies the posterior cerebellar artery to the thalamus and occipital cortex. As a result, symptoms vary widely depending which brain region is predominantly affected.
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 result in a type of stroke called lateral medullary syndrome.
The anterior inferior cerebellar artery (AICA) is one of three pairs of arteries that supplies blood to the cerebellum.
The superior cerebellar artery (SCA) is an artery of the head. It arises near the end of the basilar artery. It is a branch of the basilar artery. It supplies parts of the cerebellum, the midbrain, and other nearby structures. It is the cause of trigeminal neuralgia in some patients.
Anterior spinal artery syndrome is syndrome caused by ischemia of the area supplied by the anterior spinal artery, resulting in loss of function of the anterior two-thirds of the spinal cord. The region affected includes the descending corticospinal tract, ascending spinothalamic tract, and autonomic fibers. It is characterized by a corresponding loss of motor function, loss of pain and temperature sensation, and hypotension.
Bulbar palsy refers to a range of different signs and symptoms linked to impairment of function of the glossopharyngeal nerve, the vagus nerve, the accessory nerve, and the hypoglossal nerve. It is caused by a lower motor neuron lesion in the medulla oblongata, or from lesions to these nerves outside the brainstem, and also botulism. This may be caused by any of a number of genetic, vascular, degenerative, inflammatory, and other underlying conditions. It can be differentiated from pseudobulbar palsy. When there is airway obstruction, intubation is used.
Benedikt syndrome, also called Benedikt's syndrome or paramedian midbrain syndrome, is a rare type of posterior circulation stroke of the brain, with a range of neurological symptoms affecting the midbrain, cerebellum and other related structures.
Posterior spinal artery syndrome(PSAS), also known as posterior spinal cord syndrome, is a type of incomplete spinal cord injury. PSAS is the least commonly occurring of the six clinical spinal cord injury syndromes, with an incidence rate of less than 1%.
Posterior circulation infarct (POCI) is a type of cerebral infarction affecting the posterior circulation supplying one side of the brain.
A brainstem stroke syndrome falls under the broader category of stroke syndromes, or specific symptoms caused by vascular injury to an area of brain. As the brainstem contains numerous cranial nuclei and white matter tracts, a stroke in this area can have a number of unique symptoms depending on the particular blood vessel that was injured and the group of cranial nerves and tracts that are no longer perfused. Symptoms of a brainstem stroke frequently include sudden vertigo and ataxia, with or without weakness. Brainstem stroke can also cause diplopia, slurred speech and decreased level of consciousness. A more serious outcome is locked-in syndrome.
Cerebellar stroke syndrome is a condition in which the circulation to the cerebellum is impaired due to a lesion of the superior cerebellar artery, anterior inferior cerebellar artery or the posterior inferior cerebellar artery.
Claude's syndrome is a form of brainstem stroke syndrome characterized by the presence of an ipsilateral oculomotor nerve palsy, contralateral hemiparesis, contralateral ataxia, and contralateral hemiplegia of the lower face, tongue, and shoulder. Claude's syndrome affects oculomotor nerve, red nucleus and brachium conjunctivum.
Babinski–Nageotte syndrome is an alternating brainstem syndrome. It occurs when there is damage to the dorsolateral or posterior lateral medulla oblongata, likely syphilitic in origin. Hence it is also called the alternating medulla oblongata syndrome.
Cerebellar cognitive affective syndrome (CCAS), also called Schmahmann's syndrome is a condition that follows from lesions (damage) to the cerebellum of the brain. It refers to a constellation of deficits in the cognitive domains of executive function, spatial cognition, language, and affect resulting from damage to the cerebellum. Impairments of executive function include problems with planning, set-shifting, abstract reasoning, verbal fluency, and working memory, and there is often perseveration, distractibility and inattention. Language problems include dysprosodia, agrammatism and mild anomia. Deficits in spatial cognition produce visual–spatial disorganization and impaired visual–spatial memory. Personality changes manifest as blunting of affect or disinhibited and inappropriate behavior. These cognitive impairments result in an overall lowering of intellectual function. CCAS challenges the traditional view of the cerebellum being responsible solely for regulation of motor functions. It is now thought that the cerebellum is responsible for monitoring both motor and nonmotor functions. The nonmotor deficits described in CCAS are believed to be caused by dysfunction in cerebellar connections to the cerebral cortex and limbic system.