Navigation

The internal carotid artery and its branches occlusion syndromes

Middle cerebral artery occlusion syndromes

Branch of the middle cerebral artery in the brain cortex arterial blood supply side surface of the cerebral hemispheres, with the exception of the frontal pole, strip, located along the border verhnevnutrenney frontal lobe, which are supplied with arterial blood, anterior cerebral artery, and the lower temporal gyrus related to the basin of the posterior cerebral artery.

Middle cerebral artery supplies arterial blood following brain regions:

  • cortex and white matter of the brain from the side and bottom of the frontal lobe
  • motor cortex (fields 4 and 6, the cortical centers of sight, motor speech center in the dominant hemisphere Broca's area)
  • cortex and white matter of the brain side of the parietal lobe (sensory cortex, angular gyrus and supramarginal)
  • lateral and upper parts of the temporal lobe and the islet brain
Middle cerebral artery is most often exposed to thrombosis and embolism, which lead to ischemic stroke.

Perforating branches of the middle cerebral artery supplying arterial blood following brain regions:

  • putamen
  • outer division of the globus pallidus of the brain
  • posterior thigh of the internal capsule below the plane that intersects the upper boundary of the globus pallidus
  • adjacent part of the radiate crown
  • body of the caudate nucleus
  • upper and lateral segments of the head of the caudate nucleus

Embolism and thrombosis, most often exposed to middle cerebral artery basin vessels. With complete occlusion of the lumen (occlusion) blocked artery trunk as perforating branches to the deep white and gray matter of the brain, and large branches to the surface of the cerebral cortex. The classic picture of the lesion is characterized by hemiplegia (paralysis of half of the body) and unilateral anesthesia (loss of sensitivity than half of the body) on the opposite side of the body.

With involvement in the pathological process in the dominant hemisphere stroke patient's brain, there is also a total sensorimotor aphasia (impairment of perception and reproduction of speech). In cases of non-dominant hemisphere lesions of the brain clinical symptom complex is complemented apraktoagnoziey and anosognosia (inability to understand or recognize objects). If the patient has dysarthria (impairment proper motion of the vocal apparatus during speech playback), then dysphasia (impairment of speech perception and reproduction) is observed.

MRI angiography of cerebral vascular shows a left middle cerebral artery thrombosis (white arrow).

Visible neurologic manifestations of lesions of the middle cerebral artery basin often noted at occlusion (occlusion) of the lumen of this artery trunk embolus. To establish an effective collateral blood circulation of the cerebral cortex at a specific time, but it leads to the development of partial occlusion of the lumen of syndromes in the trunk of the middle cerebral artery on the background of its atherosclerosis with subsequent thrombosis.

Partial neurological syndromes are also found at middle cerebral artery basin embolism. Embolus can get into the trunk of the artery, to spread further upward (distally), penetrate into the overlying (distal) branch and subject to further dilution (lysis). In accordance with the process objective and subjective neurological symptoms varies. Certain syndromes are diseases caused by embolic occlusion (occlusion) of one of the branches include:

  • weakness in the wrist
  • only weakness of the upper extremity (shoulder syndrome)
  • lesion mimic muscles with motor aphasia and weakness in his hand or without it (frontal opercular syndrome)

Sensory impairments, weakness in the limbs and motor aphasia suggests embolism at the site of exit from the upper branches of the division. When re-aphasia without paresis, probably a lesion in the lower division of the middle cerebral artery, as coming from a branch supply blood to the rear area of ??the dominant hemisphere sensory cortex. The sudden appearance of the difficulties caused by ignoring half of the body and spatial agnosia, with no evidence of paralysis of the lower division of the damage of the middle cerebral artery non-dominant hemisphere of the brain of the patient.

 

Middle cerebral artery syndrome:

Signs and symptoms
Structures involved
Paralysis of the contralateral face, arm, and leg; sensory impairment over the same area (pinprick, cotton touch, vibration, position, two-point discrimination, stereognosis, tactile localization, barognosis, cutaneographia) Somatic motor area for face and arm and the fibers descending from the leg area to enter the corona radiata and corresponding somatic sensory system
Motor aphasia Motor speech area of the dominant hemisphere
Central aphasia, word deafness, anomia, jargon speech, sensory agraphia, acalculia, alexia, finger agnosia, right-left confusion (the last four comprise the Gerstmann syndrome) Central, suprasylvian speech area and parietooccipital cortex of the dominant hemisphere
Conduction aphasia Central speech area (parietal operculum)
Apractognosia of the nondominant hemisphere, anosognosia, hemiasomatognosia, unilateral neglect, agnosia for the left half of external space, dressing “apraxia,” constructional “apraxia,” distortion of visual coordinates, inaccurate localization in the half field, impaired ability to judge distance, upside-down reading, visual illusions (e.g., it may appear that another person walks through a table) Nondominant parietal lobe (area corresponding to speech area in dominant hemisphere); loss of topographic memory is usually due to a nondominant lesion, occasionally to a dominant one
Homonymous hemianopia (often homonymous inferior quadrantanopia) Optic radiation deep to second temporal convolution
Paralysis of conjugate gaze to the opposite side Frontal contraversive eye field or projecting fibers

Anterior cerebral artery occlusion syndromes

Anterior cerebral artery of the brain has two segments:

  • pre-communicating (A1 ) segment of the circle of Willis, or stem, the segment that connects the internal carotid artery from the anterior communicating artery
  • post-communicating (A2) segment, originating from the junction of A1 segment of the anterior communicating artery

A2 segment of anterior cerebral artery cortical branches through their supplies blood 2/3medialnoy front surface of the orbital part of the frontal lobe, frontal lobe pole, strip the bark along the border and verhnesredinnoy 2/3mozolistogo front of the body. On the other hand, the A1 segment of anterior cerebral artery gives a lot of deep penetrating branches, going mainly to the anterior thigh of the internal capsule, anterior perforated substance, almond-shaped body, the anterior hypothalamus and the lower part of the head of the caudate nucleus of the brain.

Cerebral infarcts (strokes) in a pool of anterior cerebral artery are rare. Blockage (occlusion) of the trunk or A1 segment of anterior cerebral artery is usually well compensated by the possibility of collateral blood flow from the opposite side. The most serious impairments arise in cases where both anterior cerebral artery originated from a single trunk (in case of congenital anatomical features of the structure of the patient), blockage (occlusion), which leads to a massive heart attack in the basins of the anterior cerebral arteries of both hemispheres of the brain.

Clinical manifestations of blockage (occlusion) in a pool of both anterior cerebral arteries include bilateral pyramidal disorders with paraplegia (paralysis of the left and right halves of the body) and marked changes in the psyche in connection with bilateral lesions of the frontal lobes of the brain.

 

Anterior cerebral artery syndrome:

Signs and symptoms
Structures involved
Paralysis of opposite foot and leg Motor leg area
A lesser degree of paresis of opposite arm Arm area of cortex or fibers descending to corona radiata
Cortical sensory loss over toes, foot, and leg Sensory area for foot and leg
Urinary incontinence Sensorimotor area in paracentral lobule
Contralateral grasp reflex, sucking reflex, gegenhalten (paratonic rigidity Medial surface of the posterior frontal lobe; likely supplemental motor area
Abulia (akinetic mutism), slowness, delay, intermittent interruption, lack of spontaneity, whispering, reflex distraction to sights and sounds Uncertain localization—probably cingulate gyrus and medial inferior portion of frontal, parietal, and temporal lobes
Impairment of gait and stance (gait apraxia) Frontal cortex near leg motor area
Dyspraxia of left limbs, tactile aphasia in left limbs Corpus callosum

 

The vascular plexus of anterior artery occlusion syndromes

Anterior artery of the choroid plexus of the brain begins from the internal carotid artery supplies blood back hip of the internal capsule and white matter of the brain from the side and behind of it, through which the portion of the optic fibers from the lateral geniculate body to the calcarine sulcus. This area of the brain supplied with blood of:

  • penetrating vessels going from the trunk of the middle cerebral artery (artery of lenticular nucleus and the striatum)
  • penetrating branches of the posterior communicating artery
  • posterior artery of the choroid plexus

Therefore, the full clinical syndrome of contralateral hemiplegia in the form of (paralysis of the muscles on the opposite side), hemianesthesia (hypoesthesia) and gomonimnoy hemianopsia (loss of half the visual field on the affected side of the brain) can not develop. Instead, there are syndromes with a minimum severity of neurological focal disorders.

Indeed, in cases of surgical occlusion of the anterior artery of the choroid plexus for the treatment of Parkinson's disease in some patients does not show signs of lack of blood circulation in the area of ??its basin. Patients who originally observed the detailed clinical symptoms often recover completely or partially, apparently thanks to a sufficient level of collateral blood flow in this part of the brain.

 

Internal carotid artery occlusion syndromes

The clinical picture of occlusion of the internal carotid artery of the brain varies depending on what is the cause of ischemia: spreading thrombosis, embolism, or low blood flow. Occlusion (blockage) of the internal carotid artery may be asymptomatic. Extensive cerebral infarction (stroke) with involvement of deep gray and white matter, cortical surface develops rarely, if thrombus occluding the lumen extends to the internal carotid artery and penetrates into the trunk of the middle cerebral artery and anterior cerebral artery or if the fragment is separated thrombus embolism entails a high or anterior cerebral artery.

Symptoms identical to those in the occlusion of the middle cerebral artery trunk. At the same time engaging in the pathological process of anterior and middle cerebral arteries hemiplegia, aphasia or unilateral anesthesia and is often accompanied by anosognosia stupor. When the posterior cerebral artery comes from the internal carotid artery (fetal posterior cerebral artery ), it can also be clogged by the mechanisms described above, which is accompanied by symptoms of damage her basin.

Atherosclerosis with thrombosis of the internal artery weed can cause transient ischemic attack (TIA) or stroke (cerebral infarction).

When symptomatic lesions of atherosclerosis with thrombosis of the internal carotid artery, regardless of the cause of cerebral ischemia in the basin often suffers from a region of the middle cerebral artery supplied with blood. Cerebral infarction (stroke) due to low blood flow, often localized in the distal cortical branches of the basin of the middle cerebral artery, leading to the development of transient or gradually increasing weakness in the muscles of the pelvic and shoulder girdles and upper limbs. Sometimes there are episodes of transient cerebral ischemia, accompanied by dysphasia (impairment of the understanding or reproduction of speech) or hemiparesis (muscle weakness, half of the body) with a duration of 10-15 minutes, followed by regression of neurological symptoms. The maximum number of similar episodes of transient ischemic attack (TIA) patients per day up to 5-10.

With the involvement of the dominant hemisphere of the brain in transient ischemic attack (TIA), one can observe transient aphasia or dyscalculia (impairment of the account). With involvement of the non-dominant hemisphere of the brain may occur transient neglect of the body. With the damage of the lower division of the middle cerebral artery of the dominant hemisphere aphasic The expressed frustration with the fugitive jargon, with the written and spoken language the patient can not understand (Wernicke aphasia). Even arterioarterialnyh embolism neurological symptoms is often transient in nature due to the fact that emboli can cause an incomplete occlusion of the trunk or branches of the middle cerebral artery, or be subjected to lysis (dissolution) and transported to the distal (above the blockage of the lumen) direction.

In most cases, it turns out that if the neurological symptoms of cerebral ischemia when held long enough, but less than 24 hours, then it is due to embolism of the artery. In those cases where the neurological symptoms of cerebral ischemia is transient (transient) in nature and is retained only a few seconds or minutes, it is usually difficult to differentiate between embolic and hemodynamic its nature.

In addition to the brain, the internal carotid artery supplies blood optic nerve and retina through the ophthalmic artery. Approximately 25% of clinically manifested occlusion (blockage of the lumen) of the internal carotid artery occasionally arises transient blindness in one eye. In the future a high probability of permanent blindness. Describing such an episode, a patient may tell the doctor about a feeling or subsiding and disappearing shadows crossing the field of view or loss of peripheral regions of the visual field. There are also complaints of blurred, blurred vision in the affected eye or in the absence of upper or lower half of the visual field. Most often these symptoms persist for a few minutes. Less commonly, a stroke at the same time celebrate the occlusion (blockage of the lumen), ophthalmic artery or central retinal artery.

 

Common carotid artery occlusion syndromes

When the common carotid artery occlusion can be observed all the neurologic symptoms of occlusion of the internal carotid artery. At the "pulseless disease" or syndrome, aortic arch possible occlusion of both common carotid arteries in the places they are released.

Anatomy of the common carotid and internal carotid artery gives to understand the mechanism of ischemic stroke.

In the diagnosis of this condition by occlusion of both common carotid arteries are the leading symptoms of the following:

  • the absence of pulsations on carotid and radial artery
  • fainting when rising from a horizontal position
  • recurrent episodes of loss of consciousness
  • headaches
  • pain in the neck
  • transient blindness (one-or two-sided)
  • blurred vision during exercise
  • early cataracts
  • atrophy and retinal pigmentation
  • atrophy of the iris
  • leucoma
  • arteriovenous anastomoses peripapillyarnye
  • atrophy of the optic nerves
  • intermittent weakness of the masticatory muscles

Often there is a partial syndrome of the aortic arch, consisting of various combinations of stenosis and occlusion of the carotid, subclavian and innominate artery.

See also