What is Moyamoya Disease?
Moyamoya disease is a consideration where there is chronic and progressive narrowing of walls of internal carotid arteries characterized by thickening of the walls , lead in a specify or stenosed inner diam of the artery . This progressive narrowing may bit by bit cause utter blockage in the arteries and result in apoplexy . to overcompensate for the decreased lineage rate of flow in the narrow arteries , our brain shape confirmatory ancestry vessel , so that the divest arena of the brain can receive oxygen - rich blood . Moyamoya disease was discovered by the Japanese and they termed these collateral vessels as “ moyamoya , ” which means “ pouffe of bullet , ” in Japanese . The collateral watercraft are bantam and have a hazy appearance when seen on an angiogram . The tiny moyamoya collateral vessel are more fragile than the normal blood vessels and can well rupture and run into the brain resulting in hemorrhage . Both side of the brain are unremarkably sham by Moyamoya and this disease is also usually associated withaneurysms .
When the carotid arteries become narrow down and the bloodline flow becomes slow , it increase the peril of clot formation and transient ischaemic approach ( TIA ) or a full - fledged separatrix . for compensate for the decreased blood flow , our head slowly forms “ detour ” in the shape of lowly collateral blood vessels to supply blood to the affected regions of the encephalon . As mentioned before , these petite blood line vessels resemble a wisp of smoke when pick up on an angiogram thus give this disease its name “ Moyamoya ” which means a “ comforter of smoke ” in Japanese .
When the unconscious process of stop starts , it run to worsen the same way . As of now , there are no known medication to aid reverse the closure . If the patient support bleeding or a major stroke , then there may be lasting red of function in the patient . It is significant that this condition is name as early as potential and the treatment started instantly . Surgical treatment is often recommend in Moyamoya disease .
Stages of Moyamoya Disease
Moyamoya disease is classified into the come after stages depending on its advancement and angiographic determination :
Stage I : There is pin down of the internal carotid arteries .
Stage II : The moyamoya vessels develop at the base of the brain .
Stage III : There is worsening of the moyamoya vessels and increase in the narrowing of the internal carotid arteries . The diagnosis of this disease is usually made at this stage .
Stage IV : There is increase in the collateral vessels from the scalp and reduction of moyamoya vessels .
Stage V : step-down of moyamoya watercraft and meaning internal carotid artery narrowing .
Stage VI : The moyamoya watercraft disappear completely and the internal carotid arteries are altogether obstruct with significant collateral vessels from the scalp .
Signs & Symptoms of Moyamoya Disease
Transient ischemic plan of attack which consists ofhemorrhagic shot , ischaemic strokeor miniskirt - chance event in the affected role is the initial symptom of moyamoya disease . This occurs because of hindrance in the oxygen copious roue flow to the brain . haemorrhagic stroke takes place when the tiny blood vessels burst and the parentage leaks into the brain . The symptom of hemorrhagic stroke as well as ischaemic stroke consist of indifference or weakness in the arm or stage , difficulty in speaking , or paralysis which can affect one side of the body . Headacheis also a common symptom in haemorrhagic accident . Patient can experience other symptoms also such as cognitive or learning deadening andseizures .
Given below is a list of symptoms of Moyamoya disease which need immediate medical care :
symptom of Stroke Consist of : Blurry or unhinged sight , weakness or paralysis affecting one side of the trunk , headaches , slur words , loss of sensory faculty of tasteor smell , difficultness in speak , unfitness to take the air , unfitness to stick out upright and seizures .
symptom of a Brain Hemorrhage Which Require Immediate Medical Attention Include : Nausea , vomiting , lethargy , fatigue , vision changes , severe headache , impuissance / indifference in some part of the torso , sudden loss of consciousness , loss of coordination / balance , difficulty speaking , difficulty in see speech , feeling of a “ foreign ” gustatory modality in the mouth and seizures .
Causes & Risk Factors of Moyamoya Disease
Diagnosis of Moyamoya Disease
If the patient role is get symptoms resembling a stroke then patient is relate to a brain surgeon . The surgeon then asks questions regarding the symptoms of the affected role and also patient ’s previous aesculapian history , family chronicle and the medication which the patient is taking . After aesculapian history is taken , a strong-arm examination is perform . Imaging trial are done to serve name this term , as they discover the characteristic narrowing of the arteries and the collateral line of descent vessels of moyamoya , which have the hazy appearance of a “ puff of pot . ” Diagnostic imaging tests can also show multiple small strokes in the patient . A right diagnosing of moyamoya disease can be made if the MRI scan images show decreased blood period in the internal carotid artery , the anterior and middle cerebral arteries ; and increased collateral profligate flow rate at the base of the mastermind . Angiogram is often needed to confirm the diagnosing of moyamoya disease .
Magnetic Resonance Imaging ( MRI ) scan uses radio - frequency and magnetised field waving to generate detailed look-alike of the soft tissue of the psyche . Magnetic Resonance Angiogram ( MRA ) can also be done during the MRI scan by inject a contrast agent into the patient ’s rakehell , which can expose a clearer image of the arteries of the mentality . Magnetic Resonance Imaging is a noninvasive trial .
Angiogram is a operation where a catheter is introduced into the artery and pass via the blood vessels to the brain . After the catheter is in place , the doctor injects a contrast dyestuff into the stemma after which x - ray are taken . Angiogram help in try out all the full of life arteries to the mental capacity including the home carotid arteries , international carotid arteries and vertebral arteries . Imaging tests are important to discover any pre - existent collateral vessel , in case if the surgery is done then the surgeon can take tending to invalidate disrupting these collateral vessels . Arteriovenous malformationsor aneurysms can often be seen with moyamoya disease and they can also be detected during an angiogram . Angiogram is an invading operation .
Computed Tomography ( CT ) Perfusion Imaging help in find blood flow in the mental capacity . This test also help the surgeon in planning the surgery . A contrast agent is injected into the blood watercourse , which allows the doc to assess the amount of origin menses that is progress to the brain and to determine the parts of the wit that are at a high risk for stroke . When Computed Tomography Perfusion imagination is done , Diamox , a medication , is given to exposit the artery which also move as a “ strain test ” for the brain .
Computed Tomography Angiography ( CTA ) scan apply 10 - beam of light to render detailed ikon of anatomic complex body part of the brain . A direct contrast agent is injected into the blood stream to consider the arteries of the brain more distinctly . CTA scan is a very honorable trial run in providing pic of both the soft tissue paper as well as blood vessels . Computed Tomography Angiography is a noninvasive test .
Cerebral Blood Flow Studies include the Xenon - Enhanced CT scan , Transcranial Doppler Ultrasonography ( TCD ) , Single Photon Emission Computed Tomography ( SPECT ) scan , and Positron Emission Tomography ( PET ) scan also can be done to help with the diagnosing and treatment of moyamoya disease .
Treatment for Moyamoya Disease
Presently , there are no medicine which can repeal the narrowing of the arteries in moyamoya disease . The aim of intervention for moyamoya disease is cutting down the risks of repeated strokes by doing an arterial shunt or by take form a raw blood supply to the moved part of the brain . Anti - platelet agents , which include medicines like acetylsalicylic acid , are given to keep the formation of clot . In patients who are endure from TIA and stroke , aspirin helps in reducing the risk of occurrence of a damaging stroke . fit in to studies , aspirin used alone is not effective in treatment of moyamoya disease . Surgery is unremarkably recommended for treatment of moyamoya disease .
Treatment for patients suffer from long - condition damage from stroke consists ofphysical therapy , occupational therapyand speech therapy to help the patient regain function and cope with their handicap .
Surgical Treatment for Moyamoya Disease
operating room is unremarkably recommended for patient with moyamoya disease who are having progressive or perennial slash or TIA . There are various surgical procedures available for moyamoya disease with the end of preventing more strokes by revascularization or furbish up the blood flow to the affected portion of the encephalon . The operative procedure can be divided into two radical ; one which demand unmediated connection between the blood vessels and the other which involves indirect connectedness between the stemma vessels . Generally , verbatim bypass procedure are done in older small fry and adults ; whereas collateral procedure are done in children below the age of 10 years .
Cerebral Bypass Procedure is a operative procedure , which postulate the direct method of revascularization by unite a parentage vessel present outside the Einstein to a blood watercraft present inside the brain . This will reroute or bypass the blood catamenia around the damaged narrowed / draw a blank artery . Superficial secular artery to middle cerebral artery or STA - MCA is the commonest bypass subprogram used and gives an prompt melioration in the pedigree stream . In case where the superficial secular arterial blood vessel is not sufficiently crowing or is not available to practice for electrical shunt , then a different arterial blood vessel needs to be used . This is determined after the surgeon has refresh the image of the arteries from CT angiogram or angiogram .
Encephalo - Myo - Synangiosis ( EMS ) is a surgical function that is also an indirect method of revascularization where the surgeon analyse the temporalis muscle and places it onto the surface of the brain through an opening in the skull . bit by bit there is organization of new vessel between the brain and the descent - full-bodied muscle .
Encephalo - Duro - Arterio - Synangiosis ( EDAS ) is a procedure which involves the indirect method of revascularization where the superficial secular artery is put in contact with the surface of the brain . The sawbones makes a hole in the skull forthwith under the artery and the artery is then sutured to the brain ’s surface after which the osseous tissue is replace . As fourth dimension goes , angiogenesis occurs where there is formation of little arterial vessels to the brain .
Encephalo - Duro - Arterio - Myo - Synangiosis ( EDAMS ) is a surgical subprogram which is also an indirect method of revascularization and which combines the technique of EMS and EDAS .
Omental Transposition is a procedure that is another collateral method acting of revascularization where the omentum , which is very abundant in lineage supplying , is put on the mastermind ’s surface and finally it is carry that the vessels will produce into the brain and heighten the origin supply .
Multiple Burr Holes Procedure is another indirect method of revascularization where the surgeon drill multiple small holes in the skull , so that young vessels can maturate into the mentality from the scalp .
Life Expectancy, Recovery & Prognosis in Moyamoya Disease
It is unmanageable to predict the prognosis and life expectancy of the patient role having moyamoya disease as the natural history of this condition is not unclouded . The progression of Moyamoya disease can be dull with the patient agony from occasional stroke or TIAs ; or there can be rapid worsening of this disease where the patient ’s health decay . The prognosis and liveliness expectancy of the patient having moyamoya disease depends on the speed and the degree of the narrowing and blockage in the arterial blood vessel . Prognosis also reckon on the ability of the patient role to forge good validatory circulation , the age of the patient when the symptoms started , whether one or both side of meat of the mental capacity are pretend , whether the patient has suffer a stroke , patient role ’s world-wide health , the extent of disability which the affected role has as a effect of a solidus and how soon the treatment start after the diagnosis . The neurologic consideration of the patient is also crucial in set the recovery and life expectancy of the patient role .
According to studies , about 50 to 60 % of patients who do not seek discourse for moyamoya disease will have progression of the disease and have minify life anticipation and wretched prognosis whereas surgical treatment of patients has break a swell decrease in the progression of this disease .
As far as recovery from Moyamoya disease is worry , it is authoritative for family appendage to interpret that this is a reform-minded disease and there is uninterrupted decline in quality of the narrowing of the blood vessels of the brain . Symptoms can become bit by bit dangerous over a period of meter and patient can also suffer multiple strokes in a brusk straddle of meter . Surgery is done to provide a raw and healthy germ of blood circulation to the brain and to cut down the endangerment of a animation - threatening fortuity .
The prognosis run to be first-class if there is operative intervention done in affected role before a disabling stroke and even in hard moyamoya disease . In affected role who do not have any symptoms , surgical treatment help in protecting against stroke and also increases the life expectancy of the patient role . However , if the patient is not treated , then there is worsening of moyamoya disease with clinical deterioration in the patient role along with potentially irreversible neurologic disability .
