Three-dimensional MRI of hemifacial spasm with surgical correlation

Girard, Nadine; Poncet, M.; Caces, F.; Tallon, Y.; Chays, A.; P, Martin-Bouyer; Magnan, J.; Raybaud, Charles

doi:10.1007/s002340050366

Cited by 112 publications

(68 citation statements)

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“…One hypothesis is that continuous or pulsatile compression is thought to cause focal demyelination, reorganization, and axonal hyperactivity at the junction between the central glial and peripheral nonglial junction. [18][19][20] The other hypothesis is that impaired blood flow by a neurovascular compression may result in reduced vascular perfusion. 21 These hypotheses, however, do not explain all symptoms seen in vascular compression syndromes.…”

Section: Discussionmentioning

confidence: 99%

Vascular Loops at the Cerebellopontine Angle: Is There a Correlation with Tinnitus?

Gültekin¹,

Çelik²,

Akpek³

et al. 2008

AJNR Am J Neuroradiol

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Section: Discussionmentioning

confidence: 99%

Vascular Loops at the Cerebellopontine Angle: Is There a Correlation with Tinnitus?

Gültekin¹,

Çelik²,

Akpek³

et al. 2008

AJNR Am J Neuroradiol

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“…5) Microvascular decompression of the facial nerve is performed in patients with severe symptoms and has been successful in a high percentage of cases. 3,5,8,11) Here we report a case of vertebral artery aneurysm causing progressive HFS which was successfully treated with endovascular coil embolization.…”

Section: Introductionmentioning

confidence: 92%

“…Facial nerve irritation or compression by vascular structures, most frequently elongated arteries, is a widely accepted cause of HFS, 3,5,8,11) but pathological lesions such as tumors, 10) angiomas, 2,4) and arteriovenous malformations 9) may also be involved. Aneurysms in the vertebrobasilar system rarely cause HFS.…”

Section: Introductionmentioning

confidence: 99%

Endovascular Treatment of Vertebral Artery Aneurysm Manifesting as Progressive Hemifacial Spasm-Case Report-

Matsumoto

Kimura

Kakita

2005

Neurol. Med. Chir.(Tokyo)

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A 62-year-old woman presented with right hemifacial spasm persisting for 6 months. Brain magnetic resonance imaging and digital subtraction angiography showed a wide-neck aneurysm of the intracranial portion of the right vertebral artery. The patient underwent endovascular trapping of the aneurysm by coil embolization of the parent vessel on both sides of the aneurysm. The patient experienced gradual disappearance of the hemifacial spasm within 3 months. No relapses occurred during a follow-up period of 3 years. Magnetic resonance imaging revealed shrinkage of the vertebral artery aneurysm which had compressed the facial nerve. Endovascular trapping of a vertebral artery aneurysm can be used to treat hemifacial spasm caused by an aneurysm instead of surgical microvascular decompression.

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“…4 This sequence is also useful to study masses in the CPA cistern, especially in cases of hearing impairment.…”

Section: Uses Of Constructive Interference In Steady Statementioning

confidence: 99%

Constructive Interference in Steady State Imaging in the Central Nervous System

Gonçalves¹,

Amaral²

2011

US Neurology

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Constructive interference in steady state (CISS) imaging is a member of the family of fast gradient echo (GRE) sequences. The CISS sequence is particularly dependent on high gradient amplitude and slew rates. When inside a magnetic resonance imaging (MRI) scanner, the randomly moving protons in the patient's body align along the longitudinal z-axis.The z-axis is a magnetization vector parallel to both the long axis of the patient's body and the bore of the scanner. This magnetization force, represented as a vector along the positive side of the z-axis, is called longitudinal magnetization (LM). When a radiofrequency pulse (RFP) is applied, the magnetization vector is tipped to the transverse plane.This tipped magnetization vector has two components: the LM, which recovers, and the transverse magnetization (TM), which decays during each repetition time (TR) period in the x-axis.CISS is a 'green' sequence. The main recycling idea is not to waste the signal from the decaying TM in every RFP, because it is this signal that provides the T2 properties of a given tissue. Instead of being lost, the TM is reinforced into the transverse plane. The TM is recovered by applying an 180° phase shift during each TR period, after which the TM shifts in the transverse plane. The following RFP simultaneously tips a component of the residual TM back along the z-axis and a portion of the LM into the transverse plane (x-axis). After multiple TR periods have elapsed, this feeding of the LM into the TM, and vice versa, eventually establishes an equilibrium state of both the LM and the TM.It must be stressed that it is necessary to keep the TR shorter than the T2 relaxation time of the tissue; in this way, there is insufficient time for the TM to decay completely before the next RFP excitation. To achieve CISS images, residual TM is always necessary. Once the equilibrium is reached, two types of signal are produced: the first is a post-excitation signal, which consists of free induction decay arising from the most recent RFP, and the second is the echo reformation prior to excitation, when residual echo is refocused at the time of the subsequent RFP. Constructive Interference in Steady State Imaging in the Central Nervous System AbstractConstructive interference in steady state (CISS) is a fully refocused fast-gradient echo sequence that is mainly used in the assessment of the central nervous system. The most important advantages of steady-state imaging are short acquisition times, high signal-to-noise ratio, and better contrast-to-noise ratio. Owing to its cisternographic effect, CISS is useful in the assessment of the cranial nerves, and can also be used when studying cysts, cystic masses, and neurocysticercosis and in hydrocephalus cases. CISS has been shown to be useful in spinal imaging, especially in cases of arteriovenous malformation and when it is helpful to better characterize intra-and extramedullary cystic abnormalities. KeywordsMagnetic resonance imaging, fast-gradient echo sequence, steady-state imaging, constructive inte...

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Three-dimensional MRI of hemifacial spasm with surgical correlation

Cited by 112 publications

References 0 publications

Vascular Loops at the Cerebellopontine Angle: Is There a Correlation with Tinnitus?

Vascular Loops at the Cerebellopontine Angle: Is There a Correlation with Tinnitus?

Endovascular Treatment of Vertebral Artery Aneurysm Manifesting as Progressive Hemifacial Spasm-Case Report-

Constructive Interference in Steady State Imaging in the Central Nervous System

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