Relationship Between Factors Associated With Posterior Fossa Anatomy And Primary Trigeminal Neuralgia After 3-D Magnetic Resonance Imaging Inspection

Objective: To analyze the relationship between factors associated with posterior foaas anatomy and primary trigeminal neuralgia(PTN) as well as the prognosis of microvascular decompression(MVD) after 3—D magnetic resonance imaging(MRI) thin slice scan inspection.Methods: Enrolled 63 PTN patients who received treatment in the Department of Neurosurgery of the First Affiliated Hospital of Xinjiang Medical University from March 2013 to March 2015,according to inclusion and exclusion criteria.Also enrolled 20 healthy people with matched gender,age and nationality who voluntarily took MRI inspection in the physical examination center in the hospital during the same period.Before operation,cerebral MRI plain scan and 3D—MRI thin slice scan by internal auditory canal were undertaken on the subjects.Factors associated with the posterior fossa anatomy were observed,including the volume of cerebellopontine angle(CPA), the volume of trigeminal nerve root,the sectional area of trigeminal nerve root and the length of trigeminal nerve root.MVD treatment was undertaken on all PTN patients.The subjects were divided into effective group(n=50) and ineffective group(n=13),and the relationship between the prognosis of MVD treatment and general data as well as factors associated with posterior fossa anatomy was analyzed.Results: Subjects of control group had no significant differences in CPA volume,the volume of trigeminal nerve root,the sectional area of trigeminal nerve root and the length of trigeminal nerve root between left side and right side(P >0.05).PTN patients had small CPA volume,trigeminal nerve root volume and trigeminal nerve root sectional area on the affected side than those on the healthy side(P <0.05);the affected side and the healthy side were not significantly different in the length of trigeminal nerve root(P >0.05).Effectivegroup and ineffective group were not significantly different in gender,age,nationality,the side affected,the trigeminal nerve affected and the the length of trigeminal nerve root(P >0.05);effective group and ineffective group were significantly different in disease duration,offending ressel,the relation between blood vessel and nerve,CPA volume,trigeminal nerve root volume and trigeminal nerve root sectional area(P<0.05).Conclusion: Smaller CPA volume and atrophy,smaller volume and smaller cross—section area of trigeminal nerve root are influencing factors for the occurrence of PTN.Long disease duration,vein being offending vessel,definite oppression relation between blood vessel and nerve,small CPA volume,and atrophy,smaller volume and smaller cross-section area of trigeminal nerve root are associated with poorer prognosis of PTN patients after MVD treatment.