Gamma Knife radiosurgery for trigeminal neuralgia secondary to megadolichobasilar artery: a prospective series of 29 cases with more than one year of follow upKeywords: pain, gamma knife, trigeminal neuralgia, outcome, vascularInteractive Manuscript
Ask Questions of this Manuscript:
What is the background behind your study?
Trigeminal neuralgia can be caused by large vessel vascular compression.
What is the purpose of your study?
This study analyses prospectively the long term results of Gamma Knife surgery (GKS) in order to consider its potential role in nowadays armamentarium as treatment for trigeminal neuralgia secondary to megadolichobasilar artery (MBA).
Describe your patient group.
Between December 1992 and November 2010, 33 consecutive patients presenting with ITN secondary to MBA were operated by GKS and followed prospectively in Timone University Hospital.
Describe what you did.
The follow up is at least of 1 year in 29 patients. The median age was 74.90 years (min 51; max 90). The GKS typically was performed using MR and CT imaging guidance and a single 4 mm isocenter. The median of the prescription dose (at the 100%) was 90 Gy (min 80; max 90). The target was placed on the cisternal portion of the V-th nerve. Clinical and dosimetric parameters were analyzed. GKS was the first surgical procedure in 23 patients (79.31%).
Describe your main findings.
The median follow- up period was 46.12 months (12.95 to 157.93). All the 29 patients (100%) were initially pain free in a median time of 13.5 days (0, 240). Their probability of remaining pain free at 0.5, 1, 2 years was 93.1%, 79.3% and 75.7% respectively, attending at this moment the flat part of the curve. Seven patients (24.13%) experienced a recurrence with a median delay of 10.75 months (3.77, 12.62). The actuarial rate of recurrence was not higher than in our population with essential TN although atypical pain was associated with a much higher risk of recurrence (HR= 6.92, p= 0.0117). The hypoesthesia actuarial rate at 0.5 years was 4.3% and at 1 year reach 13% and remains stable till 12 years with a median delay of onset of 7 (5, 12) months. Female patients had a statistically much lower probability of developing a facial numbness (p of 0.03). No patient reported a bothersome hypoesthesia.
Describe the main limitation of this study.
This was a retrospective review.
Describe your main conclusion.
Retrogasserian high dose GKS turned out to be very safe with only 13.04% hypoesthesia, which was never disabling (0%) while achieving high quality pain control.
Describe the importance of your findings and how they can be used by others.
The majority of the patients demonstrated a prolonged effect of radiosurgery in absence of any trigeminal nerve disturbance.
Trigeminal neuralgia can be caused by large vessel vascular compression.
This study analyses prospectively the long term results of Gamma Knife surgery (GKS) in order to consider its potential role in nowadays armamentarium as treatment for trigeminal neuralgia secondary to megadolichobasilar artery (MBA).
Between December 1992 and November 2010, 33 consecutive patients presenting with ITN secondary to MBA were operated by GKS and followed prospectively in Timone University Hospital.
The follow up is at least of 1 year in 29 patients. The median age was 74.90 years (min 51; max 90). The GKS typically was performed using MR and CT imaging guidance and a single 4 mm isocenter. The median of the prescription dose (at the 100%) was 90 Gy (min 80; max 90). The target was placed on the cisternal portion of the V-th nerve. Clinical and dosimetric parameters were analyzed. GKS was the first surgical procedure in 23 patients (79.31%).
The median follow- up period was 46.12 months (12.95 to 157.93). All the 29 patients (100%) were initially pain free in a median time of 13.5 days (0, 240). Their probability of remaining pain free at 0.5, 1, 2 years was 93.1%, 79.3% and 75.7% respectively, attending at this moment the flat part of the curve. Seven patients (24.13%) experienced a recurrence with a median delay of 10.75 months (3.77, 12.62). The actuarial rate of recurrence was not higher than in our population with essential TN although atypical pain was associated with a much higher risk of recurrence (HR= 6.92, p= 0.0117). The hypoesthesia actuarial rate at 0.5 years was 4.3% and at 1 year reach 13% and remains stable till 12 years with a median delay of onset of 7 (5, 12) months. Female patients had a statistically much lower probability of developing a facial numbness (p of 0.03). No patient reported a bothersome hypoesthesia.
This was a retrospective review.
Retrogasserian high dose GKS turned out to be very safe with only 13.04% hypoesthesia, which was never disabling (0%) while achieving high quality pain control.
The majority of the patients demonstrated a prolonged effect of radiosurgery in absence of any trigeminal nerve disturbance.
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