March Case Studies from The Neurography Institute
Tuesday, 15 March 2011 08:00
Welcome to the March 2011 edition of The Neurography Institute's case studies.
In this issue, we will examine two cases of hamstring problems accurately identified as nerve-related and treated through the use of magnetic resonance neurography.
Case 1: Pelvic Sciatic Nerve Entrapment Syndrome
Above: Hamstring disruption at ischial tuberosity
The images (above and below) demonstrate the significant irritative change with broadening and flattening of the sciatic nerve through the mid to distal ischial tunnel.
The sciatic nerve undergoes a marked increase in image intensity at the level of the obturator internus tendon as it descends through the inferior portion of the ischial tunnel.
In this area, there is evidence of a significant tear in the hamstring attachment to the ischial tuberosity. Associated with this is the tear or disruption of the quadratus femoris muscle.
The area of greatest irritation within the sciatic nerve is just above the level of the hamstring attachment tear.
This finding is consistent with a pelvic sciatic nerve entrapment syndrome such as an ischial tunnel syndrome.
Above: hamstring attachment disruption
Case 2: Variant Left Pelvic Sciatic Nerve Entrapment
Above: partially detached hamstring at the ischial tuberosity
These images (above and below) reveal a few different findings. At the level of the sciatic notch, two anatomical variants were noted. First, there is some splitting of the piriformis muscle; although there is no passage of components of the sciatic nerve through the muscle. Second, the tibial and peroneal components of the sciatic nerve do appear to be separated by the passage of venous structures between them.
There is a complex and elaborate venous variceal pattern and associated with the sciatic notch in the exit of the sciatic nerve. The sciatic nerve itself demonstrates some moderate increase in image intensity as it traverses the venous elements that cross between its components as it exits the sciatic notch.
Additionally, the image demonstrates hyperintensity in the area of the trochanteric bursa consistent with the trochanteric bursitis and evidence of a significant tear of the hamstring attachment to the ischial tuberosity with inflammatory components extending up to the level of the obturator internus tendon at the superior margin of the ischial tuberosity.
There is a significant increase in image intensity within the sciatic nerve leading to marked fascicular hyperintensity change as it descends through the lower ischial tunnel past the area of the hamstring attachment tear.
These findings are consistent with a variant left pelvic sciatic nerve entrapment syndrome with an abnormal piriformis muscle, venous abnormalities, and a hamstring tear at the ischial tuberosity.
Above: Detached hamstring on coronal