supraorbital notch

Physical Examination

A thorough history should first be obtained to identify any previous trauma or inciting events that could lead to SN.  This is then followed by a visual inspection and physical examination of the forehead, eyebrow, nasal region, and supraorbital foramen.  There will be tenderness to palpation over the supraorbital foramen with possible radiation of symptoms along the nerve distribution of the affected side.  Support the head with the non-examining hand, then palpate over the orbital rim, feeling for the supraorbital notch (Figure 5).  Parasthesias should replicate the pain complaints, and, with careful palpation, the examiner should be able to identify the slim, string-like vertical SON structure.  Move the thumb medially to feel the supratrochlear groove.

 

 

Ultrasound Examination

Using ultrasound (US) to block the supraorbital nerve can be beneficial over the landmark-guided or fluoroscopic approaches.  The linear probe is placed horizontally across the supraorbital notch (Figure 6).  With direct visualization of the supraorbital foramen, proper needle placement can be achieved as well as avoiding inadvertent needle placement into the foramen.  In a recent cadaveric study, Spinner and colleagues¹⁸ demonstrated that ultrasound-guided blocks of the supraorbital and infraorbital nerves had greater accuracy than conventional landmark-based techniques.  The results of the study showed that the US accuracy rate was 100% (18 of 18) for the in-plane approach and 94% (17 of 18) for the out-of-plane approach.  Thirty-five injections were considered accurate (97%) with overflow, and one injection was inaccurate.  The study concluded that ultrasound-guided injections had a higher degree of accuracy versus the standard techniques used today.  The US technique would be performed the same as the conventional landmark-guided technique with improved visualization of the target.