Comparative study of cranial topographic procedures: Broca's legacy toward practical brain surgery

In many locations, neurosurgeons still use stereotactic- or anatomic-based craniocerebral topography systems to identify cortical landmarks. However, their predictive value for identifying two key landmarks--the central sulcus (CS) and lateral sulcus (LS)--has never been evaluated. We quantitatively compare leading craniocerebral topographic methods and review their historical significance for neurosurgery.

On 12 cadaveric head sides, the methods of Broca, Reid, Poirier, Taylor-Haughton, and Rhoton were used to predict positions of the CS and LS. After craniotomy, the actual CS, LS, and the superior and inferior Rolandic points were identified. Distances between predicted positions and actual structures were measured, and the systems were compared.

The actual superior Rolandic point was 4.6 +/- 2.9 mm anterior to prediction by Broca's method; 4.3 +/- 2.13 mm anterior to the Poirier, Taylor-Haughton, and Rhoton methods; and 3.26 +/- 3.17 mm anterior or posterior using Reid's method. The actual inferior Rolandic point was anteroinferior to all predictions: 5.87 +/- 3.1 mm by Rhoton, 6.97 +/- 3.55 mm by Broca, 7.64 +/- 2.54 mm by Poirier, and 7.61 +/- 3.85 mm by Reid and Taylor-Haughton. The actual LS was 2.33 mm away from the predicted point using Poirier's method, and 2.00 mm away from the predicted point using the Reid, Taylor-Haughton, and Rhoton methods.

Predicting positions of the CS and LS to within a few millimeters, these landmark methods remain reliable for cerebral localization. Largely initiated by the work of Paul Broca, these systems lay at the development of a practical method of neurosurgery in the late 19th century.