Change in connection between corticospinal tract and Broca's area during motor recovery in a patient with an intracerebral hemorrhage

The present study reported a 42-year-old male patient who underwent conservative management for a spontaneous intracerebral hemorrhage in the left corona radiata and the basal ganglia. The patient presented with complete weakness of the right upper and lower extremities at the onset of intracerebral hemorrhage; however, he showed progressive motor recovery to the level that he was able to extent the affected extremities against some resistance at 5 weeks after onset. The corticospinal tract of the affected （left） hemisphere connected to the left Broca＇s area at 3 weeks after onset as shown by diffusion tensor tractography. By contrast, this connection had disappeared at 5 weeks after onset as shown by diffusion tensor tractogaphy. Transcranial magnetic stimulation study showed that no motor evoked potential was elicited from the affected （left） hemisphere at 3 weeks after onset, but motor evoked potentials were elicited at 5 weeks after onset. These findings suggest that the connection between the injured corticospinal tract and Broca＇s area in this patient appears to be a compensation for severe motor weakness; consequently, the connection seems to disappear with motor recovery.

Preoperative functional MRI localization of language areas in Chinese patients with brain tumors Validation with intraoperative electrocortical mapping

Ten Chinese patients with brain tumors involving language regions were selected. Preoperative functional MRI was performed to locate Broca＇s or Wernicke＇s area, and the cortex that was essential for language function was determined by electrocortical mapping. A site-by-site comparison between functional MRI and electrocortical mapping was performed with the aid of a neuronavigation device. Results showed that the sensitivity and specificity of preoperative functional MRI were 80.0% and 85.0% in Broca＇s area and 66.6% and 85.2% in Wemicke＇s area, respectively. These experimental findings indicate that functional MRI is an accurate, reliable technique with which to identify the location of Wernicke＇s area or Broca＇s area in patients with brain tumors.

Curvature range measurements of the arcuate fasciculus using diffusion tensor tractography

Because Broca＇s area and Wernicke＇s area in the brain are connected by the arcuate fasciculus, understanding the anatomical location and morphometry of the arcuate fasciculus can help in the treatment of patients with aphasia. We measured the horizontal and vertical curvature ranges of the arcuate fasciculus in both hemispheres in 12 healthy subjects using diffusion tensor tractography. In the right hemisphere, the direct curvature range and indirect curvature range values of the arcuate fasciculus horizontal part were 121.13 ± 5.89 and 25.99 ± 3.01 degrees, respectively, and in the left hemisphere, the values were 121.83 ± 5.33 and 27.40 ± 2.96 degrees, respectively. In the right hemisphere, the direct curvature range and indirect curvature range values of the arcuate fasciculus vertical part were 43.97 ± 7.98 and 30.15 ± 3.82 degrees, respectively, and in the left hemisphere, the values were 39.39 ± 4.42 and 24.08 ± 4.34 degrees, respectively. We believe that the measured curvature ranges are important data for localization and quantitative assessment of specific neuronal pathways in patients presenting with arcuate fasciculus abnormalities.

Fractionated resection on low grade gliomas involving Broca＇s area and insights to brain plasticity

Background Resent advances on functional mapping have enabled us to conduct surgery on gliomas within the eloquent area. The objective of the article is to discuss the feasibility of a planned fractionated strategy of resection on low-grade gliomas （LGGs） involving Broca＇s area. We report the first surgical series of planned fractionated resections on LGGs within Broca＇s area, focusing on language functional reshaping. Methods Four patients were treated with fractionated operations for LGGs involving Broca＇s area. All cases underwent conventional magnetic resonance （MR） scanning, language functional MR and diffusion tensor imaging （DTI） before operation. The resections were then performed on patients under awake anesthesia using intraoperative electrical stimulation （IES） for functional mapping. Pre- and post-operative neuro-psychological examinations were evaluated.Results Total resections were achieved in all cases as confirmed by the postoperative control MR. After transient language worsening, all patients recovered to normal 3-6 months later. Language functional MR scannings have shown language functional cortical and subcortical pathway reorganization （in the perilesion or contra-lateral hemisphere） after the operation. All patients returned to a normal socioprofessional life. Conclusions By utilizing the dynamic interaction between brain plasticity and fractionated resections, we can totally remove the tumor involving Broca＇s structure without inducing permanent postoperative deficits and even improve the quality of life.