1. A possible role of BA8 in Pre-surgical fMRI
A possible role of BA8 in Pre-surgical fMRI
homage to an
exceptional scientist
Korbinian Brodmann →
 In 1909, >100 years ago, Brodmann published his cytoarchitectonal map of brain areas.
Although the Brodmann areas have been discussed, debated, refined, and renamed
exhaustively during a century, they remain the most widely known and frequently cited
cytoarchitectural organization of the human cortex Functions have been
attributed to these areas, such as the sensory cortex, the motor homunculus,
the visual cortices and the linguistic areas.
Korbinian Brodmann: Vergleichende Lokalisationslehre der Grosshirnrinde in
Ihren Prinzipien dargestellt auf Grund des Zellenbaues,
Johann Ambrosius Barth Verlag, Leipzig, 1909

2. it is also suggested that activation in BA8 encodes “hope”,
 Brodmann area 8, or BA8, is part of
the frontal cortex in the human brain. and is
situated just anterior to the premotor cortex (BA6)
it includes the frontal eye fields
(so-named because they are believed to play
an important role in the control of eye movements)
fMRI demonstrates that BA8 activation occurs
when subjects experience uncertainty
(Volz et al. Brain Research, 2005, 67: )
it is also suggested that activation in BA8 encodes “hope”,
a higher order expectation linked with uncertainty

3. BA8
Broca

4. Broca fasciculus arcuatis Wernicke BA8 parieto-temporal-occipital
antero-temporal associations area
parieto-temporal-occipital
associations area

5. robust paradigms were used to activate eloquent centers of the brain,
including motor strip, the visual cortex, areas involved in memory and,
perhaps most important, areas governing speech and language;
In 100 presurgical patients analysis was made of the linguistic areas

6. connections in the language domain
adapted from:
DTI tractography of the Human’s language pathways
Glasser MF, Rilling JK, Cerebral Cortex, 18, , 2008

7. connections in the language domain
BA8
adapted from:
DTI tractography of the Human’s language pathways
Glasser MF, Rilling JK, Cerebral Cortex, 18, , 2008

8. Aphasia types
BA8

9. typical result in word generation paradigm
right-handed male, 38 years, low grade astrocytoma

10. some activation on
the right
tumor

11. BA8
Broca
BA8
transverse and sagittal images of
normal volunteer:
showing activated areas in word
generation block design
Broca predominantly activated on
the left; confirmed by BA8 activation

12. 36 year old patient with tumor in posterior insular area on the left:
BA8
Broca displaced
upwards
Broca
36 year old patient with tumor in posterior insular area on the left:
Broca on the left is pushed upwards, now close to the BA8 activation;
some Broca activation on the right, but only weak BA8 activation on
the right side

13. wordgeneration female, 22 years lefthanded there is a bilateral
activation of Broca;
BA 8 is more
activated on the right
side
tumor frontal
left parasagittal

14. bilateral activation of Broca, BA8 mainly on the right side

15. this paradigm shows bilateral activation of Broca;
BA 44
BA 8
this paradigm shows bilateral activation of Broca;
some downward displacement on the left side;
activation of Brodmann area 8 on the right side is embedded
In the tumor area
tumor

16. fasciculus arcuatus on both sides intact
Broca
Broca
WERNICKE
Wernicke
Wernicke
right
left
no fibers seen connecting to BA8

17. Connectivity and Synchronicity
there are no “wireless” connections in the brain
DTI-fiber tracking allows to depict some of the fiber connections:
a beautiful example in the linguistic areas is the connection
between the Broca executive and Wernicke receptive center:
fasciculus arcuatis
BA8 44 22

18. In this right-handed patient the arcuate fibers are well
Broca
Wernicke
fasciculus arcuatis
CST
left
right
In this right-handed patient the arcuate fibers are well
traceable on the left side, not on the right
BA8
Wernicke

19. FLAIR
male 57 years
right handed
transcortical motor aphasia

20. wordgeneration
wordgeneration
activates Broca and BA8

21. Broca mainly on the left side; BA8 also; close to tumor
posterior to anterior
BA8
BA8
BA8
Broca
tumor
Broca mainly on the left side; BA8 also; close to tumor
scattered and displaced Broca
Broca
Broca

22. Broca activated on both sides, Broca is scattered on the left,
BA8
Broca
Broca
Broca
Broca activated on both sides, Broca is scattered on the left,
patient suffers from a mild aphasia with the
characteristics of a conductive aphasia

23. Broca
Broca scattered on the left side

24. Broca Wernicke Broca Wernicke tracing started in Wernicke
starting in Broca no arcuate fibers can
be traced; some fibers encompass
the tumor
tracing started in Broca
Broca
Wernicke
Broca
tracing started in Wernicke
Wernicke

25. tumor Broca Wernicke tracing started in Wernicke
tracing started in Broca
Wernicke
tracing started in Wernicke

26. ? BA8 tumor Broca arcuate fibers tracked from Broca Wernicke
corticospinal tracts
arcuate fibers tracked from Wernicke
tumor ?
BA8
Broca
Wernicke
no fibers tracked linking
language areas to BA8

27. view from above
right
tumor
arcuate fibers
corticospinal tracts
arcuate fibers tracked from Wernicke

28. right ↔
anterior
tumor
bird’s eye stereoscopic view

29. Paul Broca
Korbinian Brodmann
Carl Wernicke

30. Conclusion:
Although the connection between Broca and BA8 could not be established
in the same way as the Broca-Wernicke connection the synchronicity between
the activations makes it useful to confirm the activity of Broca by the activation
of BA8,
especially in those cases
where there is displacement of Broca,
where language dominance is important,
and in cases with bilateral activation when a quantifiable difference between
the two sides exists.
This, of course, is important in pre-operative cases,
but has also great impact on the study of language development and aphasias.