A Lesion-Proof Brain? Multidimensional Sensorimotor, Cognitive, and Socio-Affective Preservation Despite Extensive Damage in a Stroke Patient

You wouldn't be so baffled by this if you actually had an objective diagnosis done with MRI and PET scans to see the exact areas of damage. She was bilingual which is indicative of better recovery due to better brain reserve.
http://journal.frontiersin.org/article/10.3389/fnagi.2016.00335/full?

Adolfo M. García^1,2,3, Lucas Sedeño^1,2, Eduar Herrera Murcia⁴, Blas Couto¹ and Agustín Ibáñez^1,2,5,6,7*

• ¹Laboratory of Experimental Psychology and Neuroscience, Institute of Cognitive and Translational Neuroscience, INECO Foundation, Favaloro University, Buenos Aires, Argentina
• ²National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
• ³Faculty of Elementary and Special Education, National University of Cuyo, Mendoza, Argentina
• ⁴Departamento de Estudios Psicológicos, Universidad Icesi, Cali, Colombia
• ⁵Universidad Autónoma del Caribe, Barranquilla, Colombia
• ⁶Center for Social and Cognitive Neuroscience, School of Psychology, Universidad Adolfo Ibáñez, Santiago de Chile, Chile
• ⁷Centre of Excellence in Cognition and its Disorders, Australian Research Council, Sydney, NSW, Australia

In this study, we report an unusual case of mutidimensional sensorimotor, cognitive, and socio-affective preservation in an adult with extensive, acquired bilateral brain damage. At age 43, patient CG sustained a cerebral hemorrhage and a few months later, she suffered a second (ischemic) stroke. As a result, she exhibited extensive damage of the right hemisphere (including frontal, temporal, parietal, and occipital regions), left Sylvian and striatal areas, bilateral portions of the insula and the amygdala, and the splenium. However, against all probability, she was unimpaired across a host of cognitive domains, including executive functions, attention, memory, language, sensory perception (e.g., taste recognition and intensity discrimination), emotional processing (e.g., experiencing of positive and negative emotions), and social cognition skills (prosody recognition, theory of mind, facial emotion recognition, and emotional evaluation). Her functional integrity was further confirmed through neurological examination and contextualized observation of her performance in real-life tasks. In sum, CG's case resists straightforward classifications, as the extent and distribution of her lesions would typically produce pervasive, multidimensional deficits. We discuss the rarity of this patient against the backdrop of other reports of atypical cognitive preservation, expound the limitations of several potential accounts, and highlight the challenges that the case poses for current theories of brain organization and resilience.

Introduction

The mind-brain association, as conceived in clinical neuroscience and neuropsychology, is an abstract generalization. In working with multi-participant samples, behavioral findings stem from data averages while anatomical results are obtained by transforming brain images into a standard coordinate space. In both cases, strict outlier exclusion criteria are applied, so that atypical patterns are removed from ensuing models. These steps are critical and perhaps unavoidable to characterize the organ's functional organization with some degree of external validity. Indeed, thanks to this approach, replicable associations have been established between damage to circumscribed regions and impairments of specific functions, including motor (Zgaljardic et al., 2003), somatosensory (Meyer et al., 2016), socio-cognitive (Gold and Shadlen, 2007; Ibáñez et al., 2010, 2016b; Couto et al., 2013; Baez et al., 2014, 2016b,c; Melloni et al., 2016), interoceptive (Couto et al., 2015; García-Cordero et al., 2016), executive (Rabinovici et al., 2015; Sedeño et al., 2016), linguistic (Ullman, 2008; Cardona et al., 2014; García and Ibáñez, 2014, 2016; Bocanegra et al., 2015; García, 2015; Melloni et al., 2015; García et al., 2016a,b,c; Abrevaya et al., 2017), and pragmatic (Kaplan et al., 1990; Stemmer, 2008) skills.

However, such well established anatomo-clinical links (and the theoretical views construed around them) are sometimes challenged by unusual individual cases which do not easily fit mainstream models in cognitive neuroscience. Such reports include that of a man who efficiently served as a civil servant although he had progressively lost roughly 75% of his brain (Feuillet et al., 2007), that of a housewife with only mild motor symptomatology despite primary cerebellar agenesis (Yu et al., 2015), or multiple patients exhibiting considerable restitution of language skills following early left hemispheromotomy (e.g., Hertz-Pannier et al., 2002). The same is true of studies showing preserved pre- and post-operative temporal functions in patients with large perisylvian arachnoid cysts (Kunz et al., 1988), although such malformations typically impair various cognitive domains (Wester, 2008). Cases such as these are valuable because, in their exceptionality, they invite us to extend our current conceptions of brain organization, plasticity, and functional compensation, beyond the robust patterns that emerge in typical, averaged, normalized data.

Building on these premises, we present the remarkable case of patient CG, who exhibits widespread sparing of sensorimotor, cognitive, and socio-affective functions despite extensive brain damage acquired in adulthood. In particular, as shown below, CG's unusual pattern of preservation was convergently corroborated through neuropsychological assessment, multiple experimental tasks, neurological examination, and even naturalistic observations of her daily functioning. The case could thus prompt new reflections on the functional organization of various neurocognitive systems.

Case Description

More at link.