Depression and Cognitive Complaints Following Mild Traumatic Brain Injury, by Jonathan M. Silver, MD, Thomas McAllister, MD, and David B. Arciniegas,MD (Am. J. Psychiatry 2009 :166:653-661 is a truly elegant paper discussing this subject from experience with detail. It's an essential read for anyone treating pateints with depression and mTBI.
What I am essentially copying here is from Table 1 in this paper. I have seen this information elsewhere and it's standard in neuropsychiatry and behavioural neurology texts. Like everything else in this paper it was presented here in a readable and easy to comprehend and clinically useful way.
Structure Function Consequence of Injury
ROSTRAL and VENTRAL BRAINSTEM, THALAMUS
Reticulothalamic system Arousal Impairment of Counsciousness
Reticulocortical system Arousal, facilitating cortical activity Hypoarousal, inattention, impaired information processing
Hypothalamus Autonomic,, neuroendocrine, Dysautonomous, thermoregulation problems, altered feeding behaviours,
Circadian, some lower level social endocrine dysfunction, sleep wave cycle disturbances, pathological affect
functions (laughter and anger)
Ventral forebrain Cholingeric supply to medial and Impaired information processing in multiple cognitive domains, neo cortical areas particularly attention, memory, and executive functions
Entrorhinal-hippocampal Complex Multimodal informationa filtering Impaired sensory gating, attention, working memory and
Declarative memory, some aspects of declarative memory
Attention and working memory
Amygdala Generation of contextually relevant Affective placidity, Kluver-Bucy-like presentations, alternatively
emotional and social behaviour anxiety
Anterior/Polar cortex Semantic memory, semantic aspects Disturbances in semantic memory, functional communication
of language, sensory limbic integration impairments, impaired sensory-limbic, facial, social and emotional
face recognition, social and emotional processing, impaired social/empathic function
processing, "theory of mind"
Ventral frontal cortices Comportment, control of primitive Disinhibition, irritability, emotional dysregulation, agitation, aggression
Anterior Cingulate cortex Motivation Apathy
Inferolateral prefrontal cortex Working memory Working memory impairments
Dorsolateral prefrontal cortex Executive function Impairments in complex cognition, including executive control of attention,
memory, language, motor planning, as well as sequencing, set shifting
abstraction, judgment, insight
White Matter Connections between cortical areas Impaired cognitive, emotional and behavioural functions, supported by
particularly in frontal and temporal affected white matter, slow, inefficient information processing.
areas, facilitation of information
My columns got smunched by the editor so it's best to go to the paper. The rest of it is an excellent and must see read. I've just listed these areas to show where the lesions are being deliniated in a beyond Broca way that's clinically relevant.
This is geographical presentation but then there are the neurochemical transmissions with both facilitating and dampening process. Coupled to this is the endocrine modulating effects and the fluid these systems sit in, a kind of 'soup' which is affected by quite a variety of spices in addition to sometimes being affected by heat or cold.