Vista Centre

Providing support to individuals living with the effects of Brain InjuryProviding support to individuals living with the effects of Brain Injury

Brain Anatomy, Function and Symptoms

Brain Structure

Function

Associated Signs and Symptoms

Cerebral Cortex

Cerebral Cortex - Ventral View (from bottom)

Ventral View
(from bottom)

The outermost layer of the cerebral hemisphere which is composed of gray matter. Cortices are asymmetrical. Both hemispheres are able to analyze sensory data, perform memory functions, learn new information, form thoughts and make decisions.

Left Hemisphere

Left Hemisphere

Sequential Analysis: systematic, logical interpretation of information. Interpretation and production of symbolic information:language, mathematics, abstraction and reasoning. Memory stored in a language format.

Right Hemisphere

Right Hemisphere

Holistic Functioning: processing multi-sensory input simultaneously to provide "holistic" picture of one's environment. Visual spatial skills. Holistic functions such as dancing and gymnastics are coordinated by the right hemisphere. Memory is stored in auditory, visual and spatial modalities.

Corpus Callosum

Corpus Callosum

Connects right and left hemisphere to allow for communication between the hemispheres. Forms roof of the lateral and third ventricles.
  • Damage to the Corpus Callosum may result in "Split Brain" syndrome.

Frontal Lobe

Frontal Lobe - Ventral View (from bottom)

Ventral View
(from bottom)

Side View

Cognition and memory.

Prefrontal area: The ability to concentrate and attend, elaboration of thought. The "Gatekeeper"; (judgment, inhibition). Personality and emotional traits.

Movement:

Motor Cortex (Brodman's): voluntary motor activity.

Premotor Cortex: storage of motor patterns and voluntary activities.

Language: motor speech

  • Impairment of recent memory, inattentiveness, inability to concentrate, behavior disorders, difficulty in learning new information. Lack of inhibition (inappropriate social and/or sexual behavior). Emotional lability. "Flat" affect.
  • Contralateral plegia, paresis.
  • Expressive/motor aphasia.

Parietal Lobe

Parietal Lobe

Processing of sensory input, sensory discrimination.

Body orientation.

Primary/ secondary somatic area.

  • Inability to discriminate between sensory stimuli.
  • Inability to locate and recognize parts of the body (Neglect).
  • Severe Injury: Inability to recognize self.
  • Disorientation of environment space.
  • Inability to write.

Occipital Lobe

Occipital Lobe

Primary visual reception area.

Primary visual association area: Allows for visual interpretation.

  • Primary Visual Cortex: loss of vision opposite field.
  • Visual Association Cortex: loss of ability to recognize object seen in opposite field of vision, "flash of light", "stars".

Temporal Lobe

Temporal Lobe

Auditory receptive area and association areas.

Expressed behavior.

Language: Receptive speech.

Memory: Information retrieval.

  • Hearing deficits.
  • Agitation, irritability, childish behavior.
  • Receptive/ sensory aphasia.

Limbic System

Limbic System

Olfactory pathways:

Amygdala and their different pathways.

Hippocampi and their different pathways.

Limbic lobes: Sex, rage, fear; emotions. Integration of recent memory, biological rhythms.

Hypothalamus.

  • Loss of sense of smell.
  • Agitation, loss of control of emotion. Loss of recent memory.

Basal Ganglia

Basal Ganglia

Subcortical gray matter nuclei. Processing link between thalamus and motor cortex. Initiation and direction of voluntary movement. Balance (inhibitory), Postural reflexes.

Part of extrapyramidal system: regulation of automatic movement.

  • Movement disorders: chorea, tremors at rest and with initiation of movement, abnormal increase in muscle tone, difficulty initiating movement.
  • Parkinson's.

Thalamus

Thalamus

Processing center of the cerebral cortex. Coordinates and regulates all functional activity of the cortex via the integration of the afferent input to the cortex (except olfaction).

Contributes to affectual expression.

  • Altered level of consciousness.
  • Loss of perception.
  • Thalamic syndrome - spontaneous pain opposite side of body.

Hypothalamus

Hypothalamus

Integration center of Autonomic Nervous System (ANS): Regulation of body temperature and endocrine function.

Anterior Hypothalamus: parasympathetic activity (maintenance function).

Posterior Hypothalamus: sympathetic activity ("Fight" or "Flight", stress response.

Behavioral patterns: Physical expression of behavior.

Appestat: Feeding center.

Pleasure center.

  • Hormonal imbalances.
  • Malignant hypothermia.
  • Inability to control temperature.
  • Diabetes Insipidus (DI).
  • Inappropriate ADH (SIADH).
  • Diencephalic dysfunction: "neurogenic storms".

Internal Capsule

Internal Capsule

Motor tracts.
  • Contralateral plegia (Paralysis of the opposite side of the body).

Reticular Activating System (RAS)

Reticular Activating System (RAS)

Responsible for arousal from sleep, wakefulness, attention.
  • Altered level of consciousness.