Info
🌱 來自: Huppert’s Notes
Brain🚧 施工中
Brain
Cerebral cortex
• Functions: Higher processing
• Clinical effects of a lesion: Contralateral motor, sensory, visual symptoms
• Regions: See Figure 12.2
FIGURE 12.2: The cerebrum. A) Regions of the cerebrum. B) Vascular supply to the cerebrum. C) The cortical homunculus, which is a distorted representation of the human body based on the neurologic “map” of the areas of the human brain dedicated to processing motor (red) and sensory (blue) functions for different parts of the body.
- Frontal:
• Function: Motor, social judgment, executive function, voluntary horizontal gaze initiation
• Vascular supply: ACA (legs), MCA (face/arms > legs)
• Lesion: Disinhibition, apathy, personality/behavioral change; contralateral motor weakness
- Parietal:
• Function: Sensory, visuospatial, attention, vision
• Vascular supply: ACA, MCA
• Lesion: Contralateral visual, tactile, and auditory neglect
- Temporal:
• Function: Hearing, emotion, memory
• Vascular supply: MCA, PCA
• Lesion: Problems with speech and language, memory loss
- Occipital:
• Function: Vision
• Vascular supply: PCA (macula supplied by the MCA)
• Lesion: Contralateral hemifield vision loss
Cerebellum
• Function: Detects “motor error” and helps correct it. Vermis = trunk. Hemisphere (lateral) = limbs
• Lesion: Vertigo, nystagmus, nausea/vomiting, (usually) ipsilateral ataxia
Brainstem
• Description: Includes midbrain, pons, and medulla
• Function: Cranial nerves, motor and sensory tracts
• Lesion: Diplopia, facial weakness, facial sensory loss, dysphagia, dysarthria; contralateral weakness and numbness in the body; “crossed” weakness (with UMN signs) and sensory abnormalities of the head and limbs (e.g., weakness in the right face and the left arm and leg)
Thalamus
• Function: Sensory and motor relay station; emotion
• Lesion: Contralateral symptoms, based on nuclei affected
Basal ganglia
• Function: Initiation of purposeful movement; suppresion of unwanted movement. Dopamine = movement
• Lesion: Difficulties with speech, posture, movement on the contralateral side. Forms a circuit with the cortex on the SAME side
Hypothalamus
• Function: TAN HATS to Bed (Thirst/water balance, Adenohypophysis control, Neurohypophysis and Hormones, Hunger, Autonomic regulation, Temperature regulation, Sexual urges, Circadian rhythm)
• Lesion: Depends on the nuclei affected
Limbic system
• Description: Includes hippocampus (first affected by anoxic damage), amygdala, cingulate gyrus, fornix, mammillary bodies, septal nucleus
• Function: Emotions, behavior, eating, memory
• Lesion: Change in the ability to perceive hunger/satiety, emotional changes, amnesia, seizures
Spinal cord
• Description: Includes the white matter tracts which contain the ascending sensory pathways, descending motor pathways, and nerve cell bodies (Figure 12.3)
FIGURE 12.3: Transverse section through the spinal cord. The main descending motor tracts (red) and ascending sensory tracts (blue) are shown. In the dorsal column, the gracilus and cuneatus tracts are shown (gracilus = legs, cuneatus = arms).
• Lesion: Presence of a horizontal level below which sensory, motor, and autonomic function is impaired