chapter 26: neurological disorders Flashcards
Which demographic is at the highest risk of traumatic brain injury (TBI)?
Males ages 15-30.
What are compensatory behaviours?
Behaviours by other mechanisms in the brain that perform the function of an injured/lost function.
Define the terms coup, contrecoup, shearing (in the context of closed-head injuries).
Coup: damage to brain at site of blow caused by brain impacting skull
Contrecoup: damage to brain on side of brain opposite to site of area due rebounding and impacting skull
Shearing: twisting and breaking of nerve fibres caused by rapid movement of brain inside skull
Define hematoma and edema.
Hematoma: mass of blood trapped in the skull
Edema: swelling that can result in pressure on delicate nervous tissue in brain
Which metrics does the Glasgow Coma Scale measure?
Eye opening, motor response, verbal response.
Scores of _ or less on the Glasgow Coma Scale are associated with severe head injury, _ to __ for moderate, __+ for mild injury.
8 (severe), 9 to 12 (moderate), 13+ (mild).
Recovery from TBI can take up to __________, most recovery takes place in first __________.
2 to 3 years, 6 to 9 months.
What is the distinction between symptomatic and idiopathic seizures?
Symptomatic: associated with known cause (e.g. infection, trauma, fever, etc.)
Idiopathic: Spontaneous; no known cause
What is an aura?
Subjective sensation, perception, or motor experience associated with the onset of a seizure.
What are some precipitating factors for seizures in susceptible individuals?
Drugs, emotional distress, fever, hormonal changes, hyperventilation, sensory stimuli, sleep, sleep deprivation, trauma.
What are focal seizures versus generalized seizures?
Focal: begin in one location in brain, electrical activity spreads to involve other regions
Generalized: Seizure activity occurs in both hemispheres, no clear focus
What are the four phases of generalized seizures? Describe their symptoms and associated EEG activity.
Start state: no symptoms, normal EEG activity
Tonic phase: patient detects aura; rapidly increasing EEG activity
Clonic phase: stereotyped convulsions, loss of consciousness and/or breathing; EEG pulses
Coma phase: comatose state; EEG activity of coma patient, less brain activity than resting state
What are akinetic seizures and myoclonic spasms? What do they share in common?
Akinetic seizure: characterized by sudden collapse without warning
Myoclonic spasm: large seizures characterized by flexion or extension of entire body
Both typically only occur in children
What are dissociative seizures and how are they unique?
Seizures that resemble focal seizures but have no EEG changes. Patients report feeling cut off from surroundings (out-of-body experience).
What are some treatments used to end seizures (that have already begun)?
GABA agonists, glutamate antagonists.
What are some drugs used to inhibit seizure development or propogation?
GABA agonists, sodium-channel blockers, anaesthetics, anticonvulsants.
Drugs are __-__% effective in treating seizures. If not, what other interventions are sometimes resorted to?
30-40%; surgery or DBS.
What cells can develop into brain tumours? Why not other kinds of brain cells?
Glial cells or other supporting cells. Neurons do not grow and divide and therefore cannot become tumours.
What is the difference between benign and malignant tumours?
Benign tumours generally do not reoccur after removal, malignant tumours are progressive.
Describe encapsulated tumours, infiltrating tumours, and their respective differences.
Encapsulated tumours: localized in one place, can put pressure on surrounding tissue
Infiltrating tumours: interact with surrounding cells, can destroy or interfere with them