Questions on sleep, consciousness, and seizures Flashcards
What are the stages of sleep and their associated characteristics and wave patterns?
[Awake: beta 14-40Hz, high frequency, low amplitude, desynchronized____Stages 1 and 2, drowsy: theta 4-8Hz K complexes and sleep spindles______Stages 3 and 4, deep sleep: delta 0.5-4, low frequency, high amplitude, synchronized
Distinguish between coma, persistent vegetative state, and brain death?
[Coma: unarousable, unresponsiveness, brainstem reflexes, posturing often present____Persistent Vegetative State: no meaningful responses to stimuli; reduced cerebral metabolism; brainstem reflexes present. Generally assigned diagnostically only after 6-12 months. Patient has no awareness of self or environment, may be able to breathe spontaneously with stable cardiovascular system, will have cycles of eye opening and closure, may groan and grunt, show stereotyped primitive movements, typically displays decorticate rigidity ___Brain Death: no EEG, other evidence of forebrain or brainstem function, including no reflexes; patient will require ventilation. Condition must be irreversible. Pupils are fixed, dilated, unreactive, no corneal reflexes, oculocephalic (doll’s eyes) and oculovestibular (caloric) reflexes absent, no purposeful movements or facial grimacing
What physiological signs are associated with slow wave sleep (Stages I-IV)?
[slow eye movements; decreases in heart rate, breathing, blood pressure, temperature, and body movement (able to move but quiescent)]
The ventrolateral preoptic nucleus (VLPO) inhibits ascending monoaminergic and cholinergic input from which system to lower activity in non-REM sleep?
[Reticular activating system (RAS)]
What are the key features of a coma?
[Unarousable & unresponsive; Brainstem reflexes, posturing often still present; no purposeful movements; Persists for at least 1 hr (compared to concussion); EEG shows abnormal patterns with little variability over time; If coma deepens EEG decreases and may disappear indicating brain death]
If someone does not recover from a coma, they may enter into a more long-term vegetative state. The key features of persistent vegetative state are?
[EEG rhythmic resembling sleep-wake cycles; May breathe unaided (i.e. intact brainstem circuits) are “awake” but not conscious of surroundings; May open eyes and orient toward an auditory or tactile stimulus; May groan or grunt, but no meaningful speech; Structural (CT/MRI) brain damage often present; Persists for ≥6 months; “Cognitive” death: only autonomic functions remain no meaningful responses to stimuli; reduced cerebral metabolism]
Someone may show improvement from a coma and enter into a minimally conscious state that includes the following?
[Occasional purposeful responses to stimuli; Show limited awareness of self or environment (e.g. eye movements that pursue stimuli); Some intelligible speech (single words) though not reliable]
The Glasgow coma scale is used?
[ to measure deficits associated with level of consciousness. The scores can range from 3-15. A patient who is completely unresponsive will score 3. A patient that is fully responsive and intact will score 15. Any deficits in the categories measured will result in a score <15.
What are the main features of a simple partial seizure?
[Generally consciousness is intact; Can have positive symptoms (hand twitching) or negative symptoms (cessation of language); Symptoms can differ based on location of seizure focus (e.g. primary sensory area or association area) Seizures arising from a source in the primary motor cortex can involve a rhythmic jerking (clonic) or sustained contraction (tonic)]
What are the main features of a complex partial seizure?
[This includes impaired consciousness; Often have automatisms – repetitive behaviors such as picking at clothes, lip smacking, hand/arm or foot/leg movements; May vocalize (grunt, scream, talk); It could also manifest as simple staring or unresponsiveness; There are post-ictal (after the seizure) deficits such as confusion, amnesia for the event, tiredness, unresponsiveness]
What are the main features of a generalized tonic clonic seizure?
[Generally begins with a tonic phase with impaired consciousness and contraction of all muscles; Followed by clonic phase with rhythmic bilateral jerking contractions of extremities (usually flexion) at about 1Hz; This will gradually slow over seconds to minutes and then cease; Incontinence and tongue biting are common; Post-ictal – initially they are unresponsive and usually panting and tachycardic because of the huge effort; Then they will start moving around though they may still be minimally responsive, very tired, confused, amnestic for the event, and may have a headache]
What are the main features of an absence seizure?
[Brief episodes of staring and unresponsiveness lasting for about 10 seconds or less; No post-ictal state except for a lack of awareness of the ‘lapse’ that just occurred; These are generalized because on EEG one sees generalized 3-4Hz spike and wave discharges]
