sleep, cerebellum, thalamus, basal ganglia, movement Flashcards
Sleep cycle is regulated by …. , which is driven by ….
circadian rhythm (noctural release of ACTH, prolactin, melatonin, norepinephrine) suprachiasmatic nucleus of hypothalamus
REM - duration / time
increases through the night
- every 90 mins
benzodiazepines clinical use in sleep
- night terrors
2. sleepwalking
REM - extraocular movements is due to
activity of paramedian pontine reticular formation/conjugate gaze center
substance that affect delta waves
alcohol, benzodiazepines and barbiturates –> decrease delta wave sleep
substance that affect REM
alcohol, benzodiazepines, barbiturates and norepinephrine –> decreased REM sleep
stage of sleep - proportions and waves
- awake with eyes open - Beta
- awake with eyes closed - Alpha
- Non-REM stage N1 - 5% - theta
- Non-REM stage N2 - 45% - sleep spindles and K complexes
- Non-REM stage N3 - 25% - delta
- REM - 25% - beta
stage of sleep - situations
Awake (eyes open) - alert, active metal concentration Non-REM stage N1 - light sleep Non-REM stage N2 - Deeper sleep Non-REM stage N3 - Deepest non-REM slow REM - Loss of motor tone increased brain oxygen use increased and variable pulse and BP
Non-REM sleep - stage N2 - special characteristic
when bruxism occur
Non-REM sleep - stage N3 - special characteristic
when sleepwalking, night terrors and bedwetting occur
REM sleep - special characteristic
when dreaming and penile/clitoral tumescence occur
- memory processing function
Cerebellum - Lateral - function
voluntary movement of extremities
Cerebellum - Lateral injured –>
propensity to fall toward injured (ipsilateral side)
intention tremor
Cerebellum - medial structures
midline structures (vermal cortex, fastigial nuclei) and flocculonodular lobe (vestibulocerebellum)
Cerebellum - medial structures lesions –>
- truncal ataxia (wide-based cerebellar gait )
- nystagmus
- head tilting
- dysarthria
(bilateral motor deficits affecting axial and proximal limb musculature)
Thalamus - anatomical function
Major relay for all ascending sensory information except olfaction
Thalamus - most important nuclei
ventral posteriolateral (VPL) vental posteriomedial (VPM) lateral geniculate nucleus (LGN) medial geniculate nucleus (MGN) ventral lateral (VL)
ventral posteriolateral (VPL) - input / destination / information
- spinothalamic and 2. dorsal columns/medial lemniscus –> 1ry somatosensory cortex
information: Pain, temperature, pressure, touch, vibration, proprioception
vental posteriomedial (VPM) - output / input
output: 1ry somatosensory cortex
input: trigeminal and gustatory pathways
lateral geniculate nucleus (LGN) - input /output / information
CN II (optic nerve) --> calcarine sulcus information: vision
ventral lateral (VL) - input .
- Basal ganglia 2. Cerebellum –> motor cortex
information: motor
medial geniculate nucleus (MGN) - input / output / information
superior olive and inferior colliculus of tectum –> auditory cortex of temporal lobe
- hearing
thalamic nuclei that send informations to 1ry somatosensory cortex (and informations)
VPL - Pain, temperature, pressure, touch, vibration, proprioception
VPM - trigeminal and gustatory pathways
cerebellum lesion - manifestation (for every area)
- Lateral injured –> propensity to fall toward injured (ipsilateral side), intention tremor
- medial lesion –> truncal ataxia (wide-based cerebellar gait ), nystagmus, head tilting, dysarthria
Dopaminergic pathways - types
- Mesocortical
- Mesolimbic
- Nigrostriatal
- Tuberoinfundibular
Dopaminergic pathways - commonly altered by
- drugs (eg. antipsychotics)
2. movement disorders (eg. Parkinson)
Dopaminergic pathways - types and symptoms of altered activity
- Mesocortical –> negative symptoms (eg. flat affect, limited speech)
- Mesolimbic –> positive symptoms (delusions, hallucinations) (IF INCREASED ACTIVITY)
- Nigrostriatal –> extrapyramidal symptoms (tardive dyskenisia,akathisia, parkinsonism, dystonia)
- Tuberoinfundibular –> increased prolactin –> decreased libido, sexual dysfunction, galactorrhea, gynecomastia (in men)
Basal ganglia are important in / input
voluntary movements and making postural adjustments
- input: cortical
provides negative feedback to cortex to modulate movement
basal ganglia - structures
- striatum (ραβδωτό)
- Lentiform (φακοειδής)
- Substantia nigra
- subthalamic nucleus
basal ganglia - striatum =
putamen + caudate
basal ganglia - Lentiform =
putamen + globus pallidus
basal ganglia - putamen - responsible for
motion regulation
basal ganglia - caudate - responsible for
cognitive
globus pallidus is divided to
- Globus pallidus externus
2. Globus pallidus internus
basal ganglia - 2 main pathways
- excitatory pathway (direct) –> increases motion
2. inhibitory pathway (indirect) –> decreases motion
Movement disorders - types
- athetosis 2. chorea 3, Dystonia 4. Essential tremor
- Hmiballismus 6. intention tremor 7. Myoclonus
- Resting tremor
Essential tremor - presentation / worsen with
high frequency tremor with sustained posture (eg outstretched arms), worsened with movement or when anxious
Essential tremor - treatment
- β-blockers (nonselective –> eg. propranolol)
- primidone
- patients often self medicate with EtOH
essential vs resting (on movement)
essential –> worsened on movement (and resting –> alleviated by intentional movement
intention tremor - presentation / charact lesion
slow, zigzag motion when pointing extending toward a target
- cerebellar dysfunction
essential vs intention tremor (speed)
essential - high frequency
intention –> slow
Chorea - presentation / chorea means (as a world) / characteristic lesion
sudden, jerky purposeless movements
chorea –> dancing
- Basal ganglia (Huntington)
hemiballismus - presentation / characteristic lesion
sudden, wild flailing of 1 arm +/- ispilateral leg
- contralateral subthalamic nucleus (eg. lacunar stroke)
Myoclonus - presentation / common in
sudden brief uncontrolled muscle contraction
- hiccups are common
metabolic abnormalities such as liver or renal failure
Hemiballismus course - course
Recovers spontaneously over months
