Term
| areas invovled in programming-planning |
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Definition
| premotor areas, basal ganglia, cerebellum |
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Term
| areas invovledi n iniation of movement |
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Definition
| basal ganglia, supplementary motor area |
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Term
| cortical areas involvedi n motor plalnning |
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Definition
| are already components of corticospinal/bulbar systems: premotor area, posterior parietal cortex. Primary motor cortex |
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Definition
| located clsoe to premotor areas, gaze to teh opposite side. |
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Definition
| mediates speech,Involved in coordinating complicated movents in mouth etc. |
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Term
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Definition
| premotor cortex and supllementary motor area. Receive input form posterior parietal cortex and then project to motor cortex and downwards (motor cortex to brainstem pathways to medial motor nueron pools, corticobulbar and coritcopsinal tracts and indireclty to alpha motor nuerons in limbs.) Premotor areas are invovledi planning |
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Term
| whe nis the premotor area active |
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Definition
| when we think about doing an action/ plan to do it our premotor cortex starts becomign active. It resopnds primarily to visual and somatosnesory cues (external) |
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Definition
| respond when we observe an action, critical for learning thorugh imitation |
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Term
| supplementary omtor area when is it active |
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Definition
| (it is the medial premotor area, medial to the premotor cortex) inovlvedi nplanning of motor sequences in reposne to itnernal signals . contributes to postural adjustemnts, body orientation and grasping. Example: when asked to do simple finger movement supllementary motor area is not active, when asked to do more complciated one primary cortex as wel as suplemmentary motor area are active , when asked just to think about teh movements (mentally rehearse) onl the supllemnteary motor area is active |
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Term
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Definition
| inability to perofrm complex sequence of movements despite intact sensation,automatic motor output, and coprehension of the task |
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Term
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Definition
| ask patient to carry out imaginery actions (ie.e. brushign teeth)- will show lack of coordiantion or the idea is wrong (i.e. using finger to brush teeth). |
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Term
| structures of basal ganglia |
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Definition
| caudate nucleus and putamen (cropus straitum). Putaemn and globus pallidus (lentiform nuclei). subhtalamic nuclus (diencephalon). Substantia nigra (midbrain): |
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Term
| substantia nigra location and components |
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Definition
| midbrain, pars reticulata, pars compacta. |
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Term
| subthalamic nuclei location |
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Definition
| ventralto the thalamus, laterlat o the hypothalamus |
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Term
| look at basal ganglia aatomy picture |
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Definition
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Term
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Definition
communciated heavily with regiosn for plannign in motor cortex. FUnction: initation of movements and faciliation of automatic movements, organization fosequential movements ex. :fixed action movements.
after we learne a series of movements, basal ganglia takes over and becoems palce where we pattern and generate sequencs of movements. |
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Term
| cells within basal ganglia function |
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Definition
| .Several proejctions amde in from seeral areas of the cortex into basal ganglia (including all motor cortical areas). Caudate/putamen are the main receiving area of tehse proejctions.. Nigrostriatal dopamien is what mediates basal ganglia activity. caudate/putamen contain medium spiny neurons, which produce inhibitory outputs usign GABA to globus pallidus and to subtantia nigra pars reticulata. Globus pallidus outputs are also inhibitory |
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Definition
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Definition
| done by globus pallidus itnernus, which at resti nhibits Va/Vl. Dinhbiitoin canoccur. This is when Globus pallidus get sinhibited - allowing va/vl to furhter excitem otor cortex. Excitation of Gpi ihibits va/vl which leads to decreased exication fo motor cortex. |
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Term
| basal ganglia direct pathway |
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Definition
| input from cortex to corpus striatum into Gpi inhibits Gpi leadign to disinhbition. Substantia nigra pars comapcta releases dopamine which excites corpus striatum leadign to further disinhibtion (works through dopa 1 receptor) |
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Term
| basal ganglia indirect pathway |
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Definition
| whereas the direct pathway faciliates movement. The indirect pathway inhibits it. Operates via disinhibtion of subthalamic nuclei. This leads to activation of Gpi and inhibition of Va/Vl. sbustantia nigra pars compacta operates via da2 receptors to inhibit the striatum, which results in inhibition of the indirect pathway. |
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Term
| substantia nigra reticulata acts just like the globus pallidus interna |
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Definition
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Term
| movement disroders: diseases of the basal ganglia |
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Definition
| extrapyramidal. can have negative and positive signs. contralateral deficits. |
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Term
| negative signs of extrapyramidal disorders |
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Definition
| akinesia- no mveement, bradykiensia- slowed movements, decreased postural adjustments. Hypokinesia- decreased amplitude of movements (seen in handwriting). |
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Term
| postiive signs of basal ganglia disorders |
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Definition
| dyskiensias (choera athetosis, ballismus), rigidity (increased resistance to movements too much tone), tremor () ,dystonia (fixed postures due to abnormal activation of muscles) |
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Term
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Definition
| nearly continosu rapid movements of face tongue limbs, seen in huntingtons and parkinsons (when traeted with levadopa, duet o incerasedi nput on dopaminergic receptors). |
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Term
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Definition
| slow writhing movments , mostly y in distal extremities |
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Term
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Definition
| lesion in stratium ,,common in cerebral palsy |
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Term
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Definition
| violent , flinging movements occuring at rest- lesion in suthalamic nucleus. |
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Term
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Definition
| from antipsychotic drugs (DA antagonists leading to hypersenstitivity), can cause any dyskinesia |
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Term
| Huntingtons disease and basal ganglia |
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Definition
| autosomal dominant disease leadign to neurodegeneration fo cudate/putamen cells, which leads to disinhibtion of subthaalamus, and increased activation of indirect pathway. hutingtons corea |
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Term
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Definition
| somewaht responsvie to dompameinergic agents. icnreaased tone in some muscles leading to twisted posture. eamples: torticollus |
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Term
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Definition
| laryngeal muscles are hypertonic |
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Term
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Definition
| basal ganglia disorder. sudden brief action preceded b urge to perform it. Can e motor or vocal. tics accesory nerve involvement |
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Term
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Definition
| whole body is jerking in repsosnet o input. |
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Term
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Definition
| 3rd most common neruo disease average age of s onset is 55. caused by loss of cells in substantia nigra 9nigrostriatal pathway) |
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Term
| parkinsons disease symtpoms |
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Definition
| bradykinesia (negative) resting tremor (pill roll)(positive). rigiidity (positive). Postural instability (negative). ALso masked face, parkinsons gait and loss of automaticity |
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Term
| parkinsons disease mechanism |
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Definition
. Los of faciliation when da1 pathway is removed. Decreased moveent= lsos of faciliato nof that pathway. = decreawesed movement. Inhibtion becoems stronger, we have decrased movement
indirect pathway: dopaminergic pathway was faciliating movment because it was inbhiting inhibitory pathawy. When we lose that we have more inhibtion of movement, not inhibting inhibitory pathway. Incrased movement inhibtion |
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Term
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Definition
| bradkyinesia and another amin symptom, exlucion criteria and supportive criteria (unilateral onset persisetn asymmetry, resposne to levodopa, disease progression) |
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Term
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Definition
| Just hydropcephalus, repaeated head injuries, repeated strokes. |
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Term
| parkinsosn clincial progression |
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Definition
| decrease in strial dopaien over time, clicnical diagnosso f parkinsosn doesn tahppen until after 70-80 percent of dopamien is lost |
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Term
| honeymoon period ofparkinsons |
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Definition
| the amount of tiem that domapien is efective and useful treatment. Overtime, when off medication becoem very bradykientic. When on , too much movement. |
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Term
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Definition
| pharmaceutical: Va/VL thalamci lesions (for tremors). pallidotomy (removal fo GP) for tremor and rigidity. Depe brain stimualtion-- pallidum, va/vl, subthalmic nucleus. |
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Term
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Definition
| Gpi or subthalamic nucleus stim, provides inputs that override patholoical dischargepatterns. |
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Term
| 4 parallel pathways in basal ganglia |
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Definition
| body movemennt loop oculomotor loop, prefrontal- cognition and limbic- reward system |
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