Basal Ganglia (new) Flashcards
what is the basal ganglia?
what is it involved in?
when does the basal ganglia become active?
Basal ganglia translates the idea of movement
into the motor expression of that idea.
involved in voluntary muscle movements and posture.
it comes active before a movement
the basal ganglia has these neurological structure components:
- Caudate nucleus
- Lentiform nucleus
- Claustrum
- Corpus Striatum
- Neostriatum
- Amygdaloid body
the basal ganglia has these basal nucleus for each neurological strucutre:
neurological structure / basal nucleus each structure
- Caudate nucleus = Caudate nucleus
- Lentiform nucleus = Globus pallidus + Putamen
- Claustrum = Claustrum
- Corpus Striatum = Lentiform + Caudate
- Neostriatum = Caudate + Putamen
- Amygdaloid body = Amygdaloid nucleus
basically the neurological can be 1 or 2 structures that get named together, the basal nucleus is each structure individually
identify
what do you get if you have a lesion of the splenium of the corpus callosum?
alexia withough agraphia
can’t read byt can write
identify
the basal ganglia divides into 2 pathways… what are these?
what happens when each gets activated?
1) direct: disinhibits thalamic motor nuclei (the ventral anterior and ventral lateral or VA and VL), resulting in cortical activation and movement initiation.
2) indirect: inhibits the VA and VL, resulting in reduction in cortical activation and movement suppression.
Name the afferent pathways going into the basal ganglia?
from where is each going to?
- Corticostriatal: Cortex to striatum
- Nigrostriatal: SNpc to various BG structures (and others).
- Amygdalostriatal: Amygdala to ventromedial caudate and putamen (suggests that BG may have limbic and non-limbic components).
- Thalamostriatal: From centromedian (and other) thalamic nuclei to striatum.
name the efferent (away form striatum) pathways going away from the basal ganglia?
- Striatopallidal: From striatum (caudate and putamen) to globus pallidus.
- Striatonigral: From striatum to substantia nigra.
- Ansa lenticularis: Globus pallidus to thalamus.
- Fasciculus lenticularis: Globus pallidus to subthalamus.
identify the blood supply to the basal ganglia
what is dyskenesia?
what is Hyperkinesia?
what is Hypokinesia?
- Movement disorders
- Involuntary spontaneous movements.
- Lack of spontaneous movement, and slowing of voluntary movement.
is there muscle weakness in basal ganglia disorders? Why?
no because there is no UMN or LMN damage
what are these Hyperkinetic Dyskinesia disorders:
- Chorea
- Athetosis
- Dystonia
- Ballismus
- Chorea: A series of rapid, jerky, involuntary movements.
- Athetosis: Continual uncontrolled writhing movements (disappear during sleep).
- Dystonia: A severe form of athetosis. Extreme contraction of antagonist muscle groups results in limbs locked in one position for long periods of time. Also may go in and out of muscle spasms.
- Ballismus: Involuntary flinging of limbs.
What is the most common hyperkinetic disorder originating in the basal ganglia?
Why does it happen?
Huntington’s Disease
loss of GABA enkephalinergic neurons in the striatum.
what can sometimes precede the development of involuntary motor movements?
What is the main symptom?
what can be seen in the brainstem with this disorder?
Dementia
Choreiform movements
Degeneration of caudate nucleus and subsequent
enlargement of ventricles.
identify where each disorder happens
what is ballismus or hemiballismus?
Stroke-induced, results in involuntary flinging of contralateral limbs.
what is another name for Sydenham’s Chorea?
what age will this affect?
this usually happens after what?
What symptoms do you see?
St Vitus dance
5-15
a viral infection, like strep or acute rheumatoid fever
- milk-maids grasp, darting tongue
- choreic movements, *pronator sign (hands up and they pronate)
- behavioral and cognitive changes
what is the most common type of hypokinetic dyskenesia?
What characterizes this disease? (symptoms)
Parkinson’s disease
- Bradykinesia: Poverty and slowness of movement
- Tremor: Only seen while extremity is at rest;
disappears during sleep.
- Rigidity: Resistance to passive limb movements
- tremor and rigidity are both together called= Cogwheel rigidity
what happens in parkinson’s disease?
at what age does parkinson’s start?
what is the most prominent symptom of Parkinson’s?
there is a Loss of neuromelanin (as substantia nigra cells die), and Lewy bodies proliferate.
40-70
Bradykinesia
Parkinson-like conditions are referred to as what?
The term primary Parkinson’s Disease, (‘true’ PD), is used for what form of the disease?
Parkinsonism
for the idiopathic form which has no complicating
factors.
Name a drug that induced Parkinsonism by going straight to the substantia nigra and killed everything.
MPTP
Name other causes of non-idiopathic Parkinsonism.
- MPTP
- Head trauma (ie. Muhammed Ali)
- Viral infections (ie. Encephalitis lethargica)
- Toxins (such as manganese and carbon monoxide)
how do you treat parkinson’s?
give L-DOPA which gets converted in the brain to dopamine
Sinemet (dopa+carbidopa)
what is the surgery treatment for parkinson’s?
Pallidotomy and thalidotomy: lesioning ‘non-essential’ portions of these structures
Deep brain stimulation:
Bilateral electrodes targeted at the:
- Thalamus: Effective in reducing tremor (resting and essential tremor).
- Subthalamus: Potentially very effective in reducing tremor and most other PD symptoms.
- Globus pallidus: Electrodes here may reduce drug-induced side effects in patients who have already received pallidotomy.
What is Essential tremor?
tremor that is ongoing, not resting tremor
what is the 3rd most common movement disorder after essential tremor?
dystonia
what is Dystonia?
why does it happen?
at what age is it early onset?
and late onset?
Dystonia is a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements, or abnormal postures.
following lesions of the lentiform nucleus.
less than 28; after 28
what is Tourette’s Syndrome characterized by?
what is rare in Tourette’s?
multiple motor tics (the tics are non-rhythmic and temporarily suppressible, and usually preceded by a premonitory urge) and at least one verbal tic
Copralalia (obscenities), echolalia (repeating other’s
words), palilia (repeating one’s own words) are rare
in Tourettes
What is Wilson’s Disease?
what symptoms can we see?
Copper accumulation in the liver which can be deposited in the eyes, kidneys and brain
- neurological: behavior changes, hypo- or hyper-kinetic symptoms (dystonia, etc.) as copper accumulates mostly in the lentiform nuclei.
- Kayser-Fleicher rings
- infertility
- arrhythmias
Lesion to these structures will result in what disease?
- Globus pallidus
- Striatum/neostriatum
- Subthalamic nucleus
- Substantia nigra
- Various structures
- Damage during pregnancy
- Tourette’s
- Huntington’s
- Ballismus
- Parkinson’s
- Wilson’s
- Cerebral palsy
what kind of cerebral palsy happens with corticospinal or motor cortex damage?
what kind of cerebral palsy happens with cerebellar damage?
what kind of cerebral palsy happens with Basal Ganglia damage?
Spastic cerebral palsy
Ataxic cerebral palsy
Athetoid/Dyskinetic
