Basal Ganglia

What are the main components of the basal ganglia?

Lentiform nucleus, Putamen, Globus Pallidus I and II, Caudate nucleus.

What is the function of the striatum in the basal ganglia?

It receives projections from the cerebral cortex and the substantia nigra.

What are the two major pathways involved in the basal ganglia?

Direct pathway and indirect pathway.

How do glutaminergic fibers affect the striatum in the direct pathway?

They excite the striatum.

What neurotransmitter do GABAergic neurons from the striatum use to inhibit the Globus Pallidus I and SNpr?

GABA.

What is the overall effect of the direct pathway on the motor cortex?

Excitation of the motor cortex leading to initiation of movement.

What happens to the subthalamic nucleus in the indirect pathway?

It is excited, which leads to inhibition of the motor cortex.

What characterizes hypokinetic disorders?

Breakdown of the direct pathway.

What are some symptoms of akinesia?

Impaired ability to initiate voluntary movement.

What is a common symptom of Parkinson's disease?

Resting tremor.

What treatment is commonly used for Parkinson's disease?

Administration of L-DOPA.

What is Huntington's disease?

An autosomal dominant hereditary disease resulting in degeneration of neurons in the striatum.

What are the symptoms of Huntington's disease?

Chorea, cognitive deterioration, and psychiatric disturbances.

What is Sydenham's chorea associated with?

Rheumatic fever.

What results from degeneration of the globus pallidus?

Athetosis.

What causes ballism?

Lesion of the subthalamic nucleus.

What is Wilson's disease?

An autosomal recessive disorder that leads to copper metabolism issues.

What is the typical presentation in the eyes of patients with Wilson's disease?

Kayser-Fleischer ring.

What is dystonia musculorum deformans?

A rare hereditary condition associated with injury to the lentiform nucleus.

What are focal dystonias?

Movements such as torticollis, blepharospasm, dysphonia, facial spasm, and writer's cramp.

Which nucleus is involved in both the direct and indirect pathways of the basal ganglia?

Subthalamic nucleus.

What does a GABAergic projection to the thalamus from the globus pallidus result in?

Inhibition of the thalamus.

What type of fibers does the nigrostriatal pathway involve?

Dopaminergic fibers.

What is the immediate precursor to dopamine?

L-DOPA.

What changes can occur in gait due to Parkinson's disease?

Shuffling or festinating gait.

How long do patients typically survive after the onset of Huntington's disease?

15-20 years.

What type of movements are characteristic of dyskinesias?

Involuntary movements.

What neurotransmitter predominates in the excitatory path to the motor cortex?

Glutamate.

What is the effect of the direct pathway on the thalamus?

Exhibition of thalamic excitation.

What kind of movements characterize athetosis?

Slow, sinuous, writhing movements.

What is another name for chorea associated with rheumatic fever?

Sydenham's chorea.

What is the significance of dopaminergic fibers in the indirect pathway?

They cause inhibition despite overall excitation in the striatum.

What is one of the main characteristics of hyperkinetic disorders?

Breakdown of the indirect pathway.

What is the goal of treatments like pallidotomy in patients with Parkinson's disease?

To alleviate some Parkinsonian signs.

What kind of changes do patients with Wilson's disease experience in their liver?

Progressive degeneration.

What condition is characterized by transient, reversible childhood movements associated with rheumatic fever?

Sydenham's Chorea.

What type of disorder is dystonia classified as?

Movement disorder characterized by involuntary muscle contractions.

What causes the rigidity often seen in Parkinson's disease?

Increased muscle tone.