Chapter 18: Limbic System

CHAPTER 18: LIMBIC SYSTEMAbdullah Tawakul

Neurology AHD

March 2ed ,2011

PAUL BROCA (1824-1880)

Anatomical and Clinical Review• Limbic functions can be divided into..

Anatomical and Clinical Review• Limbic cortex..

Limbic structures

• This myelinated structure projects between the hippocampus and mammillary body?

Optic radiationThe FornixCorpus callosum Internal capsule external capsule

• What are the C-shaped structure that follow the curve of the lateral ventricles ?

The fornixThe Cudate nucleusCorpus callosum

• This radical surgical procedure has been used to control violent, antisocial behavior?

Frontal Lobectomy.

• Amygdala composed of three main nuclei ?

CorticomedialBasolateralCentral

• What are the diencephalic structure involved in limbic system?

HypothalamusThalamus : MD and Anterior neuclus Habenula

• The brain stem nuclei that are involved in limbic system?Interpeduncularsuperior central dorsal and ventral tegmentalparabrachialperiaqueductal grayreticular formation nucleus solitarius dorsal motor nucleus of vagus

• Olfactory pathway ..?

• Name three Intracerebral vascular lesions which could lead to memory deficits?

Rupture of A-com aneurysm ( basal forebrain, medial

diencephalon, and frontal lobes)

Top of the basilar artery lesions (Bilateral medial temporal or medial diencephalic supplied by PCA)

Artery of Percheron lesion .. single paramedian thalamoperforator artery (Bilateral medial thalami)

• What are the three components of the hippocampal formation ?

Dentate gyrusThe subiculumThe hippocampus

• This cortex is unique among sensory systems that it receive direct input from secondary neurons without an intervening thalamic relay?

The primary olfactory cortex.

• Which region of the parahippocampal gyrus serves as the most important relay between the hippocampal formation and association cortices?

• A) Piriform and periamygdaloid cortex• B) Entorhinal cortex• C) Parahippocampal cortex• D) Perirhinal cortex• E) Orbital frontal cortex

List the synapses of the perforant and the alvear pathways?

Entorhinal cortex >Dentate gyrus >Hippocampus (CA1&3) >subiculum > Entorhinal cortex

Subiculum > Entorhinal cortex.

Compare explicit and implicit memory ?

• Match function for each of the following structures?

Medial temporal lobes Verbal fluency Right temporal lobe Task switchingLeft frontal lobe explicit memoryDorsolateral frontal lobes visuospatial memory

JAMES PAPEZ (1883-1958)

• Name all the structures and the connections involved in the Papez circuit?

• Which syndrome is caused by bilateral lesions of the amygdala and adjacent temporal structures and What are its main characteristics?

Kluver-Bucy syndrome:• Docility, non-aggressive behavior• Hyperorality• Hyperphagia• Hypersexuality• Visual agnosia• Memory loss

• What is Wernicke Korsakoff syndrome?

• Deficiency:

• Incidence:

• Clinical pic:

• Pathology:

• Amnesia:

Thiamine deficiency

Alcoholics and patients with malnutrition.

Confusion, opthalmoplegia, ataxia….coma

Mammillary bodies necrosis.

Anterograde and retrograde.