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Telencephalon

Telencephalon. White matter . Basal ganglia. Telencephalic white matter. Projection fibers Corona radiata Commissural fibers Corpus callosum rostrum, genu, trunkus, splenium Commissura anterior Commissura fornicis Association fibers Fibrae arcuatae breves Fibrae arcuatae longi.

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Telencephalon

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  1. Telencephalon White matter. Basal ganglia

  2. Telencephalic white matter Projection fibers Corona radiata Commissural fibers Corpus callosum rostrum, genu, trunkus, splenium Commissura anterior Commissura fornicis Association fibers Fibrae arcuatae breves Fibrae arcuatae longi

  3. Association fibers 5 5 3 1 1 4 2 1. Fasciculus longitudinalis superior 2. Fasciculus longitudinalis inferior 3. Cingulum 4. Fasciculus uncinatus 5. Fibrae arcuatae brevae

  4. Association fibers(lateral aspect) 1. Fasciculus longitudinalis superior 3. Fasciculus uncinatus 2. Fasciculusoccipitofrontalis4. Fasciculusperpendicularis inferior occipitalis

  5. Asociation fibers(medial aspect) 1. Cingulum 4. Fasciculusoccipitofrontalissuperior 2. Fasciculus uncinatus 5. Fasciculusperpendicularis occipitalis 3. Fasciculus longitudinalis inferior

  6. Speech areas

  7. Commissural fibers Corpus callosum symmetrical areas of the hemispheres splenium, corpus, genu, rostrum Commissura anterior temporal lobes olfatory bulbs Commisssura posterior leftand right parts oftectum& tegmentum of midbrain Commissura fornicis between both crura of fornix

  8. Corpus callosum - forceps minor - forceps major - tapetum Commissura anterior - pars anterior -pars posterior Commissura anterior (frontal section)

  9. Commissural fibers • Corpus callosum 3. Forceps minor • Commissura anterior 4. Forceps major

  10. Lateralisation of functions

  11. Split brain syndrome А. Dominant hemisphre- mention the stimulus B. Nondominant hemisphere- points the stimulus C. Anomia – can not name stimuli on the left hand D.Alexiain the left visual fields E.Test – hybrid face - the patient answers man, but point the woman

  12. Projection fibers

  13. Capsula interna 1. Crus anterior between nucl. caudatus и nucl. lentiformis -stripes of grey matter 2. Genu 3. Crus posterior Pars thalamolentiformis • between thalamus & nucl. lentiformis Pars retrolentiformis Pars sublentiformis 1 2 3

  14. Capsula interna 1. Tractus corticonuclearis 2. Tractus corticospinalis 3. Fibrae corticothalamicae 4. Fibrae thalamocorticales 5. Radiatio acustica 6. Radiatio optica 14. Fibrae corticorubrales

  15. White matter (frontal section) 1. Corpus callosum 2. Capsula interna 3. Fasciculus occipitofrontalis superior 4. Fasciculus longitudinalis superior 5. Fasciculus occipitofrontalis inferior 6. Cingulum 7. Fasciculus uncinatus 8. Fasciculus longitudinalis inferior

  16. Basal ganglia

  17. Location Section through the base of hemisphere exposes a. Paired nuclear masseswithin the hemispheres. b. Surounded by white matter (capsula interna, capsula externa, capsula extrema)

  18. A Б

  19. Basal gangliaComponents Components of theBasal ganglia Corpus Striatum Striatum ----- Caudate Nucleus & Putamen Pallidum ----- Globus Pallidus (GP) Substantia Nigra Pars Compacta (SNc) Pars Reticulata (SNr) Subthalamic Nucleus (STN) Ventral Striatum и Ventral Pallidum Nucleus Accumbens Septi Noncholiergic part of Substantia Innominata

  20. Basal ganglia Components STRIATUM Nucleus Caudatus Caput, (Corpus), Cauda Caudolenticular bridges of grey matter Putamen Striatum Ventralis: Nucleus Accumbens (Septi)

  21. Basal Ganglia Components Striatal Compartments (Mosaic or Modular Organization) 1. Striosome (Patches) - 10-20% of total striatal mass - low acetylcholinesterase (AchE) activity - high substance P (SP), neurotensin (NT), tyrosine hydroxylase - high expression of D1 dopamine receptor - high opiate receptor 2. Matrix - high acetylcholinesterase (AchE) activity - high somatostatin (SRIF) activity - high D2 dopamine receptor

  22. Basal Ganglia Introduction Traditional Concepts of Basal Ganglia Corpus Striatum Caudate Nucleus Lenticular Nucleus Putamen Globus Pallidus Paleostriatum Pallidum Corpus Amygdaloideum Archistriatum Neostriatum Striatum

  23. Lateral surface of basal ganglia 1. Putamen 2. Tail of caudate nucleus 3. Caudatolenticular gray bridge 4. Amygdaloid body 5. thalamus

  24. 1. head of caudate nucelus 2. body of caudate nucelus 3. caudatolenticular gray bridge 4. putamen 5. tail of caudate nucleus 6. external segment of globus pallidus 7. internal segment of globus pallidus 8. amygdaloid body 9. nucleus accumbens septi Medial surface of basal ganglia

  25. Components of Basal Ganglia Putamen Globus pallidus external segment internal segment Subthalamic Nucleus Substantia nigra Internal capsule

  26. Basal Ganglia Connections Input Portion STRIATUM (Caudate Nucleus and Putamen) Output Portion 1. PALLIDUM (Globus Pallidus) 2. SNr (Substantia Nigra, Pars Reticulata)

  27. Basal ganglia Connections А. Striatum (nucl. caudatus + putamen) 1. Afferent fibers а. Cortex (sensimotor – gyrus paracentralis) b. Thalamus – nucl. centromedianum, NVL, NVA c. Substantia nigra d. Nuclei raphe 2. Efferent fibers a. Pallidum [striopallidal] b. SN [strionigral]

  28. Basal ganglia Connections B. Globus pallidus (pallidum) 1. Afferent fibers а. Striatum (striopallidal fibers) b. Nucleus subthalamicus (fasciculus subthalamicus) c. Cerebral cortex d. Substantia nigra e. Nuclei raphe 2. Efferents fibers a. Common final pathway to thalamus b. Ansa lenticularis, fasciculus lenticularis, fasciculus subthalamicus

  29. Basal ganglia Connections

  30. Basal Ganglia (Main Motor Circuit) Connections Supplementary Motor Area (SMA) STRIATUM (Putamen) Primary Motor Area (M I) pyramidal tract ansa lenticularis THALAMUS (VLo, VApc, CM) PALLIDUM (GPi) lenticular fasciculus LMN

  31. Basal Ganglia and Pyramidal Tract SMA (supplementary motor area) upper motor neuron UMN BASAL GANGLIA CIRCUIT pyramidal tract lower motor neuron LMN

  32. Functional role Regulate the motor activitybyintrinsic and extrisic feed-back circuits • Role in the control of movements • Suppress the motor tone • Suppress the excesive and unnecessary movements

  33. Signs in lesion of basal ganglia 1. Akinesia & bradykinesia -difficulty in initiation and cessation of movement 2. Rigidityof muscles 3. Involutary movements (hyperkinesia) – tremor, tics, balism, chorea, atetosis, distonia

  34. Basal Ganglia Functional Consideration Functional Consideration 1. Selection of “Preprogramed (learned) motor plans” Basal Gangla Circuit ---- Selection Mechanism Selection Inability -------- Akinesia and Hypokinesia Faulty Selection ----------- Hyperkinesia 2. Generation (learning) of motor programs Programming of several motor fragments into complex motor routines Cerebral Palsy ------------- Disordered motor program

  35. SYDENHAM’S CHOREA Clinical Feature - Complication of Rheumatic Fever - Fine, disorganized , and random movements of extremities, face and tongue - Accompanied by Muscular Hypotonia - Typical exaggeration of associated movements during voluntary activity - Usually recovers spontaneously in 1 to 4 months Principal Pathologic Lesion: Corpus Striatum

  36. HUNTINGTON’S CHOREA Clinical Feature - Predominantly autosomal dominantly inherited chronic fatal disease (Gene: chromosome 4) - Insidious onset: Usually 40-50 - Choreic movements in onset - Frequently associated with emotional disturbances - Ultimately, grotesque gait and sever dysarthria, progressive dementia ensues. Principal Pathologic Lesion: Corpus Striatum (esp. caudate nucleus) and Cerebral Cortex

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