Anatomy & Function of Temporal lobe

Contains the information of anatomy and function of each Brodmann's area, localisation and assessment of temporal lobe.

1. temporal lobe: Anatomy & Function Presenter:- Dr Zuber Ali Quazi Senior Resident DM Neurology

2. Lateral Surface of Temporal lobe

3. Inferior Surface of Temporal lobe

4. Superior Surface of Temporal lobe

5. Boundaries of Temporal lobe- Lateral surface

6. Boundaries of Temporal lobe- Medial surface

7. Area 52 – Parainsular area Junction of temporal lobe and insula.

8. Area 41- Auditory cortex Auditory - Basic Processing

9. Area 42- Auditory cortex Auditory - Basic Processing

10. Area 22 - Superior temporal gyrus, of which the Caudal part of this area contains the Wernicke's area Complex Sound processing

11. Area 21 – Middle temporal gyrus Auditory- Complex Sound Processing

12. Area 20- Inferior temporal gyrus Visual – Visual Integration

13. Area 38 – Temporopolar area Most rostral part of the Superior and Middle temporal gyri. Recognition of familiar voices

14. Area 39- Angular Gyrus Complex language functions (i.e. reading, writing and interpretation of what is written ) Arithmetic and spatial cognition. D istinguishing left from right by integrating the conceptual understanding of the language term "left" or "right" with its location in space.

15. Area 27 – Piriform cortex Olfaction

16. Area 34 – Dorsal entorhinal cortex The entorhinal area is the main interface between the hippocampus and neocortex and  involved in memory, navigation and the perception of time . Gateway.

17. Area 28 – Ventral entorhinal cortex

18. Area 35 – Perirhinal cortex (in the rhinal sulcus ) Interconnecting the hippocampal formation Object recognition and in storing information about objects

19. Area 36 – Ectorhinal area Encoding of memory

20. Papez Circuit C ontrol of emotional expression Memory storage

21. Hippocampus Mammillary bodies Mammillothalamic tract Anterior Thalamic Nuclei Cingulate Gyrus

22. Cingulate Gyrus Parahippocampal gyrus

23. Functions of Temporal lobe Dominant Temporal lobe:- Auditory perception Language and Verbal memory Smell Non- Dominant Temporal lobe:- Non verbal memory

24. Memory Medial temporal lobe – Short term/ Episodic memory Lateral temporal lobe – Long term – Semantic memory. H ippocampus - formation of long-term memory, modulated by the amygdala Auditory Rt side- Melody, pitch and sound intensity. Lt side- Generation and understanding words. Unilateral destruction of Auditory cortex- Difficulty in sound localization. Bilateral destruction ---- decrease in auditory acuity / Cortical deafness. Visual I nterpret the meaning of visual stimuli and establish object recognition. The ventral part of the temporal cortices --- involved in high-level visual processing of complex stimuli S uch as faces (fusiform gyrus) and scenes ( parahippocampal gyrus ). Anterior parts of the ventral stream for visual processing are involved in object perception and recognition . Language recognition P rocessing of semantics in both language and vision. L anguage comprehension. Identification and categorization of stimuli. Matching auditory and visual stimuli. Emotional functions.

25. Affect and Personality Personality in Temporal lobe lesions :- Overemphasizing trivial and petty details. Egocentricity (Preoccupation with one’s own internal work). Perseveration. Paranoia. Pedantic speech. Preoccupation with religion. Proneness to aggression. Vestibular functions :- Some fibres from vestibular input are relayed in STG. Lesions– episodic vertigo. Biological motion perception. Refers to where an individual ascribes goals and mental states to another's actions or when an individual imagines, executes, or observes actions. Area- STS

26. Symptoms of Temporal lobe Lesion Disturbance of Auditory sensation and perception. Disorder of Music perception. Disorder of Visual perception. Disorder of time perception. Disturbance in selection of visual and sensory input. Impaired organization and categorization of sensory input. Inability to use contextual information. Impaired long term memory. Altered personality and affective behavior. Altered sexual behavior.

27. Inferomedial Aspect ( Amygdala & Hippocampus) Amnesia Right – Visuaspatial Left – Verbal involvement Anterior Tip (Bilateral lesion) Kluver - Bucy syndrome Visual agnosia Oral exploratory behavior Loss of fear. Hypersexuality

28. Localization of Temporal lobe Epilepsy Automatism Location Oral automatism Medial temporal lobe Postictal cough Temporal lobe Postictal nose wiping Ipsilateral temporal lobe Ictal spitting Temporal lobe Whistling Temporal lobe Autonomic Location Ictal Vomiting Right Temporal lobe Ictal urination Right Temporal lobe Piloerection Left temporal lobe Speech Location Ictal speech arrest Temporal lobe ( Dominant) Ictal speech preservation Temporal lobe ( non dominant) Postictal aphasia Temporal lobe ( Dominant)

29. Test for Evaluation of Temporal lobe function In MMSE:- Orientation to Time place person ( Mainly by IPL) Recall Language (Naming, Repetition, 3 step command, Comprehension) Other parts of the brain also involved in executing these tests . In Lobar function test Recent memory Remote memory Visual memory

30. Other tests Rey Complex figure test – Non verbal memory --- Right temporal lobe For this test, a patient is asked to copy a complex figure to the best of their ability. Once completed; 45 minutes later the subject is asked to reproduce the same figure only this time just from their memory.

31. Other tests Dichotic listening test:- Assess auditory processing capacity Auditory information is presented to both ears of the pt , and is instructed to immediately repeat the auditory input from any one ear.

32. Token test Language comprehension For this test, the examiner will place out 20 token all of which vary in color and size. The examiner will then instruct the patient to touch certain tokens.

33. Mooney Closure Test Visual processing capacity Right Temporoparietal junction --- Ventral visual stream. The examiner presents to the patient abstract pictures. The pictures clearly represent a face or object but are only marginally abstract.

34. References Localization in Clinical Neurology, Paul W. Brazis 7 th edi (SAE). Bradley 8 th edition. J. A. Kiernan, "Anatomy of the Temporal Lobe", Epilepsy Research and Treatment, vol. 2012, Article ID 176157, 12 pages, 2012. https://doi.org/10.1155/2012/176157 Patel A, Biso GMNR, Fowler JB. Neuroanatomy, Temporal Lobe. [Updated 2021 Jul 31]. Bajada CJ, Haroon HA, Azadbakht H, Parker GJM, Lambon Ralph MA, Cloutman LL. The tract terminations in the temporal lobe: Their location and associated functions. Cortex. 2017 Dec;97:277-290.

35. Thank you