Temporal lobe

neuro psychiatric aspects of temporal lobe

1. Dr. Mosam Phirke , Resident, Psychiatry Department, L.T.M.M.C.& G.H., MUMBAI.

2. Temporal Lobe One of the four major lobes of cerebral cortex. Located beneath lateral fissure Processing sensory input into derived meaning Appropriate retention of visual memory Language comprehension Emotional association Seat of human para -psychological and psychic abilities

3. FUNCTIONAL AREAS

4. Temporal Lobe Anatomy & Function Lateral Surface Heschl’s gyrus (a.k.a. Transverse temporal gyrus ) Superior temporal gyrus Superior temporal sulcus Middle temporal gyrus Inferior temoral gyrus

5. FUNCTIONAL AREAS

6. Temporal Lobe Anatomy & Function Medial Surface Fusiform gyrus Hippocampal gyrus Amygdala Dentate Gyrus Inferior temporal sulcus

7. Blood Supply Lateral Surface Medial & Inferior Surface Inferior Branch of MCA Temporal Branch of PCA

8. Connections of Temporal Lobe Hierarchical sensory pathway Dorsal auditory pathway Polymodal pathway Medial ( mesial ) temporal pathway Frontal lobe projection

9. Functions of Temporal Lobe Visual memory Memory formation (long term storage of sensory inputs) Processing sensory input Auditory (superior temporal gyrus)- processing input Visual (fusiform and inferior temporal gyrus)- object recognition Olfactory ( entorhinal cortex) Gustatory (insular cortex) Language recognition (Wernicke's area) Identification and Categorization of Stimuli Emotional response is associated with a particular stimulus

10. Temporal Lobe Testing

11. Symptoms of Temporal Lobe Lesions Disturbance of Auditory Sensation and perception Disturbance of selective attention of auditory and visual input Disorders of visual perception Impaired organization and categorization of verbal material Disturbance of language comprehension Impaired long term memory Altered personality and affective behavior Altered sexual behavior -Kolb & Wishaw (1990)

12. Left superior temporal gyrus difficulty in discriminating speech Right superior temporal gyrus inability to discriminate melodies and produce prosody Inferior temporal gyrus inability to recognize objects, called Visual agnosia Fusiform gyrus inability to recognize face, called Prosopagnosia (face blindness)

13. Organization & Categorization Left temporal lobe lobotomies lead to impairment in the ability to categorize words or pictures of objects Posterior lesions lead to a difficulty in recognizing specific word categories Language Comprehension Stimuli can be interpreted in different ways depending on the context Example: Fall - the season or a tumble

14. Memory Antero-grade Amnesia Amnesia for events after bilateral removal of the medial temporal lobes Infero -temporal Cortex Conscious recall of information Left temporal lobe Verbal memory Right temporal lobe Impaired recall of nonverbal material

15. Affect Stimulation of anterior and medial temporal cortex produces feelings of fear Temporal Lobe Personality ( Geschwind syndrome) Personality that overemphasizes trivial and petty details of life Pedantic speech (an overly formal speaking style inappropriate to the conversational setting) Egocentricity (preoccupation with one’s own internal world) Perseveration Paranoia Preoccupation with religion Proneness to aggression

16. Sexual Behavior Severe damage to temporal lobe show increase sexual behavior

17. 1. Aphasia Wernicke’s aphasia Wernicke’s area affected Deficit in comprehension of spoken speech Difficulty in repetition & responding commands Impaired spontaneous speech, writing & reading Para- phasic errors, neologism & grammatical mistakes Fluent speech with normal rhythm & inflexion - Lishman’s Organic Psychiatry Pure word deafness Primary auditory area affected Deficit in understanding of spoken speech Difficulty in repetition & cannot write to dictation Normal fluent speech, writing & reading Agnosia for spoken words but comprehend reading Fluent speech with normal rhythm & inflection

18. Temporal lobe aphasia

19. Conduction Aphasia Affect Arcuate Fasciculus which connects Wernicke’s & Broca’s area Speech & writing are impaired as in wernicke’s aphasia Repetition is severely impaired Comprehension of spoken & written material well preserved - Lishman’s Organic Psychiatry

20. Conduction Aphasia

21. 2. TEMPORAL LOBE EPILEPSY Temporal lobe epilepsy (TLE) was defined in 1985 by the International League Against Epilepsy (ILAE) as a condition characterized by recurrent unprovoked seizures originating from the medial (Hippocampus, Para-hippocampal gyrus, Amygdala) or lateral temporal lobe ( Neocortex ) Begins in late childhood or early adulthood Most common of anatomically defined syndromes (around 60%) Most varied and complex auras Resembles with symptoms of psychiatric disorder - Lishman’s Organic Psychiatry

22. CAUSES Hippocampus sclerosis a.k.a. Mesial temporal sclerosis or Ammon’s horn sclerosis Childhood febrile convulsions Tumors Cortical dysplasia 2ry to encephalitis and meningitis Head injury or vessel malformation Trauma Congenital brain malformations - Lishman’s Organic Psychiatry

23. Types- 1. Simple 2. Complex Auras- 1.Epigastric aura 2.Cephalic aura 3.Affective aura (Anxiety, Fear) Ictal - Oral automatism Manual automatism Speech automatism / Vocalization Illusions and Hallucinations Experiential phenomenon Affective Features Non convulsive status epilepticus - Lishman’s Organic Psychiatry

24. 3. Klüver–Bucy syndrome Klüver–Bucy syndrome is a syndrome resulting from bilateral lesions of the anterior temporal lobe including amygdaloid nucleus Amnesia Docility Hyperphagia / Dietary changes Hyper- orality Hyper-sexuality Visual agnosia Others- Hyper-metamorphosis, diminished emotional affect - From Wikipedia, Free encyclopedia

25. 4.Temporal Lobe Infarct Middle cerebral artery- Wernicke’s aphasia Conduction aphasia With or without sensory-motor deficit Posterior cerebral artery- Recent memory loss

26. 5. Temporal Lobe Tumors Patients with temporal lobe tumors experience psychiatric, behavioral, or personality changes Patients with tumors of the temporal lobe who have temporal lobe seizures often have seizure-associated schizophrenia-like psychotic symptoms Symptoms include-Auditory hallucinations and atypical dream-like episodes, depersonalization, blanking-out spells May present with depression and frontal lobe–like apathy & irritability or with features suggesting hypomania or mania, Personality changes commonly occur and may be one of the earliest indications of an undiagnosed temporal lobe tumor

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