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

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

FUNCTIONAL AREAS

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

FUNCTIONAL AREAS

Temporal Lobe

• Anatomy & Function–Medial Surface• Fusiform gyrus• Hippocampal gyrus• Amygdala • Dentate Gyrus• Inferior temporal sulcus

Blood Supply

Lateral Surface Medial & Inferior Surface

Inferior Branch of MCA Temporal Branch of PCA

Connections of Temporal Lobe

1. Hierarchical sensory pathway

2. Dorsal auditory pathway

3. Polymodal pathway

4. Medial (mesial) temporal pathway

5. Frontal lobe projection

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

Temporal Lobe Testing

Symptoms of Temporal Lobe Lesions

1. Disturbance of Auditory Sensation and perception

2. Disturbance of selective attention of auditory and visual input

3. Disorders of visual perception

4. Impaired organization and categorization of verbal material

5. Disturbance of language comprehension

6. Impaired long term memory

7. Altered personality and affective behavior

8. Altered sexual behavior

-Kolb & Wishaw (1990)

• 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)

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

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

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

Sexual Behavior

• Severe damage to temporal lobe show increase sexual behavior

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

Temporal lobe aphasia

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

Conduction Aphasia

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

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

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

3. Klüver–Bucy syndrome Klüver–Bucy syndrome is a syndrome resulting from bilateral

lesions of the anterior temporal lobe including amygdaloid nucleus

1. Amnesia

2. Docility

3. Hyperphagia / Dietary changes

4. Hyper-orality

5. Hyper-sexuality

6. Visual agnosia

7. Others- Hyper-metamorphosis, diminished emotional affect

- From Wikipedia, Free encyclopedia

4.Temporal Lobe Infarct

Middle cerebral artery-• Wernicke’s aphasia• Conduction aphasia• With or without sensory-motor deficit

Posterior cerebral artery-• Recent memory loss

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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