Superior Temporal surface

• The superior surface forms the lower limit of the lateral fissure and overlaps the insula.

• Within the lateral fissure, three or four transverse temporal gyri (Heschl 41,42)

Lateral surface

• Above – posterior ramus of lateral fissure

• Below – inferiolateral border of hemisphere

• Superior, middle and inferior sulci and gyri

Inferior Temporal Surface

Histology

• Temporal lobe– Six layered fairly equally

developed pyramidal and granular layer

• Hippocampus– Three layered allocortex

Connection

• Affrents– Auditory cortex

• Medial Geniculate body

– Middle and inferior temporal lobe

• Occipital lobes

• Efferent– Opposite temporal lobe

• Anterior commissure• Middle corpus callosum

– Anterior temporal and orbitofrontal

• Uncinate fasciculus

– Broca’s area, motor cortex• Arcuate fasciculus from

Posteriosuperior temporal

– Superior temporal cortex– Limbic and paralimbic

cortex

Function

• Auditory - Visual discrimination

• Memory• Emotion

• Great integrator of sensation, emotion and behavior – Williams

• All sensory modalities are integrated into ultimate self awareness

Visual dysfunction (21,37)

• Unilateral lesion– Upper quadranopia (optic radiation)

– Visual Hallucination (middle and inf temporal gyri – 21, 37)

– Altered visual perception• Object appear too large – macropsia

• Too small – micropsia

• Too close or too far

• Unreal

• Bilateral lesion– Psychic blindness, oral exploration

Hearing dysfunction (41,42)

• Unilateral lesion – Threshold of brief auditory

stimuli elevated

– Spoken words less clear

– Distorted words are less clear

– Difficulty in equalizing sound presented to both ear

– Rapidly presented words and number in both ear difficult to perceiving

• Bilateral lesion– Cortical deafness –

unaware of deafness

– Associated with aphasia

Auditory Agnosia (21,22)

• Agnosia for sound– All noises (bell, running of

water, rustling of paper)are indistinguishable

– Associated with auditory verbal agnosia and amusia

• Amusia – Rt middle temporal

• Recognition of familial melody and ability to name it

• Perception of pitch and timber

• Ability to produce and read and write music

• Lowering of duration of note, timber intention of sound

• Memory of melodies and harmony

– Left middle temporal lobe• Naming of musical score and

all the semantics (writing and reading) aspect of music

• Auditory verbal agnosia (word deafness)

• Failure of left temporal lobe of deloading the acoustic signals of speech and converting them to appropriate motor expression.

Auditory Illusion and Hallucinations

• Auditory illusion (sound)– Either lobe lesion

• Loud or less loud

• Modification of timber and tonality

• Paracusias - Strange or disagreeable

• Repeated perseveration

• Auditory hallucinations – Either temporal lobe

• Elementary hallucination and dreamy state

– Left posterior lesion • Complex polymodal

(musical and voices) hallucination

Vestibular disturbance

• Superior and posterior part of temporal lobe posterior to auditory cortex in the first and second temporal convolution

• Activation – Vertigo

• Destruction– Change in the pattern of of optokinetic

stimulation

Time

• Disturbance of time perception– Either temporal lobe– Time stand still or pass great speed– Confessional state, post seizure, Dementia

Non auditory syndromes

• Amnesic dysnomia – defect in the retreval of words (inferio temporal lesion)

• Dominant lobotomy – failure of learning presented through visually presented material

• Non dominant lobotomy – failure of learning through visually presented material

• Either lobotomy 20% - prefrontal syndrome

Emotional visceral and Sexual function

• Uncinate fit – dreamy state, gustatory and olfactory hallucination

• Posterior temporal activation – complex memories of visual and auditory images with strong emotional content

• Amygdaloid complex stimulation – olfactory sensation – complex emotional

experience of past– Increased BP and pulse– Sexual abrasion

• Excessive arousal• Over activity• Reduced capacity

Temporal lobe functional localization

• Transverse gyri of Heschle 41,42 – primary auditory cortex

• Area 22 (planum sphenoidale) posterior to Hescle gyri on the superior surface auditory area

• Function– Verbal and Nonverbal

discrimination

• Vestibular receptive zone

posterior to auditory

• Middle and Inferior convolution – – visual discrimination

• Spatial orientation

• Estimation of depth and distance

• Stereoscopic vision

• Hue perception

• Medial temporal lobe– Visceral brain

– Hippocampal connection

Anterior Temporal Function

1. Auditory memory disturbance

2. Learning and retention of verbal material regardless of whether material is auditorily or visually presented and regardless of whether patient is tested using recall or recognition techniques.

3. Left anterior temporal lobe does not affect memory for places, faces, melodies- etc.

4. Right anterior temporal lobe damage impairs recognition and recall of visual and auditory patterns that do not lend themselves to verbal coding.

5. Difficulty remembering short auditory stimulation.

6. Deja vu.7. Hallucinations (auditory

and/or visual).8. Disinhibited social

behavior.

Anterior Temporal Tests

1. Paired associates Seashore Rhythm Test

2. Left vs. right 1. Paired Associates

Verbal Story for Immediate Recall

2. Visual Memory Seashore Rhythm Test

3. Visual Memory Seashore Rhythm Test

1. Repeat short and long sentences

2. Discern presence of deja vu. Presence of deja vu does not help to lateralize lesion .

3. Discern presence and nature of hallucinations

4. Obtain recent history concerning quality of social judgment

Middle Temporal dysfunction

1. Acoustico-mnestic disorders, can't retain series of sounds, syllables or words in memory.

– Comprehension of individual words intact but cannot retain more than 2 or 3 at once.

– In mild cases, patient can retain essential elements of series but cannot remember correct order.

– Problem is due to increased mutual inhibition of auditory traces.

2. Do not have difficulty with phonemic learning.

3. Difficulty reproducing words or word series under complicated conditions.

4. Impaired ability to name series of objects.

5. Stimulation gives hallucinations, memory images, changes in state of consciousness.

Middle Temporal Tests

1. Paired associates, long vs. short series of words, verbal story for immediate recall.

1. Check for comprehension of individual words in above tests.

2. If items are remembered, check for proper ordering.

3. Increase intervals between presentation of individual items in series and see if performance improves.

1. Auditory

Discrimination Test

2. Introduce a distraction

interval before patient

repeats series.

3. Ask to name several

objects individually

and then all at once

Right Temporal dysfunction

1. Right temporal lesion effects tend to be notable statistically but of less clinical significance.

2. Visual analysis (nonverbal primarily)

– Impairment of simple and complex visual analysis, but some negative findings.

– Impairment of short-term nonverbal memory.

– Impaired perception of tachistoscopically-presented letters.

– Prosopoagnosia (especially with anterior lesions).

– Impaired recognition of objects seen from unusual angles

3. Auditory analysis (nonverbal) – Impairment of short-term

auditory memory. – Perception of short sounds

impaired. – Impaired recognition of familiar

sounds. – Impaired tonal discriminations,

timbre discriminations, and amplitude discriminations.

– Amusia. – Impairment of contralateral ear

input in dichotic listening.

Right Temporal dysfunction

4. Constructional tasks – Visual construction impairment

proportional to tissue loss. – Impairment in maze learning

(visual and proprioceptive feedback).

– Enlarged left-hand margin in dictation.

5. Psychiatric personality phenomena with right temporal epilepsy – Personality changes. – Psychiatric symptoms. – Deja vue. – Metamorphopasias.

6. Psychometric findings – Temporary decline in

Performance IQ following lobectomy.

– Impairment on WAIS Picture Arrangement.

– Impairment on Binet Memory for Designs

– Possible impairment of WAIS Block Design?.

7. Persistence in maintaining a hypothesis even after being informed it was not correct.

Right Temporal Tests

• Impairment on WAIS Picture Arrangement.

• Impairment on Seashore Test of Musical Talent (especially Tonal memory, Timbre, Loudness, and Time).

• Dichotic thresholds. • Impairment of short-term

memory for other nonverbal acoustic tasks.

• Lezak and others – Have the patient identify a tune

the examiner hums. If unsuccessful, try several other familiar melodies to check for amusia.

– Test pitch discrimination with pitch pipe.

– Have patient try to discriminate (or imitate) different rhythmic tapping patterns. A memory component may be added.

– Test recognition of familiar sounds.

– The examiner may pair verbal and nonverbal material to clarify the interpretation of a patient's failures.

Right Temporal Tests

• Impairment of short-term memory for other nonverbal acoustic tasks.

• Visual recognition deficits (prosopoagnosia included)

– Impairment of recognition of photographs of faces.

– Impairment on Closure Faces Test (Mooney).

– Impairment on McGill Picture Anomalies Test.

– Difficulty in identifying pictures of objects viewed from unusual angles.

• Impairment of other nonverbal visual tests of short-term memory and visual discrimination or Binet Memory for Designs Test.

• Corsi's block-tapping test. • Impairment on stylus maze tasks

(visual or proprioceptive feedback).

• Impairment in enumeration of tachistiscopically-presented dots.

• Enlarged left margins in dictation. • In epileptics a history of strong

deja vue experiences or metamorphopsia

Left temporal dysfunction

• Auditory deficits (right ear)

– Intracranial localization of sound is impaired.

– Increased threshold for perception of short bursts of sound.

– Increased threshold for some frequencies.

– Failure to perceive brief simultaneous auditory stimulation.

• Visual deficit (both eyes)

– Upper right quadrantanopsia.

• Other complex sensory deficits

– Right hand tactile performance difficulty.

– Right hand finger agnosia.

Left temporal dysfunction

• Language deficits – Decoding of speech sounds

(phonemes) is impaired. – Problems with verbal

repetition. – Problems with auditory

comprehension of speech. – Receptive aphasia (deficits

in all language qualities). – Impairment of dichotic

listening to verbal material. – Intellectual impairment on

verbally mediated intellectual processes.

• Memory impaired for verbal material.

• Impairment on measures of higher cortical functions (Trails A and Trails B).

• Emotional disturbances – Perceptual distortions,

alterations of mood, obsessional thinking, psychosis, temper outbursts, hypo and hypersexuality

Left temporal tests

• Auditory tasks – Binaural localization of

clicks. – Simultaneous auditory

messages. – Short duration tone

bursts-threshold testing.

– Frequency threshold testing.

– Dichotic listening.

• Visual testing – Test visual

perimetry.

• Complex sensory tests – Tactual

performance test. – Finger agnosia test.

Left temporal tests

• Linguistic abilities tests – Speech sound perception test. – K-V auditory discrimination test. – Token test (for comprehension). – Aphasia exams – Wepman-Reitan Aphasia

Screening Test. – Porch Index of Communicative

Ability. – Boston Diagnostic Aphasia

Examination. – Dichotic listening.

• Measures of Intelligence – Wechsler Adult Intelligence Scale;

sensitive subtests include similarities, arithmetic, and digit symbol.

• Assessment of verbal memory – Hebb's recurring digits (digit span

with every third list is repeated). – Consonant trigrams (recall of a

spoken set of three consonants following distraction).

– Discrimination of recency (subject required to indicate which of two verbal stimuli they have seen most recently).

– Recall of Logical Memory from Wechsler Memory Scale after a 1 hour delay.

– 7 Assessment of higher cortical functions

– Trails A and Trails C.

• Emotional disturbances – MMPI.

Wernicke’s Area

• Motor weakness is typically minimal or absent.

• There may be a partial hemianopsia

• Word output is normal or increased, with many paraphasic errors, and speech is often incomprehensible (jargon aphasia).

• Paraphasic errors include elogisms ("Slep", "gort"), phonetic distortions ("good" for "wood") and semantic mistakes (Chevy for Ford).

• Auditory (speech) and visual (reading) comprehension are severely disturbed.

• The patient cannot follow 2 or 3 part commands

• One part commands can often be followed

• Repetition is impossible. • The severe comprehension

disorder often makes testing of other cognitive functions difficult.

A region of the brain located in the posterior, superior temporal gyrus, adjacent to the cortical region for hearing

Aphasia Tests

1. Porch Index of Communicative Ability (PICA)

2. Token Test

3. Token Test (3E-item version) – Appears to be a useful and

convenient device to diagnose aphasia impairment of language comprehension.

4. Boston Diagnostic Aphasia Battery

5. Western Aphasia Battery

6. Minnesota Test for Differential Diagnosis of Aphasia

7. Halstead-Wepman Aphasia Screening Test

8. Head's Serial Tests 9. Language Modalities Test10. Illinois Test of Psycholinguistic

Abilities 11. Michigan Picture Language

Inventory 12. Functional Communication

Profile 13. Examining for Aphasia 14. Sklar Aphasia Scale 15. Neurosensory Center

Comprehensive Examination for Aphasia

Either Temporal dysfunction

• Upper quadranopia

• Hallucination– Auditory,

– visual,

– olfactory and

– gustatory

• Altered visual perception– Object appear too large –

macropsia

– Too small – micropsia

– Too close or too far

– Unreal

• Auditory– Threshold of brief auditory

stimuli elevated

– Spoken words less clear

– Distorted words are less clear

– Difficulty in equalizing sound presented to both ear

– Rapidly presented words and number in both ear difficult to perceiving

• Dreamy state with uncinate seizure• Emotional and behavioral changes• Delirium

Bitemporal dysfunction

• Kluver Bucy syndrome (Animal)– Apathy and placidity – lack

of usual emotional reaction to stimuli

– Increased sexual activity– React to every visual

stimuli without recognizing it (Psychic blindness) oral exploration

• Sham rage• Korsakoff amnesic defect

• Human bitemporal lesion– Kluver bucy like + aphasia,

amnesia and bulimia

• Bilateral inferior and medial temporal lesion– Sham rage like – React to every stimuli with

extreme belligerence, screaming, cursing , biting and spiting

• Bilateral post cortical lesion– Cortical deafness – unaware

of deafness