Explaining various psychiatric disorders and normal psychological and neurological functions as a function of various lobes of cortex

1. Moderator
Dr. Bandna Gupta, MD
Dr. Adarsh Tripathi, MD
Presenter
Dr. Aditya Agrawal, JR1

2.  Introduction
 Frontal lobe :
 Areas, functions, tests and implications
 Parietal lobe :
 Areas, functions, tests and implications
 Temporal lobe :
 Areas, functions, tests and implications
 Occipital lobe :
 Areas, functions, tests and implications
 Summary
 References

3.  Cerebrum - The largest
division of the brain. It is
divided into two hemispheres,
each of which is divided into
four lobes.
 Cerebral Cortex - The
outermost layer of grey matter
making up the superficial
aspect of the cerebrum.
 Gyri – Elevated ridges
“winding” around the brain.
 Sulci – Small grooves dividing the
gyri

5. AREAS
 Primary motor area (BA 4)
 Premotor area (BA 6)
 Supplementary motor area
 Broca’s area
 Frontal eye field (BA 6,8,9)
 Prefrontal cortex
Pressman, P., & Rosen, H. J. (2015). Disorders of Frontal Lobe Function. Neurobiology of Brain Disorders, 542–557. doi:10.1016/b978-0-12-398270-4.00033-1

6.  Primary motor cortex
 Execution of motor movement
 Premotor cortex
 Planning and programming of motor
movements;
 sequencing and organization of motor
movements
 Supplementary motor cortex
 Mediate internal needs with external
demands in order to initiate motor
programme;
 intentional preparation for movement;
 procedural memory
 Frontal eye field
 Voluntary eye movement;
 select target and command
movements
 Motor speech area (Broca’s area)
 Expressive speech
 Prefrontal Cortex
 Human personality
 Anticipation
 Planning
 Initiative
 Memory
 Control of decision making

7. DORSOLATERAL PFC
 Control behavior
 Working memory & Long-term memory
formation
 Preparation and execution of act (executive
functions)
ORBITOFRONTAL PFC
 Decision making
 Flexible Control of excitation & inhibition
Emotional control of behaviour
 Reward
 Implicated in Obsessions, impulsivity and
aggression

•

8.  Primary motor area
 Motor strength of hand grip
 Motor speed as in finger tapping
 Premotor area
 Sensory motor ability : touch each finger to
thumb
 Apraxia : blow a kiss or demonstrate the use
of shovel
 Supplementary motor area
 Frontal release signs - Primitive reflexes
(grasp, sucking, palmo mental reflex)
 Broca’s area
 non fluent, dysarthric speech

9.  Frontal eye field
 Pursuit movement: Follow hand movements from
left to right and up and down
 Saccadic movement: Ask him to move eyes from
left to right and up and down
 DLPFC
 Executive functions tests such as (COWAT test,
FAS test, Trail making test, wisconsin card
sorting test, Luria test, visual pattern completion
test, Alternating Sequencing Task, Tower of
London test )
 OFC
 Go-No Go test, Stroop test
 Other tests
 Judgement, insight, Social appropriateness

10. • Frontal Assessment Battery:
• Similarities (conceptualization)
• Lexical fluency (Mental flexibility)
• Motor series (programming)
• Conflicting instructions (sensitivity to interference)
• Go-no go task (inhibitory control)
• Prehension behaviour (environmental autonomy)
Dubois, B. ; Litvan, I.; The FAB: A frontal assessment battery at bedside. Neurology. 55(11): 1621- 1626, 2000

11. PREMOTOR SYNDROME
 No paralysis
 Loss of fine motor function
 Spasticity, rigidity, grasp reflex in
severe damage
MEDIAL PREFRONTAL SYNDROME
 Difficulty in initiation & performance
of limb, eye, speech movements
 Hypokinesia, akinetic mutism-
cingulate lesion
 Gegenhalten, waxy flexibility
 Alien limb
 Pseudo-depression: adynamia with
disorders of attention and motility
Pressman, P., & Rosen, H. J. (2015). Disorders of Frontal Lobe Function. Neurobiology of Brain Disorders, 542–557. doi:10.1016/b978-0-12-398270-4.00033-1

12. DISORDERS OF ABSTRACT THINKING
 Difficulty on conceptual task
 Unable to inhibit customary mode of
responding due to interference with
voluntary control of inhibition
LANGUAGE DISORDER
 Impaired ability to construct original,
improvised, extended speech
 Broca’s aphasia/ Expressive aphasia-
agrammatism
 Frontal adynamic aphasia/ Prefrontal
aphasia
 Hesitant speech
 Paraphasias (incorrect pronounciations)
 Drop grammatical functions

13. BEHAVIOURAL SYMPTOMS
Utilization behaviour/ aliean hand/
magnetic apraxia/ compulsive
utilization
Perseveration behaviour
Inappropriate aggression
Inappropriate sexual behaviour
Inappropriate humour and telling of
pointless and boring stories referred as
Witzelsucht

14.  I/L Optic Atrophy
Damage to CN II passing below the
frontal lobe
 I/L Anosmia
Damage to CN I coming out of cribriform
fossa
 Sphincteric disturbance
Urinary incontinence in socially
inappropriate situations (loss of social
control)

15. ORBITOFRONTAL SYNDROME
Disinhibition-hallmark
Motor Disinhibition: Hyperactivity and
increased speech, perseveration
Instinctive Behaviour: Hypersexuality,
hyperphagia
Intellectual :Grandiose and paranoid
ideas, flight of ideas.
Sensory disinhibition :Visual and
auditory hallucinations
Emotional disinhibition: Euphoria,
elation, and irritability
Pathological joking (witzelshucht)
Impairment in
personality
social behaviour
spontaneous arousal of attention
arousal/motivation
ability to focus attention,
initiating behaviour
goal directed and purposeful
behaviour
ability to change mental set

16. DORSOLATERAL PREFRONTAL
SYNDROME
(Area 8,9,10,46)
Attention disorder-
dysexecutive
syndrome
Low arousal or
alertness
Difficulty in Sustained
Attention
Digit vigilance test
Deficits in Selective
Attention
trail making test
Visual Search Visual & pictorial
scanning test
Memory dysfunction
Difficulty in
voluntary learning
Loss of recent
memory
Impaired working
memory
N back test, Delayed
response ability test
Planning
dysfunction
Failure to formulate
and carry out new
plans
Tower of London test
Lack of anticipation
of consequence

17.  Depression- Increased Rt. Frontal and decreased Lt. Frontal
metabolic activity and vice-versa. Target for neuromodulation.
 Schizophrenia- Hypofrontality associated with disturbance of
socialization and personality. Orbitofrontal dysfunction leading to
impulsivity (also found in OCD, Impulse control disorder and
Borderline personality). Correlation with Dorsolateral prefrontal
cortex dysfunction.
 Alzheimer- processing of short term memory in neocortex.

18.  Autism- Hypofronatilty leading to inattention, difficulty in abstract
thinking.
 Catatonia – gegenhalten, waxy flexibility, mutism, apathy – medial
frontal lobe syndrome, automatic obedience
 OFC Syndrome – Resembles manic/hypomanic state

19.  Superior temporal lobe
 Areas 41,42,22
 Primary auditory area (BA 41)
 Auditory Association area (BA 42)
 Higher Auditory Association Area (BA
22)
 Middle temporal lobe (BA 21)
 Inferior temporal lobe (BA 20)
 Temporal pole (BA 38)
 Rhinal cortex
 Fusiform gyrus
 Parahippocampal gyrus

20.  AUDITORY – primary & Association
 OLFACTORY - primary & Association
 VISUAL
 Object and face recognition
 Perception of motion
 Meyer’s fibres (inferior optic radiation)
 MEMORY
 EMOTIONAL & SOCIAL
 LANGUAGE AREAS
 Wernicke's area- posterior temporal lobe of
usually the left hemisphere
 AFFECTIVE LANGUAGE AREAS
 Involved in the nonverbal emotional
components of language - present in the
hemisphere opposite Brocas's and
Wernickes's areas.

21.  Memory testing
 Immediate, recent, remote
 wechsler’s memory scale
 New learning ability
 Four unrelated words
 Verbal story recall
 Visual memory (REY COMPLEX FIGURE/ REY-
OSTERRIETH TEST
 Language testing
 FAS test
 Naming word finding
 Auditory processing (dichotic words and
melodies)
 Visual processing (Mooney closure test)

22. DISORDERS OF AUDITORY AND VISUAL PERCEPTION:
 Lesions of the left superior temporal gyrus- difficulty in speech
perception, discriminating speech and the temporal order of sounds is
impaired.
 Lesions of the right superior temporal gyrus- disorders of perception of
music with inability to discriminate melodies and produce prosody.
 Lesions in inferior temporal cortex- inability to recognise faces
(prosopagnosia).
 Disturbance of visual and auditory input selection- impairment of
working memory and judgement about the recency of events

23. DISORDERS OF MEMORY
 There is complete anterograde amnesia following bilateral removal of
medial temporal lobes, including hippocampus & amygdala.
 The left side is responsible for verbal material and the right for non-
verbal memory such as faces, tunes and drawings.
APHASIA
 Wernicke’s/ Fluent aphasia

24. KLUVER-BUCY SYMDROME:
 Due to a bilateral destruction of the amygdaloid body and inferior
temporal cortex.
 Visual agnosia
 Hypermetamorphosis (to touch every visual stimulus)
 Hyperorality
 Hypersexuality
 Inability to recognize emotional significance of visual stimuli
 Diminished fear response/ placidity
 Amnesia.

25. TEMPORAL LOBE EPILEPSY
 Varied and complex aura, memory impairment, perceptual disturbances,
depersonalization, anxiety, dream like state,
 Autonomic dysfunction, automatism and stereotypies,
 Post ictal – psychotic illness
 Inter ictal – personality changes

26. TEMPORAL LOBE PERSONALITY CHANGES (Geschwind Syndrome)
 hyper-religiosity,
 hypergraphia,
 hyposexuality,
 Homourless, Excessive philosophical content (Left > Right)
 Irritability, hostility and aggression
 Excessive emotionality from sadness to elation (Right > left)
 Overlapping symptoms in TLE and FTD

27.  Schizophrenia- Temporo-parietal in auditory hallucinations in
schizophrenia.
 Anxiety disorders- medial temporal involvement such as PTSD.
 Hippocampus- Alzheimers disease
 Temporal lobe epilepsy- hallucinations, memory impairment, depression
and Geschwind syndrome

28.  Post central gyrus/ primary
sensory cortex
 Somasthetic association
area
 Superior parietal lobule
 Inferior parietal lobule
o Angular gyrus
o Supra marginal gyrus
o Precuneus
o Paracentral lobule

29.  Primary somasthetic area
 Body image representation
 Somasthetic association area
 body in space
 tactile discrimination
 Superior parietal lobule (5,7):
 somasthetic integration
 Visual spatial properties
 Visual attention
 Motivation and grasping functions
 voluntary motor movement
 influence of emotion, attention and
motivation on behaviour

30. Spatial information processing:
 Posterior parietal cortex
 Object recognition
 object identification
 Guidance of Movement
 Sensorimotor Transformation
Medial parietal region (MPR)
 Spatial Navigation
 Cognitive spatial map
 INFERIOR PARIETAL LOBULE
 Involved in reading, calculations
 Visual processing areas:
 Control of saccadic eye movements
 Visual control of grasping
 Visually guided grasping movements

31.  Sensory testing
 Two-point discrimination
 Stereognosia and graphesthesia
 Calculations
 Language testing
 Comprehension (verbal and written)
 Praxis - serial movement copying
 Constructional apraxia
 reproduction drawings,
 drawing to command,
 block designs

32.  Spatial processing
 Left right discriminations self, cross
command self, examiner, cross command
examiner)
 Geographical localization
 Hemineglect
 Simultaneous bilateral stimulation
 Line bisection
 Finger agnosia (verbal, nonverbal)

33.  Post central gyrus/ primary sensory cortex
 Localization of touch
 Two-point discrimination
 Stereognosia and graphesthesia
o Calculation
o Right left orientation (Finger Agnosia)
o Geographical orientation
o Constructional ability tests
o Hemispatial neglect

34.  Lesions to the postcentral gyrus produce:
 Abnormally high sensory thresholds
 Impaired position sense
 Deficits in stereognosis, or tactile perception
 Afferent paresis : Clumsy finger movements due to lack of feedback about finger
position
 Astereognosis
 Simultaneous Extinction
 Agnosias
– Asomatognosia: Loss of knowledge or sense of one’s own body
– Anosognosia: Unawareness or denial of illness
– Anosodiaphoria: Indifference to illness
– Asymbolia for pain: Absence of normal reactions to pain
– Finger Agnosia: Unable to identify own fingers when asked to point to them.

35. Symptoms of Posterior Parietal Lobe Damage
 Contralateral Neglect
– Lesion most often in the right inferior parietal lobe
–Defective sensation or perception and attention
 Deficits in drawing appear after damage to the right parietal lobe
 Disengagement : Shifting attention from one stimulus to the next
 Gerstmann Syndrome
– Finger agnosia
– Right-Left Confusion
– Agraphia
– Acalculia
– Results from a left parietal lobe lesion

36.  Acalculia
 Language difficulties – Words have spatial organization • “tap” vs. “pat”
 Movement Sequencing
 hemianopia
 Ideomotor Apraxia

37.  No clear division on lateral
surface of brain
 Medial Surface
– Parieto-occipital surface
– Calcarine Sulcus:
 Contains much of primary visual cortex
 Separates upper and lower visual fields
 Ventral Surface
– Lingual gyrus
– Fusiform gyrus

38.  Vision begins in V1 (primary
visual cortex), that is
heterogeneous, and then travels
to more specialized cortical zones
 Selective lesions up the hierarchy
produce specific visual deficits
 Lesions to V1 are not aware of
seeing

39.  Snellen chart – visual acuity
 Object recognition and naming
 Face recognition – prosapgnosia
 Cookie theft picture - simultagnosia

40.  C/L Homonymous hemianopia
with macular sparing
 Visual illusions/ hallucinations
 Colour agnosia, anomia
 Object Agnosia
– Apperceptive Agnosia
– Simultagnosia
– Results from bilateral damage to the
lateral parts of the occipital lobes
 Associative Agnosia
– Results from lesions to the anterior
temporal lobes
 Prosopagnosia
 Alexia
Form of object agnosia - inability to construct
perceptual wholes from parts
Form of associative agnosia - word memory is
damaged or inaccessible
Results from damage to the left fusiform and
lingual areas

41. Network Brain Areas Function
Central executive DLPFC,
Lateral Post. Parietal cortex
Attention
Working memory
Decision making
Salience ACC,
VMPFC
Detection of relevant
incoming stimuli
Default Medial PFC
PCC
Medial post. parietal cortex
Internal cognition
Theory of mind

42. LOBE FUNCTION ASESSMENT
PSYCHIATRIC
IMPLICATION
FRONTAL
Movement planning
Execution
Speech, memory
Attention emotion
Stroop test Wisconsin test
Tower of London
Trail making
Word generation
Go-no-go test
Schizophrenia
Alzheimer
ADHD
Autism
Depression
TEMPORAL Auditory
Visual
Olfactory
Memory
Emotional
Word fluency
Digit span
Route learning
Figure reproduction
Schizophrenia
Anxiety disorder
Alzheimer
Temporal lobe epilepsy
PARIETAL Somatoperception
Visual processing
Movement sequencing
Calculation
2 point discrimination
Bender gestalt
Koh’s block
Kimura box
Alzheimer
Metabolic
Enecephalopathy
Gerstmann syndrome
OCCIPITAL Vision Vision assessment Visual agnosias

43.  Kaplan & Sadock's comprehensive textbook of psychiatry (10th edition)
 Bickerstaff’s neurological examination in clinical practice (7th edition)
 David, Fleminger – Lishman’s organic Psychiatry, 4th edition
 Snell’s Clinical Neuroanatomy,7th edition
 Pressman, P., & Rosen, H. J. (2015). Disorders of Frontal Lobe Function.
Neurobiology of Brain Disorders, 542–557.