1. Disorders of higher mental function
Amnesia, Aphasia,
Apraxia, Agnosia
Delirium & Dementia
2. Lateralization of brain function
Brain- two cerebral hemispheres, connected
by corpus callosum
95% of R-handed & 80% of L-handed people
have L hemisphere dominance for language
Lateralization-
L hemisphere- exact calculation;
language- grammar, vocabulary, literal
R hemisphere- approximate calculation;
language- intonation/accentuation,
prosody, pragmatic, contextual
3. Amnesia
Defect in memory
Organic or functional
Forms-
Anterograde-inability to memorize new things
Retrograde- inability to recall pre-existing memories
Types-
Immediate- few seconds- in delirium
Recent- minutes-days- in dementia/delirium
Remote- months-years- usually intact, till late dementia
Causes- delirium, post-traumatic, dementia
4. Types of amnesia
Delirium- loss of all memory with
loss of orientation to time, place, person
Post-traumatic- transient or permanent,
related to degree of injury
Transient global amnesia- impaired recent memory,
due to hippocampal dysfunction, complete recovery
within a day
Blackout- anterograde amnesia following binge
drinking
Korsakoff’s syndrome- due to thiamine-B1 deficiency,
severe memory loss with ataxia & confabulation
Drug-induced- midazolam & propofol- medical use,
recent memory loss of procedural events
5. Disorders of language
Language- a system of signs-symbols or gestures-
for encoding & decoding information
Aphasia- defective processing of linguistic
information- receptive and/or expressive
Speech- a modality to convey language
Dysarthria- defective articulation- pure motor,mainly
consonants; due to neurological injury affecting
V,VII,IX,X,XII cranial n.
Dysphonia- impaired sound production- mainly
vowels, due to defect in larynx/vocal cords
6. Aphasia
Causes- stroke, trauma, tumor, degenerative
Manifestations-
Inability to comprehend
Inability to speak spontaneously & fluently
Inability to form words or neologisms
Inability to read/write
Inability to name
Inability to repeat/persistent repetition
7. Testing for aphasia
Spontaneous speech- fluency, volume,
initiation, pauses
Naming- name objects
Repetition
Comprehension- point to objects named
Reading
Writing
8. Types of aphasia
Wernicke’s- temporal lobe
Defect in comprehension, fluent nonsensical speech
Broca’s- frontal lobe
Defect in expression- non-fluent, effortful, slow speech
Associated right face/arm hemiparesis
Conduction- arcuate fasciculus/auditory cortex
Poor repetition & naming, good comprehension, fluent speech
Global- Wernicke’s + Broca’s
Pure word deafness- impaired auditory comprehension
Pure word blindness- impaired reading comprehension
9. Apraxia- motor
Loss of ability to carry out learned
purposeful movements,
despite having desire & physical
ability to do so
10. Types of apraxia
Ideomotor- inability to carry out a motor
command, limb or buccofacial
Ideational- inability to create a plan for or an
idea of a specific movement
Constructional- inability to draw or construct
simple configurations
Speech- impaired ability to speak
Gait- impaired coordination of leg movements
11. Agnosia- sensory
Loss of ability to recognize-
object/person/shape/sound/smell-
without any sensory or memory loss
12. Types of agnosia
Alexia- inability to recognize text
Amusia- inability to recognize/appreciate music
Apperceptive- unable to distinguish visual shapes,
can’t copy shapes
Integrative- can identify elements/parts, but not
integrate them into whole
Prosopagnosia- inability to recognize familiar faces
Astereognosia- inability to recognize objects by
touch, based on its texture, size or weight
Visual- inability to recognize objects by seeing them