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SEMINAR ON: ‐
HIGHER MENTAL FUNCTIONS
SUBMITTED BY: ‐ PRIYA KUBERAN
MODERATED BY: ‐ Mr. KARTHIK BABU
CONTENTS
Introduction
The Cerebral Cortex
The Limbic System
The Reticular Activating System
Physiology of Consciousness, Thoughts & Memory
Higher Mental Functions
Consciousness
Attention
Speech
Orientation
Memory
Intellect
Emotions and Behaviour
Perception
References
HIGHER MENTAL FUNCTIONS INTRODUCTION
The importance of neurological examination in the diagnosis of the diseases of the nervous
system cannot be overemphasized. In no other branch of medicine is it possible to build up a
clinical picture so exact‐ with regard to localization and pathologic anatomy‐ as it is in neurology.
This requires not only diagnostic acumen but also a thorough knowledge of the underlying
anatomy and physiology of the nervous system, vascular supply, neuropathology, psychology,
psychiatry, neuropharmacology and related disciplines. In addition, neurologic practice demands
knowledge of neuroradiology, electroencephalography, electromyography, neurochemistry,
microbiology, genetics, neuroendocrinology, neurotransmitters, immunology, epidemiology and
an understanding of the neuromuscular system.
Following any major neurological condition, a detailed assessment of the patient helps us not
only in arriving at a diagnosis but also in planning the management. The subjective line of
questioning includes the demographic details of the patient, any other relevant personal
information as well as a detailed history. The objective data often includes a comprehensive
examination of the patient and the various aspects of neurologically relevant information that
would help us in arriving at a provisional diagnosis, later confirmed by radio diagnosis and other
such investigative procedures.
Before we venture into the evaluation of the higher mental functions, it is very important for
us to understand the anatomical structures involved. Also of prime importance is to understand
the physiological processes taking place in each of those structures.
THE CEREBRAL CORTEX
The functional part of the cerebral cortex is a thin layer of neurons covering the surface of all
the convolutions of the cerebrum. This layer is only 2‐5 millimeters thick with a total area of
about one quarter of a square meter. The total cerebral cortex contains about 100 billion
neurons.
Most of the neurons are of three types: ‐ 1) granular (also called stellate) 2) fusiform and 3)
pyramidal (named for their characteristic pyramidal shape). The sensory areas of the cortex as
well as the association areas between sensory and motor areas have large concentrations of
these granular cells, suggesting a high degree of intracortical processing of incoming sensory
signals within the sensory areas and association areas.
Anatomical and Functional Relations of the Cerebral Cortex to the Thalamus and Other Lower
Centers.
All areas of the cerebral cortex have extensive to‐and‐fro efferent and afferent connections
with deeper structures of the brain. It is especially important to emphasize the relation between
the cortex and the thalamus.
The cortex operates in close association with the thalamus and can almost be considered both
anatomically and functionally a unit with the thalamus i.e. the thalamocortical system. Almost all
sensory pathways from the sensory receptors and sensory organs to the cortex pass through the
thalamus with the principal exception of some sensory pathways.
Brodmann’s classification of the functional areas of the cerebral cortex 1) Frontal lobe
• Area 4: Primary motor cortex (planning and execution of movements)
• Area 6: Pre‐motor cortex (sensory guidance of movement; control of proximal
and trunk muscles of the body)
• Area 8 inferior part: Frontal eye field (Conjugates eye movement to
contralateral side)
• Parts of Areas 6 and 8: Supplementary Motor Area (Production of postural
responses; programming for complex movements)
• Areas 9, 10, 11, 12, 32, 46 & 47: Prefrontal cortex (visceral and emotional
activities; intellectual activities such as planning, judgement, problem solving and
conceptualization)
• Area 44: Broca’s area (Language production)
2) Parietal lobe
• Area 1, 2 & 3: Primary somtosensory area (tactile discrimination; position sense)
• Area 43: Primary gustatory area (perception of taste)
• Areas 5, 7, 39 & 40: Parietal association area (Input from visual, motor cortex
and all association areas; Function in hand performance)
3) Temporal lobe
• Areas 41 & 42: Primary auditory cortex (processing of auditory information)
• Area 22: Auditory association cortex (Language understanding and formulation)
• Areas 20, 21, 27, 28, 29, 30, 34, 36, 38: Limbic temporal cortex (visceral functions,
emotions, behaviour, long term memory)
4) Occipital lobe
• Area 17: Primary visual cortex (macular vision)
• Area 18 & 19: Parastriate and peristriate cortex (reception of visual information
from area 17 bilaterally; Complex processing for colour, movement direction,
visual interpretation)
Functions of specific cortical areas
Studies in human beings have shown that different cerebral cortical areas have separate
functions.
Functional areas of the brain as determined by electrical stimulation
Locations of major association areas of the cerebral cortex as well as primary and secondary
motor and sensory areas
The primary motor areas have direct connection with specific muscles for causing discrete
muscle movements. The primary sensory areas detect specific sensations – visual, auditory or
somatic – transmitted directly to the brain from the peripheral sensory organs.
The secondary areas make sense out of the signals in the primary areas. For instance, the
secondary sensory areas begin to analyze the meanings of specific sensory signals.
The association areas receive and analyze signals simultaneously from multiple regions of both
the motor and sensory cortices as well as from sub cortical structures
The most important association areas are: ‐
1) Parieto‐occipitotemporal association areas
• Analysis of spatial co‐ordinates of the body
• Computes the co‐ordinates of the visual, auditory and body surroundings.
• Wernicke’s area for language comprehension
• Area for initial processing of visual language (reading)
• Naming objects
2) Pre‐frontal association areas
• Carries out thought processes in our mind
• Planning motor activities
• Processing of information
• Elaboration of thoughts
• Stores short term basis “working memories” that are used to combine new
thoughts
• Broca’s area (provides the neural circuitry for word formation, plans motor
patterns for expressing individual words or even short phrases, works in close
association with the Wernicke’s area)
3) Limbic association area
• Primarily concerned with behaviour, emotions and motivation.
• Facial recognition: the occipital portion of the facial recognition area is contiguous
with the visual cortex while the temporal portion is in association with the limbic
system.
Functions of the corpus callosum and the anterior commissure
The corpus callosum and the anterior commissure mainly transfer thoughts, memories, training
and other information between the 2 cerebral hemispheres
The corpus callosum makes the information stored in the cortex of one hemisphere available
to corresponding cortical areas of the opposite hemisphere. It makes the two sides operate co‐
operatively at superficial subconscious level.
The anterior commissure connects the areas of two sides of the brain for emotions i.e. the
temporal cortices and adjacent areas. It plays additional role in unifying the emotional responses
of the two sides of the brain.
THE LIMBIC SYSTEM
The limbic system is a set of brain structures that form the inner border of the cortex that
supports variety of function including emotions, behaviour, long‐term memory and olfaction.
The parts of the limbic system are the amygdala, hippocampus, parahippocampal gyrus,
cingulate gyrus, fornix, hypothalamus and the thalamus. In addition the mammillary body,
pituitary gland, olfactory bulb and the orbitofrontal cortex also form the part of the limbic system.
The functions of the limbic system are as follows:‐
• Formation of long term memories and spatial memories
• Regulation of the autonomic nervous system via hormone production and release i.e.
homeostasis
• Affects and regulates blood pressure, heart rate, hunger, thirst, sexual arousal and
sleep/wake cycle.
• Olfaction
• Involved in reward, pleasure and addiction
• Involved in decision making
THE RETICULAR ACTIVATING SYSTEM
The reticular activating system (RAS) is an area of the brain (including the reticular formation
and its connections) responsible for regulating arousal and sleep‐wake transitions.
The RAS is composed of several neuronal circuits connecting the brainstem to the cortex.
These pathways originate in the upper brainstem reticular core and project through synaptic
relays in the rostral intralaminar and thalamic nuclei to the cerebral cortex.
The areas traditionally included in the RAS are:
• Mesencephalic nucleus
• Thalamic intralaminar nucleus
• Dorsal hypothalamus
• Tegmentum
The RAS consists of evolutionarily ancient areas of the brain, which are crucial to survival and
protected during adverse periods. As a result, the RAS still functions during the inhibitory periods
of hypnosis.
PHYSIOLOGY OF THOUGHTS, CONSCIOUSNESS & MEMORY
A thought results from a pattern of stimulation of many parts of the nervous system at the
same time, probably involving most importantly the cerebral cortex, thalamus, limbic system and
upper reticular formation of the brainstem. The stimulated areas of the limbic system, thalamus
and reticular formation determine the general nature of the thought giving it qualities such as
pleasure, displeasure, pain, comfort, crude modalities of sensation, localization to gross areas of
the body and other general characteristics.
However, specific stimulated areas of the cerebral cortex determine discrete characteristics of
the thought such as a) specific localization of sensation on the surface of the body and of objects
in the fields of vision. b) feeling of texture of silk c) visual recognition of a pattern on the wall.
Thus the specific interpretations by the areas of the cerebral cortex form the major aspect of the
higher mental functions.
Memories are often thought of as being positive recollections of previous thoughts or
experiences but the greater share of our memories are negative ones. The brain has the capability
to learn to ignore information that is inundated upon it due to sensory information from all our
senses i.e. information that is of no consequence. This results from inhibition of synaptic
pathways for this type of information; the resulting effect is called habituation. This is a type of
negative memory. Conversely, for incoming information that is of importance such as pain or
pleasure, the brain has a different automatic capability of enhancing and storing the memory
traces. This is positive memory, which results from facilitation of synaptic pathways due to a
process called memory sensitization.
Higher mental functions is a phrase that is used to encompass attention, thought, learning,
memory, understanding, perception, intelligence and language.
Includes every mental process that may be described as an experience of knowing including
perceiving, recognizing, conceiving and reasoning. It will also include functions like emotions and
behaviour.
These functions are tested in detail if the patient’s history or behaviour during the general
examination has provided a reason to suspect some defect. There are many sophisticated tests of
higher function, which can be applied to test intelligence as well as in disease. However, much can
be learned from simple bedside testing.
The purpose of testing is to: ‐
• Document the level of function in a reproducible way
• Distinguish focal and diffuse deficits
• Assess functional level within the community
• Plan a management protocol according to the functions preserved
• Correct the lost functions
Various regions in the brain are responsible for all the functions, either exclusively or in
coalition. The major areas responsible for the higher mental functions are the cerebral cortex
mainly, along with the thalamus, midbrain, the reticular activating system and the limbic system.
Obviously, if the patient complains of any alteration in the higher mental functions mentioned
above, one should proceed with a detailed evaluation of the same. In other patients, the history
often gives you clues about their mental function. History from the relatives and friends is often
essential, especially if there is an obvious dysfunction in speech.
When you test higher functions the tests should be applied as:
1) An investigative tool directed towards the problem
2) Screening tests to look for evidence of involvement of other higher functions.
Higher mental functions are broadly classified as cognitive functions and perceptive functions.
The two largest groups of people who acquire cognitive and perceptual problems are those who
have experienced stroke and traumatic brain injury.
Cognitive processes are generally defined as the abilities that enable us to “think” which
includes the ability to concentrate, remember and learn. Executive functions like ability to plan,
manipulate information, initiate and terminate activities & recognize errors are also referred to as
being cognitive in nature.
The cognitive functions are listed as below: ‐
⇒ Consciousness: wakefulness, awareness, alertness
⇒ Attention
⇒ Speech
⇒ Orientation
⇒ Memory
⇒ Intellect
⇒ Emotions and behaviour
Perception is the ability to transform information from the senses (touch, hearing, vision, smell,
taste & kinesthesia) and then use it to interact appropriately with the environment.
CONSCIOUSNESS
Consciousness is regarded as a state of awareness of self & surrounding and responsiveness to
external stimulation and need. This is the condition of the normal person when he is awake. In
this state the individual is fully responsive to a thought or perception and indicates by his
behaviour and speech the same awareness of self and environment as that of the examiner
This normal state may fluctuate during the day from one of keen alertness or deep
concentration to one of mild general inattentiveness, but even in the latter circumstances, the
normal individual can be brought immediately to a state of full alertness and arousal.
The level of consciousness is evaluated by attempting to wake the patient first with verbal
commands, then with non‐noxious stimuli and then with noxious one.
Consciousness mainly consists of the following components:‐
• Awakeness – is the capacity to maintain a state of wakefulness in which the individual is
ready and able to respond to events in the environment
• Awareness – is a state or ability to perceive, to feel or to be conscious of events, objects
or sensory patterns i.e. human’s perception and cognitive reaction to a condition or event.
• Alertness – is a state when the patient is clearly awake and responds fully & appropriately
when spoken to or to varying stimuli.
The level of consciousness in any patient is usually evaluated using the Glasgow Coma Scale
(GCS). GCS was initially used to assess level of consciousness after head injury, but the scale is
now used by first aid, emergency medical services, and doctors as being applicable to all acute
medical and trauma patients. In hospitals it is also used in monitoring chronic patients in intensive
care.
The least score in the GCS is 3 whereas a score of 15 indicates normal level of consciousness. A
score of ≤8 indicates severe injury; a score of 9‐12 indicates moderate damage while a score of
≥13 indicates mild injury.
Score given: ‐ 4, 3, 2, 1 (best response to the no response)
Score given: ‐ 5, 4, 3, 2, 1 (Oriented to no response)
Score given: ‐ 5, 4, 3, 2, 1 (Obeys command to no response)
Dysfunctions: ‐
Depending on the GCS scores and response to various stimuli given, the following deviations from
the normal can be observed.
1) Coma: The patient appears to be asleep and is at the same time incapable of being
aroused by external stimuli or inner need;
• Reflexes may be suspended temporarily and tone might be diminished;
• Respiration may be slow, rapid, periodic or deranged;
• The depth of coma is very useful in assessing the direction in which the disease is evolving.
2) Persistent vegetative state: It is a condition of patients with severe brain damage who
were in coma but progressed to a state of partial awareness;
• The patients may blink in response to light;
• Their eyes might seem to follow objects;
• But the patient remains inattentive, does not speak and shows no signs of
awareness of environment.
3) Stupor: It is a state in which patient can be aroused only by repeated and vigorous stimuli
• The patient might open his eyes and look at the examiner
• Response to spoken command is either absent or slow/inadequate
• Restless motor activity
• Reduction in natural shifting in positions
4) Drowsiness: It is an inability to sustain a wakeful state without the application of external
stimuli
• Eyelids droop without closing completely
• Jaw and limb muscles are slack
• Limbs are relaxed
• This state is indistinguishable from light sleep
• Slow arousal elicited by speaking to the patient or applying tactile stimulation.
ATTENTION
Attention and concentration are often used interchangeably, but concentration is narrower
in meaning than attention. Attention is the capacity to detect and orient to stimuli and
information from the environment.
Attention is mainly of 4 types and each of them has to be assessed differently and separately.
• Sustained attention: is the capacity to concentrate on relevant information during a
continuous activity; also referred to as attention span.
‐ Can be examined by determining how long the patient is able to maintain attention
on a particular task (time on task)
‐ The patient often complains of “drifting off” while performing any activity and usually
occurs following severe head injuries.
• Selective attention: is the capacity to focus on a given activity or occupation despite
environmental, visual and auditory stimuli; a problem with this kind of attention is
often referred to as distractibility.
‐ Can be examined by asking the patient to do a particular task with a few
distracting factors acting in the background, for instance, music or television.
‐ The patient will often demonstrate difficulties in doing any other activity while he
is talking to the therapist.
• Alternating attention: is the capacity to move flexibly between tasks and respond
appropriately to the demands of each task
‐ Can be assessed by requesting the patient to alternate back and forth between two
different tasks, for instance, add the first 2 pair of number and then subtract the next
pair of numbers and so on.
‐ Patients will often have difficulties with more complex activities of daily living such as
cooking a meal or driving.
• Divided attention: is the capacity to respond simultaneously to two or more tasks.
‐ Can be assessed by asking the patient to perform 2 or more tasks together, for
instance, talks on the phone while walking
Documentation of attention assessment should include: ‐
‐ Type of attention impaired
‐ Attention span
‐ Specific component of attention examined
‐ Slowness or hesitation in the response
‐ Duration and frequency of episodes of inattention
‐ Amount of required redirection to the task.
SPEECH Traditionally, language disorders have been divided into specific categories that originally
were thought to be due to damage to focal brain regions, usually different areas of the left
hemisphere in right‐handed patients. With current neuroimaging, brain regions giving rise to
specific types of language disorders have been found to be much larger than previously thought
and show considerable overlap. Thus fine subdivisions of language currently are of limited clinical
usefulness.
Speech defects fall into four main types:
1. Dysphasia (or if complete, aphasia)
2. Dysarthria
3. Dysphonia (aphonia)
4. Mutism
Before any detailed analysis is attempted the disturbance must be placed in one of these groups.
Methods of differentiation
• If the patient is conscious but making no attempt to speak or make sound, this is mutism. It
is usually part of a psychological disorder but may be seen in lesions affecting the anterior
part of the walls of the 3rd ventricle. Total mutism is sometimes due to profound Broca’s
aphasia, but the patient then gives the impression of both paying attention and of trying
to communicate even if unable to do verbally.
• If the patient, though speaking, fails to produce any volume of sound, or merely whispers,
this is aphonia. It is due to disorders of the larynx and the vocal chords.
• If the volume of sound and the content of speech is normal, but the articulation and
enunciation of the individual words and phrases is distorted, this is dysarthria. It is a
disorder of control of muscles producing speech, the lesion lying in upper or lower motor
neurons, cerebellar system or the muscles themselves.
• If the patient is failing to put into properly constructed words or phrases the thoughts he
wishes to express, even if articulation is adequate this then is dysphasia. The lesion is one
of the highest mechanisms of speech and must be in the dominant cerebral hemisphere
Dysphasic states also include disturbances of writing (dysgraphia), and failure to
comprehend the spoken word (receptive dysphasia) or the written word (dyslexia)
If dysphasia or dysarthria is present then the patient needs a detailed analysis.
Dysarthria can be examined by:
a) Listening to the clarity of the patient’s pronunciation
b) Asking the patient to repeat certain phrases
c) Asking the patient to read a paragraph from a book
d) Asking him to count successively to 30 or above to test for muscle fatigue
Listen to the words, whether they slur into one another; whether the rhythm is jerky, explosive or
monotonous; whether the speech is too loud or too soft; whether particular letters present
particular difficulty; whether there is a nasal tone to the speech; whether the disturbance is
constant throughout, variable or increasing towards the end of each sentence or on prolonged
counting.
Types of Dysarthria
1. Spastic dysarthria – caused by bilateral UMN disease; tongue is small and spastic; slurred
speech; limited mouth excursions; jaw jerks and palatopharyngeal reflexes are
exaggerated.
2. Rigid dysarthria – result of extra pyramidal lesions producing rigidity of face or tongue
muscles without wasting or exaggeration of reflexes; impossible for the patient to
articulate test phrases; monotonous speech; tongue and lips excursions are greatly
reduced.
3. Ataxic dysarthria – due to inco‐ordination of muscles of speech; speech is irregular, slurred
with jerky rhythm, staccato and scanning.
4. Myasthenic dysarthria
5. Dysarthria in dysphasic states.
Examination of speech
• If speech seems to be hindered, take history from relatives or friends.
• Establish if the patient is right handed or left handed
• Find out the patient’s language and education level
• Assess understanding by asking the patients simple questions
• Assess spontaneous speech
• Assess repetition
• Ask the patient to name different objects
• Test the patient’s ability to read and write
Abnormalities of speech:
I. Broca’s aphasia
‐ Also called as expressive/motor/non fluent aphasia;
‐ Disproportionate difficulty in formulation of sentences and speaking them aloud
compared with comprehending verbal and written communication;
‐ Some patients cannot speak at all;
‐ Speech melody is distorted; Sounds are more guttural and is often more explosive;
‐ The lesions in this kind of aphasia is often found in the Broca’s area (area 44);
‐ Prognosis depends on the cause and the lesion size.
II. Wernicke’s aphasia
‐ Also called as receptive/sensory/fluent aphasia
‐ Severe impairment in comprehension of verbal and written communications with the
maintenance of fluent speech;
‐ Patients are usually unaware of their comprehension difficulties and may appear
attentive and co‐operative.
‐ Speech content does not make sense; patient cannot repeat words or phrases
‐ Lesions are present in the Wernicke’s area (area 22)
‐ Many recover reasonable verbal, comprehension and usable appropriate speech.
III. Global aphasia
‐ Loss of all speech and language function
‐ Loss of comprehension of verbal and written language along with inability to
communicate in speech
‐ Patients do not obey verbal commands; cannot repeat phrases or produce meaningful
speech
‐ Lesions around the central regions surrounding the Sylvian fissure;
‐ And almost always produces an accompanying hemiparesis, hemisensory loss and
often a homonymous hemianopia.
IV. Conductive aphasia
‐ Also called as associative/commissural/deep aphasia.
‐ Patient is fluent and comprehension is unaffected but the act of repetition is poor.
‐ Lesion is normally, which interrupts the conduction between Wernicke’s area and
Broca’s area.
V. Transcortical aphasia
‐ Is mainly of two types
‐ Posterior isolation syndrome: patients are fluent but difficulty with comprehension;
repetition is better than spontaneous speech.
‐ Anterior isolation syndrome: patients are aphasic but preservation of ability to
repeat; no fluency in spontaneous speech.
‐ The perisylvian language area is disconnected from the rest of the brain.
VI. Nominal aphasia
‐ Also called as anomic/amnesic/amnestic aphasia
‐ Deficit in the naming ability with the preservation of other language functions
‐ Patients are fluent with good comprehension and good ability to repeat.
‐ It is the most common type of aphasia but the least specific.
‐ The features are normally seen in every type of aphasia and hence the term can be
used only when all the other forms are completely ruled out.
‐ Lesions are normally present in the lower temporal lobe.
VII. Subcortical aphasia
‐ Occurs if the lesions are present in regions like the thalamus, the caudate nucleus,
putamen or the internal capsule of the language dominant hemisphere
‐ Anterior syndrome: patients have low dysarthric speech with preserved
comprehension and poor naming
‐ Posterior syndrome: patient has fluent speech without dysarthia, poor comprehension
and poor naming.
‐ Repetition is preserved in both the syndromes
VIII. Amusia
‐ It is the loss of musical ability i.e. either production or comprehension of music
‐ Melody and rhythm might be affected.
Some of the lesser known abnormalities may be:‐
• Paraphrasia – using words which are nearly right
• Neologisms – using words that do not exist
• Perseveration – involuntary repetition of words after having used them once.
• Circumlocution – using long sentences to overcome failure of finding one word
ORIENTATION
It is the patient’s ability to be aware of time, person and place.
For the assessment of person related orientation
• Ask the name of the patient
• Ask the age
• Ask his middle name
• Ask the names of the relatives around him and the way they are related to him.
For the assessment of place related orientation
• Ask the patient where he is right now?
• Name of the city, state
• Ask him his address
For the assessment of time related orientation
• Ask him the date, day, time.
• Ask him whether it is morning/afternoon or evening
• Ask him the season/ the year
• Ask him since how long has he been admitted in the hospital
Any abnormality in the above examination can be termed as disorientation. It can be graded and
any management can be modified accordingly.
MEMORY
Memory is the capacity to store experiences and perceptions for recall and recognition.
Memory is broken down into 3 activities
• Acquisition/learning
• Storage/ retention
• Retrieval/ recall
Classification of memory based on sensory modalities
1. Olfactory memory
2. Gustatory memory
3. Auditory memory
4. Visual memory
5. Tactile/ kinesthetic memory
Temporal classification of memory
1. Immediate memory: also called as working memory
Mainly assessed based on the patient’s ability to repeat words or sentences as soon as
they are uttered by the examiner.
2. Short term memory
These are the speech, sight and other senses based information which can be recalled a
little while they are acquired.
3. Long term memory
Long‐term memory is mainly of two types:
Declarative memory – this is the memory that stores facts an events.
Episodic memory is the personally experienced events.
Semantic memory is the information about famous
people, events and facts.
Procedural memory – this is the knowledge of procedures, rules and skills.
This memory is very rarely affected in any neurological
condition.
Evaluation of memory
a) Immediate recall
Name and address test: tell the patient that you want him to remember a name
and address. Use the type of address that the patient would be familiar with. Note
how many errors are made in repeating it and how many times you have to repeat
it before the patient repeats it correctly
Immediate registration would mean that the patient’s immediate memory is
normal
Alternate test: Babcock sentence
Digit span forward is a good test of attention, concentration, and
immediate memory. The examiner gives the patient a series of
numbers of increasing length, beginning with 3 or 4, at a rate of about
one per second; the patient is asked to repeat them. The numbers
should be random, not following any identifiable pattern, e.g.,
a phone number.
b) Short term memory
About 5 minutes after asking the patient to remember the name and address ask
him to repeat it. Note how many mistakes he makes. The 5 minutes interval can be
used in testing other mental functions
c) Long term memory
Test factual knowledge you would expect the patient to have. This will vary
according to each patient’s history. Ask about the events happened in his life like
his wedding date, birth of his children, name of his school/ university etc.
Any obvious abnormality in any of the above examinations can be termed as
amnesia. Any psychological cause has to be ruled out in order to term it as an
organic amnesia.
Amnesia can be of 2 types
a) Retrograde amnesia: it is the inability to use information that the patient had
before the injury
b) Anterograde amnesia: it is the inability to acquire any new information after
the injury.
INTELLECT
Intelligence is a general mental capability that includes reasoning, planning, solving
problems, thinking abstractly, comprehending complex ideas, learning quickly and learning
from experience.
Although imperfect, intellectual reasoning is usually represented by an intelligence
quotient (IQ) obtained from appropriate testing instruments. An IQ score is the
performance on a standardized test adjusted to the individual’s chronological changes.
The commonly used tests to assess intelligence are:‐
• Wechler Adult Intelligence Scale
• Wechler intelligence scale for children
A commonly used rapid screening test is called the Folstein Mini Mental Status Exam.
Test scores range from 0 to 30 and scores below 24 are an indication of moderate‐to‐
severe dementia, depending on patient age and education level. The test has good
sensitivity (90%) but poor specificity (60%) for dementia because it is relatively insensitive
to mild cognitive dysfunction,
especially in higher functioning patients.
Some of the other tests for intelligence commonly used are information‐
memory‐concentration test, orientation‐memory‐concentration test, mental
status questionnaire, short portable mental status questionnaire (SPMSQ),
abbreviated mental test (AMT), neurobehavioral cognitive status
examination, short test of mental status, Cambridge cognitive examination,
and cognistat
Calculations Ability to count and calculate may be evaluated by asking the patient to count forward or
backward, to count coins, or to make change. Dyscalculia is characteristic of lesions of the
dominant parietal lobe, particularly the angular gyrus. Calculations may be more formally tested
by having the patient perform simple arithmetic problems, either mentally or on paper. The
ability to calculate depends on the patient's native intelligence, her innate number sense or
mathematical ability, and her educational level. If the patient is initially successful with very
simple calculations, she should be pressed to at least a moderate level of difficulty, e.g., 12 × 13,
17 + 11, and 26 + 14.
Impaired calculating ability may occur with posterior dominant hemisphere lesions, either as
an isolated defect or as part of Gerstmann's syndrome. These patients have a true anarithmetria,
a primary disturbance of calculating ability.
Abstract Thinking
The ability to think abstractly is typically tested by asking the patient to describe similarities
and differences and to interpret proverbs and aphorisms. Impaired abstraction occurs in many
conditions, but is particularly common with frontal lobe disorders.
Insight and Judgement Determine if the patient has any insight into her illness and the implications of any functional
impairment. Historical information from family members about the patient's actual judgment in
real‐life situations may be more enlightening than any artificial constructs. Patients with no
concern about their illness have impaired
judgement. Patients with poor judgment may behave impulsively or inappropriately during the
examination.
Many neurological conditions may impair judgment, particularly processes that affect the
orbitofrontal regions. Lack of insight into the illness, to the point of denial of any disability, may
occur with nondominant parietal lesions.
EMOTIONS AND BEHAVIOUR
These two entities are often affected due to all the other impairments associated with any
neurological condition. But some lesions in specific parts of the brain have been known to cause
certain changes in the emotional and behavioral pattern.
For instance, a patient with a prefrontal lobe lesion often tends to snow a lack of ambition,
sense of personal responsibility, social propriety and self‐monitoring. Similarly a patient with a
limbic lobe lesion has been known to develop flat emotional effect and tends to be emotionally
unstable.
(Lhermitte first described utilization behavior and imitation behavior in patients with frontal
lobe damage. Patients with utilization behavior will reach out and use objects in the environment
in an automatic manner and are not able to inhibit this response. Similarly, patients with imitation
behavior will imitate the examiner's
gestures, even if specifically told to refrain from doing so.)
Apart from the above‐mentioned ones, the other emotional and behavioural dysfunctions can
be: ‐
• Tactlessness, irritability, antisocial behaviour.
• Environmental dependency
• Mood disorders (depression, lability, mania)
• Obsessive compulsive disorder
• Impaired motivation
• Apathy
• Poor response inhibition.
PERCEPTION
Perception is the integration of sensory impressions into information that is psychologically
meaningful.
Perceptual deficits do not lie in the sensory ability itself but rather with the individual’s ability
to interpret the sensation accurately and therefore respond appropriately.
Perception is broadly classified into: ‐
• Body scheme and body image
Body image is the visual and mental image of one’s body
Body scheme is the postural model of the body including the relation of body parts to
each other and to the surroundings
Disorders: ‐
‐ Unilateral neglect
‐ Anosognosia
‐ Somatoagnosia
‐ Right‐left discrimination
‐ Finger agnosia
• Spatial relations
It denotes the relationship between self and two or more objects
Disorders: ‐
‐ Figure‐ground discrimination
‐ Form discrimination
‐ Position in space
‐ Topographic disorientation
‐ Depth and distance perception
‐ Finger agnosia
• Gnosia
It is the ability to recognize or make sense of incoming information through sensory
capacities
Disorders: ‐
‐ Visual agnosia
‐ Auditory agnosia
‐ Tactile agnosia
• Praxia
It is defined as the voluntary skilled learned movement
Disorders: ‐
‐ Ideomotor apraxia
‐ Ideational apraxia
‐ Constructional apraxia
‐ Buccofacial apraxia
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