R W N

8 Alexia without agraphia Occipitotemporal region – + +

9 Alexia with agraphia Left angular gyrus – – +

10 Nominal/anomic/amnesic Temporoparietal + + –

Lesions in the anterior limb of internal capsule/basal ganglia can produce Broca’s like aphasia.

Lesions in the thalamus can produce Wernicke’s like aphasia.

Most common type of aphasia seen in stroke: Broca’s aphasia.

Overall most common type of aphasia is anomic aphasia.

DYSARTHRIAS

Production of sounds requires:

Normal respiration

Muscles of articulation (labial, lingual, and palatal muscles)

Phonation (by larynx)

Resonance (by nasopharynx).

Articulated Sounds

Articulated labials (b, p, m, and w) are formed principally by the lips.

Modified labials (o and u, and to a lesser extent i, e, and a) are altered by lip contraction.

Labiodentals (f and v) are formed by placing the teeth against the lower lip.

Linguals are sounds formed with tongue action.

T, d, l, r, and n are tongue point, or alveolar sounds formed by touching the tip of the tongue to

the upper alveolar ridge.

S, z, sh, zh, ch, and j are dentals, or tongue blade sounds.

To hear distorted linguals, place the tip of your tongue against the back of your bottom teeth, hold

it there and say “top dog,” “go jump”, and “train”.

To hear distorted labials, hold your upper lip between the thumb and forefinger of one hand and

your bottom lip similarly with the other and say “my baby”.

Gutturals (velars, or tongue back sounds, such as k, g, and ng) are articulated between the back of

the tongue and the soft palate.

Palatals (German ch and g, and the French gn) are formed when the dorsum of the tongue

approximates the hard palate.

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Types of dysarthrias

Types Description Cause

Flaccid (lingual, buccal,

and guttural)

LMN weakness of facial, lingual, or pharyngeal muscles.

Facial paralysis causes difficulty with labials, such

as b, p, m, and w.

Tongue paralysis affects a large number of sounds,

particularly l, d, n, s, t, and x.

Palatal paralysis produces a nasal twang in speech.

Cerebrovascular accidents

(especially brainstem lesions)

Spastic (hot potato

voice)

Strained, slurred hot potato-like voice UMN weakness (bilateral), e.g.

pseudobulbar palsy

Ataxic speech

Scanning speech: Undue separation of syllables

(monosyllable speech)

Cerebellar diseases

Staccato speech: Explosive type of speech with

emphasis on syllables

Hypokinetic Slow monotonous, low voice with inappropriate silence Extrapyramidal (parkinsonism)

Hyperkinetic dysarthria Distorted speech with continuous change in articulation Chorea, athetosis, and dyskinesias

Myasthenic dysarthria Voice is normal in the beginning but becomes weak as

sentences progress

Myasthenia gravis

APRAXIA

Definition

Apraxia is impaired ability (inability) to carry out (perform) skilled, complex, and organized motor

activities in the presence of normal basic motor, sensory, and cerebellar functions.

Examples of complex motor activities: Dressing, using cutlery, and geographical orientation.

Types

Ideomotor

apraxia

Most common. It is the inability to perform a specific motor command/act (e.g. cough, lighting a cigarette

with a matchstick) in the absence of motor weakness, incoordination, and sensory loss or aphasia. Site of

lesion is bilateral parietal lobe. Buccofacial apraxia involves apraxic deficits in movements of the face and mouth. Limb apraxia encompasses apraxic deficits in movements of the arms and legs

Dressing

apraxia

Site of lesion is nondominant parietal lobe. It is inability to wear his/her dress

Constructional

apraxia

It is inability to copy simple diagrams or build simple blocks. Site of lesion is nondominant parietal lobe

Ideational

apraxia

It is a deficit in the execution of a goal-directed sequence of movements even with real object (e.g. asked

to pick up a pen and write, the sequence of uncapping the pen, and placing the cap at the opposite end).

This is commonly associated with confusion and dementia rather than focal lesions associated with

aphasic conditions

Gait apraxia

(Bruns ataxia)

Seen in normal pressure hydrocephalus (NPH)

Gaze apraxia Part of Balint syndrome

Other apraxias Speech apraxia, conceptual apraxia, and conduction apraxia

AGNOSIA

Definition

Agnosia is failure to recognize objects (e.g. places, clothing, persons, sounds, shapes, or smells),

despite the presence of intact sensory system.

Site of lesion: Contralateral parietal lobe.

Types of agnosias

Visual agnosia Failure to recognize what is seen with eyes despite the presence of intact visual pathways. The

individual can describe the shape, color, and size without naming it. Site of lesion is in the posterior

occipital or temporal lobes

Prosopagnosia A type of visual agnosia in which patient cannot identify familiar faces, sometimes the reflection of his

or her own face in the mirror even including their own. Site of lesion is parieto-occipital lobe

Simultanagnosia It is inability to perceive more than one object at a time

Autotopagnosia It is a form of agnosia, characterized by an inability to localize and orient different parts of the body

Pseudopolymelia The feeling of false—the feeling of false extremities. More frequent, the patients feel the extremities. More frequent, the patients feel the third hand

Anosognosia It is an inability or refusal to recognize a defect or disorder that is clinically evident

Auditory agnosia It consists of the loss of ability to know objects on sounds characteristic for them (clock—on ticking)

DELUSIONS

Definition

Delusion is a belief held with strong conviction despite superior evidence to the contrary (strongly

held false beliefs).

It is a disorder of content of thought.

Types of delusion (based on their content)

Persecutory

delusions

Conviction that others are out to get me

Grandiose delusions Belief that one has special powers or status

Nihilistic delusions Conviction that “my head is missing/rotting”, “i have no body”, and “I am dead”

Erotomanic delusions Believing a movie star loves them

Somatic delusions Believing head is filled with air/worms

Delusions of

reference

Believing story in a book is referring to them

Delusions of

control/passivity

Believing one’s thoughts and movements are controlled by aliens

Other delusions are Delusions of misinterpretation, hypochondrial delusions, fantastic/bizarre delusions, delusions of

passivity, delusions of jealousy

HALLUCINATIONS

Definition

Hallucinations are perceptions without external stimuli (wakeful sensory experiences of content

that is not actually present). They can occur in any sensory modality, most common being visual

or auditory.

For example, hearing voices when no one else is present, or seeing “visions”. Other types include

tactile (cocaine bug), olfactory, gustatory, command kinesthetic/psychomotor, and lilliputian and

complex hallucinations.

Pseudohallucinations

These are hallucinations that are perceived as originating in the external world, not in the patient’s

own mind.

Hypnagogic and Hypnopompic Hallucinations

In narcolepsy 2, specific hallucinations are seen. Hypnagogic: They occur when falling asleep.

Hypnopompic: They occur on waking up from sleep.

(mnemonic—hypnoGOgic hallucinations are perceived while GOing to sleep).

Hallucinations Illusions

Perceptions without external stimuli Misperceptions of real external

stimuli

For example, hallucinating that someone is talking to them when there is no actual

stimulus

For example, mistaking a rope for

snake

Functions and effects of damage to various lobes of cerebral hemispheres are listed in Table

6D(ii).1 and Figure 6D(ii).4.

Table 6D(ii).1: Functions and effects of damage to various lobes of cerebral hemispheres.

Lobe Function Cognitive/behavioral effects of damage

Frontal

Please SMILE

(MNEMONIC)

Personality

Social behavior Antisocial behavior

Micturition Incontinence

Intelligence

Language Expressive dysphasia

Emotional response Disinhibition

Parietal: Dominant side Language Dysphasia, dyslexia

Calculation Acalculia

Others Apraxia, agnosia

Parietal: Nondominant side Spatial orientation Spatial disorientation, neglect of contralateral side

Constructional skills Constructional apraxia, dressing apraxia

Temporal: Dominant side Auditory perception Receptive aphasia

Language Dyslexia

Verbal memory Impaired verbal memory

Smell

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Balance

Temporal: Nondominant

side

Auditory perception Impaired nonverbal memory

Melody/pitch

perception

Impaired musical skills (tonal perception)

Nonverbal memory

Smell

Balance

Occipital Visual processing Visual inattention, visual loss, visual agnosia (Anton–Babinski

syndrome)

Fig. 6D(ii).4: Various lobes of cerebral hemispheres.

LESIONS OF NONDOMINANT (RIGHT) HEMISPHERE

Neglect

Definition → directed inattention, or a relative lack of attention, paid to one hemisphere; patients are less aware (or

completely unaware) of objections or actions in one side of the world (usually the left).

Diagnosis

Severe forms → patients completely ignore left side, denying that, such as side even exists; they may leave their left side

ungroomed, unshaven, and undressed; may leave food on left side of plate uneaten; may deny they have a left hand, and

when confronted with it, may claim that it is actually the examiner’s.

Milder forms → may perform actions with their left side only with encouragement or after repeated prodding.

Most sensitive sign → extinction to double simultaneous stimulation; sensory stimuli applied singly to either side are

properly felt, but when both sides are stimulated simultaneously, only the non-neglected side is felt; extinction may exist

with tactile, visual, or auditory stimulation.

Etiology → lesions in right hemisphere (frontal or parietal lobe), most commonly an acute finding after stroke.

Frontal lobe lesion → more of a motor neglect in which patient has tendency to not use left side for motor actions

Parietal lobe lesion → more of a sensory neglect in which stimuli from the left side tend to be ignored.

Others

Prosody → while semantic elements of language (pure meaning) reside in dominant hemisphere, some other elements

of successful oral communication (e.g. proper voice inflection) reside in nondominant hemisphere

Anosognosia → tendency to be unaware of one’s deficits in some patient’s w/right hemispheric lesions

For example, patient with complete left hemiplegia may insist on immediate discharge from hospital because he feels

nothing is wrong

For example, patient with dense left hemianopia may wonder why she keeps bumping into others since she notices

nothing wrong with her vision.

NOTES

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