L6-->Thalamus and Cerebral Cortex - Neuroanatomy

Thalamus

1. Sensory and motor relay station

2. Integrative center

3. Perceives pain but cannot localize

What does the thalamus integrate?

1. Cerebral cortex

2. Basal ganglia

3. Hypothalamus

4. Brain stem

Cerebellum Function

1. Muscle control

2. Balance

3. Movement coordination

Cerebellar Disorders Physical Characteristics

1. Ataxia

2. Decreased DTR on affected side

3. Asthenia (easy fatiguability)

4. Tremor (intention)

5. Nystagmus

Basal Ganglia Functions

1. Motor control

2. Motor learning

3. Executive functions

4. Emotions

Parkinsonism (Hypokinetic Basal Ganglia Disorder)

1. Rigidity

2. Slowness

3. Resting tremor

4. Mask facies

5. Shuffling gait

Hyperkinetic Basal Ganglia Disorder

1. Chorea

2. Athetosis

3. Hemiballismus

Agnosia

Inability to interpret sensations and recognize things

Causes of Agnosia

1. Stroke

2. TBI

3. Alzheimer's Dementia

Visual Agnosia Classification

1. Apperceptive

2. Associative

Apperceptive Visual Agnosia

1. May not be able to recognize, draw, or copy objects

2. Parietal/Occipital lobe injury

Associative Visual Agnosia

1. May be able to draw or copy but not name object

2. Damage to bilateral inferior occipitotemporal cortex

Auditory Agnosia

1. Inability to recognize familiar sounds

2. Typically a/w right sided temporal lesions

What can patients with auditory agnosia do?

Read, write, and speak normally

Tactile Agnosia

1. Inability to recognize objects by touch

2. Can recognize by site

3. Injury to parietal lobe

Work Up for Agnosia

1. Neuro exam

2. Psychological exam

3. MMSE for cognition

4. Boston Diagnostic Aphasia Examination

Treatment of Agnosia

1. Tx underlying cause

2. Could be d/t stroke, infection, tumors

3. Physical/Speech/Occupational Therapy

Apraxia

1. Loss of ability to execute or carry out skilled movement and gestures

2. Still has the physical ability to perform them

Causes of Apraxia

1. Stroke

2. Dementia

3. Tumor

4. Neurocognitive D/O

5. Brain injuries

What areas of the brain can be damaged causing apraxia?

1. Parietal lobe

2. Frontal cortex

3. Basal ganglia

4. Interconnecting white matter to those areas

Types of Apraxia

1. Ideomotor

2. Ideational

3. Conceptual

4. Limb-kinetic

Ideomotor Apraxia

1. Damage to left parietal love

2. Difficulty performing tasks involving tools or objects

3. Examples: brushing teeth or using a comb

Ideational Apraxia

1. Damage to parietal lobe and connection between parietal and frontal lobe

2. Difficulty with performing tasks with multiple steps

Conceptual Apraxia

1. Damage to parietal lobe

2. Difficulty to using objects appropriately

3. Example: using screwdriver to write

Limb-Kinetic Apraxia

1. Damage to primary motor cortex

2. Difficulty with fine motor skills

3. Example: Buttoning a shirt, using chopsticks

Evaluation of Apraxia

1. Neuro exam

2. Test for individual features and types

3. Eliminate other neurodegenerative disorders

Treatment of Apraxia

Speech/occupational therapy

Aphasia

Loss of language function after injury in dominant hemisphere

Types of Aphasia

1. Receptive

2. Motor

3. Expressive

Receptive Aphasia

1. Involves difficulties with reading and listening; AKA Wernicke's aphasia

2. Lack of language comprehension

Motor Aphasia

Involves difficulties with writing and talking

Expressive Aphasia

Difficulty speaking fluently

Where is the injury in receptive aphasia?

1. Injury to dominant cerebral hemisphere in the temporal lobe (wernicke's area)

2. Closely associate with auditory cortex

3. Reading often impaired

Cause of Receptive Aphasia

Ischemic stroke

How does speech present in receptive aphasia?

Normal rate, rhythm, and grammar, but non-sensical or inappropriate

Semantic paraphasia error

1. May substitute similar words

2. watch for clock

Phonemic paraphasia error

1. May substitute similar syllable

2. Dock for clock

Physical Exam For Receptive Aphasia

1. Neuro exam

2. Assessment of speech and fluency

3. Ability to name objects

4. Comprehension and following commands

5. Repeat phrases

6. Reading

7. Writing

Receptive Aphasia Work Up

1. Boston Diagnostic Aphasia Exam - 90+ min

2. Evaluates reading, writing, verbal production, auditory comprehension

3. Neuroimaging

Treatment of Receptive Aphasia

1. Speech and language therapy

2. Neuropsychology referral (pt have difficulty understanding there is problem)

3. Family and social support

4. Recovery peaks b/t 2-6mo after initial injury

Transcortical Motor Aphasia

1. Damage to anterior/superior frontal lobe of dominant hemisphere

2. Usually follows CVA

Signs and Symptoms of Transcortical Motor Aphasia

1. Reduced output of speech

2. Good auditory comprehension

3. Difficulty with spontaneous speech (can repeat phrases)

4. Difficulty initiating conversation but are good listeners (cooperative and task oriented)

Causes of Motor Aphasia

1. Infarct in anterior/superior frontal lobe (middle cerebral artery)

2. Injury to Broca's and Perisylvain cortex

3. TBI

4. Tumors

5. Progressive neurologic disorders

Evaluation of Motor Aphasia

1. Neuro exam

2. Assessment of speech and fluency

3. Ability to name objects

4. Comprehension and following commands

5. Repeat phrases

6. Reading

7. Writing

Motor Aphasia Imaging

1. CT

2. MRI

3. PET scan

Treatment of Motor Aphasia

1. Speech therapy

2. Limit gestures

3. Promoting Aphasics' Communicative Effectiveness (PACE)

Expressive Aphasia aka Broca Aphasia

1. Injury to dominant inferior frontal lobe (Broca's area)

2. Non-fluent speech

Non-fluent Speech of Expressive Aphasia

1. Wording finding issues

2. Loss of grammatical structure

3. Diminished ability to repeat phrases

Causes of Expressive Aphasia

1. CVA (MCA or ICA)

2. TBI

3. Tumors

4. Infection

Physical Exam of Expressive Aphasia

1. Neuro exam

2. Assessment of speech and fluency

3. Ability to name objects

4. Comprehension and following commands

5. Repeat phrases

6. Reading

7. Writing

Treatment of Expressive Aphasia

1. Speech/language therapy

2. Melodic intonation (still able to sing)

Broca's vs Wernicke's

1. B- anterior lesions of cerebral cortex (frontal lobe

2. W- posterior lesions of cerebral cortex (temporal lobe)

3. b- aphasic zone (nonfluent, omit nouns and connectors)

4. w- words are plentiful to excessive and speech iappropriate

5. W- circumlocution, neologisms

Cerebral Cortex

1. Functions as visual/auditory memory storage

2. Implicated in hallucination and dreams

3. Multiple areas of integration to process speech

Cerebral Cortex Processing Injuries

1. Speech injury leads to aphasia

2. Sensory injury leads to agnosia

3. Motor injury leads to apraxia

Silent Area

1. Area involved in storage of visual and auditory information

2. Lie outside the classic models of motor, sensory, and language function

3. Implicated in hallucinations and dreams

Symptoms of Silent Area Disorders

1. Amnesia

2. Auditory hallucinations

3. Deja vu

Neglect

1. Malfunction/injury to one hemisphere of the brain

2. Results in contralateral spatial disorientation

When does neglect occur?

After right middle cerebral artery stroke

Components of Neglect

1. Sensory

2. Motor

3. Perception

4. Visuospatial

5. Behavior

Process of Neglect

1. Right hemisphere injury stimulates left hemisphere to increase activity

2. Results in attention diversion and eye movements to the right side

3. Severity of neglect measured by Kessler Foundation Neglect Assessment Process

KF-NAP Categories

1. Limb awareness

2. Personal belongings

3. Dressing

4. Grooming

5. Gaze orientation

6. Auditory attention

7. Navigation

8. Collisions

9. Eating

10. Cleaning after meal

Types of Spatial Neglect

1. Perception-attention neglect

2. Motor intentional aiming deficits

Perception-Attention Neglect

Sensation intact but pt fails to perceive events on neglected side

Motor- Intentional Aiming Deficits (Spacial Neglect)

Difficulty initiating or performing movement even through motor function intact

Symptoms of Neglect

1. Anosognosia (unaware of deficit)

2. Self neglect (only perform on unaffected side)

3. Anosodiaphoria (unconcerned about deficit d/t emotional dysfunction in limbic system)

Exam Findings of Neglect

1. Allochiria

2. Allesthesia

3. Somatoparaphrenia

Allochiria

1. Patient ignore left sided stimuli

2. In assumed right sided injury

Allesthesia

1. May look to the right when approached from the left side

2. Assumed right sided injury

Somatoparaphrenia

1. Believe left side belong to someone else

2. Assumed right sided injury

Physical Exam for Neglect

1. Cancellation Test

2. Line Bisection Test

3. Double-Stimulanteous Stimulation

Cancellation Test - Neglect

1. Multiple scattered lines on a piece of paper, have them cross or circle them

2. Pt will neglect left side of paper, if right sided injury

Line Bisection Test - Neglect

1. Draw horizontal line across paper and have pt draw vertical line in the middle

2. Vertical line will be more to the right side

Double-Simultaneous Stimulation (Extinction Test) - Neglect

1. Have patient count fingers in both hemifields of vision

2. Will ignore left side if right sided injury

3. Sign of severity of injury and termed "extinction"

Treatment of Neglect

1. PT

2. OT

3. Medications

4. Neuropsych eval

PT for Neglect

1. Motor therapy

2. Attempts to help direct attention/function to neglected side

OT for Neglect

1. Prism adaptation treatment

2. Limb activation and optikinetic stimulation

Prism Adaptation Treatment

1. 10 session in 14 days

2. Helps shift attention to affected side by 11 degrees

3. Creates unconscious movement of neglected side

Limb activation and optikinetic stimulation

1. Movement of left side through area of neglect

2. Potentially helps to reorganize neural connections

Neuropsych Eval for Neglect

Ophthalmology referral to r/o vision disorder

Medications for Neglect

1. Cholinesterase Inhibitors

2. Stimulants

3. Do not use benzo, anticholingerics, antidopaminergics, sedatives

Why do we avoid benzo, anticholingerics, antidopaminergics, sedatives in treatment of neglect?

Induce delirium

Cholinesterase Inhibitors for Neglect

1. Donepezil

2. Rivastigmine

3. Use in Class IIb stroke patients for cognitive impairments

Stimulants for Neglect

Methylphenidate