Transcript Prezentace aplikace PowerPoint

Examination of higher cerebral
functions
Examination of higher cerebral
(mental) functions
• It should be a requisite part of standard neurologic
examination – at least Mini Mental State Examination
should be performed in neurologic pts.
• It has to be systematic and hierarchic
(level of consciousness  directed attention  cognition, mood,
speech)
• Golden neurologic rule „to localize a lesion“ should
be applied for mental functions too (neuronal networks).
• Extremely important is thorough history taking (changes
in pt’s behavior) and focusing on the pt’s behavior during
the examination (evaluation of his/her appearance, cooperation,
attention, memory, mental flexibility, social adaptability, ability of
nonverbal communication, depressive symptomatology, etc.).
Bedside tests of attention
• Luria (fist-palm-side) test
• Luria sketch (visual completion test) (alternating square and pointed figs.)
• Continuous performance test
After registering target digit in presented digit chain a subject has to knock on a table
4-9-1-7-5-4-0-7-9-2-4-3-7-5-0-2
• Digit span test (3-7) – subject has to learn and repeat long digit
chains of random numbers (also test on short-term memory)
Large-scale neural network for directed attention
(Mesulam MM)
Neglect syndrome
= a failure to report, respond, or orient to contralateral novel
stimuli that is caused by damage of large-scale neural
network for directed attention and not by an elemental
sensorimotor deficit.
It is a form of selective unawareness.
Pts with neglect syndrome often appears to be unaware of
contralateral stimuli, they ignore these items, and do not
react to them.
Within neglect there can be hemiakinesia (motor neglect =
movement deficiency = pseudohemiparesis), anosognosia (inability to
recognise and to understand own physical disability /especially motor
deficit – hemiplegia/ that is actually denying by the patient) and/or
anosodiaforia (absence of concomitant emotions for serious functional
deficit).
Cognitive skills
Dominant hemisphere disorders
Listen to language pattern - hesitant
- fluent
Expressive dysphasia
Receptive dysphasia
Pt. does not understand simple/complex
spoken commands (e.g. „Hold up both arms“)
Ask the patient to name objects
Nominal dysphasia
Does the patient read correctly?
Dyslexia
Does the patient write correctly?
Dysgraphia
Ask the patient to perform a numerical
calculation, e.g. serial 7 test, where 7 is
subtracted serially from 100.
Dyscalculia
Can the patient recognise objects?
e.g. ask patient to select an object from
a group.
Agnosia
Cognitive skills
Non-dominant hemisphere disorders
Note patient’s ability to find his way
around the word or his home.
Geographical agnosia
Can the patient dress himself?
Dressing apraxia
Note patient’s ability to copy a geometrical
pattern, e.g. ask patient to form a star with
matches or copy a drawing of a cube.
Constructional apraxia
Memory
episodic m.
(autobiographic data)
(mesiotemporal regions
– hipp,entorh, perirh, GP)
long-term m. (> 1 min)
Explicite memory
(declarative)
semantic m.
(encyclopedic knowledge)
(more extensive reg. – MT+LT,P,O)
F
(visual x verbal, recall
x recognition)
short-term (working) m. (30-40 s)
(digit span)
(DLPFC + associative visual and auditory areas)
procedural m. (completing word fragment, m. for movements)
Implicit memory
(subcortical circuits – BG, cerebellum + ctx visual, motor,..)
demonstrated by completion
priming
of tasks that do not require
conscious processing
= the ability to acquire a motor skills or cognitive routines by experience
HOSP----
Bedside memory testing is limited!
Testing requires alertness and is not possible in a confused
or dysphasic patient!
•
Short-term memory – DIGIT SPAN TEST – ask the patient to repeat a
sequence of 5, 6, or 7 random numbers.
•
Long-term memory – ask the patient to describe present illness,
duration of hospital stay or recent events in the news (RECENT
MEMORY), ask about events and circumstances occuring more than
five years previously (REMOTE MEMORY).
•
Verbal memory – ask the patient to remember a sentence or a short
story and test after 15 minutes.
•
Visual memory – ask the patient to remember objects on a tray and test
after 15 minutes
Reasoning and problem solving
• Test patient with two-step calculation, e.g. ‘I wish to
buy 12 articles at 7 cent each. How much change will
I receive from €1?’.
• Ask patient to reverse 3 or 4 random numbers.
• Ask patient to explain proverbs.
The examiner must compare patient’s present
reasoning ability with expected abilities based on
job history and/or school work!
Affect
Note the patient’s affect!
• Does the patient seem depressed?
• Loss of interest, euphoria, or social disinhibition may
be signs of frontal lobe dysfunction. Emotional
behavior such as aggression and anger may arise
from damage to the limbic system.
• Emotional lability should prompt further examination
to look for upper motor neuron signs and a
pseudobulbar palsy.
Determination of hemispheric
dominance
Interview about writing, eating with spoon, throwing a ball, kicking,
step; tapping – domin. hand 50/min, nondomin. hand 45/min.
Left hemisphere is dominant in 95% right-handers and 60% lefthanders!
Left hemisphere – dominant for speech and motor
functions, reading, writing, counting, recognition of colors,
verbal memory, important for linguistic thinking, ...
Right hemisphere – dominant for attentional functions,
prosopognosia, prosodia (affective component of speech),
nonverbal communication (ability to „read from face“),
visuo-spatial perception, visual and topographical
memory, recognition of music, …
; score > 24 normal; < 24 suggests dementia