Frontal Lobe Flashcards
(34 cards)
Examination to assess higher mental function
MMSE (Mini Mental State Examination)
Components in MMSE
ORAR LC
Orientation
Registration
Attention
Recall
Language
Coppying
Areas on frontal lobe
Primary motor cortex (precentral gyrus) (area 4)
Pre motor area(area 6)
Supplementary motor (area 6)
Frontal eyefield (area 8)
Broca’s area (area 44,45)
Prefrontal cortex (area 9,10,11,12)
How much percentage of motor fibres orginate from primary motor cortex?
30%
What are the specialised cells present in primary motor cortex?
Betz cells
Advantages of Betz cells
They needed only lowest threshold to initiate the motor activity
Function of primary motor cortex
Initiate
Fine, skilled, voluntary movements
How much percentage of motor fibres orginate from pre motor and supplementary motor cortex?
30%
Function of premotor and supplementary motor area
Prepare for
Fine, skilled, voluntary, movements
What does preparation for Fine, skilled, voluntary, movements mean?
Altering tone for the posture
Proximal muscle alignment
Antagonist muscle inhibition
B/l lesion in premotor and supplementary motor area manifestation?
Spasticity
Re emerging of Primitive reflexes
Steps involving in performing a fine, skilled, voluntary movement
1) Planning and Coordination by Basal ganglia
2) preparation by PMA and SMA
3) Initiation by primary motor cortex
4) Finesse by Cerebellum
What is Motor homunculus?
Motor homunculus is a representation of how different parts of the body are mapped onto the primary motor cortex in the brain
In which area of cortex is lower limb situated?
Medial side
Importance of paracentral lobule
If there is lesion in paracentral lobule then urinary incontinence occur
How to differentiate Anterior cerebral and Middle cerebral artery lesions?
ACA supplies medial side of frontal lobe, which governs lower limb and bladder so if there is lesion in ACA then there will be lower limb weakness and urinary incontinence
MCA supplies Superotateral surface which governs upperlimb and face so if there is lesion in MCA then there will be Upper limb and face weakness
What will be the presentation in motor cortex lesion?
C/L weakness and inability to perform fine skilled voluntary movements
Define UMN lesion
Lesion anywhere from cortex to Anterior horn cells of grey matter
Ischemic lesions will produce C/L weakness but irritating lesions will produce what?
C/L simple motor partial seizure aka (jacksonian march)
To see left side which frontal eye field is activated?
(Lt) FEF activates (Rt) LR and (Lt) MR
(Rt) FEF activates (Lt) LR and (Rt) MR
Connection of FEF from one side to its C/L 6th CN nucleus is through what Structure?
PPRF Para Pontine Reticular Formation
In Frontal lobe lesion patient looks towards or away from lesion?
Pt looks towards the lesion
In PPRF lesion patient looks towards or away from lesion?
Pt looks away from lesion
Connection of 6th CN nucleus of one side to its C/l 3rd CN nucleus to other side is through which Structure ?
MLF- Medial Longitudinal Fasciculus
