Select Brain Lesions - Neurology

Snapshot
- A 35-year-old woman presents to the emergency department with lower extremity weakness and double vision. Past medical history is significant for multiple sclerosis which is treated with Rituximab. Physical examination is significant for 2/5 strength in the bilateral lower extremity as well as right-sided internuclear ophthalmoplegia. MRI of the brain and spine shows new hyperintense lesions. (Lesion affecting the medial longitudinal fasciculus)

                        Introduction
                    
                        Select Central Nervous System Lesions
Lesion
Clinical Features
Frontal lobe
Frontal lobe lesions can result in disinhibitionand animpairment in
judgment
orientation
concentration
frontal release signs
magnetic gait
Frontal eye field (FEF) lesions can result ineye deviation towards the side of the lesionan example is a stroke affecting the FEF
Parietal lobe
Lesions affecting the
dominant parietal (usually the left) cortex results in Gerstmann's syndrome
agraphia
acalculia
finger agnosia
right-left confusion
non-dominant (usually the right) parietal cortex results incontralateral hemineglect
distortion of perceived space
extinction
Temporal lobeLesions affecting the superior temporal lobe (Wernicke area) can result Wernicke aphasia and a right superior quadrant visual defect
Lesions affecting limbic structures can result in deficits inconsolidation andbehavioral changes
Seizures in the medial temporal lobe limbic structures results in
emotions such asfear
deja vu
olfactory hallucinations
Bilacteral lesions in the amygdala results inKluver-Bucy syndrome
BrainstemLesions affecting thesuperior colliculusParinaud syndrome
reticular activating systemdecreased consciousness and coma
basal gangliaresting tremor
chorea
athetosis
medial longitudinal fasciculusinternuclear ophthalmoplegia
paramedian pontine reticular formationeyes look aways from the side of the lesion

Select Central Nervous System Lesions
Lesion	Clinical Features
Frontal lobe	Frontal lobe lesions can result in disinhibitionand animpairment in judgment orientation concentration frontal release signs magnetic gait Frontal eye field (FEF) lesions can result in eye deviation towards the side of the lesion an example is a stroke affecting the FEF
Parietal lobe	Lesions affecting the dominant parietal (usually the left) cortex results in Gerstmann's syndrome agraphia acalculia finger agnosia right-left confusion non-dominant (usually the right) parietal cortex results in contralateral hemineglect distortion of perceived space extinction
Temporal lobe	Lesions affecting the superior temporal lobe (Wernicke area) can result Wernicke aphasia and a right superior quadrant visual defect Lesions affecting limbic structures can result in deficits in consolidation andbehavioral changes Seizures in the medial temporal lobe limbic structures results in emotions such as fear deja vu olfactory hallucinations Bilacteral lesions in the amygdala results in Kluver-Bucy syndrome
Brainstem	Lesions affecting the superior colliculus Parinaud syndrome reticular activating system decreased consciousness and coma basal ganglia resting tremor chorea athetosis medial longitudinal fasciculus internuclear ophthalmoplegia paramedian pontine reticular formation eyes look aways from the side of the lesion

Action	Numeric Key	Letter Key	Function Key
Show Bullets		S	Enter (frontside only)
20%	1	N
40%	2	H
60%	3	F	Enter (backside only)
80%	4	E
100%	5	M
Toss	0	T