Brain Lesions Flashcards
Parietal lobe lesions
sensory inattention
apraxias
astereognosis (tactile agnosia)
inferior homonymous quadrantanopia
Gerstmann’s syndrome (lesion of dominant parietal): alexia, acalculia, finger agnosia and right-left disorientation
Occipital lobe lesions
homonymous hemianopia (with macula sparing)
cortical blindness
visual agnosia
Temporal lobe lesions
Wernicke’s aphasia: this area ‘forms’ the speech before ‘sending it’ to Brocas area. Lesions result in word substituion, neologisms but speech remains fluent
superior homonymous quadrantanopia
auditory agnosia
prosopagnosia (difficulty recognising faces)
Frontal lobe lesions
expressive (Broca’s) aphasia: located on the posterior aspect of the frontal lobe, in the inferior frontal gyrus. Speech is non-fluent, laboured, and halting
disinhibition
perseveration
anosmia
inability to generate a list
Cerebellum lesions midline lesions: gait and truncal ataxia
hemisphere lesions: intention tremor, past pointing, dysdiadokinesis, nystagmus
Medial thalamus and mammillary bodies of the hypothalamus
Wernicke and Korsakoff syndrome
Subthalamic nucleus of the basal ganglia
Hemiballism
Striatum (caudate nucleus) of the basal ganglia
Huntington chorea
Substantia nigra of the basal ganglia
Parkinson’s disease
Amygdala
Kluver-Bucy syndrome (hypersexuality, hyperorality, hyperphagia, visual agnosia
Lesions of the vagus nerve (CN X) may result in:
Uvula deviates away from the site of the lesion
Loss of gag reflex (efferent)
Brown sequard syndrome
Spinal cord hemisection (damage limited to one half), leading to paralysis on side of lesion and loss of sensation on opposite side.
• corticospinal tract damage- loss of upper motor neuron innervation leading to ipsilateral spastic paralysis below level of lesion due to damage to lateral corticospinal tract. Damage to lower motor neuron at level of spinal injury leading to ipsilateral flaccid paralysis of muscles supplied at spinal level
• Dorsal column medial lemniscus- ipsilateral loss of vibration, proprioception and fine touch
• Spinothalamic tract- contralateral loss of pain and temperature sensation : 1-2 levels below lesion due to damage of lateral spinothalamic tract
• Ipsilateral loss of motor and sensory function use at the level of the injured segments due to direct damage to ventral and dorsal grey matter
Features of upper motor neuron disorder
Spasticity
Spastic weakness
Brisk reflexes
Positive Babinski reflex
Common causes of UMN damage
Brain/brain stem- stroke, tumours, demyelination (MS)
Spinal cord - MS, cord compression, spinal cord degenerative causes = Hereditary spastic paraparesis, vitamin B12 deficiency
Features of lower motor neuron disorder
Weakness- flaccid
Reduced tone
Muscle wasting
Fasciculations
Absent deep tendon reflexes
Causes of LMN injury
Motor neuron - MND , polio
Motor nerve roots- radiculopathy, Guillain Barre syndrome
Motor nerves- neuropathies, radiculopathies
Neuromuscular junction disorder - Myasthenia gravis
Muscle disorders- Myositis, myopathies
Idiopathic Parkinson’s disease clinical presentation (TRAP)
Tremor
Rigidity
Akinesia/ bradykinesia
Postural instability
Constipation, loss of sense of smell, impaired taste, sexual dysfunction
Features of impaired peripheral nerve and neuromuscular junction
Numbness , tingling, burning, freezing pain
Weakness and muscle wasting
Poor balance
Deformities secondary to weakness
Causes of peripheral nerve damage
Diabetes
Idiopathic
Leprosy
HIV
Deficiency states eg B12 folate
Alcohol/toxins/drugs
Hereditary neuropathies
Paraneoplastic syndromes
Metabolic abnormal - porphyria
Myasthenia gravis
Antibody mediated neuromuscular junction disorder
Where would the lesion be if it results in total blindness in the left eye
Left optic nerve
When will a person with damage to CN IV complain of double vision
When they look down
Ptosis of the eyelid due to
Damage of CN III on same side
Damage to which nerve will result in loss of the corneal (blink) reflex on the affected side
Trigeminal (V)
Innervated by ophthalmic nerve- nasociliary branch and VII temporal and zygomatic branches
In which type of lesion are forehead muscles spared
UMN lesion
Symptoms of Bell’s palsy
Droopy eyelid, dry eye or excessive tears
Facial paralysis, twitching or weakness
Drooping corner of mouth, dry mouth, impaired taste
Which nerve causes nystagmus (rapid eye movements) when diseased
Vestibulocochlear (CN VIII)
Tumour of the vestibulocochlear nerve
Cause paralysis of muscles of facial expression (compresses CN VII)
Damage to Hypoglossal nerve
Paralysis of the ipsilateral half of tongue (‘licks the lesion’)
Brown-Sequard syndrome leads to two-point discrimination appreciation below level of the lesion on
The same side- DCMLs decussates in meddulla
Brown-Sequard syndrome leads to…
Same side hemiplegia
Brown-Sequard syndrome leads to loss of pain and temperature appreciation on the
Opposite side
Spinothalamic tract crosses from 2 vertebral segments below
Brown-Sequard syndrome leads to loss of proprioceptive information conveyed to the
Ipsilateral cerebellum
Spinocerebellar tract projects ipsilaterally
Damage to the semi-circular canals results in
Nystagmus with the slow phase towards the damaged side and the rapid rest away from it
Cerebellar lesions have a….. effect
Ipsilateral
Damage to the papez circuit will mainly affect which function
Memory
CN V lesion
loss of facial sensation
loss of corneal reflex
deviation of jaw towards the side of lesion
paralysis of mastication muscles
CN III lesion
dilated, fixed pupil
a ‘down and out’ eye
ptosis
CN VII lesion
loss of corneal reflex
loss of taste (anterior 2/3rds of the tongue)
flaccid paralysis of upper + lower face
hyperacusis
A 48-year-old man with type 2 diabetes mellitus, who smokes 30 a day and is overweight presents with bilateral “glove and stocking” loss of pain, temperature and pin prick sensation.
Which of the following spinal tracts is affected?
Spinothalamic
A sexually active 75-year-old gentlemen presents with a stamping gait. He is diagnosed with tabes dorsalis. On examination he has a loss of joint position sense and cannot feel the tuning fork (vibration) when placed on his medial malleolus.
Which of the following spinal tracts is affected?
Dorsal column medial lemniscus pathway
A 73 year old lady presents to her GP surgery with an intensely itchy vesicular rash in a horizontal line at the level of the nipple.
What is the most likely diagnosis?
Shingles
Damage to the LEFT VIth cranial nerve causes double vision. Which of the following is the most likely problem for the patient?
Double vision which is worse when looking to the left
A 47 year old patient with severe rheumatoid arthritis attends her General Practitioner with numbness of the distal upper limb. The pattern of numbness does not fit with a spinal nerve root or a peripheral nerve lesion. Damage to which tract of the spinal cord may lead to this pattern of sensory loss?
Cuneate fasciculus (lateral posterior column tract)
