Tract Lesions Flashcards
Effects of a lesion in the brain or spinal cord on the spinothalamic tract
Pain and temperature loss on the contralateral side
Effects of a lesion in the first order neuron on the dorsal column medial lemniscus tract
Ipsilateral loss of touch, vibration and conscious proprioception
Lesion in second or third neuron on the dorsal column medial lemniscus tract
Contralateral loss of touch, vibration and conscious proprioception
Lesion in trigeminal thalamic tract
Contralateral losses of pain, temperature, touch, vibration and proprioception
Lesion in spinocerebellar tract
Ipsilateral loss of non-conscious proprioception
Which order neurons would be affected for contralateral loss of pain and temperature
2nd and 3rd order neurons of spinothalamic tract
Corticospinal lesion effects when it is above the medulla level
contralateral hemiplegia and hemiparesis
Corticospinal lesion effects when it is below medulla level
Ipsilateral hemiplegia and hemiparesis
Effects of an UMN lesion in the corticobulbar tract
Pseudobulbar palsy for all nuclei bilaterally innervated. Deficits for nerves with single innervation and facial nerve has contralateral lower facial paralysis
Signs of lower motor neuron lesion
Hypotonia, areflexia, hypotenoa, atonia, flaccid muscle or paralysis, fasciculations, muscle atrophy
Signs of upper motor neuron lesion
Hypertonia, hyperreflexia, spasticity, positive babinski sign, clonus
Features of Horner’s syndrome
Ptosis, meiosis, anhydrosis
Causes of Horner’s syndrome
Interuption to sympathetic nerve supply, pancoast tumour, stroke and carotid artery dissection
What is pseudobulbar palsy
Bilateral lesion affecting corticobulbar tracts - UMN lesion of speech and swallow as bilateral cortical respresentation
Anatomy effected in pseudobulbar palsy
Motor cortex to motor nuclei of CN9, 10 and 12 in medulla
Features of pseudobulbar palsy
Spastic tongue, slow thick ‘hot potato’ speech, brisk jaw jerk reflex, emotional lability, other UMN features in limbs possible
Causes of pseudobulbar palsy
Vascular such as internal capsule stroke. degenerative such as MNS, supranuclear palsy. Degenerative such as upper brainstem tumours, autoimmune such as MS. Traumatic
What is bulbar palsy
LMN lesion affecting cranial nerves 9, 10 and 12
Features of bulbar palsy
Impaired speech and swallowing, absent/normal jaw jerk reflex, absent gag reflex, flaccid fascicularing tongue, quiet nasal speech and signs suggesting cause
Causes of bulbar palsy
Motor neuron disease, myasthenia gravis, GB syndrome, brainstem stroke such as lateral medullary syndrome and syringobulba
What is brown sequard syndrome
Anatomical disruption of nerve fibre tract in 1/2 spinal cord
Causes of brown sequard syndrome
Cord trauma, neoplasms, disc herniation, demyelination, infective or inflammatory lesion, epidural haematomas
Tracts affected in brown sequard syndrome
Disruption of descending lateral corticospinal, ascending dorsal column and ascending spinothalamic
Symptoms of brown sequard syndrome
Ipsilateral hemiplegia, loss of proprioception and vibration, contralateral loss of pain and temperature sensation
Management of brown sequrd syndrome
Depends on cause
What is Bells palsy
Idiopathic syndrome affecting facial nerve
Symptoms of bells palsy
Acute onset of unilateral LMN focal weakness, sparing extraocular movements and muscles of mastication. Mild-moderate post auricular otalgia, altered taste, dry eye, dry mouth, hyperacusis
Treatment of bells palsy
Oral steroids, 50ng OM for 10 days followed by taper. Management of dry eyes ect
Differential of Bells palsy
Ramsay Hunt syndrome
Causes of spinal cord pathology
Compression, herniated disc, tumour, abscess, haematoma, malformations, infections and infarctions
Possible effects of C5 lesion
Resp paralysis and quadraplegia
Possible effects of a C5-6 lesion
Paralysis of legs and hands, weakness of upper limb movements, loss of biceps jerk and brachioradialisis deep tendon reflexes
Possible effects of a C6-7 lesion
Paralysisof legs, wrists and hands, but shoulder and elbow flexion possible
Feature of spastic hemiparesis
Unilateral spastic hypertonia, hyperreflexia, ankle clonus, upgoing plantars. Pyramidal patterns of weakness, circumduction of affected limb on gait
Peripheral causes of spastic hemiparesis
Lesion in hemicord such as MS, and cord compression
Central causes of spastic hemiparesis
Lesion in contralateral cerebral hemisphere - MS, SOL, stroke or hemiplegic cerebral palsy
Features of spastic paraparesis
Lower limb spastic hypertonia, ankle conus, pyramidal weakness, hyperreflexia and upgoing plantars, scissoring gait
What can cause paralysis and Horner’s syndrome
Possible effects of C8-T1 lesion
What lesion can cause paralysis of legs
Possible effects of T1 and below lesion
Causes of Spinal cord compression
Trauma, neoplasia, disk prolapse, epidural haematoma, infection and spondylosis
Features of spinal cord compression
Acute UMN signs and sensory disturbance below lesion. Deep and localised pain often present along with stabbing radicular sensory disturbance at lesion level. Bladder/bowel control involved often
