W4: spinal cord injury and pathology Flashcards
What are some likley causes of spinal pathology for acute, sub-acute and chronic conditions?
Acute - vascular
Sub-acute: inflammatory
Longer: malignancy, degenerative
What are the key features of an upper motor neuron lesion?
Pyramidal weaknesses (preferentially spares the antigravity muscles)
Spasticity
brisk reflexes
Upgoing extensor plantar reflex (babinski sign)
Clonus
What are the features of a lower motor neuron lesion?
Flaccid muscle weakness
Normal or reduced tone
Reduced or absent reflexes
Wasting
Fasiculations (sign muscle de-afferented i.e no nerve supply)
Where are the spinal cord enlargements?
The cervical and lumbar spine.
What is the anatomy of the distal end of the spinal cord?
The end of spinal cord is called the conus medullalris
The spinal nerves that come from this is called the cauda equina
The filum terminale is a fibrous (non neural) band that extends from the conus medullaris to the periosteum of the coccyx, it stabilises the spinal cord and is made from the remenants of the meninges.
What type of symptoms to lesions in the cervical and thoracic spine present as?
Upper motor neuron signs
What type of symptoms do lesions in the lumbar spine present as?
Lower motor neuron signs
What type of symptoms do lesions in the conus medullaris present as?
Upper and lower motor neuron lesions
What lesions result in bladder and bowel symptoms?
Lesions anywhere in the spinal cord.
What are the different functions of the spinal cord?
Sensory information from the body to the brain (afferent)
Motor control from brain to the body (efferent)
Autonomic function from brain to body
Spinal reflexes.
Identify the tract in the blue part of the spinal cord
lateral corticospinal tract
Identify the tract in the red part of the spinal cord
Spinothalamic tract
Identify the tract in the gree part of the spinal cord
The posterior columns
Contains the dorsal column medial lemniscus pathway
What is the function of the lateral corticospinal tract?
Motor control
What is the function of the spinothalamic tract?
Sensory, pain and temperature
What is the function of the dorsal column medial lemniscus pathway?
Light touch sensation, vibration, proprioception and joint position sense
What is the pattern of topographic representation of the human body on the motor complex called?
Homonculus
What are the key anatomical features in term of the location of the motor tracts?
Crosses over in the medulla
Descends in the lateral spinal cord.
What are the key anatomical features in terms of the two main sensory inputs to the brain?
DCML - ascends in dorsal part of spinal cord, crosses over in the medulla
STT - crosses over immediately in the spinal cord, ascends in the lateral part of the spinal cord.
What is the key spinal anatomy relating to the autonomic tracts?
Arise from the intermediolateral column or lateral column of the spinal cord.
At level T1-L2
How do autonomic spinal cord lesions often present?
Autonomic dysfunction
Blood pressure dysregulation
Horner syndrome
Bladder and defecation control problems
What is Horner syndrome?
Distinct signs of one side of face - ptosis, miosis, anhydrosis of face
Caused by lesion along sympathetic pathway to head, neck and eye.
What is the common clinical presentation of lesion in the cauda equina?
Flaccid weakness
Normal or reduce tone (LL)
Reduced or absent reflexes (LL)
Patchy leg sensory reduction
Sphnicter involvement - reduced anal tone
What are the common clinical signs of pyramidal weakness in a patient?
Spasticity
Arm - overly flexes
Legs - stronger extensors - leads to circumduction of hips in gait