Control CS4 somatosensory disorders Flashcards
How can you tell if there is inflammation in the spinal cord on x-ray?
Spinal cord should look black on x-ray but if inflamed will appear white
How can you remember where dorsal is?
Think dorsal fin on sharks and dolphins - is the fin on their back thus the dorsal tract is towards your back/ the posterior spinal cord.
How do the somatosensory pathways travel in the spinal cord?
Spinothalamic tract sensations (crude sensation, pain and temperature) travel contralaterally
Dorsal column medial lemiscus pathway sensations (discrete touch, proprioception and vibration) travel ipsilaterally
What is brown-sequard syndrome?
A hemi-cord lesion
What is a common cause of hemi cord lesions?
Inflammation of the spinal cord aka myelitis can be due to virus or MS
What sensory loss is a hemi-cord lesion/brown-sequard syndrome and example of?
Dissociated sensory loss
What CN have somatic sensory nuclei in the brain stem?
What CN have taste/baroreceptors sensory nuclei in the brain stem
What CN have special sense nuclei in the brain stem?
What CN have somatic motor nuclei in the brainstem?
What CN have parasympathetic motor nuclei in the brainstem?
What CN have branchiomotor motor nuclei in the brainstem?
Is vertigo a symptom or a diagnosis?
Symptom
What is lateral medullary syndrome/Wallenbergs syndrome?
What can cause lateral medullary syndrome/ Wallenbergs syndrome?
A stroke due to occlusion of PICA or a vertebral artery dissection
Why are the dorsal columns not affected by an occlusion in the anterior spinal artery?
As they have collateral blood supply from the posterior spinal artery
What is anterior spinal syndrome?
When occlusion of anterior spinal artery causes loss of blood supply leading to infarction and loss of sensation and motor supply in the anterior 2/3 of the spinal cord so only proprioception and vibration sensations can be felt in the affected spinal nerves (as dorsal columns not affected)
What is a good way to think of the thalamus?
As a relay station (containing synapse) between the cortex and the spinal cord/brainstem
What is a lacunar stroke?
A non-cortical infarct due to an occlusion in a single perforating branch of a large cerebral artery
What are risk factors for a lacunar stroke?
Smoking
Hypertension
Diabetes
What is syringomyelia?
Expansion of central canal of the spinal cord (which is filled with CSF)
What fibres are affected first by syringomelia?
Crossing fibres - i.e. the fibres in the spinothalamic pathway which provide pain and temperature sensation
What are later consequences/ damage caused by syringomyelia if untreated?
Paraparesis and root lesions
How is syringomyelia treated?
Surgically
Why can sensory loss begin as a symmetrical glove and stocking distribution?
Longest nerves have highest metabolic demands so loss of sensation begins in these nerves at the distal ends
How are reflexes affected by upper motor neuron vs lower motor neuron lesions?
Upper motor neuron = Hyper reflexive reflexes
Lower motor neuron = absence of reflexes
What are risk factors of peripheral neuropathy?
Diabetes mellitus
Toxic drugs e.g. chemotherapy drugs
Autoimmune disease e.g. Gillian-barre, CIPD, vasculitis etc..
Vitamin deficiency
Pare neoplastic causes
Chronic kidney or liver disease
Inherited e.g. Charcot-Marie-tooth diesease
How can patients with subacute combined degeneration present?
Gradual onset of numb feet
Potentially with vitiligo
Unsteady +/- falling on uneven ground or in the dark
With anaemia and high mean cell volume
Loss of vibration up to the waist
Loss of proprioception in the feet
Normal strength
Intact spinothalamic pathway e.g. normal temperature and pain perception
A sensory ataxic gait
What causes subacute combined degeneration?
B12 deficiency
Anti-parietal cell antibodies
Nitrous oxide use - laughing gas/balloons
What can subacute combined degeneration lead to?
Peripheral neuropathy
Dementia
What part of the spinal cord is damaged by subacute combined degeneration?
The dorsal columns
What is the distribution of peripheral neuropathy upon onset?
Glove and stocking
