DPD 4 - Neuro Flashcards
A 59 y/o man presents w/ exertional chest pain. He has long standing HTN and has a normal ECG. O/E: Frank’s sign. What is the most likely diagnosis?
- Coronary artery stenosis
- Musculoskeletal
- Pericarditis
- Relapsing polychrondritis
- Vasculitis
Coronary artery stenosis
Note that this is exertional chest pain. Frank’s sign is a diagonal crease in ear lobe extending from the tragus across the lobule to the rear edge of the auricle and is assoc. w/ ischaemic heart disease. Indicative of CVD and/or diabetes.
What can be seen in a UMN lesion e.g. brain tumour, specifically regarding the tone, power + reflex?
Increased tone = spasticity - reduced central descending inhibition
Decreased power
Increased reflexes = brisk + upgoing plantars
What can be seen in a LMN lesion, specifically regarding the tone, power + reflex?
Decreased tone = flaccid
Decreased power
Decreased reflexes
An IVDU presents w/ slurred speech, dysphagia, diplopia, bilateral ptosis + has a sluggish pupillary response to light. He has descending symmetric muscle weakness + multiple skin abscesses on arms + legs. Where is the issue likely to be located anatomically?
- Brain
- Brainstem
- Spinal cord
- Nerve root
- NMJ
NMJ
Unlikely to be in the brainstem as this would mean CN 3/4/6/9/10/11 would be knocked off so he would be dead. This is likely to be a diffuse neuromusular issue due to the diplopia and dysphagia so a NMJ issue is likely. The multiple abscesses suggests that he has run out of veins and this is an example of skin popping (injecting heroin under the skin). Infected heroin results in causing abscess infected with Botulinum toxin - this inhibits ACh release hence NMJ issue
Name 5 cerebellar signs to do with coordination.
Ataxia = uncoordinated movements
Nystagmus
Dysdiadochokinesia = rapidly alternating movement
Intention tremor = dysmetria + pass pointing on the finger-nose-finger test
Speech = slurred, scanning
What can cause a cerebellar lesion? (x 5)
Remember V, 2 I's and 2 T's Vascular - Bleed Infection - TB, VZV, cerebellitis Inflammation - MS Tumour - Primary, secondary mets Toxin - alcohol, phenytoin
A pt presents w/ a hemisensory loss, where is the damage likely to be?
- Cerebral cortex
- Spinal cord
- Nerve roots
- Mononeuropathy
- Polyneuropathy
Cerebral cortex
Hemisensory loss = different between L and R side
A pt presents w/ a sensory loss around the umbilicus. Where is the damage likely to be?
- Cerebral cortex
- Spinal cord
- Nerve roots
- Mononeuropathy
- Polyneuropathy
Spinal cord - the distribution loss is at the same level i.e. difference at particular level
A pt presents w/ sensory loss in the lateral side of their outer thigh. Where is the damage likely to be?
- Cerebral cortex
- Spinal cord
- Nerve roots
- Mononeuropathy
- Polyneuropathy
Nerve roots (radiculopathy) as it is a dermatomal distribution
A pt presents w/ sensory loss of their lateral three fingers in the right hand. Where is the damage likely to be?
- Cerebral cortex
- Spinal cord
- Nerve roots
- Mononeuropathy
- Polyneuropathy
Mononeuropathy - specific area e.g. median nerve in CTS
A diabetic pt presents w/ sensory loss in their feet and fingers. Where is the damage likely to be?
- Cerebral cortex
- Spinal cord
- Nerve roots
- Mononeuropathy
- Polyneuropathy
Polyneuropathy - glove + stocking distribution e.g. diabetic neuropathy
A 55 y/o man presents w/ numbness + tingling in hands and feet. PMHx: T1DM. DHx: On basal/bolus insulin. Ix: HbA1c 50 mmol/mol; B12: 500 PG/ML (200-900); eGFR: 90. There is decreased sensation to peripheries (glove + stocking distribution). What would you prescribe? (Not essential)
- Codeine
- Duloxetine
- Hydroxocobalamin
- Paracetamol
- Pregabalin
Pregabalin for peripheral neuropathy
What are the causes of peripheral neuropathy? (x 6 broad categories)
- Infection e.g. HIV
- Inflammation/Autoimmune e.g. GB syndrome (= acute inflammatory demyelinating polyneuropathy assoc. w/ campylobacter jejuni infection); chronic inflammatory demyelinating polyneuropathy; CTD; Vasculitis
- Toxin e.g. alcohol, cisplatin, amiodarone, metronidazole etc
- Metabolic e.g. diabetes, B12 deficiency, amyloidosis, chronic kidney disease
- Hereditary e.g. hereditary sensory motor neuropathy - pes cavus due to long standing peripheral neuropathy. A prominent example of this is Charcot-Marie-Tooth disease
What Ix would you do if you suspected alcohol was the cause of peripheral neuropathy?
Hx
Raised GGT
Raised MCV
What Ix would you do if you suspected B12 deficiency was the cause of peripheral neuropathy?
FBC to look for anaemia
Increased MCV - macrocytic anaemia
Serum B12
Define amyloidosis
Deposition of abnormal protein in various organs which affects the function. These abnormal proteins have precursors.
What are the 2 types of amyloidosis?
- Amyloidosis w/ myeloma: myeloma = increased production of immunoglobulin w/ light chain. These light chains become the precursors of amyloid fibrils
2 Chronic infection/inflammation: serum amyloid A is an inflammatory protein
A 34 y/o woman presents w/ weakness in the legs + blurred vision. She has increased tone + hyperreflexia but decreased power and pinprick sensation in the legs. Fundoscopy shows an ill-defined optic disc. What is the cause of her blurred vision?
- Amaurosis fugax
- Anterior uveitis
- Papilloedema
- Papillitis
- Vitreous haemorrhage
Papillitis = optic neuritis = inflammation of head of optic nerve
This is associated w/ pain on eye movements + blurred vision + demyelination e.g. multiple sclerosis.
Papilloedema also has a blurred optic disc on fundoscopy but is due to increased ICP + is not painful
Her weak legs suggests lesions affecting the spinal root - spastic paraparesis = increased tone w/ weak legs
What would a lesion in the corticospinal tract cause?
Weakness, hyperreflexia + upgoing plantars - the descending motor pathway is in the corticospinal tract so a lesion would result in weakness. These pathways are inhibitory therefore lesion results in increased brisk reflexes + upgoing plantars
What would a lesion in the spinothalamic tract cause?
Loss of sensation to a level. The spinothalamic tract is the ascending sensory tract therefore a lesion would result in loss of sensation
Give examples of pathology of the spinal cord (x 4 main ones)
- Spinal cord compression
- Vascular e.g. defect of anterior spinal artery
- Infection e.g. Pott’s disease (TB of the spine)
- Inflammation (demyelination) e.g. transverse myelitis = inflammation of spinal cord assoc. w/ mycoplasma pneumonia
Other causes include:
- Toxic/metabolic: subacute combined demyelination of the spinal cord
- Tumour/malignancy: primary or secondary spinal metastasis/spinal cord tumour