Neurology Flashcards
Where does damage occur between in an UMN lesion?
Damage to motor fibres between pre-central gyrus and anterior horn cells of spinal cord (More detailed explanation: UMN lesions occur in the pyramidal/corticospinal tract. Inputs from premotor cortex, primary motor cortex and supplementary motor area [all 3 are located in the pre central gurus] are all passing through to the anterior horn cells of the spinal cord [the anterior/ventral horn is responsible for sending motor signals to muscles/glands].
What is the difference in pattern of sensory loss between UMN and LMN lesions?
UMN: central sensory loss
LMN: glove-stocking/nerve distribution sensory loss
(UMN are responsible for getting signals from cortex to spinal cord, LMNs then take it to muscle so sensory loss in LMN lesions is more focal to the area that neurone is supplying. Remember motor neurones can receive some sensory afferents hence us talking about sensory loss.)
What is the difference in pattern of tendon reflexes and tone between UMN and LMN lesions?
UMN: hyper-reflexia, hyper-tonia
LMN: hypo-reflexia, hypo-tonia
Where does damage occur between in a LMN lesion?
Damage to motor fibres between anterior horn cells of spinal cord, peripheral nerve, neuromuscular junction or the muscle
The anterior cerebral artery supplies which parts of the brain? What would be the clinical signs as a result of damage to this artery?
Supplies frontal and medial part of the cerebrum (ACA supplies all the highlighted areas in the image)
Weakness and numbness in the contralateral leg + arm symptoms
The middle cerebral artery supplies which parts of the brain? What would be the clinical signs as a result of damage to this artery?
Supplies lateral hemispheres and many deep brain structures
Contralateral hemiparesis + hemisensory loss in face and arm
(head, upper limbs or trunk can be affected. If precentral gyrus is affected this will cause contralateral loss of motor innervation to these areas. If post central gyrus is affected this will cause contralateral sensation loss to these areas).
Contralateral homonymous hemianopia
Cognitive change - dysphasia, visuo-spatial disturbance
List red flags for headache
New onset in over 55 yo Early morning onset Known/previous cancer Immunosuppressed Exacerbated by Valsalva Autonomic upset
List red flags for headache
New onset in over 55 yo (could be brain tumour, GCA or stroke) Early morning onset (indicates raised ICP) Known/previous cancer Immunosuppressed Exacerbated by Valsalva (could indicate raised ICP) Autonomic upset
an elderly alcoholic man presents with a persistent headache after falling over the previous day. On examination he has a fluctuating level of consciousness
what is this a sterotypical history for?
subdural haemorrhage
a middle-aged man presents with a head injury after falling down some stairs. After losing consciousness he quickly recovers but complains of a headache. Over the next few hours he becomes more confused and has one seizure
what is this a sterotypical history for?
extradural haematoma
The posterior cerebral artery supplies which parts of the brain? What would be the clinical signs as a result of damage to this artery?
Supplies occipital lobe
isolated/homonymous hemianopia with macular sparing
The middle cerebral artery supplies which parts of the brain? What would be the clinical signs as a result of damage to this artery?
Supplies lateral hemispheres
Contralateral hemiparesis + hemisensory loss in face and arm
Contralateral homonymous hemianopia
Cognitive change - dysphasia, visuo-spatial disturbance
List general causes of headache
Raised ICP Infections (meningitis) Giant cell arteritis Haemorrhage, trauma Venous sinus thrombosis Sinusitis Acute glaucoma
What are some prodromal signs of migraine?
Yawning
Food craving
Change in sleep/appetite/mood
What is the criteria for diagnosing migraine without aura?
5 or more eps of headache lasting 4-72h
1 of nausea, vomiting, photophobia, phonophobia
2 of unilaterality, pulsating, limiting, worse on activity
What is the treatment for acute migraine?
-NSAID (aspirin, ibuprofen)
-Anti-emetic
-Triptan (rizatriptan)
triptans are 5HT agonists
What drugs can be used for migraine prophylaxis?
1. Amitryptilline (s/e - anticholinergic i.e. dry mouth, postural hypotension, sedation) 2. Propranolol (s/e bronchospasm, peripheral vascular disease) 3. Topiramate (s/e parasthesia and weight loss) other options; Valproate Gabapentin
What are some contraindications to triptan use?
- Ischaemic Heart Disease, coronary spasm
(triptans are a 5HT agonist that work by causing vasocontriction- this counteracts the vasodilation that produces throbbing headaches- this mechasnism can also cause reduced blood flow to the heart so triptans are contrandicated in IHD)
- Uncontrolled BP
- Recent lithium/SSRI use (due to risk of serotonin syndrome- v. high levels of serotonin in the body)
How is cauda equina syndrome treated?
Immediate surgical decompression. This is a surgical emergency (consistent compression can cause irreversible nerve damage, permanent incontinence and sexual dysfunction).
If suspected do a rectal exam to look for perineal numbness and reduced surgical sphincter tone.
What causes subacute degeneration of the spinal cord?
Prolonged vitamin B12 deficiency
How do you treat an acute episode of MS?
High dose steriods (500mg oral or 1000 mg IV of methylprednisolone for 3-5 days)
N.B. This shortens the period of disability but is not treating the condition
What is Hoffman’s sign? And what does a positive Hoffman’s sign indicate?
Flexion and abduction of the thumb and flexion of the index finger when you forcefully flick the thumb of the patient’s middle finger.
(Clearer explanation and video: https://www.physio-pedia.com/Hoffmann%27s_Sign )
+ve sign indicates corticospinal tract dysfunction of the cervical segment of segments of the spinal cord (SAME AS +VE BABINKSKI’S SIGN)
What is clonus?
muscular spasm involving repeated, often rhythmic, contractions
What condition does the presence of urinary bence jones proteins indicate? Do all patients with the condition test positive?
Multiple myeloma
No; most people with MM will have positive urinary bender jones proteins but not all of them (between 50-80% of MM patients).