Neuro Flashcards
Lesion of ulnar nerve causes what features
- Claw hand - flexion of 4th + 5th fingers
- Hypothenar wasting
- Weak Thumb ADDuction
- Weak Finger ABDuction
- Pt’s unable to cross their fingers in a ‘good luck’ sign
Lesion of median nerve causes what features
Damage at wrist:
- carpal tunnel syndrome -> tingling/pain in 1st,2nd,3rd digit
- Thenar (Thumb squidgy bit) wasting -> Weak thumb ABDuction = Ape hand deformity
Damage at elbow:
- hand of benediction (pope) -> unable to make a complete fist - 1st,2nd,3rd fingers remain distended
Lesion of radial nerve
- Wrist/finger drop
- Damaged in fractures of humerus
What is subacute combined degeneration of the cord
= vitamin B12 deficiency
Bilateral/symmetrical:
- Dorsal column loss (sensory + LMN)
-> propriception and vibration sense
lost first: imbalance/ataxia +
parenthesia
- Corticospinal tract loss (motor + UMN)
Classic triad: Extensor plantar response/babinski sign, brisk knee jerks, absent ankle jerks (LMN signs more distally)
- Clinical picture is often complicated by a coexistent peripheral neuropathy, optic atrophy and cognitive impairment.
Clinical features of spinal cord compression + causes
- UMN signs and sensory disturbance below the level of the lesion.
- back pain is often also present + stabbing radicular sensory disturbance at the level of the lesion.
- Bladder and bowel involvement is also commonly seen.
Causes: Trauma, Neoplasia, Infection, Disc prolapse, Epidural haematoma
Brown-Sequard vs Subacute combined degeneration of spinal cord
Brown-Sequard - caused by hemisection of spinal cord (trauma, tumour, infection)
1. Ipsilateral spastic paresis below lesion
2. Ipsilateral loss of proprioception and vibration sensation
3. Contralateral loss of pain and temperature sensation
Subacute combined degeneration of spinal cord (vit B12 & E deficiency)
1. Bilateral spastic paresis
2. Bilateral loss of proprioception and vibration sensation
3. Bilateral limb ataxia
What is Lambert eaten Mysasthenic syndrome
- The patient presents with weakness of the lower limbs in a lower motor neuron pattern (weakness, areflexia) but this improves on exercise (unlike myasthenia gravis)
- hyporeflexia
- association with small cell lung caner
Parkinsonism with autonomic disturbance - atonic bladder, postural hypotension, erectile dysfunction is likely to be what condition rather than parkinsons?
Multiple system atrophy
Anterior vs posterior vs central cord syndrome
Anterior cord syndrome (cause = ischemia) causes complete loss of movement, and pain and temperature loss below lvl of ischemic infarction, but it preserves light touch sensations.
Posterior cord syndrome produces the opposite effect: It causes loss of light touch sensation, but it preserves movement, and pain and temperature sensation.
Central cord syndrome (injury to cervical spine) is the most common form of incomplete spinal cord injury characterized by impairment in the arms and hands and to a lesser extent in the legs.
What is a raised intracranial pressure headache
Headaches which are worse in the morning/after lying down and upon bending over. May be associated with neurological deficits e.g. seizures due to compression of cranial structures by a space-occupying lesion, such as a tumour or haemorrhage.
What is idiopathic intracranial hypertension + Mx
- young, overweight females.
headache and visual disturbance. - The headache is classically non-pulsatile, bilateral, and worse in the morning (after lying down or bending forwards).
- Visual disturbances include transient visual darkening or loss, probably due to optic nerve ischaemia, and bilateral papilloedema is seen on fundoscopy.
Mx: WEIGHT LOSS. Acetazolamide. Topiramate (prophylaxis). Repeated lumbar puncture/VPS shunt
What cranial nerves are involved in vestibilar schwannoma
5,7,8
What is Erbs palsy
injury to the C5/C6 nerves (upper BPI). It is associated with shoulder dystocia, traumatic or instrumental delivery and large birth weight.
Damaged to the C5/C6 nerves leads to weakness of shoulder abduction and external rotation, arm flexion and finger extension. This leads to the affected arm having a “waiters tip” appearance:
Internally rotated shoulder
Extended elbow
Flexed wrist facing backwards (pronated)
Lack of movement in the affected arm
Mx: Function normally returns spontaneously within a few months. If function does not return then they may required neurosurgical input.
What is a glioblastoma
Glioblastoma (type of astrocytoma) most common primary tumour in adults and is associated with a poor prognosis (~ 1yr).
Sx: RaisedICP
- headache -> worse in mornings/lying down/bending forward, constant.
- Altered mental state, Visual field defects, Seizures (particularly focal), Third and sixth nerve palsies, Papilloedema (on fundoscopy)
On imaging - solid tumours with central necrosis and a rim that enhances with contrast. Disruption of the blood-brain barrier and therefore are associated with vasogenic oedema.
Mx: surgical with postop chemotherapy and/or radiotherapy. Dexamethasone is used to treat the oedema.
What is a meningioma
Meningioma = second most common primary brain tumour in adults. Typically benign, extrinsic tumours of the central nervous system.
- cause symptoms by compression rather than invasion.
- Investigation is with CT (will show contrast enhancement) and MRI, and treatment will involve either observation, radiotherapy or surgical resection.
