Neurology Flashcards
What is conduction dysphasia?
Speech fluent, but repetition poor. Comprehension is relatively intact
Caused by lesions involving the supramarginal gyrus, which is located in the parietal lobe and receives blood supply from the middle cerebral artery.
What is Wernicke’s dysphasia?
Difficulty understanding written and spoken language despite intact speech fluency.
Caused by lesions involving the superior temporal gyrus.
What is Broca’s (expressive) dysphasia?
Typically presents with partial or complete loss of language production (spoken or written) despite retention of language comprehension.
Caused by lesions involving the inferior frontal gyrus.
What is global dysphasia?
Typically only able to produce and comprehend a very small number of words. The capacity to write and speak is significantly impaired and comprehension of language is similarly heavily affected.
Caused by lesions involving both the superior temporal gyrus and inferior frontal gyrus.
What is dysarthria?
Cerebellar lesions can cause dysarthria, which is a motor speech disorder distinct from aphasia. Patients with dysarthria find it difficult to form and pronounce words/phrases. However, the capacity to form meaningful spoken and written language, and understand language remains intact.
What is the medical treatment for seizures?
1st line - PR diazepam or buccal midazolam (prehospital); or IV lorazepam (hospital)
2nd line - IV phenytoin, levetiracetam or sodium valproate
3rd line (if 45 mins without success) - general anaesthesia or phenobarbital
What causes normal pressure hydrocephalus and what is the triad of symptoms?
Characterised by ventriculomegaly, usually with normal cerebrospinal fluid (CSF) pressures
Triad: dementia, urinary incontinence and gait abnormality
What is the presentation of a 4th nerve (trochlear) palsy?
Issues with the ability to look downward –> vertical diplopia. This would make activities such as reading and walking downstairs particularly difficult.
On examination, you would notice upward deviation that increases in adduction, slight limitation of abduction, and outward rotation of the affected eye.
What imaging should all TIA patients undergo?
Urgent carotid doppler
What is the preferred brain imaging modality for TIA patients?
MRI brain with diffusion-weighted imaging
*This is more sensitive to areas of ischaemia than contrast-enhanced MRI
Where is the lesion in a bitemporal hemianopia?
Lesion of optic chiasm
In bitemporal hemianopia, give an example of a lesion causing:
*Upper quadrant defect > lower quadrant defect
*Lower quadrant defect > upper quadrant defect
Upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour
Lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma
What are common signs in subacute combined degeneration of the spinal cord?
- Damage to the posterior columns - loss of proprioception, light touch and vibration sense (sensory ataxia and a positive Romberg’s test).
- Damage to lateral columns - spastic weakness and upgoing plantars (UMN signs).
- Damage to peripheral nerves - absent ankle and knee jerks (LMN signs).
Which do you replace first, B12 or folate?
B12
*Think BeFOre
A patient presenting to the emergency department undergoes a CT head scan. The report describes a hypodense collection around the convexity of the brain that is not limited to suture lines.
What is the most likely radiological diagnosis?
- Subarachnoid haemorrhage
- Extradural haematoma
- Acute subdural haematoma
- Chronic subdural haematoma
- Intracerebral haematoma
Chronic subdural haematoma
On CT imaging, acute haematomas appear bright (hyperdense) whereas chronic haematomas appear dark (hypodense). Extradural haematomas are limited by suture lines whereas subdural haematomas are not. Intraparenchymal haematomas arise within the brain substance. Subarachnoid haemorrhage are typically seen as hyperdensity within the basal cisterns and sulci of the subarachnoid space.
What needs to be monitored when giving phenytoin?
Cardiac monitoring due to pro-arrhythmogenic effects
What should you do if a patient on warfarin/a DOAC/ or has a bleeding disorder and they are suspected of having a TIA?
They should be admitted for a CT scan to rule out haemorrhage
What is the most common cause of cavernous sinus syndrome and what are the symptoms?
Most commonly caused by cavernous sinus tumours
Diagnosis is based on signs of pain, opthalmoplegia, proptosis, trigeminal nerve lesion (opthalmic branch) and Horner’s syndrome.
What is the first-line management for trigeminal neuralgia?
Carbamazepine
What is the management of Bell’s Palsy?
Oral prednisolone if within 72 hours of presentation
Eye drops to prevent exposure keratopathy
What drugs can cause idiopathic intracranial hypertension?
- COCP
- Steroids
- Tetracyclines
- Retinoids (isotretinoin, tretinoin) / vitamin A
- Lithium
A 72-year-old man who is being treated for Parkinson’s disease is reviewed. Which one of the following features should prompt you to consider an alternative diagnosis?
- Micrographia
- Impaired olfaction
- REM sleep behaviour disorder
- Diplopia
- Psychosis
Diplopia
Diplopia is not common in Parkinson’s disease and may suggest an alternative cause of parkinsonism such as progressive supranuclear palsy
What is pituitary apoplexy and what causes it?
Sudden enlargement of a pituitary tumour (usually non-functioning macroadenoma) secondary to haemorrhage or infarction.
Precipitating factors:
* hypertension
* pregnancy
* trauma
* anticoagulation
What is the management of pituitary apoplexy?
- urgent steroid replacement due to loss of ACTH
- careful fluid balance
- surgery
What is the usual cause of a painful 3rd nerve palsy?
Posterior communicating artery aneurysm
What are two important causes of seizure that you should rule out first?
Hypoxia and hypolgycaemia
How does a common peroneal nerve palsy present?
Weakness of foot dorsiflexion and foot eversion (foot drop) + sensory loss over the lateral aspect of the lower leg
What are common oculomotor dysfunction signs seen in Wernicke’s encephalopathy?
Nystagmus
Ophthalmoplegia - lateral rectus palsy, conjugate gaze palsy
What are features of a temporal lobe seizure?
An aura occurs in most patients:
* typically a rising epigastric sensation
* also psychic or experiential phenomena, such as déjà vu, jamais vu
* less commonly hallucinations (auditory/gustatory/olfactory)
Automatisms (e.g. lip smacking/grabbing/plucking)
Post-ictal dysphasia
What is the first line treatment of focal seizures?
- first line: lamotrigine or levetiracetam
- second line: carbamazepine, oxcarbazepine or zonisamide
What is the first line treatment of long-term generalised tonic-clonic seizures?
males: sodium valproate
females: lamotrigine or levetiracetam
What type of food diet is useful in hard-to-treat epilepsy such as in Lennox-Gastaut syndrome?
Ketogenic diet
What is Miller Fisher syndrome?
- variant of Guillain-Barre syndrome
- associated with ophthalmoplegia, areflexia and ataxia. The eye muscles are typically affected first
- usually presents as a descending paralysis rather than ascending as seen in other forms of Guillain-Barre syndrome
- anti-GQ1b antibodies are present in 90% of cases
What is thoracic outlet syndrome?
Thoracic outlet syndrome (TOS) is a disorder involving compression of brachial plexus, subclavian artery or vein at the site of the thoracic outlet. TOS can be neurogenic or vascular; the former accounts for 90% of the cases.
What is the clinical presentation of neurogenic vs vascular thoracic outlet syndrome (TOS)?
Neurogenic TOS
* painless muscle wasting of hand muscles, with patients complaining of hand weakness e.g. grasping
* sensory symptoms such as numbness and tingling may be present
* if autonomic nerves are involved, the patient may experience cold hands, blanching or swelling
Vascular TOS:
* subclavian vein compression leads to painful diffuse arm swelling with distended veins
* subclavian artery compression leads to painful arm claudication and in severe cases, ulceration and gangrene
What is the classic history of vestibular schwannoma (acoustic neuroma)?
Vertigo
Unilateral hearing loss
Unilateral tinnitus
Absent corneal reflex
What is the role of IV mannitol in raised ICP?
Used in patients with raised ICP due to trauma
It is a hypertonic agent which increases systemic osmolality, causing an osmotic shift of water out of the brain parenchyma. This medication is used in patients with raised intracranial pressure (ICP) secondary to traumatic brain injury to reduce the pressure and increase diuresis.
What is the role of IV steroids in raised ICP?
Used in raised ICP secondary to vasogenic oedema from central nervous system infections or neoplasms.
It has no role in treating raised ICP in traumatic brain injury and hence would not be appropriate in this patient.
What is Steven Johnson syndrome?
Life-threatening skin and mucous membrane disorder, commly as a reaction to certain medication
- Fever
- A sore mouth and throat
- Fatigue
- Burning eyes
- Unexplained widespread skin pain
- A red or purple rash that spreads
- Blisters on your skin and the mucous membranes of the mouth, nose, eyes and genitals
Which medications can cause Steven Johnson syndrome?
- Anti-gout medications, such as allopurinol
- Medications to treat seizures and mental illness (anticonvulsants and antipsychotics)
- Antibacterial sulfonamides (including sulfasalazine)
- Pain relievers, such as acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve)
What is the management of Steven Johnson syndrome?
Stop all medication, obtain IV access and begin fluid hydration
You can also consider:
* creams and dressings to moisturise and protect the skin
* strong painkillers to help ease any pain
* medicines to control inflammation and prevent infection
What investigation is important in acute angle-closure glaucoma?
Tonometry
What would you see on LP in GBS?
Isolated raise in protein - rise in protein with a normal white blood cell count (albuminocytologic dissociation), found in 66% of patients
What is the first investigation you do in a multiple sclerosis patient with bladder dysfunction?
USS of kidneys, ureter and bladder to assess for bladder emptying
What is syringomelia?
Dilatation of a CSF space within the spinal cord. It occurs within the cervical and thoracic segments and causes compression of the spinothalamic tracts decussating in the anterior white commissure. This results in dissociative loss of sensation of pain, temperature and non-discriminative touch. There is classically a ‘cape-like’ distribution of this sensory loss.
*Associated with Chiari formations which is herniation of cerebellar tonsils through foramen magnum
What is autonomic dysreflexia?
It is a medical emergency that usually occurs above the T6 level when there is a spinal cord injury. There is abnormal and excessive response of the autonomic nervous system where the parasymaphetic nervous system is prevented by the cord lesion. These are usually trigerred by faecal impaction and urinary retention
This results in an unbalanced physiological response, characterised by extreme hypertension, flushing and sweating above the level of the cord lesion, agitation, and in untreated cases severe consequences of extreme hypertension have been reported, e.g. haemorrhagic stroke.
Treatment: removal/control of the stimulus and treatment of any life-threatening hypertension and/or bradycardia.
What are the differences in the antibodies of Myasthenia Gravis and Lambert Eaton syndrome?
Myasthenia Gravis - antibody against Ach Receptor
Lambert Eaton syndrome - antibody against voltage gated calcium channels