Neurology Flashcards
Frontal Lobe function
- Difficulties with task sequencing
- Difficulties with executive skills
- Expressive aphasia (Broca’s) : located
in the posterior aspect of the frontal
lobe, in the inferior frontal gyrus - Anosmia
- Primitive reflexes
- Perseveration (repeatedly asking
same question or doing same task) * Changes in personality - Inability to generate a list
- Disinhibition
Parietal Lobe
Apraxias: loss of the ability to execute learned purposeful movements
* Neglect
* Astereognosis (unable to recognise
object by feeling) = tactile agnosia
* Homonymous inferior quadrantanopia * Sensory inattention
Acalculia: inability to perform mental arithmetic
* Gerstmann’s syndrome (lesion of dominant parietal):
o Alexia: in ability to read o Acalculia
oFinger agnosia oRight-left disorientation.
Temporal Lobe
Homonymous superior quadrantanopia
* Prosopagnosia (difficulty recognising
faces)
* Wernike’s (recepTive) aphasia * Memory impairment
* Auditory agnosia
Occipital Lobe
Cortical blindness (blindness due to damage to visual cortex, may present as Anton syndrome: there is blindness but patient is unaware or denies blindness)
* Homonymous hemianopia
* Visual agnosia (seeing but not percieving objects - it is different to neglect since in agnosia the objects are seen and followed but cannot be named)
DRIVING RULES (DVLA): Neurological aspect specific rules:
First seizure: 6 months off driving (if the licence holder has undergone assessment by an appropriate specialist and no relevant abnormality has been identified on investigation, for example EEG and brain scan where indicate). For patients with established epilepsy they must be fit free for 12 months before being able to drive.
* Stroke or TIA: 1 month off driving
* Multiple TIAs over short period of times: 3 months off driving
* Craniotomy e.g. For meningioma: 1 year off driving (With benign tumors and if there is no seizure history, licence can be reconsidered in 6 months if remains seizure free)
* Pituitary tumour: craniotomy: 6 months; trans-sphenoidal surgery ‘can drive when there is no debarring residual impairment likely to affect safe driving’
* Narcolepsy/cataplexy: cease driving on diagnosis, can restart once ‘satisfactory control of symptoms’
Homonymous Hemianopia
- Incongruous defects = optic tract lesion
- Congruous defects (defect is approximately the same in each eye)
optic radiation lesion or occipital cortex - Macula sparing: lesion of occipital cortex (9)
Homonymous Quadrantanopias
Homonymous Quadrantanopias
* Superior: lesion of temporal lobe
* Inferior: lesion of parietal lobe
* Mnemonic = PITS (Parietal-Inferior, Temporal-Superior)
Bitemporal Hemianopia
Lesion of optic chiasm
* 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
Nystagmus causes
Causes:
* Visual disturbances
* Lesions of the labyrinth
* The central vestibular connections
* Brain stem or cerebellar lesions.
Nystagmus which changes with the direction of gaze
nvolvement of vestibular nuclei.
Pendular Nystagmus
mostly due to loss of macular vision, but could be in diffuse brain stem lesions.
Nystagmus Jerking on lateral gaze,
brain stem or cerebellum lesion.
- Nystagmus confined to one eye
nerve or muscle lesion, or medial longitudinal bundle lesion.
Nystagmus restricted to the abducting eye on lateral gaze (ataxic nystagmus)
due to a lesion
of the medial longitudinal bundle between the pons and mid-brain as in multiple sclerosis (MS).
Upbeat nystagmus
Cerebellar vermis lesions
Downbeat nystagmus - foramen magnum lesions
Arnold-Chiari malformation
Subdural Hemorrhage
Basics
* Most commonly secondary to trauma e.g. Old person/alcohol falling over
* Initial injury may be minor and is often forgotten
* Caused by bleeding from damaged bridging veins between cortex and venous sinuses
Features
* Headache
* Classically fluctuating conscious level
* Raised ICP
Treatment
* Needs neurosurgical review
* Burr hole →
Subarachnoid Hemorrhage causes
Causes
* 85% are due to rupture of berry aneurysms (conditions associated with berry aneurysms include adult polycystic kidney disease, Ehlers-Danlos syndrome and coarctation of the aorta).
* AV malformations.
* Trauma.
* Tumours
Subarachnoid Hemorrhage investigations
- CT: negative in 5%.
- LP: done after 12 Hrs (allowing time for
xanthochromia to develop) If the CSF examination did not reveal xanthochromia, or there was still a high level of clinical suspicion, then cerebral angiography would be the next step
Subarachnoid Hemorrhage management
Neurosurgical opinion: no clear evidence over early surgical intervention against delayed intervention
* Nimodipine (e.g. 60mg / 4 hrly, if BP allows) has been shown to ↓ the severity of neurological deficits but doesn’t ↓ rebleedi
Extradural hematoma
Bleeding into the space between the dura mater and the skull. Often results from acceleration-deceleration trauma or a blow to the side of the head. The majority of epidural Hematomas occur in the temporal region where skull fractures cause a rupture of the middle meningeal artery.
Features
* Features of raised intracranial pressure
* Some patients may exhibit a lucid interval
Intracranial Venous Thrombosis
Can cause cerebral infarction, much less common than arterial causes
* 50% of patients have isolated sagittal sinus thromboses - the remainder have coexistent lateral
sinus thromboses and cavernous sinus thromboses
Features
* Headache (may be sudden onset)
* Nausea & vomiting
* Papilledema
Sagittal sinus thrombosis
May present with seizures and hemiplegia
* Parasagittal biparietal or bifrontal hemorrhagic infarctions are sometimes seen
Cavernous sinus thrombosis
Other causes of cavernous sinus syndrome: local infection (e.g. Sinusitis), neoplasia, trauma
* Ophthalmoplegia due to IIIrd, IVth and VIth nerve damage
* Trigeminal nerve involvement may lead to hyperaesthesia of upper face and eye pain
* Central retinal vein thrombosis
* Swollen eyelids