Pathology Flashcards
What is Brown-Sequard Syndrome?
Spinal Cord lesion affecting LMN
= Ipsilateral UMN paralysis loss of proprioception (touch + sensation)
Contralateral loss of pain and temperature, no reflex ( as pain crosses at entry deficit is on other side)
What happens to reflexes and muscle tone in an UMN lesion?
Paralysis (disrupted neurone pathway
But LMN pathway fine so exaggerated reflexes + tone= hyperreflexia, spastiparalysis
What is Electrophysiology used to diagnose?
Ulnar Neuropathy- cell sensory body in DRG alive but anterior horns + regions to spinal chord die.
Left with sensory + motor response from ulnar nerve but no action
What is Electromyography (EMG) used to diagnose?
NMD (tight relationship between fibres in motor units lost)= Jiter
eg./ Myathesthenia Gravis (autoimmune) antibodies to post synaptic ACh receptor = weakness and fatigue of facial muscles (+ ptosis + diplopia) treat via acetylcholinesterase inhibitor + immunosuppression
What is Electroencephalogram used to diagnose?
Looks at electrical activity within the brain
eg./ Ambulatory sleep study (over day + night)
Video telemetery- epilepsy
Encephalopathy, altered consciousness states
What happens to sensation if you damage the dorsal column?
Loose noxious mechanoreceptors on ipsiliateral side (hasn’t crossed yet)
What happens to sensation if get a lesion on anterolateral spinothalamic tract?
loose thermorecptive + nociceptive on contralateral side (cross immediately)
What is Right-Left Agnosia?
Lesion-Hemisensory neglect- can perceive sensations but can’t comprehend other side of the body
What is Acalculia?
Dominant lobe lesion- can’t count, write etc
What is Agraphia?
Less dominant lobe lesion- artistic + musical affects
What is Aphasia? What are the 2 different subtypes?
Problem with speech due to 1+ damaged areas in the brain
- Brocas Aphasia- Frontal lobe damage- understand + aware but miss small words + weakness/ paralysis of one side (motor cortex here)
- Wernicks Aphasia- Temporal Lobe Damage- fluent but meaningless speech, not aware NO paralysis
What are the 3 types of fibres found in white matter? What areas do they connect?
- Commisural Fibres- One hemisphere to another eg./ corpus callous
- Associated Fibres- Different lobes in 1 hemisphere (long/ short)
- Projection Fibres- Up (sensory) + Down (motor) through internal capsule (fibres passing to and from the cerebral cortex)
What is the basal ganglia? What is it made up of? What is its function?
A collection of neuronal cell bodies deep in cerebral hemispheres.
Composed of-
1. Caudate Nucelus
2. Lentiform Nucleus (putamen + globus pallidus)
3. Substantia Nigra (midbrain)
Regulates initiation and termination of movement (inertia)
Extrapyramidal- control of motor system
What kind of pathology is found in the basal ganglia?
Parkinsons
Chorea
Athetosis
What is hydrocephalus?
Excessive cerebrospinal fluid volume in IV spaces= dilation of ventricles + a wide range of symtoms
What is communicating hydrocephalus?
Non-obstructive
CSF production > CSF absorption OR CSF>
Uniform dilation= Inc ICP
Cause- Infection eg./ bacterial meningitis,
Subarachnoid haemorrhage, post op eg./ tumour gunge blocks, head trauma, choroid plexus papilloma (rare)
A neurological condition presents with-
Increased head circumference in neonates
and papillodema- diplopia/blurred vision, gout disturbance, 6th CN palsy, neck pain + upwards gaze difficulty in the rest of the population.
What is this pathology? How would you go about investigating and treating it?
Communicating (non-obstructive) hydrocephalus
6th nerve as passes through subarachnoid space
neck pain- tonsillar herniation
Investigate via Ct (asses ventricular size- will be dilated, 3rd ventricle ballooned), MRI, Ultrasonography in infants.
Treat via external ventricular drain (3 way tap into left ventricle (high infection risk) + mannitol (osmotic diuretic)/ communicating shunt
What in non- communicating hydrocephalus?
Obstruction
eg./ Aqueductal stenosis (kids, foramen of munro); tumours cancers and masses; cysts/ infection; haemorrhage/ haemotoma; Interventricular bleed, Spina Bifida Cystica.
Headaches in the morning are common
Treat via shunt, remove lesion (eg./ pineal tumour, ependyma, colloid cyst), 3rd ventriculostomy- hole in 3rd ventricle fluid bypasses cerebral aqueduct
What is normal pressure hydrocephalus?
Communicating Hydrocephalus on MRI. Normal opening pressure dementia like syndrome reversible with treatment via VP shunt (pressure is normal so hard to know how much to remove)
Hakims Triad- Wet, wobbly (gait) + wacky (dementia)
What clinical suspicion of disease would a lumbar puncture be required for? What are contraindications for carrying it out?
To Investigate- Meningitis Subarachnoid Haemorrhage (bilirubin levels) Meningioencephalitis (WBC) Malignancy (cytology) Infusion of drugs/ contrast Contraindications- Cardiac/ respiratory instability Localised skin/ soft tissue infection Inc ICP (head CT first) Chiari Malformation (tonsillar herniation)
how is a lumbar puncture carried out?
- Povidone- Iodine + wand + fenestrations
- Anasthetic eg./ lidocaine
- Spinal needle thorugh L3-4/4-5
- manometer, stopcock + tubing
Through erector spinal + ligament flavulum + dura (double pop)
Collect 3 tubes (Culture + gram, glucose + protein, cell count/ differential)
What are the complications of a lumbar puncture?
Spinal headache/ blackout
Epidermal occlusion cyst
Herniation- intubate, IV saline, bed back to 30-40
Nerve Trauma- feels like electric shock to Pt, withdraw needle and try again, if long shock give corticosteroids and do nerve conduction studies
What can cause bilateral hippocampal damage and what affect can this have?
Herpes Simplex
Long term memory before the damage will be intact + immediate sensory + reflective intact (as they don’t require retention through papez circuit) BUT loose ability to form new long term memories
How is amnesia caused? What are the 2 subdivisions?
Caused by disruption of reverberating neuronal circuit eg./ by head injury/ infection
1. Anterograde Amnesia- Inability to recall events AFTER incident (shot lived/ permanent)
2. Reterograde Amnesia- Can’t remember events BEFORE injury (can recall old)
Usually both present together.
If thalamus damaged but hippocampus intact get retrograde only (thalamus needed to search existing memory bank)