Chronic Neuro 1 Flashcards
What are the ascending tracts
Dorsal columns
Lateral spinothalamic tract
Ventral spinothalamic tract
What are the descending tracts
Lateral corticospinal tract
Ventral corticospinal tract
What does the lateral spinothalamic tract relay
Pain
Temperature
What do the dorsal columns relay
Deep touch
Vibration
Proprioception
What does the ventral spinothalamic tract relay
Light touch
What does the ventral corticospinal tract relay
Voluntary motor
What does the lateral corticospinal tract relay
Main voluntary motor
Generally are the upper limbs motor pathways more lateral or medial
Medial
What tract relays deep touch
Dorsal column
What tract relays vibration
Dorsal column
What tract relays proprioception
Dorsal column
What tract relays pain
Lateral spinothalamic tract
What tract relays temperature
Lateral spinothalamic tract
What tract relays light touch
Lateral spinothalamic tract
What tract relays motor signals
Lateral and ventral corticospinal
Define MS
A chronic inflammatory multifocal, demyelinating disease of the central nervous system of unknown cause, resulting in loss of myelin, and oligodendroglial and axonal pathology
4 main symptoms of MS
Optic neuritis
Motor weakness
Sensory disturbances
Fatigue
Other symptoms of MS (14)
Weakness of limbs with spasticity and hyper-reflexia Paraesthesiae, pain or sensory loss in limbs trunk, face or tongue Ataxic and spastic gait Urinary urgency and incontinence Sexual dysfunction Diplopia Vertigo and nystagmus Dysarthria Impairment of concentration or memory Hemiparesis Hemi sensory loss Visual field defect Seizures Psychiatric disturbances
What eye symptoms can you see in MS (4)
papillitis. Diplopia, nystagmus, internuclear ophthalmoplegia
Where is MS most common
In America, Canada and Nordic countries and places with a higher latitude
Which allele is linked to MS
HLA DLRB1*15
Explain what happens during an acute relapse of MS
There is inflammation in response to myelin basic protein. The inflammation leads to demyelination, which causes delay of the nerve impulse and eventually the neurological symptoms. At first these completely resolve, but as disease progresses can often be left with residual symptoms.
Why are symptoms so variable in MS
Because the amount and location of damage to the NS is different in each person with MS
What are the three phenotypes of MS
Relapsing remitting
Secondary progressive
Primary progressive
What are the 3 criteria for MS
Absence of alternative diagnosis
Dissemination in time
Dissemination in space
What evidence is used to diagnose MS (4)
Clinical history and examination
Radiological evidence – MRI
Laboratory evidence – CSF
Electrophysiology – VEPs
What imaging can show DIT and DIS and how can it show DIT
MRI GAD contrast
Acute inflammation will light up brighter due to GAD crossing the barrier as inflammation makes it leakier. The BBB is leakier for 2-6 weeks.
What CSF evidence points towards MS
Presence of oligoclonal bands solely in the CSF and not plasma
How come there are oligoclonal bands in the CSF in MS
B cells release IgG antibodies targeting the myelin, these leak into the CSF producing these oligoclonal bands
Epidemiology MG
young adult women (under 40) and older men (over 60)
Common muscles affected by MG
Eye and eyelid movement, facial expression, chewing, talking, swallowing
Common symptoms of MG (5)
Ptosis Diplopia Dysarthria Dysphagia ±SOB
Signs in MG (2)
Fatigable muscles with Normal reflexes
What is the pathophysiology behind MG
antibodies block, alter, or destroy the receptors for acetylcholine at the neuromuscular junction, which prevents the muscle from contracting. In most this is caused by antibodies to the acetylcholine receptor itself
What can antibodies be against in MG (2)
AChR
or muscle specific kinase (MuSK)
Things MG is associated with (2)
Thymic hyperplasia
Thymoma
Ix for MG (4)
Bloods – anti-AChR or anti-MuSK (but can also be seronegative MG)
EMG - demonstrates muscle weakness
CT/MRI
Difference between LEMS and MG (4)
Muscles improve after use and also LEMS has autonomic symptoms (dry mouth, constipation, incontinence)
Most common symptom in LEMS
Dry mouth due to the autonomic NS dysfunction
Pathophysiology of LEMS
There are antibodies for the voltage gated calcium channels that normally when opened lead to ACh exocytosis.
Only after repeated use of the muscle does weakness start to improve, as the incoming stimulus leads to cumulative opening of the few calcium channels not blocked by antibodies, eventually this is enough to release more acetylcholine.