Neurology Flashcards
Functions of frontal lobe
- Motor cortex for contralateral side= precentral gyrus
- Broca’s area, speech output inferior frontal gyrus
- Emotions
Function of parietal lobe
- Sensory cortex for contralateral side = postcentral gyrus
Functions of temporal lobe
- Memory
2. Wernicke’s area, comprehension of speech = superior temporal gyrus
Function of occipital lobe
- Vision
UMN signs (CNS)
- inc tone (spasticity)
- weakness, no wasting
- brisk reflexes + clonus
- upgoing plantars
LMN signs (PNS)
- Reduced tone
- weakness, wasting, fasciculation
- reduced or absent reflexes
- normal plantar
Name and describe the motor tract
Corticospinal
UMN in motor cortex (precentral gyrus) -> medulla where it crosses to contralteral side -> spinal level of action -> ventral root (LMN) -> muscle
Name the 2 sensory pathways and what they transmit
- Spinothalamic- pain and temp (coarse)
2. Dorsal/posterior column- position and vibration (fine)
Describe the spinothalamic pathway
Nociceptors or thermoreceptors detect impulse -> dorsal root -> dorsal horn and crosses to contralateral side AT SAME SPINAL LEVEL -> post central gyrus sensory cortex
Describe the posterior/dorsal column pathway
proprioceptors or mechanoreceptors detect stimuli -> afferent to dorsal root ganglion/horn -> up to medulla and CROSSES TO CONTRALATERAL SIDE AT MEDULLA-> thalamus-> sensory cortex
Biceps reflex at level
C5
Supinator reflex at level
C6
Triceps reflex at level
C7
Knee Jerk at level
L4
Ankle reflex at level
S1
What is a negative symptom
Partial or complete failure of impulse conduction leading to loss/reduction of function
What are positive symptoms
Exaggeration of a physiological phenomenon eg seizure, tremor, trigeminal neuralgia
Hemiplegia
severe/complete loss of strength on one side of body
Hemiparesis
slight weakness on one side of body
Paraparesis
bilateral leg weakness
Spondylosis
AGE RELATED degeneration of intervertebral discs
Define MND
Progressive DEGENERATION of ANTERIOR horn cells- where UMN from motor cortex synapse and LMN begin -> muscle.
MND presentation
U+LMN signs Widespread fasciculations NO sensory signs Men > women Chronic and BILATERAL symptoms can include speech
DD for MND
Cervical myelopathy (spinal cord compression)
Spinal Shock
You get ACUTELY UNEXPECTED SIGNS before correct signs develop. IE flaccid paralysis with loss of sensation and then gradually -> spasticity and reflexes ie LMN -> UMN
Guillan-Barre Syndrome Definiton
Acute DEMYELINATION of PERIPHERAL nerve roots and nerves typically post viral infection.
GBS typical presentation
LMN signs ONLY
sensory deficit
ascending weakness
generalised, bilateral signs
Causes of peripheral neuropathy (7 categories)
- congenital
- metabolic (b12 deficiency)
- Toxic (alcohol, drugs)
- Endocrine (DM, thyroid)
- Inflammatory (GBS)
- Neoplastic
- Infective (HIV, Lyme)
Define Myasthenia Gravis
Autoimmune condition attacking components of NMJ-> weakness and fatigue of skeletal muscle
Typical presentation of Myasthenia
Variable incorrect eye movements
Fatiguability
Difficulty swallowing
ADD PIC
Define functional disorders
Symptoms appear not to be caused by PHYSICAL disease, no VISIBLE pathology.
Thought to be a disturbance of FUNCTION
Define Epilepsy
A CHRONIC disorder characterised by RECURRENT SEIZURES (2 or more without clear symptomatic provocation eg alcohol withdrawal)
DD of a blackout/sudden collapse
- Faint = vasovagal syncope
- Seizure
- Cardiac syncope
other: cataplexy (temp paralysis, no LOC) and hypoglycaemic attacks
Define vasovagal syncope
Sudden and temporary IMPAIRMENT of CONSCIOUSNESS with LOSS of TONE caused by reduction of blood/oxygen to brain.
Define seizure
Clinical phenomenon due to abnormal synchronous cortical discharges
Useful features to differentiate between faint and seizure(4)
- POST event CONFUSION >2min
- Deeply bitten lateral TONGUE
- LONG T+C phases >1min
- deep CYANOSOS
NB NOT:
twitching/jerking, incontinence, pallor, bitten tongue tip, fatigue
Causes of epilepsy in adults
- unknown
- anything effecting cortical brain eg:
- stroke
- trauma
- tumour
- infection
- degenerative
- congential/genetic
Classification of seizures
Focal or Generalised Generalised: - Absence - Tonic - Tonic-Clonic Atonic, myoclonic
Define status epilepticus (acute seizures) and their treatment.
seizures 5min+ OR
2+ discrete seizure with incomplete recovery of consciousness between them.
BENZODIAZIPINES ( lorazepam) and PHENYTOIN (block Na channel) nb phenytoin is teratogenic
Mood stabilising drugs in epilepsy
CarbaMezepine (block Na channel) and laMotrigine = safe (LLT for epilepsy)
Sodium valproate uses and se
pro - best overall drug for epilepsy but teratogenic! neurodevelopment delay
Newer anti-epileptics, safer profile LLT
Lamotrigine, Levetiracetam, Topiramate
3 types of pain
- Nociceptive- caused by stimulation of primary afferent nerves responding to nocious stimuli
- Neuropathic- ECTOPIC pain signal generation, often in the ABSENCE of ongoing noxious events,due to PATHOLOGY in the P/CNS
- Psychogenic- no apparent organic basis