Clinical Flashcards
Some organisms that commonly cause meningitis?
Viruses: Herpes, EBV
Bacteria
Fungi e.g. Toxoplasma
Helminths
Fatality rate for bacterial meningitis?
10-30%
Main types of bacterial meningitis?
Meningococci, Hib, pneumococcus
Signs of meningitis? (get some)
Severe headache, neck stiffness, fever, vomiting, confusion, brudzinski’s sign, rash, bruising
Difference in the analysis of CSF in bacterial and viral meningitis?
Bacterial has neutrophils and viral lymphocytes
Glucose in bacterial is low, in viral it is normal
Protein is higher in bacterial too
Steps of meningococcal infection?
Colonise nasopharynx
Invade epithelial cells
Enter circulation and either/both the CSF and the bloodstream (septicaemia)
Treatment for ALS? How effective?
Riluzole, 3 month increase in survival
non-invasive ventilation improves quality of life
How might an axonal injury arise?
Traumatic brain injury - direct cut of the axon
MS - inflammatory lesion
Stroke - ischaemic injury
How is regeneration different in the PNS to the CNS?
Schwann cells in PNS produce high levels of growth factors, and a permissive environment for repair is created
An inhibitory environment is created in the CNS, by the glia
What is basilar invagination?
Upwards herniation of the margins of the foramen magnum into the posterior cranial fossa
What is cephaloceles?
Extracranila extensions of the parenchyma or meninges through skull defect
What protein aggregates in many neurodegenerative disorder most naotably in lewy bodies in AD?
Aβ (amyloid beta)
How does Aβ contribute to age determined macular degeneration?
Induces complement activation and this recruits inflammatory factors
Types of neurotransmission?
Which are dysfunctional?
Classical
Spillover - activation of adjacent receptors (dysfunction)
Exocytosis occuring away from membranes defined as active zones (dysfuntion)
What three things often contribute to neurodegeneration?
BBB dysfunction
Neuroinflammation (Abeta)
Neurotransmission dysfunction
Viruses that cause meningitis?
Herpes Mumps Polio Japanese encephalitis HIV
Viruses that cause encephalitis?
Herpes
Rabies
west nile virus
Japanese encephalitis
Common 5 types of Herpes viruses?
HHV - 1 + 2
HHV 3 - chicken pox/shingles
HHV 4 - EBV (glandular fever)
HHV 5 - cytomegalovirus
What is herpes Zoster?
When the virus establishes a life-long latent infection in the dorsal root ganglia, and can be reactivated
How and where do HHV 1 and 2 often infect, anatomically
They travel from peripheral nerves to the dorsal root ganglia, can travel back down peripheral nerves to reactivate
What commonly causes sporadic encephalitis?
HHV1 (95%)
What can be used to treat Herpes, especially in encephalitis?
Acyclovir
What is osteomyelitis?
Infection of bone tissue
Main three mechanisms of osteomyelitis infection?
Haematogenous - from blood
Direct inoculation
Contiguous - from adjacent soft tissue infection
Clinical features of septic arthritis?
Acute (mostly)
Pain
Fever
Movement limited
Two types of Septic arthritis?
Causes?
Chronic:
- TB
- Fungi
- Lyme disease
Acute/viral
- Rubella/vaccine
- mumps
- Hep B
What is a prion? (in prion disease)
An infection that is solely protein based, encoded by your own disease
Is there an infammatory response in prion disease?
Nope
What does prion disease cause?
Rapid neurodegeneration and death in avg. 1 year, due to accumulation of prion proteins in the brain
Three main types of primary headaches?
Tension-headache
Migraine
Cluster headaches
Who normally gets tension-headaches?
All ages
Who normally gets migraines?
Teen - young adult
Female
Who normally gets cluster headaches?
Female over 30
Common causes of raised Intracranial pressure?
Space occupying lesions
CSF blockage leading to hydrocephalus
Idiopathic intracranial hypertension
Causes of secondary headaches?
Raised ICP
Vascular
Meningitis/encephalitis
Giant cell arteritis
Types of hearing loss?
Conductive
Sensorialneural
Common causes of conductive hearing loss?
Otitis media
Otosclerosis
Trauma
Types of otitis media?
causes?
Supprative (pus-producing)
- Viral (90%)
non-supprative
- glue ear
What is cholesteatoma?
Erosion/rotting of middle ear/mastoid
Treatment for otoslerosis?
- hearing aid
- stapedectomy
What is acoustic neuroma?
Benign tumour of vestibular nerve?
two types of vestibular disorders?
Central = brainstem + cerebellum
Peripheral = inner ear or vestibulocochlear nerve
What is BPPV?
Benign paroxysmal positional vertigo
Caused by substances in the vestibular apparatus
cured through a epley movement
Three main causes of recurrent vertigo?
BPPV
Vestibular migraine
Movement provoked pathologies
What do NK cells recognise on cell surface membranes?
Glycoproteins
Raised intracranial pressure symptoms?
Headache
Nausea and Vomiting
Pupilloedema
reduced consciousness
Common causes of raised intracranial pressure?
Expanding mass
increase in CSF/water content/blood volume
What can lead to cerebral vasodilatation?
Increased PaCO2
Decreased PaO2
Decreased pH
Decreased cerebral perfusion pressure
Types of hydrocephalus?
Communicative (absorption issue)
non-communicative (blockage)
Types of cerebral drains?
Subarachnoid
Intraventricular
Intraparenchymal
Epidural
Treatment options for raised intracranial pressure?
Heads up
Venous drainage (e.g. central line)
Sedation
Hyperventilation
CSF drainage
Mannitol
Roles of the parietal, temporal, frontal and occipital association cortexes?
Parietal AC: attending to stimuli
Temporal AC: recognising stimuli
Frontal AC: planning responses
Occipital AC: recognising visual stimuli
What is neglect syndrome, what area of the brain is damaged?
When the left visual field is completely ignored by patients
Damage to the right parietal lobe
Why is neglect syndrome always caused by damage to the right parietal lobe and not the left?
The left visual field only has connections to the right parietal lobe, but the right visual field has connections to left and right
What is agnosia?
Two types?
Agnosia: inability to recognise things
Somatosensory: The inability to recognise objects by touch
Prosopagnosia: Inability to recognise faces
What is apraxia, two categories?
Conditions involving damage to the prefrontal cortex
Ideomotor:
- inability to execute learned purposeful movements
Conceptual apraxia:
- inability to complete multistep actions in the correct order
What is aphasia, the two categories, and where is damaged in those categories?
Aphasia is damage to areas of speech
Expressive is inability to produce the correct speech = motor (broca’s area)
Receptive aphasia = sensory (wernicke’s area)
Three types of learning/conditioning?
Classical conditioning - association of one thing with another causing one response to be linked to a new stimulus
Operant conditioning - Using both positive and negative reinforcement (negative reinforcement is NOT punishment but the removal of a negative thing, e.g. less hunger)
Social learning theory - complex learning requiring high amounts of cortical functioning
Two types of long-term memory?
Procedural - cognitive perceptual and motor skills
Declarative - facts
Three levels of encoding of memories?
- Structural (how it looks) - not encoded very well
- Phonemic (how it sounds) - encoded intermediately well
- semantic (what it means) - encoded very well
Types of forgetting?
Failure to encode
Decay
Retrieval failure: can’t find memory cue
motivated forgetting: repressed memories
interference: confusion with other memories
Two categories of myelopathies?
Compressive
Non-compressive
Examples of a compressive myelopathy?
Cervical spondylosis
Tumour
Epidural abscess
Trauma
Central cord syndrome
Examples of non-compressive myelopathies?
Acute: vascular infarction
Sub-acute: MS/HIV, EBV
Chronic:
hereditary spastic paraperesis MND Tumour Copper/B12 deficiency MS HIV, syphilis
Process of positive adjustment in patients with a long-term-condition
- Diagnosis
- Adjustment process
- Adjustment outcome
Stages of change in a patient?
Precontemplation
Contemplation
Preperation
Action
Maintenance/relapse
Common classifications of dementia?
Dementia with lewy bodies (15%)
Vascular (20%)
Alzheimers (60%)
Classification of dementia diagnosis?
Progressive decline in memory and other cognitive abilities > 6 months
Common features of dementia?
Apraxia/Aphasia
Cognitive decline
treatment for dementia?
AchEI - Donepezil
Memantine - stabilises glutamatergic neurotransmission
rare causes of dementia?
FTD - frontotemporal dementia
Huntingtons
CJD
Possible modes of genetics of dementia
- Autosomal dominant, every generation has it
- Familial dementia: one or more relative has it
- Sporadic: out of the blue
Details of autosomal dominant genetic inheritance of dementia?
Early onset, APP gene thought to be the cause
APOE gene also implicated
What are the functions of the reticular formation?
Ascending pain pathways
Integrative functions
What are the parasympathetic nuclei and their outputs?
Edinger westphal - Ciliary
Superior salivatory - Facial - Pterygopalatine ganglion and submandibular gland
Inferior salivatory - Glossopharyngeal - Otic
How does the corneal reflex work?
The efferent limb from each eye is the facial nerve, they then synapse on the MLF which connects the efferent limb to the afferent limb (trigeminal nerve)
If the corneal reflex arc is transected at the afferent limb what is lost?
Both corneal reflexes of the eye are lost
If the corneal reflex is transected in the efferent limb on the direct side what is lost?
The direct response is lost but the consensual is still present.
What travels in the DLF (dorsal lateral fasciculus)?
The reticulospinal tract.
The process of the pupillary light reflex?
Afferent limb - optic nerve
Efferent limb - occulomotor nerve
Optic nerve - Pretectal nuclues (PAG) - Edinger westphal nucleus (PAG) - Occulomotor nerve - Ciliary ganglion
Why do both pupils restrict even when light is shone into only one?
The pretectal nucleus sends fibres to both edinger westphal nuclei
When might the pupillary reflex be absent?
MS
Uncal herniation
Horners syndrome
What are the two eye movements transmitted by the MLF?
Circadic movements - one thing to another e.g. words (voluntary)
Smooth Pursuit movements - watching a moving object (involuntary)
What type of cortex covers most of the human brain, how many layers does it have?
Neocortex - 6 layers
What is cell layer 4 and 5 for in the neocortex, what is larger in the PMC and PSC?
Cell layer 4 is for inputs - larger in the PSC
Cell layer 5 is for output - larger in the PMC
What would a lesion to the right parietal association cortex commonly cause?
Contralateral neglect syndrome (left hemineglect)
What is the definition of agnosia/aphasia/ataxia/apraxia/amnesia?
Agnosia - inability to recognise things
Aphasia - deficits in speech
Ataxia - inability in coordination
Apraxia - deficits in planning of motor actions
Amnesia - memory deficits
Two forms of apraxia?
Ideomotor - can’t execute learned movements voluntarily
Conceptual - can’t execute multistep actions in the right order
Two types of aphasia, what is damaged in each?
Expressive - damage to brocas area - slow laboured monotonous speech
Receptive - damage to wernickes - fluent speech with the wrong words, unaware of the mistakes being made, unable to read
What area is damaged in prosopagnosia?
Fusiform gyrus in the temporal lobe
What is a depressive episode defined as?
2 of the following:
- Pervasive low mood
- reduced energy
- Reduced interest and enjoyment
For 2 weeks
