Class 16 - Alterations in Neuro - Stroke, Tumours, Infection, Seizures Flashcards
Transient Ischemic Attack
- Transient interruption of perfusion to the brain. Lasts no more than an hour.
- 80% have recurrence
- Warning of impending stroke
Ischemic Stroke
Obstruction of blood flow to th point where neurons die
- 80-87% of all strokes
Thrombotic
- Formed in the brain
- Blood clot blocks flow
- Related to atherosclerosis. The plaques can crack, bleed, and start the formation of a clot
- Risk factors: diabetes, dyslipidemia, smoking, hypertension. Males, obesity, and lack of exercise.
Embolic “thromboembolic”
- Bits of clot forms elsewhere
- Atrial fibrillation. Stasis of blood flow in the chambers, risk for clot forming, and can travel to the brain
Pathophysiology
- Interruption of blood flow leads to cell injury, inflammation, edema, ischemia, infarction (death) of brain tissue
- A surrounding area of borderline tissue
Diagnosis and Treatment
- Need a CT scan
- Possible fibrinolytic (thrombolytics) clot busters
Hemorrhagic Stroke
Spontaneous rupture of blood vessels
- 13-20% of strokes
- Higher fatality
Caused by
- Hypertension. Blood vessels in the brain may burst.
- Cerebral aneurysms (berry aneurysms) will rupture if we have a high blood pressure
- Arteriovenous malformation. Missing arterioles, capillaries, venules
Locations
- Subarachnoid
- Intracerebral
General Stroke Manifestations and Outcomes
Manifestations FAST - Facial droop - Arm Drift - Speech - Time to call 911 Weakness Trouble speaking Vision problems Headaches - hemorrhagic, worst headache ever
Outcomes
Out of 100
- 15 die
- 10 recovery completely
- 25 will recover with minor impairment
- 40 will be left with moderate to severe impairment
- 10 will require long-term care
Brain function depends on where the location of the stroke is
- Cognitive communication, comprehension disorders. Aphasia, Dysphasia, Agnosia
- Memory, attention, emotions, behaviour, personality
- Motor function, posture, muscle tone, gait, and swallowing
Levels of Preventions for Strokes
Primary
- Controlling hypertension
Secondary
- Early assessment
Tertiary
- Early CT scan to differentiate ischemic vs. hemorrhagic (stroke ambulance)
- Ischemic stroke (fibrinolytic clot buster)
- Hemorrhagic stroke (surgery to stop bleeding)
Brain Neoplasia
No proven causative agents
Primary brain tumours started in the brain Intra cerebral tumours/gliomas 1. Astrocytoma (40%) 2. Oligodendroglioma (4%) - Schwann cells are ANS - Make myelin 3. Ependymoma (3%) - Ependymal produces CSF Extra cerebral tumours 1. Meningioma (30%)
Secondary/metastatic
- 10-15% of people with other cancers will develop metastasis to the brain
- Lungs, melanoma, breast or kidnys
Incidence
- Adults: increases up to the age of 70 then decreases
- Most are supratentorial (above the brainstem and cerebellum)
Manifestations
- Local: may be malignant by location
- Generalized: related to intracranial pressure
- Treatment: Radiation, surgery. Chemotherapy generally not effective due to the BBB
Benign vs. Malignant Neoplasia of the Brain
- Differences between the two are less clear than elsewhere in the body
- Microscopically small benign tumours can cause severe debility or death
- Difficult to completely remove - tumour cells look similar to normal tissue
- Some tumours cannot be accessed
- Primary malignant brain tumours rarely metastasize outside of the brain
Bacterial Meningitis
Rapid onset
High mortality rate
Organisms vary:
1. Acute
- Escherichia coli - newborns (no vaccination)
- Haemophilus influenzae - children under 7
- Neisseria meningitides - young adults
- Streptococcus pneumoniae - mature adults
- Chronic
- Terponema pallidum - Syphilis
Risk factors:
- Open head injuries
- Basal skull fractures
- Sinusitis
- Otitis
- Immunocompromised individuals
- Dormitories, military bases (neisseria meningitides)
Manifestations
- Neurological signs: seizures, projectile vomiting
- Infectious signs:
1. Fever, tachycardia, chills, malaise
2. Lumbar puncture to culture. CSF is tested for glucose level, bacteria present = lower glucose
3. Petechiae/purpura with NM - Meningeal signs
1. Nuchal (neck) rigidity, headache, photophobia
2. Kernig’s signs
3. Brudzinski’s signs
Complications - Increased ICP, cerebral edema - Impaired level of consciousness - Seizures - Focal neurological deficits (hemiparesis) - Cerebrovascular abnormalities - Hydrocephalus - Hearing loss - Amputation - Renal failure Morality rate is 25-100%
Viral Meningitis
- Most are enteroviruses, 80 kinds
1. Mumps
2. HSV-1,2
3. Epstein Barr virus
4. Influenza type A and B
Manifestations
- Headache
- Photophobia
- Mild neck pain
- Fever
- Malaise
Treatment
- Antivirals, supportive, corticosteroids
Seizures
Abrupt, explosive, disorderly discharge of cerebral neurons
- Causes involuntary movements, behavioural and sensory alterations, as well as changes in LOC
Status Epileptics
- One long seizures, or a chain of seizures for 30 minutes
Febrile Seizures
- With a fever of 39 degrees or higher
Incidence
- 2-4% have multiple seizures
- Decreases after the age of 6
Classification
- Partial seizures: electrical discharge in one are of the brain
- Generalized seizures
1. Tonic clonic. Altered LOC, incontinent of urine, generalized arching then shaking. Grand mal.
2. Absent. Petit mal
3. Myoclonic. Jerking for only a second or two.
Provoked Seizure
A symptom of underlying disorders
- Fever
- Metabolic conditions: electrolytes, glucose, hypoxia
- CNS insult: infection, cerebral lesions, cerebral trauma
Unprovoked Epileptic Seizure
- A chronic seizure disorder with recurrent, unprovoked seizures
- Cause: genetic and environmental
Triggers
- Stress, fatigue
- Lights, music, odor
Many people experience aura
- Change in light, visual colours, or smelling different things as a warning sign before they have a seizure
