The CNS Part I Flashcards
What is Neuroglia astrocytes?
It acts as a metabolic buffers and detoxifies, and acute cell injury causing cellular swelling
What is Neuroglia oligodendrocytes?
It produces myelin, and injury of oligodendrocytes is a feature of acquired
demyelinating disorders
What is Neuroglia Ependymal cells?
It produces CSF
What are the major levels of CNS?
- Lower Brain or Subcortical Level
- Higher Brain or Cortical Level
- Spinal Cord Level
- Ascending Reticular Activating System (ARAS)
What role does the Ascending Reticular Activating System (ARAS) play?
relays stimulations from environmental stimuli to the thalamus and then to the cerebral cortex
What role does the Spinal Cord Level play?
the upper levels of the nervous system sends signals to the control centers of the cord
What role does the Higher Brain or Cortical Level play?
without the cerebral cortex, the functions of the lower brain centers are not often accurate
What role does the Lower Brain or Subcortical Levelplay?
subconscious activities of the body are controlled in the lower areas of the brain
What is the Normal Physiology of CSF?
- CSF production
- CSF functions
What is CSF production?
by the choroid plexus of each ventricle
What is CSF functions?
flow between the cranium and spine and compensate for changes in intracranial blood volume. Also the balance between production and absorption of CSF is critically important
What are is a Barrier Systems and, what are the different types of barriers?
It is a selectively inhibit certain potentially harmful substances in the blood from entering the brain or CSF
Blood-brain barrier (BBB), Blood-CSF barrier
What is Blood-brain barrier (BBB)?
a series tight junctions between endothelial cells and astrocytes with processes on capillary walls
What is Blood-CSF barrier?
formed by tight junctions between choroid epithelial cells
What is Intracranial Pressure (ICP)?
The pressure inside the cranial cavity, normally ≤15 mmHg
What is ICP/Cerebral Blood Flow/Autoregulation?
erebral blood flow (CBF) is maintained at a relatively constant level, within a mean arterial pressure range of 60 to 150 mmHg. At about 180 mmHg the autoregulation fails causing cerebral edema and increased ICP
What is the formula of CBF?
CBF = (CAP - JVP) ÷ CVR
What are two major cause’s of Elevated ICP?
- Vasogenic edema
- Cytotoxic edema
What are the Clinical Manifestations of Elevated ICP?
Global symptoms (Headache, Decreased consciousness, Vomiting), Focal symptoms (Herniation)
What is Herniation and, what is Tonsillar herniation?
the displacement of brain tissue through openings in the skull, compromises vital respiratory and cardiac centers in the medulla
What is the Pathophysiology of Normal Pressure Hydrocephalus (NPH)?
- Idiopathic NPH
- Secondary NPH
What is NPH?
it is a form of communicating hydrocephalus
What is the Clinical Triad of NPH?
Gait difficulty
Nomenclatures of Hypoxic-Ischemic Brain Injury?
- Minimally conscious state
- Persistent vegetated state (PVS)
- Coma
- Brain death
transient ischemic attack (TIA)
TIA is transient episode of neurologic abnormalities caused by focal brain or spinal cord without acute infarction, ischemic stroke is infarction of brain or spinal cord death due to ischemia, based on neuropathologic, neuroimaging and/or clinical evidence of permanent injury
What is the mechanisms of Ischemic Cell Injury and Death?
- parenchyma (core) undergoes immediate death
- injured with potential to recover (penumbra)
What’s the common etiology of Spontaneous ICH?
Hypertensive vascular abnormalities
What are types of Intracerebral Hemorrhage (ICH)?
- Subarachnoid hematoma (SAH)
- Subdural hematoma (SDH) (bridging veins)
- Epidural hematoma (EDH) AKA extradural hematoma
Where can brain parenchyma may be?
- in the frontal lobe: clinically silent
- severely in the spinal cord: disabling
- in the brainstem: fatal
What is the list of GCS score for Traumatic Brain Injury (TBI)?
- 13 to 15 (mild traumatic brain injury)
- 9 to 12 (moderate)
- 8 or less (severe)
What is the Pathophysiology of TBI?
Primary brain Injury occurs at time of trauma causes Tissue shearing at diffuse axonal injury (DAI), Resulted damage Focal cerebral contusions, Secondary brain Injury
What is the pathophysiology of Acute Mild TBI vs Concussion?
Causes neurological changes that reflects functional injury rather than structural one
What are the clinical manifestations of Acute Mild TBI vs Concussion?
Confusion and amnesia
What are contusions?
are areas of injury with localized ischemia, edema and mass effect
What is a concussion?
wide reaching injury
What is Chronic Traumatic Encephalopathy (CTE) Neuropathology?
There is superficial cortical layers
What are the clinical features of Chronic Traumatic Encephalopathy (CTE)?
Cognitive impairments (memory and executive function) Behavior abnormalities (Aggression, paranoia, impulsivity) Mood disorders (Depression, anxiety, suicidality)
What are the open and closed defects of Spinal dysraphism?
Myelomeningocele, Closed spinal dysraphism
What is Cerebral Palsy?
permanent non-progressive central motor dysfunction that affect muscle tone, posture and movement
What is the Pathogenesis of Cerebral Palsy?
Periventricular leukomalacia (PVL) (necrosis of the white matter), commonly occurs in occurs in premature infants
What happens if an individual develops a CNS Infections?
may damage the nervous system, microbes access the CNS by Hematogenous spread
What is Pathogenesis of Bacterial Meningitis?
- Colonization and invasion
- Intravascular survival
- Inflammatory response
What are the clinical presentations of Aseptic Meningitis?
similar presentation to that of bacterial meningitis, but it’s self-limited
What are the Features and the Pathophysiology of MeClinicalningitis?
Fever, headache, stiff neck, altered mental status, nausea and vomiting
What is Aseptic Meningitis?
patients who have clinical and laboratory evidence for meningeal inflammation with negative routine bacterial cultures
What is Meningitis?
inflammatory of the leptomeninges
What is Neural Tube Defects (NTDS)?
are one of the most common congenital anomalies and are the cause of chronic disability