Cerebral Spinal Fluid (CSF)

Cerebral Spinal Fluid (CSF)

• CSF is a fluid that surrounds the brain and spinal cord, providing cushioning
• CSF composition is similar to blood plasma

Ventricle

• Ventricles are cavities in the brain that are filled with CSF
• There are four ventricles: left, right, third, and fourth

Choroid Plexus

• The choroid plexus consists of specialized cells lining the ventricles
• These cells are responsible for creating CSF

Lumbar Puncture

• Lumbar puncture is a procedure used to withdraw CSF for testing
• CSF extraction takes place from the spinal column, below the spinal cord

Arachnoid Granulations

• Arachnoid granulations are bubble-like portions of the arachnoid mater
• The arachnoid mater is the middle layer of the meninges
• They extend into the draining venous sinus system
• Arachnoid granulations remove CSF from around the brain, recycling it into the bloodstream

Hydrocephalus

• Hydrocephalus is a disorder related to CSF, affecting CSF flow and reuptake
• Hydrocephalus can lead to head enlargement, developmental issues, and changes in eye gaze
• Untreated hydrocephalus may result in death
• Hydrocephalus can be developmental/acquired, treated with a shunt to siphon CSF into the abdomen

Hydrocephalus Ex Vacuo

• Hydrocephalus ex vacuo involves large spaces developing inside the cortex due to cortical tissue loss
• Cortical atrophy is seen in dementia cases
• The condition is not true hydrocephalus

Non-communicating Hydrocephalus

• Non-communicating hydrocephalus is caused by an obstruction of normal CSF flow
• CSF pressure rises behind the obstruction (between the choroid plexus and obstruction)
• Blockages can be caused by tumors, masses, blood clots, or infections

Communicating Hydrocephalus

• Communicating hydrocephalus arises from issues with CSF uptake through arachnoid granulations
• This condition leads to increased pressure throughout the entire CSF system

Shunt

• Shunts are tubes implanted in the skull to drain excess fluid in brain disorders like hydrocephalus and strokes
• Types of shunts include ventriculoperitoneal and intraventricular shunts

Blood Vessels

• Blood vessels transport blood throughout the body
• Arteries carry oxygenated blood away from the heart
• Capillaries facilitate exchange of water, O2/CO2, and waste between blood and tissues
• Veins carry de-oxygenated blood from capillaries back to the heart
• Arteries carry high-pressure blood, decreasing as they branch into smaller arteries

Blood Pressure & Capillary Beds

• Pressure is very low in the capillary beds
• This low pressure continues into the venous system
• Arteries feature a large smooth muscle layer, which provides mechanical strength to handle blood pressure

Circle of Willis

• The Circle of Willis is a circular arrangement of arteries supplying blood to the brain
• It allows for collateral blood flow in the brain

Carotid Artery

• The carotid artery supplies oxygenated blood to the head and neck
• There are two carotid arteries
• Carotid Arteries supply blood to the anterior part of the brain
• The carotid artery divides into internal and external carotid arteries in the neck

Vertebral Artery

• The vertebral artery runs up the back of the neck and joins at the skull base/forms the basilar artery
• There are two vertebral arteries
• These vessels supply the posterior part of the brain

Basilar Artery

• The basilar artery supplies blood to the pons, cerebellum, posterior cerebrum, and inner ear
• It is formed by the merging of the vertebral arteries

Middle Cerebral Artery

• Supplies the lateral cerebral cortex and anterior temporal lobes
• Strokes to this artery can affect face, arm, and language use

Anterior Cerebral Artery

• Supplies oxygen to medial portions of frontal lobes and superior medial parietal lobes
• Strokes here can affect leg use

Stroke

• Stroke involves the rapid loss of brain tissue and function due to disrupted blood supply

Transient Ischemic Attack (TIA)

• TIA is also called a 'mini stroke'
• TIA can have the same symptoms as a stroke, but the symptoms are only temporary

Ischemia

• Ischemia is the lack of oxygen due to a restriction in blood supply

Ischemic Stroke

• Ischemic stroke results from restricted blood flow to a region of brain tissue

Thrombus

• A thrombus is a clot or atherosclerotic plaque that forms in place within a blood vessel and obstructs blood flow
• A thrombus may break apart and form an embolus

Embolus

• An embolus is a moving clot that lodges in a small vessel

Carotid Stenosis

• Carotid stenosis is an abnormal narrowing of the carotid artery
• Carotid Stenosis is often caused by atherosclerotic plaque formation

Hemorrhage

• Hemorrhage is bleeding/loss of blood from the circulatory system

Hemorrhagic Stroke

• Hemorrhagic stroke occurs when blood bleeds into the brain, damaging tissue

Aneurysm

• An aneurysm is a localized, blood-filled bulge of a blood vessel

Subarachnoid Hemorrhage

• Subarachnoid hemorrhage is bleeding between the arachnoid and pial meningeal layers
• The subarachnoid space contains CSF and spider-web-like protrusions of the arachnoid mater

Intracerebral Hemorrhage

• Intracerebral hemorrhage involves bleeding within the brain tissue itself, below the pia mater

Intraventricular Hemorrhage

• Intraventricular hemorrhage is bleeding from vessels along the ventricles, directed into the ventricles

tPA

• tPA is a drug made from tissue plasminogen activator which breaks down blood clots
• tPA treats ischemic stroke if administered within 3 hours of symptom onset

Venous Malformation

• A venous malformation is a congenital vascular anomaly involving veins or veins and arteries
• Such malformations can increase the risk of bleeding and/or abnormal oxygen delivery

Arteriovenous Malformation (AVM)

• AVM is a vascular malformation where abnormal blood vessels tangle connecting arteries and veins in the brain
• This increases bleeding risk and decreases normal oxygen flow due to lack of capillary beds for gas exchange

Venous Thrombosis

• Venous thrombosis is a blood clot that forms within a vein
• In the brain, this can occur in the large venous sinuses, blocking blood flow and often being fatal

Bridging Veins

• Bridging veins drain neural tissue, puncturing through the dura mater to drain into the venous sinuses
• They may tear with trauma, leading to subdural hematomas
• Alcoholism weakens the veins and shrinks the brain, increasing stress on bridging veins

Hematoma

• A hematoma is a solid swelling of clotted blood within tissues, also known as a bruise under the skin
• In the brain, it causes local mass effects, compressing and injuring tissue

Subdural Hematoma

• Subdural hematoma is bleeding below the dura, between the dura and brain/spinal cord
• This causes blood build-up, compressing the brain due to trauma

Epidural Hematoma

• Epidural hematoma involves bleeding between the skull and dura, builds up blood and compresses the brain/spinal cord
• It often occurs due to trauma, with a skull fracture
• The onset is faster/more serious due to higher-pressure arterial blood involvement

Traumatic Brain Injury (TBI)

• TBI is damage to the brain due to external physical force, commonly known as concussion

Coup/Contra-coup Injury

• Coup/contra-coup injury results from focal injury or whiplash
• The side of the brain directly hit and the opposite side are both damaged

Diffuse Shearing Injury

• Diffuse shearing injury occurs with rapid acceleration/deceleration forces
• Cell bodies and axons are separated, leading to widespread brain injury

Phineas Gage

• Phineas Gage had a train spike shoot through his frontal cortex
• He survived, but was emotionally disturbed afterward

Blood Brain Barrier

• The blood brain barrier is a filtering mechanism of capillaries
• It carries blood to tissue, blocking certain substances like infectious agents, immune cells, and some drugs

Meningitis

• Meningitis is a viral or bacterial infection of the meninges
• Symptoms include rash, stiff neck, headache, vomiting, and mental status change

Encephalitis

• Encephalitis is an infection of brain tissue, usually viral, but can be herpes
• Symptoms include personality changes, seizures, and weakness

Measles

• Measles is a childhood infection caused by a virus
• Measles is preventable with a vaccine
• Measles symptoms include high fever, cough, runny nose, and watery eyes 7-14 days after contact with the virus
• Measles rash appears 3-5 days after the first symptoms appear

Measles Vaccine & SSPE

• The measles vaccine does NOT cause autism, but measles causes neurological complications
• Subacute sclerosing panencephalitis (SSPE) is marked by measles, followed by an asymptomatic period that averages 7 years
• SSPE includes progressive neurological deterioration, behavioral and intellectual changes, myoclonic seizures, blindness, ataxia, and death

Presentation of SSPE

• In the classic presentation of SSPE death occurs in 1 to 3 years
• Acute fulminant leads to death within 3 months

Rabies

• Rabies is a virus entering the brain via peripheral nerves
• It causes diffuse brain swelling
• Rabies symptoms include headaches, fever, rages, inability to swallow water, coma, and death

Prion

• Prion is an infectious protein molecule

Creutzfeld-Jakob Disease (CJD)/Transmissible Spongiform Encephalopathy

• CJD is commonly known as mad cow disease
• Prional infection kills off brain cells, creating numerous lacunae (‘lakes’) in the brain tissue
• CJD symptoms include dementia and problems with coordination

Encephalopathy

• Encephalopathy is a disorder/disease of the brain
• Not a single disease, but a syndrome of global brain dysfunction
• Caused by many different illnesses

Cysticercosis

• Cysticercosis occurs from infection from the pork tapeworm
• Cysticercosis symptoms include headache, stroke-like effects, brain swelling, risk of death

Brain Tumor

• Brain Tumors are intracranial growths from abnormal/uncontrolled cell division
• Tumors can be in the brain itself, cranial nerves, brain envelopes, skull, and pituitary/pineal gland
• It can also spread from other organs (metastatic tumors)
• Tumors damage through direct damage/mass effect through pressure

Holoprosencephaly

• Holoprosencephaly is a congenital disorder due to the failure of the embryonic forebrain to divide into the double lobes of the cerebral hemispheres
• It results in a single-lobed frontal brain structure, with skull and facial defects

Autism

• Autism is a diffuse developmental disorder with impaired social interaction and communication

Epilepsy

• Epilepsy is a chronic neurological disorder with recurring seizures

Neurodegeneration

• Neurodegeneration involves a progressive loss of neuron structure/function, including death

Dementia

• Dementia is a progressive decline in cognitive function due to damage or disease in the brain

Atrophy

• Atrophy is the loss of cells

Alzheimer’s Disease

• Alzheimer’s disease is a form of dementia hallmarked by loss of memory and cognitive abilities with widespread neurodegeneration