Neurology Diseases and Traumatic Brain Injury

Damage to myelin sheaths of peripheral nerves, preserving axons, leading to slower nerve conduction.

Damage to peripheral nerve axons, leading to decreased signal amplitude and progressive axon loss.

Damage to the brain caused by physical forces; may include skull fractures, parenchymal injuries, and vascular injuries.

Fracture where bone pieces shift into the cranial cavity, potentially compressing brain tissue.

Injury to the brain due to altered blood flow; includes ischemic and hemorrhagic strokes.

Stroke caused by blockage of a cerebral artery, leading to reduced blood flow to brain region.

Stroke caused by bleeding in the brain; often due to high blood pressure, aneurysms, or trauma.

Collection of blood within the skull, directly above the dura mater.

Collection of blood between the dura mater and arachnoid membrane.

Bleeding into the subarachnoid space surrounding the brain.

Balloon-like bulge in blood vessel of the brain, prone to rupture and bleeding.

Abnormal tangle of blood vessels connecting arteries and veins.

Collection of enlarged blood vessels in the brain.

Excessive fluid accumulation in the brain tissue.

Abnormal build-up of cerebrospinal fluid (CSF) in the brain.

Higher-than-normal pressure inside the skull, putting pressure on the brain.

Autoimmune disorder causing demyelination in the central nervous system (CNS).

Progressive brain disorder affecting movement due to dopamine deficiency in basal ganglia.

Neural tube defect causing incomplete closure of the vertebral column and spinal cord.

Neurodegenerative disease causing progressive loss of motor neurons.

Facial nerve paralysis of unknown origin.

Severe, recurring facial pain affecting cranial nerve V.

Immune-mediated demyelinating peripheral neuropathy.

Progressive decline in cognitive function affecting memory, thinking & behavior.

Damage to myelin sheaths surrounding axons in peripheral nerves. This disrupts nerve signal transmission, leading to slower conduction speed.

Longest axons are affected first, with damage spreading progressively closer to the cell body.

Slows down conduction velocity, as the signal has to jump between gaps in the myelin.

Reduced signal amplitude, due to loss of axons.

A fracture where bone is displaced into the cranial cavity, exceeding the thickness of the bone.

Symptoms related to lower cranial nerves, orbital or mastoid hematomas, and possible CSF leakage.

Damage to the brain caused by physical force that can include skull fractures, brain tissue damage, and vascular damage.

A blow to the head while awake often impacts the occiput, while a fall after loss of consciousness can affect the front or back of the head.

Diagnosis is most reliable when made at the time of injury or within the first 24 hours.

Change in level of consciousness (LOC) is the most reliable indicator of altered brain function.

A standardized tool for assessing level of consciousness in brain-injured individuals.

Coup injury is at the point of impact, while contrecoup is opposite to the point of impact.

Separation of the pons from medulla or medulla from cervical cord due to violent neck hyperextension.

Neurological signs and symptoms caused by a vascular mechanism, with acute onset and lasting beyond 24 hours.

A stroke's symptoms last longer than 24 hours, while TIA symptoms resolve within 24 hours.

Contralateral hemiplegia (weakness on one side of the body), hemisensory loss, and visual field blindness.

Atherosclerosis, coagulopathies, cardiac dysfunction, and atrial fibrillation.

Rupture of a blood vessel in the brain, usually due to high blood pressure, aneurysms, or trauma.

Ischemic infarcts are caused by blockage, while hemorrhagic infarcts are caused by bleeding.

Severe, chronic hypertension, diabetes, hyperlipidemia, smoking, and family history.

A brief period of normal cognition after a head injury, before consciousness deteriorates rapidly.

The middle meningeal artery.

Slowly progressive neurologic deterioration, but acute decompensation may also occur.

Rupture of a saccular aneurysm.

Cerebral aneurysms and arteriovenous malformations (AVMs).

Sudden, excruciating headache and rapid loss of consciousness.

Constriction of blood vessels around the brain, increasing the risk of ischemic injury.

Arteriovenous malformations (AVMs).

A collection of dilated, loosely arranged blood vessels with no brain tissue in between.

Increased fluid leakage from blood vessels and damage to CNS cells.

Brain injury at the point of impact, occurring when the head is immobile during trauma.

Brain injury opposite to the point of impact, occurring when the head is mobile during trauma.

Temporary neurological symptoms caused by a brief interruption of blood flow to the brain, lasting less than 24 hours.

Factors that increase your chances of having a stroke, including atherosclerosis, coagulopathies, atrial fibrillation, and high blood pressure.

Occlusive vascular disease leading to cerebral infarction can be caused by embolization from a distance, thrombosis in the brain, or various vasculitides.

The brain has limited collateral circulation, so occlusive infarcts usually begin as nonhemorrhagic events.

Brain infarcts are divided into two main categories: nonhemorrhagic and hemorrhagic, based on the presence of secondary hemorrhage.

These occur when the occlusive material in the brain dissolves or breaks apart, leading to ischemia-reperfusion injury and small bleeding events.

Mechanisms include oxidative stress, leukocyte infiltration, platelet aggregation, complement activation, mitochondrial damage, and BBB disruption.

Most commonly in the basal ganglia or thalamus.

Secondary injury and associated morbidity and mortality are much higher with hemorrhagic strokes.

A generalized reduction in brain perfusion, as in cardiac arrest, shock, or severe hypotension, or decreased oxygen-carrying capacity of the blood.

Bleeding into the space between the brain and the thin membranes covering it (arachnoid and pia mater).

The most common causes are ruptured aneurysms (balloon-like bulges in blood vessels) and arteriovenous malformations (AVMs, tangled blood vessels).

A narrowing of blood vessels in the brain after a subarachnoid hemorrhage. This constricts blood flow, and can lead to further brain damage.

A tangled mess of blood vessels where arteries and veins are directly linked, without the usual capillaries in between. This creates high blood pressure.

Sudden and severe headache, often described as 'the worst headache of my life', and rapid loss of consciousness.

It can happen in the first few days after the hemorrhage, and increases the risk of further brain damage.

Hydrocephalus - a buildup of cerebrospinal fluid (CSF) in the brain, which can put pressure on the brain and lead to neurologic issues.

Treatment focuses on preventing further bleeding, relieving pressure, and treating complications like hydrocephalus.

Patients may experience sudden loss of consciousness and rapid neurological decline.

A genetic disorder that primarily affects the nervous system, causing tumors to grow on the nerves in the brain and spinal cord.

Individuals with NF2 often have tumors on the acoustic nerve (vestibular schwannomas), leading to hearing loss and balance problems. They may also experience vision problems due to tumors on the optic nerve.

A genetic disorder caused by a mutation in the HTT gene, leading to the breakdown of nerve cells in the brain, especially in the area responsible for movement and thinking.

Huntington's disease is characterized by involuntary movements, particularly jerky movements called chorea, as well as cognitive decline and emotional changes.

The HTT gene contains a repeated sequence of three DNA building blocks (CAG). In Huntington's disease, this repeat is abnormally expanded, leading to the production of a faulty protein that accumulates in the brain and causes damage.

A chronic autoimmune disorder that attacks the myelin sheath in the central nervous system (CNS), disrupting nerve impulse transmission.

Often begins with unilateral visual impairment (optic neuritis), but most people with optic neuritis don't develop MS.

It follows a relapsing-remitting course, with periods of worsening symptoms (relapses) and periods of recovery (remissions) that eventually lead to progressive neurologic decline.

A progressive neurodegenerative disorder characterized by a deficiency of dopamine in the basal ganglia, leading to motor impairments.

Includes tremors, slow movements (bradykinesia), muscle rigidity, postural instability, and facial masking.

Abnormal protein deposits in the brains of individuals with PD, particularly in the substantia nigra, which is responsible for dopamine production.

No cure, but medications like dopamine precursors, agonists, and inhibitors help manage symptoms.

Dementia can develop in a significant number of individuals with PD, particularly with advancing age.

They initially appear in the brainstem, then progress upward into the limbic structures and eventually the neocortex.

A general lack of movement, loss of facial expressions (masking), drooling, shuffling gait, and absent arm swing.

Tissue death in the brain caused by lack of blood flow.

Brain infarcts are classified as nonhemorrhagic (no bleeding) or hemorrhagic (bleeding) depending on the presence of secondary hemorrhage.

Damage to the brain that occurs when blood flow returns after a period of blockage.

Cerebral edema caused by leaky blood vessels, often due to inflammation or tumors.

Type of hydrocephalus where CSF pressure is normal, but ventricles are enlarged, causing symptoms like dementia and walking problems.

The skull contains a fixed volume, with pressure influenced by brain tissue, CSF, and blood.

Brain tissue squeezing through a small opening in the skull, caused by increased pressure.

Brain folds (gyri) become flattened in generalized cerebral edema.

Increased pressure compresses the brain's fluid-filled cavities (ventricles).

An inflammatory myopathy affecting muscles and skin, typically with characteristic skin rashes and muscle weakness. Onset can be in childhood or adulthood.

Dermatomyositis that occurs in children, with an average age of onset around 7 years. It's the most common inflammatory myopathy in children.

Dilated capillary loops (tiny blood vessels) that can be seen on the skin, especially in the nail folds, eyelids, and gums. Common in dermatomyositis.

Small, raised bumps that appear on the knuckles, elbows, and knees, characteristic of dermatomyositis.

A purplish discoloration of the eyelids, also a feature of dermatomyositis. It's often accompanied by Gottron papules.

An inflammatory myopathy, similar to dermatomyositis but without the distinctive skin features. It primarily affects muscles causing weakness and pain.

Weakness in the muscles closest to the body's core (shoulders, hips). A common feature of dermatomyositis and polymyositis.

A group of inherited disorders that cause progressive muscle weakness and degeneration.

Muscular dystrophy that is present at birth and often progresses rapidly. Usually associated with developmental abnormalities of the brain and nervous system.

Antibodies that target a specific protein, called a helicase, involved in gene expression. They are associated with prominent Gottron papules and heliotrope rash in dermatomyositis.

Collagen, a protein, acts as a "glue" in the body, providing strength and elasticity to connective tissues.

Ehlers-Danlos syndrome (EDS) symptoms arise from faulty or reduced amounts of collagen, impacting joints, skin, and blood vessels.

Ewing sarcoma is a malignant bone tumor characterized by primitive round cells without obvious differentiation.

Approximately 80% of Ewing sarcoma cases occur in patients under 20 years old.

Common sites for Ewing sarcoma include the paraspinal tissues, pelvis, chest wall, and extremities.

Ewing sarcoma is often found in the diaphysis of long bones, specifically the femur, pelvis, and proximal humerus.

Radiographs show a destructive lytic tumor with permeative, "moth-eaten" margins and an "onion-skin" periosteal reaction.

Translocation involving the EWSR1 gene on chromosome 22 occurs in most Ewing sarcoma cases.

The EWSR1 gene encodes a chimeric EWS/FLI1 protein that dysregulates transcription, leading to uncontrolled growth.

Ewing sarcoma is the second most common malignant bone tumor in children, commonly affecting patients between 5 and 25 years old.

Most common skeletal dysplasia causing dwarfism. It's an autosomal dominant disorder with mutations in the FGFR3 gene, leading to decreased endochondral bone formation, affecting mainly long bones.

A condition with arthritis, urethritis or cervicitis, and conjunctivitis, often after infections like Chlamydia, Shigella, Salmonella, Yersinia, Campylobacter, and Clostrdioides difficile.

Shortened proximal limbs (arms and legs), an enlarged head with a bulging forehead, and a relatively normal-length trunk.

It's associated with HLA-B27 and often develops after infections, particularly genitourinary or gastrointestinal.

It starts with acute asymmetric oligoarthritis, mainly in the lower extremities, and can lead to chronic phases with recurrent arthritis, tendonitis, and lumbosacral pain.