CHAPTER 5: Brain Damage and Neuroplasticity

Tumor

-or neoplasm (literally, new growth ), is a mass of cells that grows independently of the rest of the body

- can form when cells grow and divide more than they should, or when they do not die when they should.

TYPES OF TUMORS

Benign Tumors and Malignant Tumors

Benign tumors

are non-cancerous

Examples of benign tumors

-          Uterine fibroids

-          Lipomas

-          Meningiomas

-          Osteomas

Malignant Tumors

are cancerous and likely to spread to other parts of the body such as;

-          Breast            - Lungs

-          Skin                - Brain

-          Liver               - Bone

-          Ovaries           - Prostate

Benign Brain Tumors

     Meningiomas are benign tumors that grow between the meninges

• They are encapsulated meaning they grow within their own membrane. As a result, they are particularly easy to identify on a CT scan,

• They influence the function of the brain only by the pressure they exert on surrounding tissue,

Malignant Brain Tumors

       Most brain tumors are malignant - meaning they grow diffusely through surrounding tissue.

• It is difficult to remove or destroy them completely, and any cancerous tissue that remains after surgery continues to grow.

metastatic

they grow from other parts of the body (lung cancer) and carried to the brain.

MILD NCD’S

The cognitive deficits do not interfere with capacity for independence in everyday activities

MAJOR NCD’S

The cognitive deficits interfere with capacity for independence in everyday activities

Alzheimer’s Disease

is the most common cause of NCD’s. It sometimes appears in individuals as young as 40, but the likelihood of its development becomes greater with advancing years

- It is characterized by a steady decline in cognition

Biological Basis of Alzheimer’s

the abnormal buildup of proteins, specifically amyloid plaques and tau tangles, which disrupt brain cell function and communication, leading to neuronal damage and death.

Age is the strongest risk factor for Alzheimer's disease followed by genetic mutation, acetylcholine decrease, history of vascular disease, and brain injuries

Frontotemporal lobar degeneration

progressive decline in behavior (apathy, disinhibition, stereotyped behavior) or language (aphasia) associated with degeneration of the frontal and anterior temporal lobes.

Lewy body disease Lewy Bodies

progressive cognitive impairment, recurrent complex visual hallucinations; and concurrent symptoms of rapid eye movement (REM) sleep behavior disorder; as well as hallucinations in other sensory modalities, depression, and delusions.

Biological Basis of Lewy Bodies

The abnormal accumulation of alpha synuclein protein, forming Lewy bodies, which damage brain cells and disrupt brain function.

• Risk factor genes resulting in a decline in neurotransmitter levels, particularly acetylcholine and dopamine

Stroke

 sudden-onset cerebrovascular disorders that cause brain damage.

Infarct

area of dead or dying tissue produced by a stroke.

Penumbra

·         Surrounding the infarct is a dysfunctional area.

Cerebral Hemorrhage

       occurs when a cerebral blood vessel ruptures and blood seeps into the surrounding neural tissue and damages it.

Aneurysm

is a pathological balloon like dilation that forms in the wall of an artery at a point where the elasticity of the artery wall is defective

• It can be congenital (present at birth) or due to high blood pressure

Cerebral Ischemia

       A disruption of the blood supply to an area of the brain.

4 main causes of Cerebral Ischemia

Thrombosis

Embolism

Arteriosclerosis

Atherosclerosis

Thrombosis

a plug is formed and blocks blood flow at the site of its formation.

Embolism

a plug is carried by the blood from a larger vessel, where it was formed, to a smaller one, where it becomes lodged;

Arteriosclerosis

 thickening of blood vessels due to calcium deposits

Atherosclerosis

– narrowing of blood flow due to fatty deposits

Traumatic brain injury

brain trauma with specific characteristics that include at least one of the following: loss of consciousness, posttraumatic amnesia, disorientation and confusion, or, in more severe cases, neurological signs

Concussions

- a temporary disturbance of consciousness following a blow to the head without structural damage or internal bleeding

Punch-drunk syndrome

– cognitive deficits due to cerebral scarring observed in boxers and other individuals who experience repeated concussions.

Contusions

are closed-head that produces internal hemorrhaging, called hematoma.

hematoma

a localized collection of clotted blood in an organ or tissue in other words, a bruise

Example of Substances that can cause NCD

ALCOHOL,  INHALANT, and SEDATIVE, HYPNOTIC, OR ANXIOLYTIC

HUMAN IMMUNODEFICIENCY VIRUS

HIV is found in the blood and other body fluids such as semen, vaginal secretions and breast milk of mothers infected with the virus.

Meningitis

inflammation of the meninges. Penicillin and other antibiotics sometimes eliminate bacterial infections of the brain, but they cannot reverse brain damage that has already been produced.

General Paresis

caused by Syphilis bacteria passed through contact with genital sores.

The infecting bacteria go into a dormant stage for several years before they attack many parts of the body, including the brain causing insanity and dementia

Rabies

zoonotic, viral disease affecting the central nervous system.

Spongiform encephalopathies

caused by transmissible agents known as prions (misfolded proteins).

Creutzfeldt-Jakob disease

most common type of spongiform encephalopathies, ( a rare variant is called "mad cow disease.“) characterized by neurocognitive deficits, muscle contractions, and abnormal movement

Parkinson’s Disease

movement disorder of middle and old age that affects 1-2% of the elderly population

• Although Parkinson’s patients often display cognitive deficits, the emphasis is on the involuntary tremors

substantia nigra

a midbrain structure crucial for motor control and reward processing

Biological Basis of Parkinson’s Disease

Huntington’s Disease

is rare (1 in 10,000), it has a strong genetic basis, and it is associated with severe dementia.

• As the disorder develops, rapid, complex, jerky movements of entire limbs begin to predominate

increased fidgetiness.

first sign of Huntingtons’ disease

huntingtin

a single dominant gene that passes huntington’s from generation to generation

Epilepsy

brain disease where nerve cells don't signal properly, which causes seizures

Seizures

uncontrolled bursts of electrical activities that change sensations, behaviors, awareness and muscle movements

epileptic seizure

primary symptom of epilepsy

Multiple Sclerosis

       progressive disease that attacks the myelin of axons in the CNS; so severe that the axons become dysfunctional and degenerate

• It is an autoimmune disorder a disorder in which the body s immune system attacks part of the body, as if it were a foreign substance.

Symptoms of Multiple Scleriosis

• Common symptoms of advanced multiple sclerosis are visual disturbances, muscular weakness, numbness, tremor, and ataxia (loss of motor coordination).

• In addition, cognitive deficits and emotional changes occur in some patients