mental disorders

Mental Disorders and Medication

  • Several mental disorders are the result of imbalances in brain chemistry.
  • This research has led to the development of new medications designed for treating specific mental and behavioral health disorders.

Selective Serotonin Reuptake Inhibitors (SSRIs)

  • SSRIs are a type of drug used to treat depression.
  • Definition: SSRIs inhibit the sending cell from reabsorbing the chemical serotonin.
  • Research findings suggest that depressed individuals have lower levels of serotonin compared to non-depressed individuals.
  • Mechanism: By blocking serotonin's reuptake, SSRIs enhance the effects of the existing serotonin on the receiving cell.
  • Common SSRIs include:
    • Lexapro (Escitalopram)
    • Paxil (Paroxetine)
    • Zoloft (Sertraline)

Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)

  • Definition: SNRIs block the reabsorption (reuptake) of the neurotransmitters serotonin and norepinephrine in the brain.
  • Common SNRIs include:
    • Venlafaxine
    • Desvenlafaxine
    • Duloxetine
  • SNRIs are also utilized to treat anxiety disorders.
  • Both serotonin and norepinephrine are crucial in the transmission of pain.
    • Implication: Drugs used to treat depression may also positively modulate pain sensation.

Neurological Disorders

Tetanus

  • Tetanus is a disease caused by the bacterium Clostridium tetani affecting the nervous and muscular systems.
  • Transmission: Bacteria enter through contaminated puncture wounds or animal bites.
  • Mechanism: The bacteria thrive in low-oxygen environments, leading to the death of tissues and multiplication of the bacteria.
  • The released neurotoxin impacts the motor neurons, resulting in:
    • Loss of inhibition signals to muscles.
    • Outcome: Excessive muscle contraction, prolonged spastic paralysis, and potentially death.
  • Vaccination with a modified tetanus toxin provides active immunity against the effects of the toxin and the bacteria.

Meninges and Cerebrospinal Fluid (CSF)

Meninges
  • The brain and spinal cord are covered by the meninges, consisting of three layers:
    • Pia Mater: Innermost layer, delicate and tight-fitting, contains blood vessels that nourish nerve tissue.
    • Arachnoid: Middle layer, lace-like membrane.
    • Dura Mater: Tough fibrous outer layer, protecting the CNS from mechanical damage.
  • Subdural Space: Located between dura mater and arachnoid.
  • Subarachnoid Space: Found between arachnoid and pia mater.
Ventricles and CSF
  • The brain has several cavities called ventricles, which connect to other brain sections through passageways.
  • The central canal of the spinal cord is connected to the most inferior ventricle.
  • Cerebrospinal Fluid (CSF):
    • Fills the cavities and acts as a shock absorber and protector for CNS tissues.
    • Transports nutrients (primarily proteins and carbohydrates).
    • Production: Formed continuously at a rate of 450extml450 ext{ ml} (15 ounces) per day.
    • Volume: Typically, 150extml150 ext{ ml} is present at any time in a normal adult.
    • Reabsorbed into blood vessels via arachnoid villi.

Neurological Diagnostic Tests

Common Tests and Their Purposes

  • Diagnosis of neurological disorders often requires specific tests.
    • Arteriography (Cerebral Angiography):
    • Involves inserting a catheter into an artery.
    • A dye is injected to visualize cerebral blood vessels via X-rays.
    • Can detect conditions like aneurysm, hemorrhage, cerebrovascular accidents, arteriosclerosis, and tumors.
    • Glasgow Coma Scale:
    • Assessment tool to evaluate level of consciousness.
    • Assesses eye movement, verbal response, and motor response.
    • Important for paramedics to report on patient condition during transport.
    • Computed Tomography (CT) Scan:
    • Series of X-rays to create a 3D image of the brain.
    • Useful for identifying tumors, bleeding, clots, and brain edema.
    • Takes about 15 minutes, may require contrast materials for clearer images.
    • Electroencephalography (EEG):
    • Measures electrical activity in the brain.
    • Can detect abnormalities such as epilepsy and sleep disorders but not intellectual disabilities unless linked to seizures.
    • Includes newer technologies like ambulatory EEG monitor for continuous monitoring.
    • Electromyography (EMG) and Nerve Conduction Studies (NCS):
    • EMG records electrical activity in muscles; NCS measures speed of nerve conduction.
    • Helps diagnose conditions like radiculopathy, ALS, and carpal tunnel syndrome.
    • Genetic Testing:
    • Can identify certain neurological disorders, including spina bifida, using amniocentesis or CVS.
    • Lumbar Puncture:
    • Involves CSF removal for examination, indicated in suspected infections or hemorrhages.
    • Magnetic Resonance Imaging (MRI):
    • 1977 technology using magnets to generate images.
    • Preferred for imaging the brain/spine if no metal implants are present.
    • Enhancements include MRA for blood flow imaging.
    • Myelography:
    • Injects contrast material into spinal space; viewed with fluoroscopy.
    • Used for irregularities in the spinal cord, lessened in usage due to MRI.
    • Positron Emission Tomography (PET) Scan:
    • Visualizes physiologic performance using radiolabeled agents.
    • Particularly useful for evaluating and staging malignancies.
    • Ultrasound Imaging:
    • High-frequency sound waves to obtain internal images, useful for diagnosing various conditions.
    • Neurosonography specifically analyzes blood flow to diagnose strokes and tumors.
    • X-Rays:
    • Commonly part of neurological assessments to view skeletal structures and potential abnormalities like fractures.

Alzheimer's Disease

Overview

  • Definition: Progressive degenerative disease affecting brain function, leading to impaired memory, thinking, and behavior.
  • Statistics: Approximately 6.7 million Americans reported having Alzheimer's in 2023, estimated to rise to 13.8 million by 2060 among those aged 65 and older.
  • Impact: Seventh leading cause of death in the US, with around 122,000 annual deaths attributed to the disease.

Signs and Symptoms

  • Gradual memory loss
  • Decline in routine task performance
  • Impairment in judgment
  • Disorientation
  • Personality changes
  • Difficulty in learning
  • Loss of language skills
  • Results in inability to care for oneself over time

Etiology

  • Exact cause is currently unknown.
  • Suspected causes include:
    • Genetic predisposition
    • Infectious agents (slow virus)
    • Environmental toxins
    • Immunological changes
  • The disease manifests as the extinction of certain brain cells, characterized by the presence of amyloid plaques and neurofibrillary tangles in affected brains.
  • Family history can increase risk; multiple first-degree relatives amplify this risk.
  • No cure currently exists; research aims to prevent nerve cell death and ensure neuroprotection.

Management and Care

  • Managing symptoms through medication, improving sleep, treating anxiety and depression, and promoting a structured environment is crucial.
  • Lifestyle changes: Physical exercise, healthy nutrition, social interactions, and cardiovascular health control are recommended.
  • Support for caretakers is vital given the disease's impact on daily living.
  • Average disease course ranges from 2 to 10 years, potentially extending up to 20 years.

Diagnosis

  • Typically includes taking a patient history, memory and problem-solving tests, lab and blood tests to check for beta-amyloid levels, urine tests, CSF analysis via spinal tap, and brain imaging scans (CT, MRI, PET).

Preventative Measures

  • Steps to potentially reduce Alzheimer’s risk:
    • Regular exercise
    • Balanced diet
    • Injury protection for the head
    • Strong social connections
    • Control over cardiovascular risk factors
    • Staying mentally active

Warning Signs

  • Key warning signs published by Alzheimer's Association include:
    • Memory loss disrupting daily life
    • Problems with planning or solving problems
    • Difficulty with familiar tasks
    • Confusion with time or space
    • Trouble understanding visual images and relationships
    • Language problems in speaking/writing
    • Misplacing items and inability to retrace steps
    • Poor judgment
    • Withdrawal from social activities
    • Changes in mood or personality.