Chapter 4: Neuropathology: Acquired Disorders:
Traumatic brain injury:
The peak ages for TBI are in the 1524 year range.
People older than 64 years and children younger than the age of 5 are the next
groups most at risk for TBI.
Males sustain TBI at a far greater rate than females except in the olderthan64
age range and younger than 5 years old in children.
TBI can result from a myriad of causes and the actual TBI tends to be classified as
either an open or a closed head injury.
TBI can be measured by a combination of the following factors: length of
posttraumatic amnesia (PTA), the period between receiving a head injury and
regaining continuous day to day memory for events; depth of unconsciousness
usually measured immediately after resuscitation using the Glasgow Coma Scale,
and the length of unconsciousness and/or presence of neurological signs.
The GCS measure depth of coma through determining the individual’s
responsiveness level in eye opening, motor movement, and verbal
Scores on the GCS ranges from 315, with higher scores indicating more intact
Scores of 38 are classified as having a severe TBI and those with scores of 912
having moderate TBI.
68 being severe, 35 very severe (subdivided scores)
13 and 15 are mild TBI.
▯ Open head injury:
occurs when an impact against the skull is so great that the skull is penetrated and
the brain is exposed.
Most common cause is a gunshot wound.
The force behind any sharp nonlethal object be lethal.
The rate of death is higher from open than for closed headed injury.
A clean wound implies that the damage is mainly along the path of the invading
Neuropsychological difficulties with open head injuries include specific cognitive
deficits and behavioural changes related to the site of the lesion.
Patients also show difficulties with concentration, attention, memory, and overall
Time is a very crucial factor, the sooner treatment is begun, the greater the
potential for survival.
Necessary surgical procedures will be dependent upon the type of injury incurred.
It is highly related to epilepsy, with estimates of 80% of patients experiencing
seizures within the first 24 hours.
▯ Closed head injury:
Closed head injury occurs in two stages.
The first stage is the initial impact termed coup (as an object or event interrupts
the skull covering the brain). The second stage results from the rebounding back and forth or from side to side
within the skull and is termed contrecoup.
Stronger force applied to the brain has the potential for greater damage.
Primary difficulties include diffuse white matter damage, contusion (bruising),
Diffuse axonal injury is caused by the acceleration and deceleration of the brain
impacting against the skull.
Contusions often occur under the frontal and temporal poles where the shearing
forces of the brain are impacting on the sharpest and most confined parts of the
Age group 1524 is most likely to be sustained to closed head injuries.
Most common causal factors are moving vehicle accidents, including
automobiles, motorcycles, boats, and all terrain vehicles as the source.
Another major source is participating in athletics, and more specifically in sports
that do not require protective headwear.
Most closed head injury patients often experience behavioural and/or personality
They also experience some form of depression or other emotional difficulties
usually because of changes in their life circumstances.
Another difficulty is PTSD if the closed head injury was caused by a trauma.
Patients are usually not aware of their behavior, cognitive, or physical deficits.
Treatments are similar to open head injury.
Psychoactive medications may also be necessary for some individuals.
Antidepressants have been used to alleviate the depression which may often occur
secondary to closed head injury.
Atypical antipsychotics and aticonvulsants have been used to help with anger
management and behavioral outbursts.
mild form of closed head injury.
This exists after a after an individual has received a TBI caused by a concussion.
A concussion is primarily caused by diffuse axonal injury, which axons are
damaged or destroyed because of the forces of acceleration and deceleration
acting on them and on blood vessels.
Neuropsychological deficits: attention deficits, impaired verbal retrieval, and
alcohol related disorders:
studies have shown that alcohol, especially wine, in moderation has protective
effects from cardiovascular and cerebrovascular disease.
Dependence usually based on the frequency and chronicity of drinking.
In the DSMIVTR, alcohol abuse is defined as the excess use of alcohol for a
period of 12 months.
During this time, alcohol has been shown to have a negative impact on the
individual’s social or occupational functioning. Withdrawal symptoms may include nausea, headache, shakiness, and a desire or
craving for the substance.
Binge drinking: drinking large quantities of alcohol in a short period, has become
an issue written about extensively in the popular press.
This can be toxic and the body is not able to metabolize the substance when it is
consumed so quickly, and there have been accounts of alcohol poisoning
sometimes leading to coma and death.
Working with young people, the Drug Abuse Resistance Education (DARE)
program has tried to instill in children the ability to say no to alcohol and to peer
Alcohol is a central nervous system depressant and as such depresses or slows the
functioning of structures within the CNS.
It has a paradoxical effect in the it often produces a feeling of euphoria before the
onset of depressive feelings.
Alcohol is a neurotoxin an as such could be considered a poison.
Alcohol is metabolized differently than other drugs in a process termed zeroorder
It is metabolized as a steady state, approx. one drink per hour regardless of the
amount consumed by the person.
Female metabolize alcohol more slowly than males because of their body
composition and fat distribution.
Alcohol dementia involves widespread cognitive deterioration similar to other
forms of dementia.
The dementia is progressive and involves cognitive and memory abilities along
with abstract reasoning.
Korsakoff’s syndrome is characterized by difficulty with short term memory and
other memory deficits.
Street Drugs (illegal substances):
herbal form and hashish is the resinous form of the plant cannabis sativa.
Biological compound is marijuana is THC.
It is currently thought to be the most popular illicit drug among younger people
with alcohol remaining the number one drug.
The Marijuana Policy Project states that cannabis is an ideal therapeutic drug for
cancer and AIDs patients who often have depression, as well as nausea and weight
loss caused by chemotherapy.
considered a CNS stimulant, cocaine is highly addictive due to the rush, which is
experienced through inhalation.
It increases the level of dopamine in the reward circuits in the brain, which leads
to craving and a higher threshold for a euphoric reaction to the drug.
Long term users of cocaine may have cognitive deficits with memory and
concentration difficulties the most significant. Seizures occure with many habitual as well as new users.
Hypertension and other symptoms of CNS overstimulation such as strokes may
fMRI shows abnormal metabolism and hypoperfusion both when subjects are
using cocaine and in chronic users when abstinent.
The neuroimaging findings are consistent with findings of slowed mental
processing, memory impairment, and reduced mental flexibility.
Withdrawal from cocaine is neither life threatening nor terribly painful.
Symptoms of irritability, restlessness, confusion, sleep disorder, and abnormal
muscle movements have been observed.
the first opiate drugs were derived from the opium poppy.
Heroin, morphine, and codeine are all forms of synthetic derivation.
Opiates were extremely important within the early Egyptian and Greek cultures.
The major use for narcotics is pain control.
Narcotics also have effects on the gas