Page 30 - Handbook of Electronic Assistive Technology

Chapter 1 • Basic Neurosciences With Relevance to Electronic Assistive Technology 17

generally associated with more severe cognitive and focal neurological deficits; however,
there is usually reasonable resolution. Severe injury is generally associated with poor prog-
nosis regarding morbidity or mortality.
Trauma: Damage to the CNS occurs in over 50% of cases as a component of a multiple
trauma injury. Injuries can be open and closed: directly to the brain or CNS tissue (concus-
sion or contusion) or from bleeds (haematomas – intracerebral, epidural and/or subdu-
ral). These can lead to a build-up of intracranial pressure causing secondary damage from
swelling and compression or herniation of parts of the brain tissue through narrow spaces;
seriously bad news as this almost invariably leads to coma and death.
Infection: The CNS is at risk of infection by a wide range of organisms, including bac-
teria, viruses and parasites, in spite of a variety of site-specific protection mechanisms.
Dependent on the predilection of the organism concerned, they cause a spectrum of dif-
ficulties tending to infect either the brain itself or its lining, or both – encephalitis or men-
ingitis or meningoencephalitis.
Assessment and treatment is based on finding the correct organism via blood tests and
lumbar puncture (in the absence of raised intracranial pressure, which is a complete red
flag for sticking a needle anywhere near the back).
Postinfective: Some toxins and/or organisms set up an inflammatory response in the
brain that leads to reactive autoimmune encephalitis, such as streptococcus, measles and
chicken pox, see later.

Stroke
• Total childhood incidence – 6/100,000/year.
• Total adult incidence – 1.13/1000/year in 2016, slightly lower than in 2006.
• Stroke is the third biggest recorded cause of premature death in the United Kingdom.
• Relative incidence increases with age, obesity, gender (more men affected) and
deprivation.

A stroke occurs when the blood supply to part of the brain is cut off. It can happen
because of a clot blocking a blood vessel (ischaemic 80%) or from a bleed into the brain
(haemorrhagic 20%) when a weakened blood vessel bursts.
Emergency assessment and treatment is vital and long-term rehabilitation is necessary
to minimise the impact of damage to the cells and pathways of the brain.
Patterns of particular challenges are dependent on the size and position of blood ves-
sel, areas of the brain affected and therefore the extent of damage.
There are a number of standardised scoring scales used to assess severity, involvement,
management and prognosis.
Initial evaluation is focused on working out whether it is caused by a clot or bleed,
where the problem is and what caused it. Early neuroimaging is obviously necessary with
either computerised tomography or MRI scans.
Problems of motor control, cognition, behaviour, gross and special sensation are
all seen though not universally. Long-term disability is seen in around 50% of people