Types of injury

Brain Areas

Traumatic Brain Injury (TBI)

Traumatic injuries are caused by impacts that directly harm the brain. The most common cause in industrialised countries is road traffic accident but others include:

  • Assault (e.g. during muggings or street fights)
  • Falls (often associated with alcohol, but also at work or at home), sporting accidents
  • Penetrating injuries like gunshot wounds

TBIs tend to be diffuse, messy injuries, with many areas of the brain affected. Brain tissue gets bruised, torn and crushed in an impact and can be further damaged by bleeding and swelling afterwards. For this reason, TBI’s can result in more than one kind of impairment for the survivor, but common areas of difficulty are memory, self-awareness, organisation, attention and concentration.

Stroke

A ’stroke’ refers to an event in which a person collapses or becomes unresponsive due to a problem with the blood supply inside the brain. A stroke can be caused by many different things including:

  • Heart failure
  • Blood clots (or ‘embolisms’, which block the blood vessel)
  • Ruptured aneurism (or Arterial-Venous Malformation) or some other blood vessel damage

The brain stops functioning very quickly if its blood supply is interrupted, and unconsciousness can occur very quickly after a serious stroke. Bleeding inside the brain can take up space, crushing brain tissue and causing cells to die off as well as starving those regions that would normally be receiving the blood. Because strokes are caused by vascular problems, the injuries involved tend to be more isolated or clearly defined than TBIs. This does not mean that strokes are less serious than TBIs but it does mean that the functional impairments people experience after stroke can be more isolated than in TBI. Because the blood vessels in the brain are largest in the temporal lobes, impairments are often associated with the functions of these areas: speech and right-sided body movement (for left-sided stroke), spatial awareness and left-sided body movement (for right-sided stroke).

Hypoxia/Anoxia

This is injury caused by lack of oxygen to the brain. Like all organs, the brain relies on oxygen for its survival and function. Unlike other tissues, the cells of the brain die very quickly if starved of oxygen - damage can occur in only a few seconds if the supply is reduced (hypoxia) or stopped (anoxia). Reduction in oxygen supply can result from anything that interferes with a person’s breathing or blood circulation, e.g. heart attack, choking, drowning or major blood loss. Many parts of the brain are vulnerable to this kind of damage and impairments can affect a number of areas of function.

Infection

Occasionally bacteria or viruses may get inside the brain and cause infection. Infection of the membranes around the brain (meningitis) and of the brain tissue itself (encephalitis) can both lead to brain injury, although this is not common. Infections of this sort include tuberculosis, herpes simplex and amoebic infection. Different areas of brain are affected by different diseases, but similar to other injuries, damage caused by infection may lead to problems with memory, self-awareness, organisation or a number of other areas.

Predicting outcomes

There is no way to confidently predict the long-term outcome for a person with brain injury. Various means are used to describe the severity of an injury (e.g. depth and length of coma, amount of memory loss during and after injury, extent of tissue damage). But none of these can reliably predict long-term functioning or what a person’s individual experience of injury will be like. In some cases, the consequences of a moderate or mild injury can be very serious for the individual. Equally, some people with severe injuries make very good recoveries. The important thing to recognise about brain injury is that each one is very different from the next but any person who experiences it is likely to undergo profound changes. Anyone with a brain injury will need some support to understand and make the best of their experiences. Family members will also likely need some help. In some cases this is as simple as a conversation. In others the support needs to last longer and be more complex. Either way, the most important thing is that the support is relevant to the person in question. With brain injury there is no one-size-fits-all solution.