This summary is in the process of being updated. In the meantime, please refer to the most up-to-date guideline on the Encephalitis Society website

An overview on acquired brain injury

  • Acquired brain injury (ABI) refers to all types of brain injury that occur after birth and are non‑progressive
  • Causes of ABI are various including:
    • traumatic (e.g. accidents, falls, assault)
    • stroke, tumour, or cerebral abscess
    • toxic (e.g. drugs, alcohol, or other chemicals)
    • anoxic (e.g. heart attacks, carbon monoxide poisoning)
    • metabolic disorder (e.g. liver and kidney disease)
    • infectious (e.g. encephalitis, meningitis)

Challenges in recognising and managing acute signs of brain injury

  • Irrespective of the cause, in many cases, the effects (both mortality and morbidity) of a brain injury can be limited if diagnosed early
  • A brain injury is usually diagnosed and treated in A&E. Nevertheless, some people may see a GP first when they have a brain injury, before they get to the hospital
  • Recommendations:
    • recognise early symptoms and signs of neurological conditions (acute presentations), especially non-specific symptoms and signs
    • get a full history of the illness from the patient and/or the family
    • warn family about features which signify a deterioration, and may require them to rapidly attend A&E
    • be aware that the evolution of neurological conditions can be sudden and unexpected

Challenges in recognising ABI and its after-effects

  • There are many difficulties inherent in recognising the after-effects of ABl. This is due to a number of reasons, including:
    • the person often looks physically well and there may be no outward signs
    • the symptoms associated with ABI can be confused with other symptoms and causes (e.g. mental health problems, substance misuse, metabolic disorders, or malingering) or misattributed to factors such as stress
    • the brain injury may not have been diagnosed at all (e.g. in cases of concussion), or the person did not seek medical attention
    • the brain injury happened in childhood, but the effects become apparent later in life
    • there is no evidence of ABI on MRI/CT scan

Common difficulties following ABI

GPs are often in the difficult position of being the primary source of support and referral to specialist services for people with ABI. Therefore, it is important for GPs to be aware of problems that commonly occur after ABI, obtain a thorough history of the onset and time course of these, and know how they can best help people with ABI

  • Cognitive problems, include difficulty with:
    • processing information
    • attention and concentration
    • memory
    • planning, problem solving, and organisation
    • language
    • visuospatial skills
  • Emotional and behavioural problems:
    • depression and anxiety
    • poor self-awareness
    • aggression
    • impulsivity and disinhibition
    • personality change
    • poor emotional regulation
  • Physical problems:
    • fatigue
    • headaches and pain
    • seizures
    • difficulties with movement, balance and coordination
    • problems with speech and swallowing
    • incontinence
    • sensory problems
    • hormonal imbalance
  • Social impact—the implications of difficulties with cognitive, emotional, behavioural and physical problems can be many and varied. Some of the potential outcomes are listed below:
    • difficulty with self care (e.g. showering, cleaning. shopping, cooking)
    • inability to catch public transport
    • being unable to return to driving
    • sexual dysfunction
    • relationship problems
    • substance misuse
    • difficulty returning to education/work
  • Impact on carers—family caregivers play an important role in providing social, emotional and practical support. However, such caring is often associated with high levels of distress, depression, grief, anxiety, reduced perception of quality of life (QOL) and other emotional and physical health issues

What can GPs do to help?

  • A supportive GP is crucial to the long-term management of people who have an ABI. Some patients require more support than others. Often, the more promptly a GP can provide help, the better the outcomes for patients and their families. There are a range of ways in which GPs can assist

Promote self management of symptoms

Refer for rehabilitation and other special investigations

  • The aim of rehabilitation is to help the person with ABI acquire the knowledge and skills needed for optimal social functioning. Good rehabilitation involves a holistic approach. It recognises the complex cognitive, emotional, behavioural, physical and social problems faced by people with ABI and their families
  • Unfortunately, it is not uncommon to find that many people with ABI are discharged from hospital without adequate assessment or consideration of their longer term rehabilitation needs. Rehabilitation can be a very long journey and some people can benefit from rehabilitation many years later
  • Vocational rehabilitation helps people retain or regain the ability to participate in work
  • Key rehabilitation professionals that may be able to help:
    • neuropsychologist
    • occupational therapist
    • speech and language therapist
    • dietician
    • neurophysiotherapist
    • rehabilitation medicine consultant
    • neurologist
    • neuropsychiatrist
    • social services/mental health crisis teams
    • epilepsy nurse specialist
    • pain management services
    • continence services
    • psychosexual services
    • ear, nose, and throat specialists/audiologists/opthalmologist
    • endocrinologists/neuroendocrinologist
    • immunologist
  • For more information on rehabilitation please visit:
  • Other additional considerations for support include:
    • providing advice in relation to a return to driving
    • assist with a return to work
    • help with obtaining benefits
    • patient and carer support

Unique challenges in the diagnosis and management of after‑effects of encephalitis

  • Encephalitis is an inflammation of the brain caused either by an infection invading the brain (e.g. infectious encephalitis) or through the immune system (e.g. autoimmune encephalitis). In 40–60% of encephalitis cases no cause is identified
  • It is important to differentiate encephalitis from other disorders that may cause similar neurological symptoms but have very different treatments. Disorders that mimic those of encephalitis include bacterial meningitis, stroke, brain tumours, drug reactions, and metabolic disturbances
  • Infectious encephalitis:
    • aciclovir is the most frequently used anti-viral drug. It is effective against the herpes simplex virus and varicella zoster virus. Unfortunately, for many viral infections there are no specific treatments at present
    • tend to occur only once and it is very rare for infectious types of encephalitis to recur later in life
  • Autoimmune encephalitis:
    • treatments for include drugs such as: steroids, intravenous immunoglobulin (IVIG), and plasma exchange
    • in some cases, there is a risk of recurrence
  • The acute stage of encephalitis may be followed by a phase of fairly rapid improvement and a slower recovery can continue over the years to come
  • The loss of brain function from ABI can range from very minor impairment, such as some loss in speed of thinking, to more significant impairments
  • The degree and type of damage will vary according to the cause, the severity of the inflammation, the parts of the brain affected, and any delay in treatment


  • The range of symptoms and their rate of development vary widely and can make the diagnosis of encephalitis difficult:
    • flu-like illness
    • high temperature
    • headache
    • seizures
    • inability to speak
    • inability to control movement
    • photophobia
    • neck stiffness
    • confusion
    • drowsiness
    • coma
    • uncharacteristic behaviour
  • Recognition of the symptoms should lead to rapid admission to hospital and prompt treatment!
  • New types of autoimmune encephalitis:
    • anti-NMDA receptor encephalitis can manifest with psychiatric symptoms rather than neurological usually following a flu-like illness. In a patient with no history of psychiatric illness this diagnosis may be considered
    • LGI1/voltage-gated potassium channel complex-antibody associated limbic encephalitis. Initially, family members usually notice that their relative becomes forgetful, drowsy and withdrawn. Patients can also develop mood disorders or bizarre thoughts and behaviours. In addition seizures frequently occur
  • Prompt recognition of these types is vital because the treatment (early and adequate) can influence the outcomes!

The GPs role in early diagnosis of encephalitis

  • A GP plays a critical role in recognising the early symptoms and early referral to hospital. A patient who displays symptoms and signs of encephalitis should be admitted to hospital as an emergency and started on aciclovir/ immunotherapy immediately. If admission is delayed the risk of serious and permanent neurological sequelae and even death is greater. Please refer to the Guidelines for Diagnosis of Infectious Encephalitis. ( for more details
  • Current or recent febrile illness with altered behaviour or consciousness should raise the possibility of encephalitis
  • Discussion with the family regarding the person’s history of the illness and behaviour can help the diagnosis
  • A lumbar puncture and brain scan will be arranged for suspected cases once in hospital and it may be a good idea to prepare the family that this is a possibility
  • When supporting people with encephalitis it is important for GPs to be aware that:
    • long term changes in cognitive, emotional, behavioural, and physical functioning can occur following encephalitis
    • for some these changes have a devastating impact on their social functioning and quality of life, also affecting their families as is the case for people with other ABls
    • due to the nature of their difficulties, people with encephalitis may be more likely than those with other ABIs to be discharged from hospital without their longer term needs being recognised
    • the problems that people experience post-encephalitis may become more apparent not immediately after returning homefrom hospital, but when they attempt more challenging roles such as returning to work
    • when encephalitis is experienced in childhood, this can have implications for an individuals’ ability to engage in social roles that does not become fully apparent until later childhood, adolescence or adulthood
    • timely access to rehabilitation is important for improving longer term outcomes
  • People with encephalitis benefit from this same sorts of support and rehabilitation previously outlined

full guideline available from…

The Encephalitis Society. Diagnosing and managing the after-effects of acquired brain injury in adults including encephalitis: a guide for general practitioners.
First included: June 2016.