Post-Concussion Syndrome

Minor Traumatic Brain Injuries

Post-concussion syndrome is the name given to the 10% of people who have a minor closed head injury and experience a range of symptoms such as mood and anger problems, concentration difficulties, headaches and fatigue that may persist for years, sometimes for life. More often than not these people are treated for the symptoms with little if any efficacy.

Post-concussion syndrome

When the head receives a sharp blow, the difference in the movement between the brain and the skull produces forces that result in traumatic brain injuries (TBIs). Although maximum injury is suffered at the point of impact, the frontal and temporal regions have been shown to be consistently vulnerable to contusions regardless of the direction or the point of impact due to percussion and shearing forces on delicate brain tissue [1]. A "contre-coup" due to a percussion wave travelling through the brain matter and impacting the skull diagonally opposite can cause further contusion, and shear forces at the boundary between white and grey matter can result in axonal shearing [1].

 The term Post-concussion syndrome or post-concussional disorder as it is referred to in the DSM-IV has been used to describe the range of residual symptoms that persist 12 months and beyond, sometimes years after the injury. Although minor head injuries are generally considered benign, a significant number of people report persistent symptoms for weeks or months [2] and some for years after injury [3-17] despite a lack of evidence of brain abnormalities on MRI and CT scans.  The core deficits of post-concussion syndrome overlap with those of Attention Deficit Disorder, Adjustment disorder and Mood Disorders. In addition, sufferers often report memory and socialisation problems, frequent headaches and personality changes.

 The cluster of symptoms reported by these patients is referred to as the Post-concussion syndrome.  The following are amongst the most commonly reported symptoms of post-concussion syndrome [4, 6].

• Attention deficits, difficulty sustaining mental effort.

• Fatigue and tiredness

• Impulsivity, irritability

• Low frustration threshold

• Temper outbursts and changes in mood

•  Learning and memory problems

• Impaired planning and  problem solving

• Inflexibility, concrete thinking

• Lack of initiative

• Dissociation between thought and action

• Communication difficulties

• Socially inappropriate behaviours

• Self-centeredness and lack of insight

• Poor self-awareness

• Impaired balance

• Dizziness and Headaches [6, 15, 18, 19]

• Personality changes [20, 21]

Often despite several of these chronic symptoms, there is no evidence of brain abnormality from conventional structural neuroimaging tests, such as CT scans and MRIs. Consequently the person can be labelled a "hot head" with a "short fuse" or as having either a mood disorder or anger problem, or as having a personality or psychological disorder.

 Symptoms have an organic basis.

The fact that these complaints seem to contradict the "negative" medical findings has often generated controversy as to whether post-concussion syndrome has an organic or psychological basis [4]. However, over the past 30 years evidence for an organic (brain based) aetiology (original cause) of post-concussion syndrome has accumulated through studies of cerebral blood flow, neuropsychological deficits, evoked potential recordings, PET, SPECT, MRI and quantitative EEG or QEEG [22-30]. The nature of concussive head injury has been extensively discussed and theoretical concepts have been formulated which are supported by QEEG evidence [31, 32].

 Assessment of Post Concussion Syndrome

In the tests described next, scores are statistically compared to large databases of people with no disorders. The tests have been published and validated in peer reviewed scientific studies and are suitable for use in diagnostic systems. Together they can provide convergent evidence of an organic basis for a post-concussion syndrome, which requires specialised treatment with Neurotherapy [33].

Quantitative EEG (QEEG)

QEEG is the statistical evaluation of the electrical activity of the brain. It is particularly suitable for the evaluation of post-concussion syndrome, as it is empirical, objective, non-intrusive and has been shown to be highly accurate in identifying and discriminating various neurophysiological patterns of brain dysfunction associated with MTBI and post-concussion syndrome [33-35].
A recently published review of the scientific literature confirms studies that suggest that QEEG is superior to other structural Neuroimaging techniques in detecting brain dysfunction related to MTBI and post-concussion syndrome [33].

MTBI Discriminant Analysis

The TBI probability index provides a statistical probability that the person has suffered a mild traumatic brain injury [35]. It provides further evidence to support the conclusion of an organic basis for symptoms of post-concussion syndrome [35]

There are in excess of 34,000 QEEG papers published since 1990, and there are no concerns in these papers about false negatives from QEEG Discriminant Functions. The only negatively critical paper about the clinical uses of QEEG was published in 1997 by Newer from the Academy of Neurology. The opinions expressed in that paper were refuted and discredited by the Clinical EEG and Clinical Neuroscience Society [36] as they were shown to be based solely on innuendo and vague unsupported statements, without a comprehensive review of the extensive literature. Since then The QEEG Neuroguide system used in the diagnosis of post-concussion Syndrome has been approved by the FDA on the basis of its efficacy

IntegNeuro? Neuropsychological Cognitive Battery.

IntegNeuro is an easy to use, fully automated and computer administered series of 14 separate neuropsychological cognitive tests (tests of mental functioning) that reflect an individual’s cognitive performance profile. The test battery draws on the Brain Resource International Database, which consists of over 1000 normal individuals who have undergone a complete neurophysiological and neuropsychological battery of tests [37]. IntegNeuro is used to establish the degree of cognitive impairment due to stroke, head injuries and dementias, and to evaluate treatment progress.

Test of Variables of Attention (T.O.V.A)

The Test of Variables of Attention (TOVA) is a computer administered continuous performance task, which requires participants to press a specially designed micro switch whenever a "target" appears on the screen, and to refrain from pressing when a "non-target" appears. The scores are compared to an age appropriate database to produce standardised scores, which gives useful, objective information on four variables of attention described next.

·                                 Attention and the ability to concentrate and sustain mental effort 

·                                 Impulse control

·                                 Processing speed (reaction time)

·                                 Distractibility (variability in responses)

 The TOVA is an objective, independent and empirical measure to quantify the degree of impairment to the attention system and to measure the progress of treatment.

Treatment of Post-Concussion Syndrome

A review paper in the October 2004 issue of Clinical EEG and Neuroscience concluded that QEEG was the most sensitive neuroimaging tool for the assessment of post-concussion syndrome and that Neurotherapy had been shown to be the most promising treatment to date for post-concussion syndrome [33]. 

Medication, Counselling and Cognitive Rehabilitation

Medication may provide temporary relief from pain and counselling may help some persons understand the need to control their impulses and anger. However, there is no evidence in the literature that medication or cognitive rehabilitation can effectively restore cognitive deficits or concentration in post-concussion syndrome.

Neurotherapy

People with attention deficits and MTBI tend to have an excess of slow-wave brain electrical activity and coherence abnormalities. Neurotherapy (EEG biofeedback) uses operant conditioning of the EEG to give patients audio/visual rewards for producing more normal patterns of brainwave activity.
Since the 1970s studies have shown that, through Neurotherapy, patients can be taught to promote normal functioning in the brain by normalising dysfunctional brainwave patterns [33, 38-41]. A more recent improvement in Neurotherapy is in the use of QEEG to identify the specific brainwave patterns that need to be redressed [42-44].
Neurotherapy can also be used for improved concentration and enhancement of mental performance in persons without post-concussion syndrome. Look up the references web page on this site for a copy of a major review of the literature published in October 2004 in Clinical Electroencephalography, a peer reviewed medical journal from the USA.

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