Brain Shock. Is it PTSD, TBI or both?

Brain shock: The new Gulf War syndrome
22 April 2009 by Michael Bond

ONE look at the effects of a bomb blast suggests that you'd have to be extremely lucky to emerge from one unscathed. If you were not burned by the explosion or blasted by shrapnel, the chances are you'd be hit by the shock wave. Travelling at several hundred metres per second, this causes massive fluctuations in air pressure which can knock you unconscious, rupture air-filled organs such as eardrums, lungs and bowels, and stretch and distort other major organs.

Soldiers serving with coalition forces in Afghanistan and Iraq know only too well how devastating bombs can be. The effect of shrapnel on bodies - amputated limbs, broken bones, lacerated and burned flesh - is plain enough. Less obvious and harder to understand are the long-term effects of the shock wave on the brain.

Weeks, months, or sometimes years after being concussed in an explosion, thousands of soldiers are reporting a mysterious clutch of problems. Dubbed post-concussion syndrome (PCS), symptoms include memory loss, dizziness, headaches, unexplained pains, nausea, disturbance of sleep, inability to concentrate and emotional problems.

The US military and veterans' groups see PCS as a growing problem, and the US government is pouring millions of dollars into investigating it. Some doctors, however, particularly in the UK, believe that for many patients the symptoms ascribed to PCS are not caused by concussion at all, but by the shock and stress of wartime events. It may even be getting mixed up with post-traumatic stress disorder (PTSD), an acknowledged psychological reaction to disturbing events. "Some people are saying it's a hideous mistake and that we're talking up a problem," says Simon Wessely, a psychiatrist and director of the King's Centre for Military Health Research at King's College London.

Simple concussion from a blow to the head is not a new problem, of course. Common causes are falls, car accidents or sports such as rugby and football. It can lead to a brief loss of consciousness, amnesia or confusion. Although longer-lasting symptoms are occasionally reported, sufferers usually recover within days or weeks.

Battlefield explosions are nothing new either. For soldiers serving in Iraq and Afghanistan, one of the biggest threats they face is from roadside bombs, often improvised from cast-off artillery shells or other weapons. While more soldiers than ever are surviving such blasts, thanks to better body and vehicle armour, they are often left with concussion, or mild traumatic brain injury (mTBI) as it is usually termed in this context.

The other two papers are perhaps more significant as they involve large epidemiological studies in soldiers, rather than civilians, and looked at symptoms over the long term. Both research teams concluded that persistent cognitive problems after an mTBI were in most cases due to psychological causes such as depression and PTSD.

In the first study, researchers questioned more than 2500 US infantry soldiers three to four months after they returned from a year-long tour of duty in Iraq, asking them about their combat experience, any injuries they had suffered and any persistent symptoms. Around 15 per cent of them had suffered an mTBI, and these soldiers had significantly more mental and physical problems than those with other injuries (The New England Journal of Medicine, vol 358, p 453). Charles Hoge at the Walter Reed Army Institute of Research in Silver Spring, Maryland, who led the study, thinks the primary cause of their ill health was probably not concussion but "exposure to a very intense traumatic event that significantly increases the risk of PTSD".

Hoge reasons that PTSD is a more likely cause than mTBI, having many common symptoms. In addition, the psychological symptoms of PTSD persist, while the effects of concussion usually disappear quickly. "When a soldier gets concussed as a result of a blast on the battlefield, that is clearly a close call," says Hoge. "Such traumatic events can set up a cascade of neurochemical events that happen with PTSD, and that can lead to a host of symptoms."
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Brain shock: The new Gulf War syndrome