Concussion and mild head injury
- 1Cas Van Der Veer Chair in Parkinson’s disease and movement disorders, Neurology Department, Christchurch Hospital, Christchurch, New Zealand
- 2Post Doctoral Fellow, Van Der Veer Institute for Parkinson’s and Brain Research, Christchurch, New Zealand
- 3Consultant Psychiatrist, Van Der Veer Institute for Parkinson’s and Brain Research, Christchurch, New Zealand, and Concussion Clinic, Burwood Hospital, Christchurch, New Zealand
- Correspondence to: Dr T Anderson, Van Der Veer Institute for Parkinson’s and Brain Research, 16 St Asaph Street, Christchurch, New Zealand;
A concussion is a physical injury to the head resulting in altered mental function, with expectation of recovery within 2–3 weeks. In a significant minority of cases the symptoms persist longer, thereby comprising a symptom complex commonly referred to as the “post concussion syndrome”, that is, one or more somatic (for example, headaches, dizziness), cognitive (for example, poor concentration, memory), or behavioural/affective (for example, irritability, mood swings) symptoms. Unfortunately, the referral of a patient with the possibility of post concussion syndrome to a busy neurology outpatient clinic can precipitate an inward sigh of reluctant resignation in even the most diligent neurologist or neurosurgeon. We know we are in for a potentially lengthy consultation—long on symptoms and short on signs. Moreover, the process can be convoluted and meandering, as unrewarding for the patient as it is unsatisfying for the clinician.
It is important to acknowledge at the outset that there is a dearth of evidence-based knowledge of the underlying pathogenesis, and even less of the best management of post concussive symptoms. Thus, much of the information and advice in this article is empirical and based on expert and personal experience.
DEFINITION OF CONCUSSION AND MILD HEAD INJURY
The terminology surrounding trauma to the head confuses patients, doctors, and lay commentators alike. Terms such as concussion, mild head injury, mild TBI (traumatic brain injury), cerebral concussion, and post concussion syndrome are often used interchangeably to describe the physical injury itself as well as its immediate and later symptomatic consequences. There is in fact no commonly agreed definition of concussion, or whether it even differs from the term mild TBI. Our own working definition is that concussion is an acute trauma-induced change of mental function which generally lasts less than 24 hours (with or without preceding loss of consciousness) and associated with other symptoms (such as headaches and dizziness) which …