The Concussion Puzzle

ALTERNATIVE METHODS OF CONCUSSION ASSESSMENT
Piecing Together the Concussion Puzzle

By: Kevin M. Guskiewicz, Ph.D.

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THE HIDDEN INJURY

By Ethel Dimont


Reports of the cumulative effects of multiple head injuries, as well as multiple head impacts, on long-term cognitive functioning are causing clinicians to rethink their approach to managing concussions. The literature has revealed deficiencies in neurocognitive functions such as attention span, memory, concentration and information processing as a result of cerebral concussions. Alternative testing as well as historical perspective of postural stability and neurocognitive testing are essential.

A variety of assessment tools are available for detecting a mild traumatic brain injury following a concussion or blow to the head. However, their practicality is often questions, especially in sport settings. Assessment of mild traumatic brain injury can be likened to piecing together a very complex puzzle. There are several pieces to this concussion puzzle, and it is the clinician’s job to place as many pieces together as possible before making a diagnosis. Some of these pieces may include, but are not limited to:

1. Assessing cognitive abilities
2. Motor functioning (including balance and reaction time)
3. Symptoms such as headaches, dizziness, blurred vision, memory deficits, etc.
4. History of prior MTBI

Though this chapter is geared primarily to head injuries sustained in sport activities, the same problems and difficulties apply to most head injuries, especially where injuries are invisible.

It is essential for physicians to keep clear records of the patient’s symptoms for future decisions pertaining to severity of injury and possible future need for rehabilitation. Many methods of assessing the severity of head and brain injury have already been developed. Computer Tomography (CT) and Magnetic Resonance Imaging (MRI) have enhanced the capability of diagnosticians to identify certain types of brain injuries and their severity. Two widely accepted methods to assess the severity of brain injury are the Glasgow Coma Scale (GSC) and the Abbreviated Injury Scale (AIS). However, their usefulness is questioned in many instances, especially in managing sport-related head injury. [Because these injuries are often hidden, or considered a closed head injury, which often are not even confirmed by the CT or MRI.]

The (GCS) requires observation of the patient while their eyes are open, verbal performance, and motor response, but several problems limit its applicability in certain cases. For example, having the patient’s eyes open may be impossible with facial swelling, and verbal response may be compromised by endotracheal tube.

The AIS is designed to assess overall bodily injury along with severity of injury to specific body parts. The AIS avoids some of the problems of the GCS administration, but according to Sorenson and Kraus, in the book Physical Management in Neurological Rehabilitation, by Maria Stokes, AIS has some of its own limitation. The scale depends on a valid physician diagnosis, and a clear enumeration of symptoms in the medical record to allow assignment of an injury score.

If we view the body as a computer, sending signals from the brain to tell the body what is required of it, or if there is a problem, it becomes a bit easier to understand some of the complicated systems the human body uses to enable it to function on the level it does.


POSTURAL CONTROL SYSTEM:

The postural control system is responsible for the maintenance of upright posture and balance. This system operates as a feedback control circuit between the brain and the musculoskeletal system.


VESTIBULAR AND VISUAL SYSTEM

The vestibular and visual systems work very closely in attempting to retain upright balance. The vestibular apparatus is the organ responsible for detecting sensations concerned with equilibrium. It mainly contributes to posture by maintaining reflexes associated with keeping the head and neck in a vertical position and allowing the vestibular apparatus to control eye movement.


PROPRIOCEPTIVE SYSTEM:

The proprioceptive system is best described through the tactile senses, and the sense of position, which determines the relative actions and rate of movements of the different part of the body.

A complex network of neural connections and centers are related by peripheral and central feedback mechanisms. A hierarchy integrating the cerebral cortex, cerebellum, basal ganglia, brainstem, and spinal cord is primarily responsible for controlling voluntary movements.


PATHOLOGICAL BALANCE ASSESSMENT:

Disorders of orientation and balance can be very debilitating, especially in an athletic environment. The complexity of the balance system makes localization of the problem difficult, since the abnormality may occur in one or more of the sensory modalities (vision, vestibular, somatosensory) or in the motor system involved in carrying out a particular movement.

Contrary to clinical belief, studies have demonstrated that motor deficits are present in mild head injury patients one year after injury, suggesting that motor skills should be routinely assessed after a concussion.

Symptoms in persons with cerebella damage generally include the following:

1. Cannot perform movements smoothly

2. Walk awkwardly, with the feet well apart. Difficulty in maintaining balancing causes unsteadiness of gait.

3. Cannot start or stop movements quickly or easily. Motions are slow and irregular.

4. Cannot easily combine the movements of several joints into a smooth, coordinated motion. i.e.: To move the arm, they must first move the shoulder, then the elbow, and finally the wrist.

PATHOLOGICAL NEUROCOGNITIVE ASSESSMENT

Neuropsychological techniques have been developed to reliably assess the extent of neurocognitive deficits following cerebral concussion in athletes. Due to the variability of neurocognitive abilities of athletes, acquisition of baseline (pre-injury) measurements for comparison with post-injury measurements is a necessity when instituting a neuropsychological testing program for athletes. This model is not realistic for use in a clinic or hospital setting, but has endless potential when used in the sports medicine where baseline testing is possible for athletes who have a higher risk for injury.

Neuropsychological testing has revealed cognitive declines in as little as 24 hours post injury from the pre-season levels in areas of attention, concentration, and rapid-complex problem solving. These mild deficits were directly correlated with reported symptoms of increased headaches, dizziness, and memory problems. Most test include 5-8 sub tests which assess the various domains of cognitive functioning (re: working memory, mental processing speed, and attention: concentration, procedural reaction time, and visual scanning abilities.)


RECOMMENDED PROTOCOLS FOR ASSESSMENT OF CONCUSSION

This can best be accomplished through the use of a symptom checklist. An on-line check list can be obtained from The Brain Injury Resource Center, http://www.headinjury.com/checktbi.htm. Using the total symptom score and the total number of symptoms reported takes some of the guesswork out of determining an athletes readiness to return to activity. The additional use of objective measures such as postural stability assessment and neuropsychological evaluation can be invaluable to the sport medicine clinician.

These three measure (symptom checklist, postural stability assessment, and neuropsychological evaluation), combined with a thorough clinical examination provide the best resources for making a sound clinical diagnosis and a safe return to participation. The certified athletic trainer and team physician can therefore more easily detect lingering symptoms such as irritability, sadness, concentration deficits, etc.

The athlete should always be referred to a neurosurgeon if post-concussion symptoms worsen within the first few hours post-injury. Neuropsychologists can also play an important role if the symptoms persist during the first several days post-injury. They have advanced training in the administration and interpretation of neuropsychological tests. It is recommended that all sports medicine teams include a neurosurgeon and neuropsychologist, at the very least, for referral purposes.

Understanding that no two head injuries are created equal will help one to realize that this is a complex problem. Some injuries will resolve quickly, and never present any recurrent complications. Others, even those that may appear to be very mild, can result in persistent symptoms that lasts for weeks, months, or even years.

Future research will inevitably develop additional concepts that will aid those with head injuries. Until then, with present knowledge, everyone should be able to agree that no athlete should be permitted to return to competition while still symptomatic, nor should any person suffering from post-concussion syndrome attempt a quick entry back into activities that may predispose them to complicate or interrupt the healing process. Admittedly, though these signs and symptoms are often difficult to assess objectively, erring on the side of caution is the most logical way to deal with piecing together the concussion puzzle.