Examination of Mild TBI

• The military conflicts in the Middle East and increased media attention to sports-related concussion have highlighted the impact of mild TBI or post-concussion injury and the need for appropriate assessment and management
• Between 1.6 and 3.8 million sports-related mild TBIs occur annually in the United States, and approximately 12% of military personnel report symptoms consistent with blast-related mild TBI
• Mild TBI


  A type of TBI induced by biomechanical forces that disrupt physiological brain function. It results from forces transmitted to the brain as a result of a direct blow to the head, neck, or elsewhere on the body
• Mild TBI is primarily a functional injury of the central nervous system, which is thought to be due to metabolic dysfunction, neurotransmitter disturbances, and microstructural changes
• Postconcussion syndrome


  Up to 10% to 20% of people with mild TBI experience this and have deficits months to years after the initial injury
• Persons with mild TBI often experience a combination of neurocognitive deficits and postural control and balance impairments, and they self-report symptoms such as blurred vision, nausea, light sensitivity, sleep disturbance, and ringing in the ears
• Clinical diagnosis of mild TBI

  Made by assessing the mechanism of injury and symptoms which can include cognitive impairments, personality changes, rapid mood swings, postural control and balance impairments, visual disturbances, behavioral impairment, and possible sleep disturbance

  
• Because a mild TBI results in functional changes, neuroimaging is usually not indicated
• The PT examination should be conducted in a closed, quiet environment that is not likely to exacerbate symptoms and begin with tests least likely to provoke symptoms
• Symptoms of concussion


  • Somatic complaints such as headache, light, and sound sensitivity
  • Cognitive changes such as reduced concentration or memory, slowed processing
  • Vestibular problems such as dizziness and balance impairments
  • Behavioral and emotional complaints such as sleep disruption, anxiety, and irritability

  
• Self-report symptom scales


  Ask patients to rate the severity of postconcussion symptoms
• Self-report symptom scales


  • Neurobehavioral Symptom Inventory
  • Post-Concussion Symptom Scale
  • Dizziness Handicap Inventory
  • Activities-Specific Balance Confidence scale
• Concussion may lead to neurocognitive dysfunction secondary to axonal shearing, secondary neuronal death, altered cerebral blood flow, and dysregulated biochemical function
• Primary neurocognitive deficits


  • Attention
  • Memory
  • Executive functions
  • Word retrieval
  • Social language skills and pragmatic skills
• Computerized tests to assess cognition after mild TBI

  Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT)

  
• Attention deficits


  • Noise and feeling overstimulated while attempting to complete daily tasks
  • Not able to sustain attention as long as they could before the TBI
  • Any tasks requiring alternating and divided attention result in significant fatigue, frustration, and sometimes lability
  • Attempt to ameliorate these deficits with sunglasses, noise-cancelling headphones, dimming lights, and reducing/controlling the amount of tasks
• Memory deficits


  • Deficits in immediate, delayed, episodic, working, and prospective memory
  • Unable to recall conversations, planned events, information just read, when or if medication was taken, and other daily interactions and new information
  • Recall of new information is further impaired when visual or auditory distractions are present

  
• Executive function deficits


  • Changes in mood and emotional control are reported: lability with anger, sadness, and laughter at inappropriate times or not consistent with premorbid status
  • Inability to manage schedules, make adjustments with change, identify alternate solutions, and predict outcomes are demonstrated
  • Social skills/pragmatics differences are also experienced: inappropriate comments, difficulty with humor and sarcasm, and "personality changes"
  • These deficits are further impaired by the lack of awareness and social repair abilities
• Word retrieval deficits


  • Patients experience and report inconsistent difficulty in word retrieval that is significantly increased from premorbid levels
  • Speed of word retrieval is also significantly reduced from premorbid function
• Social language/pragmatic skills deficits

  • Subtle changes in their social language/pragmatic skills
  • Difficulty with topic maintenance, inappropriate behavior for the setting, inability to use or understand humor or sarcasm, difficulty with social repair skills, perseveration on topics, and emotional control
• Vestibular dysfunction after mild TBI

  Includes benign paroxysmal positional vertigo of the posterior or lateral canals and unilateral vestibular hypofunction of central origin
• The incidence of vestibular-related symptoms such as dizziness, vertigo, imbalance after blast-related mild TBI ranges from 24 to 83% and is seen in the acute, subacute, and chronic stages
• Vestibular and postural control deficits in sports-related mild TBI

  • BPPV
  • Impaired dynamic gaze stabilization
• Tests to assess vestibular and balance deficits

  • Positional tests such as the Dix-Hallpike test and supine roll test
  • Vestibular ocular reflex testing
  • Dynamic visual acuity testing
  • Balance Error Scoring System (BESS)
  • HiMAT
  • Dynamic Gait Index
  • Functional Gait Assessment
  • Balance Evaluation Systems Test
• Oculomotor dysfunction is present in approximately 65% of patients with mild TBI due to blast injury which may result in impairments in vergence, accommodation, version, and alignment and cause headaches, blurred vision, and difficulty reading

  
• Oculomotor impairments are common after sports-related mild TBI, as oculomotor control can be compromised through axonal injury or blunt trauma to the ocular motor systems
• Symptoms of oculomotor deficits

  • Blurred vision
  • Diplopia
  • Eye strain
  • Difficulty in reading
  • Dizziness
  • Headaches
  • Ocular pain
  • Poor concentration
• Vestibular Ocular Motor Screening (VOMS)

  Examines five aspects of vestibular oculomotor function: smooth pursuit, horizontal and vertical saccades, near point convergence distance, horizontal vestibular ocular reflex, and visual motion sensitivity
• Patients with mild TBI can have exercise intolerance, post-traumatic headache, temporomandibular disorder, and cervical dysfunction
• Mild TBI can lead to physiological dysfunction, including neurometabolic challenges, altered cerebral blood flow, and/or autonomic dysfunction resulting in exercise intolerance
• Buffalo Concussion Treadmill Test


  A standardized, progressive exercise test that can diagnose exercise intolerance after concussion and differentiate between factors other than exercise tolerance that may be impacting post-concussion symptoms
• In most cases of mild TBI the symptoms subside relatively quickly, and patients are able to return to prior level of activity. The majority of adults who sustain a concussion will resume normal activities within 10 to 14 days
• However, with some patients symptoms can persist for long periods of time post-injury and have persistent postconcussion syndrome
• Factors associated with increased concussion risk, more severe presentation, and protracted recovery

  • Prior history of concussion
  • Female sex
  • Younger age
  • Posttraumatic migraines
  • Psychiatric disorders
  • History of learning disability
  • Dizziness present at 1 or 2 weeks after injury
  • Symptom of fogginess postinjury
  • Cognitive deficits in the first few days following concussion

  
• Patients with history of learning disability had protracted recovery following mild TBI
• Dizziness present at 1 or 2 weeks after injury appears to be predictive for development of persistent postconcussion syndrome
• Patients reporting the symptom of fogginess postinjury appear to have a more severe and protracted recovery course
• Cognitive deficits in the first few days following concussion are predictive of more complicated and prolonged recovery and is magnified when more areas of cognitive function are involved
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