essential neurology for concussion evaluations neurology for concussion evaluations aftab merchant,...
TRANSCRIPT
Essential Neurology for Concussion Evaluations
Aftab Merchant, MBBS, FCPS
Professor Pre-Clinical Sciences
Cleveland University – Kansas City
Learning Objectives
• Recognize the clinical features of concussion
• Differentiate between concussion and
structural head injury
• Recognize the sequelae and complications of
concussive injury
• Outline the assessment procedures for
patients with concussion
Traumatic Brain Injury (TBI)
Mild TBI occurs with head injury due to contact
and/or acceleration/deceleration forces
Pathophysiology of TBI
Primary Brain Injury
• Occurs at the time of trauma
• Results in focal contusions and hematomas
• Due to
– Direct impact
– Rapid acceleration / deceleration
– Penetrating injury
– Blast waves
• Surgical treatment
Pathophysiology of TBI
Secondary Brain Injury
• Cascade of molecular injury mechanisms
• Includes
– Electrolyte imbalances
– Inflammatory responses
– Secondary ischemia from vasospasm
– Focal microvascular occlusion
– Free-radical injury
– Neurotransmitter-mediated excitotoxicity
Structural Brain Injury
• Cerebral contusions
• Epidural hematoma
• Subdural hematoma
• Subarachnoid hemorrhage
Cerebral Contusion
• Most frequently encountered lesions
• Permanent damage to small blood vessels on
the surface of the brain
• Acceleration-deceleration injury
• Coup-contrecoup injuries
Epidural Hematoma
• Collection of blood between skull and dura
• Caused by fracture of the bone
• Rupture of middle meningeal artery
• Lens shaped lesion on CT
• Intracranial pressure increases � herniation
and death
• Lucid interval may precede neurologic
deterioration
Subdural Hematoma
• Venous bleeding between the dura and
arachnoid membranes
Pathogenesis
• Bridging veins between brain and dural
sinuses are torn
• Slowly enlarging blood clot covers the
convexity of the brain
Subdural Hematoma
Causes
• Blunt trauma
• Anticoagulants, hemophilia
• Child abuse, shaken baby syndrome
• Spontaneous
Risk Factors
• Elderly persons
• Alcoholics
Subdural Hematoma
Clinical Features
• Progressive neurological signs
• Fluctuating consciousness level
Complications
• Herniation and death may occur
• Dementia (chronic subdural hematoma)
Diagnosis: CT scan (imaging test of choice)
Subarachnoid Hemorrhage
• Bleeding into subarachnoid space
• MCC is rupture of saccular (berry) aneurysm
• Berry aneurysm lacks a media layer
• Most are located in anterior circle of Willis
Subarachnoid Hemorrhage
Clinical Features
• Sudden onset of a severe headache
• Described as the “worst headache ever”
• Nuchal rigidity
• LP shows xanthochromia
Subarachnoid Hemorrhage
Diagnosis
• CT scan without contrast (best test)
• MRI is most useful for posterior fossa infarcts
Complications
• Further hemorrhage
• Hydrocephalus
• Permanent neurologic deficits
Vascular Pathologies
• Cerebral vessels associated with vascular
pathologies:
Epidural
hemorrhageMiddle meningeal artery
Subdural
hemorrhageBridging veins draining into the
sagittal sinus
Subarachnoid
hemorrhageBerry aneurysms in the circle of
Willis
Concussion
Concussion is a brain injury and is defined as a complex pathophysiological process affecting the brain, induced by traumatic
biomechanical forces.
McCrory P. et al. Br J Sports Med 2013;47:250
Pathophysiology
Diffuse Axonal Injury
• Mild TBI results in diffuse axonal injury
• DAI affects individual nerve fibers
• Axons are severed
• Disruption of communication
• Neuron may die or swell
Pathophysiology
Rotation of head at
the time of impact
can also damage
the axons.
Department of Neurological Surgery, Weill Cornell Medical College
Pathophysiology
• Disruption of axonal neurofilament
organization impairs axonal transport
• Release of excitatory neurotransmitters
• Generation of free radicals
Concussive injury reflects a physiological
disturbance rather than a structural injury to the brain
Mardissi M et al. Aus Fam Phy 2014; 43:3
In concussion, the exterior remains unbroken and intact while the inside contents are completely misplaced.
Etiology
• Mild traumatic brain injury (mTBI)
• Due to sudden movement of brain in the skull
• Chemical changes makes brain more
sensitive to any increase stress or injury
The management of concussion in sports. Neurology 1997; 48:581
Clinical Presentation
AsymptomaticRegular
symptoms
Asymptomatic
becomes
symptomatic
Dramatic
symptoms
Diagnosis
Clinical symptoms
Physical signs
Cognitive impairment
Neurobehavioral features
Sleep disturbances
Signs and Symptoms
Somatic
Headache
Pressure in head
Neck pain
Dizziness
Blurred vision
Balance problems
Sensitivity to light
Sensitivity to
noise
Feeling like ‘in a
fog’
Fatigue
Low energy
Cognitive
Difficulty:
• Concentrating
• Remembering
Confusion
Emotional
More emotional
Irritability
Sadness
Nervous or
anxious
SleepDisturbances
Drowsiness
Trouble falling
asleep
Hallmark Symptoms
• The hallmark symptoms of concussion are
confusion and amnesia
• Alteration in mental status characteristic of
concussion can occur without loss of
consciousness
Duhaime AC et al. J Neurosurg 2012
Collins ME et al. JAMA 1999
Red Flags
Headache worsens Can’t recognize people or places
Seizures Increasing confusion
Focal neurologic signs Weakness / numbness in arms or legs
Neck pain Unusual behavioral change
Repeated vomiting Decreasing state of consciousness
Slurred speech Very drowsy or cannot be awakened
Complications
Second impact syndrome
• Acute, progressive diffuse cerebral edema
• Disordered autoregulation
Post-concussion syndrome
• Seen in <1% of cases
• Symptoms lasting >3 months
Complications
Post-traumatic headaches
• Onset of headache within 7 days after injury
Post-traumatic epilepsy
• Two fold increase in the risk of epilepsy for
the first five years
• Seizures occurring within the first week are
not considered epilepsy
Complications
Post-traumatic vertigo
• Direct injury to cochlea or vestibular structure
• Labyrinthine concussion due to blunt trauma to membranous labyrinth
Cranial nerve injuries
• Anosmia (CN I)
• Diplopia (CN III, IV, VI)
• Facial pain (CN V)
Complications
Chronic traumatic encephalopathy
• Cognitive impairment
• Neuropsychological symptoms
(behavior, personality changes, depression,
and suicide)
• Parkinsonism
• Speech and gait abnormalities
Chronic Traumatic Encephalopathy
CTE is a progressive disease of the brain
found in athletes (and others)
with a history of repetitive brain trauma
CTE Center, Boston University
International Conferences on Concussion in Sport
2001: Vienna 2004: Prague
2008: Zurich 2012: Zurich
Assessment
Three main points where assessment is
valuable:
• Pre-participation evaluation
• On-site at the time of injury
• Post-injury in office setting
Pre-participation Evaluation
Ask specific questions about:
• previous symptoms about concussion
• length of recovery
• perceived number of concussions
• previous head, face, cervical spine injuries
• details regarding protective equipment used
at the time of injury
On-site Evaluation
• Address first-aid issues first
• If there is a loss of consciousness then
document the length of time the person
remained unconscious
Glasgow coma scale (GCS)
• Record level of consciousness using
Glasgow coma scale
• A person suspected of having a concussion
should not return to activities (play) on the
same day.
On-site Assessment
• Evaluate orientation and cognitive functioning
• Conduct serial monitoring
• Standard orientation questions like time,
place, and person have been shown to be
unreliable in the sporting situation.
Modified Maddocks
• Maddock’s questions are used to determine the impact of the patient’s memory at the time of the incident
• Review SCAT3 with the following slides
Onsite Standardized Assessment of Concussion (SAC)
• Onsite SAC is used for cognitive assessment
• Includes:
– Orientation questions
– Immediate memory of a five word list
– Concentration using digits backwards
– Delayed recall
SAC: Delayed Recall
• Perform delayed recall after completion of the
Balance and Coordination Examination.
• Ask the person to recall words from the list of
words read earlier.
In-office Assessment
• Comprehensive history
• Neurological examination should include
– Mental status
– Cognitive functioning
– Gait and balance
• Determine the clinical status
• Determine the need for neuroimaging
Comprehensive History
• Determine if the impact was directly to the head or transmitted to the head.
• Find out if there was any loss of consciousness, if so, how long.
• Ask if there is any amnesia for the event.
• Determine if there is an observer to collaborate what happened.
• Find out if baseline assessments were done (SAC)
• Ask if there is history of concussions. If so, what are the details?
Neurological Examination
• Neurological examination should include
– Mental status
– Cognitive functioning
– Gait and balance
• Test of memory, orientation, and
concentration as provided in the SAC is
recommended.
Standardized Assessment of Concussion (SAC)
• SAC is used for cognitive assessment
• Includes:
– Orientation questions
– Immediate memory of a five word list
– Concentration using digits backwards
– Delayed recall
Balance and Gait
Balance and Error Scoring System (BESS)
• Double leg stance
• Single leg stance
• Tandem stance
Tandem Gait
Postural stability testing assesses the motor domain of neurological functioning
BESS: Common Errors
• Hands lifted off iliac crest
• Opening eyes
• Step, stumble, or fall
• Moving hip into > 30 degrees abduction
• Lifting forefoot or heel
• Remaining out of test position for > 5 sec
SAC: Delayed Recall
• Perform delayed recall after completion of the
Balance and Coordination Examination.
• Ask the person to recall words from the list of
words read earlier.
Coordination Examination
Upper limb coordination
• Finger-to-nose task
(5 correct repetitions in < 4 seconds = 1)
Clinical Status
• Assess for the presence and severity of the symptoms using a Likert scale (0 to 6)
• 22 common symptoms are listed on SCAT3
evaluation form
Clinical Status
• Determine if the symptoms have changes
• Do symptoms worsen with activity?
• Has patient experienced any retrograde or
anterograde amnesia?
• Is there any change in behavior?
Neuroimaging
• Conventional structural neuroimaging is
typically normal in concussion injuries
Consider neuroimaging if:
• prolonged disturbance of conscious state
• focal neurological deficit
• worsening symptoms
Neuropsychology Testing
• Conduct clinical NP assessment including cognitive function on all your patients suspected of having a concussion
• Formal NP testing is not required for all patients
• Formal NP testing, if needed, should be performed by a neuropsychologist
• Routine baseline NP testing not recommended
Sport Concussion Assessment Tool 3 (SCAT3)
• Tool developed by a group of international
experts at the 4th International Consensus
meeting on Concussion in Sport held in
Zurich, Switzerland in November 2012
• Published in The BJSM Injury Prevention and
Health Protection, 2013, Volume 47, Issue 5
SCAT3 and Child SCAT3
• SCAT3 is used primarily for patients aged 13
and older
• Child SCAT3 is used for children aged 5 to 12
years old
• SCAT3 should not be used as a stand alone
method for diagnosis and management of
concussion
Special Considerations
Children and adolescents
– Child SCAT3 to assess children (5-12 years)
– Modified Maddock’s score with age-
appropriate questions
– Symptom evaluation to include both child and
parent reporting
– SAC with age-appropriate questions and
concentration test
Special Considerations
Elite vs. Non-elite athletes
– All athletes regardless of the level of
participation should be managed using the
same treatment and return to play protocol.
Treatment and Follow-up
• Physical and cognitive rest
• Pharmacology in some cases
• Graded return to activities
Rest
• Rest both from physical and cognitive
exertion for at least first 24-48 hours
• Physical and cognitive activity increases
post-concussive symptoms severity and
prolongs recovery.
• In most cases, no other intervention is
required.
Pharmacology
Two situations where pharmacology plays a role.
• In the management of specific prolonged
symptoms, e.g., sleep disturbance and anxiety.
• To modify the underlying pathophysiology of the
condition with the aim of shortening the duration
of concussion symptoms
Return to Activities Protocol
Step 1No activity, complete rest until asymptomatic.
Proceed to step two when symptoms are gone.
Step 2 Light aerobic exercise
Step 3Sport-specific exercise and training.
No contact or risk of contact.
Half days at school or work
Step 4Non-contact training drills
Light resistance training and progress to heavy weights
Full days at school or work
Step 5 Full contact training after medical clearance
Step 6 Return to competition
Treatment and Follow-up
• Majority of the patients with concussion will
recover spontaneously in less than 10 days
• If symptoms last beyond 10 days or become
worse then the patient’s treatment plan might
need to be modified.
Prevention
• Recognition of the concussive injury is of
primary importance
• Helmets are not concussion-proof
• Mouthguards are a controversial area
• Rule changes to reduce injury
Concussion
• An injury to the brain that causes a brief disruption in mental status
• Not life-threatening
• Often no STRUCTURAL damage but FUNCTIONAL damage is present
• Potential to cause long-term damage
References
• McCrory, P., et al. Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012. British Journal of Sports Medicine 2013; 47:250-258.
• McCrory, P., et al. Sport Concussion Assessment Tool – 3rd Edition. British journal of Sports Medicine 2013; 47: 259-262.
• Makdissi M, Davis G, McCrory P. Updated guidelines for the management of sports-related concussion in general practice. Australian Family Physician 2014; 43(3):94-99.
• Rutland-Brown W, Langlois JA, Thomas KE, Xi YL. Incidence of traumatic brain injury in the United States, 2003. J Head Trauma Rehabil 2006;21:544.
• Liao CC, Chiu WT, Yeh CC, et al. Risks and outcomes for traumatic brain injury in patients with mental disorders. J Neurol Neurosurg Psychiatry 2012; 83:1186.
• Grady GF, Master CL, Gioia GA. Concussion Pathophysiology: Rationale for Physical and Cognitive Rest. Pediatric Annals 2012; 41(9):377-382.
• Crossman, A.R., Neary D. Neuroanatomy: An Illustrated Colour Text, 5th ed. New York: Churchill Livingstone Elsevier, 2015.
• Bickley, L.S., Szilagyi, P.G. Bates’ Guide to Physical Examination and History Taking, 12th ed. Philadelphia: Wolters Kluwer, 2017.
• Report of the Quality Standards Subcommittee of the American Academy of Neurology. Practice Parameter: The management of concussion in sports (summary statement). Neurology 1997;48:581-585.
• Lopez V, Ma R, Weinstein MG, Cantu RC, Myers LS, Nadkar NS, et al. Concussive Injuries in Rugby 7s. Medicine & Science in Sports & Exercise. 2016;48(7):1320–30.
• Duhaime AC, Beckwith JG, Maerlender AC, et al. Spectrum of acute clinical characteristics of diagnosed concussions in college athletes wearing instrumented helmets: clinical article. J Neurosurg 2012 Dec;117(6):1092-9.