Latent Effects of Concussion on Vestibular Functioning

Salvador Bondoc

Case Timothy is a high school junior who was referred to an

outpatient rehab facility due to shoulder and neck pain. He reported that his shoulder problem was associated with a car accident from 4 months ago but his symptoms did not occur until 4 weeks ago. Timothy happen to work at a shop 4 hours daily as part of his HS.

Provocative tests indicate impingement syndrome. His condition was treated conservatively. He progressed very well. However, he felt he could use more “therapy.” One day, he came to the clinic upset that he may have to attend summer school. His grades have suffered since the car accident. He said that he has troubles taking tests and reading.

Case His pediatrician has already cleared him from any

neurological signs. He also has undergone a battery of psychological tests at the request of the mother to determine whether there may be cognitive effects of concussion. The psychologist cleared him. The psychologist also determined that there an underlying depression is less likely.

Timothy and his mother disclosed that he has been sleeping a lot but such sleep does not feel restful. “It’s hard to wake him up,” exclaimed the mother.

He used to be an active gamer but lately, video games and sitting in front of the computer would give him headaches. One time, we tried playing the Wii Tennis. Peculiar behaviors were noted…

What do we know about Concussions in Adolescents and Young Adults?

Concussions

Part of Brain Injury spectrum (NINDS, 2012) Accounts for 75 to 90% of BI Used interchangeably as mild TBI

But TBI is assessed based on target measures Glasgow Coma Scale Lost of consciousness (LOA) Post-traumatic amnesia (PTA)

How about concussions?

Issues

Sports-related concussions are most cited in the literature MVAs are most common causes of

concussions in 15-24 years

Return to play is the target outcome Teens drop out of school, Adults

lose their jobs & go into long term depression

Latent effects have been examined in the literature but only recently given relevance

Issues

1.4 Million go to the ED due to head trauma 1.1 Million receive care

from ED and discharged

Not all those who receive concussion seek medical help

Post-Concussion Syndrome

Cluster of physical, psychosocial and cognitive impairments or symptoms, foremost of which include: Headaches Fatigue Irritability Dizziness Decreased memory Decreased attention, distractibility

Persists in 15-40% in young persons adults for months to years

Underreported PCS Conditions

Executive dysfunctions (MacLennan & MacLennan, 2007)

Postural instability or poor vestibular integration (Bara et al, 2010)

Visual processing and visual motor (Heitger et al, 2009)

Long term studies show that most lingering effects tend to be Cognitive (decreased attention, concentration, memory)

or Emotional (lability, irritability, depression) in nature

Decreased cognitive performance

Decreased visual-motor functioning May be readily detected

Impaired vestibular functions May come and go

Oculomotor and Vestibular Dysfunctions are poorly detected

by brain neuroimaging diagnostics

Clinical Rationale

Clients often manifest oculomotor and vestibular disturbances together Blurred or double vision Bouncing images

+ Vertigo Tipping over or falling

Oculomotor Disturbance, Vertigo and Nystagmus have Brainstem and/or Cerebellar origins

6 Physiologic Forms of Oculomotor Function

Gaze pursuit

Saccade

Fixation

Vergence

Vestibulo-ocular reflex

Optokinetic reflex (pursuits + saccades)

All functions are intended to keep the visual target stable (on the macula)

Red Flags

Parameter Behavioral Signs

Posture Head tilt

Eye Motility Misalignment, nystagmus

Gaze ahead, up, down, side

Horizontal/vertical rebound nystagmus[Can the nystagmus be suppressed?]

Pursuit Appears saccadic

Saccades @ 10o and 40o

Imprecise, lag speed, non-conjugated

VOR 1 Poor fixation with rapid head thrust

VOR 2 No VOR suppression (central)

Ruling Things Out

Peripheral vestibular impairment is a diagnosis of exclusion – i.e., no oculomotor disturbances

Unilateral oculomotor presentation is a peripheral condition

Bilateral presentation is central in nature Isolated gaze impairments have brainstem

origin; may affect some VOR Cluster of gaze impairments have

cerebellar origin; often accompanied by balance impairments

Other Clinical Screens Modified Epley/ Dix-

Hallpike Maneuver Peripheral lesion

Head-shaking Test Peripheral Central (cross

coupling)

Back to the Case

While playing Wii Tennis, Timothy would stumble backwards as the ball “approached” him. He also had trouble sidestepping and appeared to get “clumsier” as the game went on.

During break, Timothy had his head slumped down and one eye was squinting. Although there was no nystagmus noted he seemed to struggle with looking straight ahead.

Timothy’s manifestations prompted a more thorough vestibular screening. No signs of nystagmus was noted with gaze, pursuit and saccades, but his modified CTSIB results showed significant findings.

CTSIB Modified

EYES OPEN EYES CLOSED

FEET ON FIRM SURFACE

All Senses On-Line,

“Balanced”

Vestibular, Somatosensory

available

FEET ON UNEVEN SURFACE

Somatosensory inaccurate;Vestibular +

Visual available

Vestibular demands increased

Balance Master

Eyes closed, Compliant

surface

More on the Case

After discussion with pediatrician, Timothy was “discharged” from hand therapy and was “picked” again for OT to address neuro concerns.

Insurance authorized 4 visits + eval.

Two main foci of intervention were: Self-management (fatigue) Vestibular retraining

Is this Best Practice?

Practice Implications

Vestibular and oculomotor dysfunctions Have latent manifestations Are associated with decreased cognitive

performance and participation

OT practitioners must routinely screen clients for persons with history of concussion Start with Rivermead PCS Quest (RPQ). Screen further based on RPQ

Visual motor Vestibular Executive function

Case Conclusion

Timothy’s mother decided that he should take the year off from school.

He was referred for NeuroOptometrist who identified problems with anti-saccade latency.

He qualified for BRS assistance. He began working at a garden center and took a liking for growing roses.

He stopped counseling indicating that the strategies he learned from OT were more useful.

After 3 months