On April 8, 2013, plaintiff Danny Clark, 60, a gas pump technician, was driving on the westbound side of West Avenue D, also known as State Route 138, near its interchange with 90th Street West, in Lancaster, when he encountered a dust storm that caused traffic to slow. As a result, he gradually decreased his speed to nearly a complete stop, but was rear-ended by a tractor trailer driven by Oliver Ross. Clark claimed he sustained of his head, neck, and back. Clark sued Ross and the owner of Ross’ vehicle, Market Transport Ltd. Clark alleged that Ross was negligent in the operation of his vehicle and that Market Transport was vicariously liable for Ross’ actions. The defendants stipulated to liability., Clark struck his head on the back window of his truck’s cabin and was knocked unconscious. After regaining consciousness, Clark was transported home by a colleague. However, several hours later, he presented to a Kaiser urgent care facility, in Bakersfield, with complaints of neck pain, back pain, and headaches. Clark received minor treatment for a laceration to the back of his head and was sent home. Clark returned to Kaiser twice more over the next month with allegedly worsening symptoms. He was ultimately diagnosed with a subdural hematoma due to a slow bleed that had accumulated over time. As a result, he was immediately referred to a neurosurgeon and underwent a craniotomy for the evacuation of the subdural hematoma on May 21, 2013. Clark then began a course of cognitive therapy at Centre for Neuro Skills, in Bakersfield, for five days per week over three months. Clark claimed that he suffered traumatic brain injury that directly led to an overall change in his personality and cognitive abilities, as well as caused post-concussion syndrome, insomnia, post-traumatic stress disorder, emotional lability, hearing loss, visual changes, vertigo and a pituitary gland deficiency that required growth hormone replacement. He also claimed that he sustained a cervical strain and the onset of carpal tunnel syndrome as a result of the accident. The plaintiff’s treating doctors opined that Clark was no longer capable of performing his job and that Clark’s symptoms were likely permanent. Thus, Clark sought recovery of past and future medical expenses, past and future loss of earnings, and damages for his past and future pain and suffering. Defense counsel contested the causal link between the collision and Clark’s brain bleed. Counsel also challenged the severity of Clark’s , especially the nature and extent of his cognitive dysfunction and emotional lability. Defense counsel further asserted that Clark did not require additional future care for his cognitive condition, and disputed the necessity of some of Clark’s medications and treatments.