Hi,
The symptoms that your husband describes may be those of Post Concussion Syndrome. Post-concussion syndrome, is a set of symptoms that a person may experience for weeks, months, or occasionally years after a concussion, a mild form of traumatic brain injury. Symptoms may include headache, difficulty concentrating, irritability etc. Though there is no treatment for PCS itself, symptoms can be treated; medications and physical and behavioral therapy may be used, and patients can be educated about symptoms and their usual prognosis. Majority of PCS cases disappear after a period of time. Please go for MRI of the brain and consult a neurologist to find out if there is any serious injury to the brain, and for the symptomatic treatment. Hope this helps you. Take care and regards!