While the initial neurologic symptoms following concussion typically resolve quickly, many will have symptoms that evolve over the ensuing 1–3 days. The majority of patients experience a complete recovery in 2–4 weeks. However, about 20% of patients experience persistent symptoms lasting months to years. Postconcussive symptoms vary significantly between individuals but include headache, neck pain, sleep disturbances and fatigue, vestibular dysfunction, mood disturbances, and cognitive changes. Identifying the specific symptoms helps individualize treatment. Women, those with prior traumatic brain injury, and those with preexisting anxiety and depression are at higher risk of developing persistent symptoms.
Precise definitions vary, but generally postconcussive syndrome can be considered when persistent symptoms are experienced for greater than 1–3 months after injury. If symptoms persist at 1 month postinjury, it is reasonable to start treatment to facilitate recovery.
Headaches are common in the acute period after head impact but can become persistent. Many of these have migrainous features, though other headache types can also develop. Pharmacologic therapy is identical to that used for abortive and preventative management in headache not related to concussion (see Chapters 65 and 66 ).
Neck pain is a frequent complaint, particularly after hyperextension injuries. Muscular tension in the neck may cause cervicogenic headaches. Occipital neuralgia may be present. Physical therapy is the mainstay of treatment. Occipital nerve blocks may be considered for those with symptoms consistent with occipital neuralgia. Pharmacologic therapy with muscle relaxants and/or benzodiazepines, particularly diazepam, may be helpful but should be limited to short-term use of not more than 1 week.
Sleep disturbances after concussion are common. While the immediate postinjury period is typically characterized by hypersomnolence, chronic sleep disturbances include insomnia, excessive daytime sleepiness, and sleep fragmentation. Obstructive sleep apnea can develop or become symptomatic. As poor sleep can aggravate other symptoms, screening for and treating sleep disturbances early is particularly important. A variety of pharmacologic and nonpharmacologic approaches can be used (see Chapter 78 ), though they have not been studied specifically in postconcussive syndrome.
Vestibular dysfunction, characterized by dizziness and imbalance, and tinnitus can be particularly disabling after concussion. These disturbances are closely related to oculomotor dysfunction, which may manifest as abnormalities of near-point convergence, saccades, and smooth pursuits. Patients often describe worsening symptoms with visual scanning, such as when reading, using phone or computer screens, being in crowds, or driving, or with rapid head and eye movement, such as bending over or turning around quickly. Vestibular physical therapy is the primary treatment. Pharmacologic agents like meclizine or benzodiazepines are of little benefit and should not be routinely used.
Mood disturbances are both a risk factor for persistent postconcussive symptoms and a consequence of concussion. Depressive symptoms, including fatigue, irritability, difficulty sleeping, impaired concentration, and anxiety, are associated with poorer recovery after concussion. Posttraumatic stress and anxiety disorders are also commonly associated with these injuries. Treatment should incorporate a multimodal approach that includes pharmacologic management and psychological support. Serotonin selective reuptake inhibitors (SSRIs) are generally favored over other antidepressants, although tricyclic antidepressants can be considered in those with concurrent chronic headache or neck pain.
Cognitive complaints can include trouble concentrating, irritability, and short-term memory impairment. Other symptoms that can exacerbate cognitive deficits, such as headaches, poor sleep, and depressive symptoms, must be treated. Neuropsychological testing can identify areas of difficulty and help to guide cognitive therapy. There are limited data regarding the use of stimulants and agents like amantadine to improve cognitive functioning after concussion.