This troublesome problem has been mentioned in several places earlier in the chapter, as well as in Chap. 10 in relation to headache. When the syndrome is protracted, neurologists are vexed by the condition—a problem intensified by worried patients and family. It has some similarities to the posttraumatic stress disorder, and had in the past been aptly termed “posttraumatic nervous instability syndrome” and “traumatic neurasthenia” by Sir Charles Symonds, among many other names. Headache, dizziness, poor endurance, and lack of mental clarity are the central symptoms.
The cranial pain is either generalized or localized to the part that had been struck and variously described as aching, throbbing, pounding, stabbing, pressing, or band like; it is remarkable for its variability in an individual patient. The intensification of the headache and other symptoms by mental and physical effort, straining, stooping, and emotional excitement is characteristic; rest and quiet tend to relieve it. Headaches may present a major obstacle to convalescence.
Dizziness, another prominent symptom, is usually not a true vertigo but a giddiness or light-headedness. The patient may feel unsteady, dazed, weak, or faint. However, a certain number of patients describe symptoms that are at least consonant with labyrinthine disorder; objects in the environment move momentarily, and looking upward or to the side may cause a sense of imbalance. Labyrinthine tests may show hyporeactivity of one side of the vestibular apparatus but more often they disclose no abnormalities. McHugh found a high incidence of minor abnormalities by electronystagmography, both in concussed patients and in those suffering from whiplash injuries of the neck; but we find much of the data difficult to interpret. Exceptionally, vertigo is accompanied by diminished excitability of both the labyrinth and the cochlea (deafness), and one may assume the existence of direct injury to the eighth nerve or end organ. Intolerance of alcohol is reported by some patients.
These physical symptoms resolve in several weeks in the majority of patients. When the symptoms persist, the patient becomes intolerant of noise, emotional excitement, and crowds. Tenseness, restlessness, fragmentation of sleep, inability to concentrate, feelings of nervousness, fatigue, worry, apprehension, and an inability to tolerate the usual amount of alcohol complete the clinical picture. The resemblance of these symptoms to those of anxiety and depression and to other forms of “posttraumatic stress disorder” is apparent.
The postconcussion syndrome complicates all types of head injury, mild and severe. Once established, it may persist for months or even years, and it tends to resist all varieties of treatment. Any relationship to the earlier described chronic traumatic encephalopathy is uncertain. Strangely, this syndrome is almost unknown in children under the age of approximately 6 years. Characteristic also is the augmentation of both the duration and intensity of this syndrome by problems with compensation and litigation, suggesting a psychologic factor. In countries where these matters are a less-prominent part of the social fabric, the occurrence of posttraumatic syndrome is far less frequent. Environmental stress assumes importance as well, for if too much is demanded of the patient soon after injury, irritability, insomnia, and anxiety are enhanced. In this connection, an interesting experiment was conducted by Mittenberg and colleagues (1992). A group of subjects with no personal experience or knowledge of head injury was asked to select from a list of those symptoms that they would expect after a concussive head injury. They chose a cluster of features virtually identical to that of the postconcussion syndrome. The high background rates of various components of the postconcussion syndrome make it appear to be more prevalent than it truly is. The prospective study by Meares and coworkers found that, when compared to a group of patients who had noncranial trauma, the rates of the features of the syndrome were the same and that the strongest predictor of its occurrence was a previous anxiety disorder. However, the symptoms undoubtedly occur in well-adjusted, high-functioning individuals and should not be dismissed as simply anxiety.