Persistent Post-Concussion Syndrome After Its Withdrawal from DSM-5 and ICD-11: Definitional Disagreement and the Neurocognitive Gap

A substantial minority of patients do not recover fully after mild traumatic brain injury. Persistent post-concussion syndrome includes both cognitive and non-cognitive manifestations, yet DSM-5 and ICD-11 withdrew the syndrome as a distinct diagnosis and reorganized its persistent sequelae exclusively within neurocognitive categories. While this reorganization addresses the cognitive component of the syndrome, it provides no single category for its non-cognitive consequences, including vestibular, oculomotor, headache-related, autonomic, sleep, and pain-related manifestations. In some patients, these may be the most disabling consequences of the injury. This narrative review examines the resulting diagnostic gap and other continuing disagreements. Published criteria differ in symptom count, duration, and other requirements, yielding an unacceptably wide range of prevalence estimates, from 11.4% to 38.7%. We review the current status of this syndrome and propose an approach that separates diagnosis from attribution. Finally, we discuss the interactions between cognitive and non-cognitive consequences through shared neural substrates, so abnormalities in one domain may influence function in another. Because cognitive and non-cognitive manifestations may dissociate, a patient may have normal or minimal findings in one domain and functionally significant abnormalities in the other; therefore, evaluation confined to one domain alone (as reflected in the new classifications) cannot exclude the syndrome.