Table 1 Model specific pros and cons of experimental models
From: Persistent post-traumatic headache: a migrainous loop or not? The preclinical evidence
Model | Pros | Cons |
|---|---|---|
Penetrative injuries | ||
Controlled cortical impact (CCI) injury | - It affords control all over biomechanical parameters. - It lacks the risk of rebound or second-hit injury, as can happen with gravity-driven devices. - The dura mater is not pierced during the procedure - Allows researchers to quantify the relationship between measurable engineered parameters (e.g., force, velocity, depth of tissue deformation) and the extent of (either functional and/or tissue) impairment. - Injury can be controlled to produce a range of injury magnitudes, allowing gradable functional impairment, tissue damage, or both. - It is the best characterized model of PTH in rodents | - The need for a craniotomy contrast with the fact that the majority of PTH cases results from non-penetrative head injuries. - Craniotomy per se can produce inflammation and sensitization of meningeal afferents, thus proper selection of controls is mandatory. - Pharmacological intervention is not applicable. |
Lateral fluid percussion (LFP) injury | - It produces a robust and reproducible behavioral phenotype (cephalic hypersensitivity) that is suited to the study of PTH in rodents. - It exhibits predictive validity and the reliability of the technique enables the evaluation of various pharmacological and genetic manipulations before or after the induction of injury. | - It does lack translational relevance primarily due the invasive craniotomy required, and subsequent compromise of dural integrity even before the injury is applied. - Still limited application. - As only hind paw allodynia was evaluated, it is difficult to determine the relevance to PTH. |
Non-penetrative injures | ||
Weight-drop injury | - It produces a robust behavioral phenotype, with strong translational relevance making it eminently suitable for the study of PTH. - The severity of the injury can be modified by adjusting the weight and height from which it is dropped. - Variations exist as to whether the skull or scalp are kept intact during the procedure - Increased translational value as the location and magnitude of the head traumas that lead to PTH are highly variable. | - The variability of the procedure itself; may hardly ensure that hits are identical to each other and also to avoid rebound second hits - Pharmacological intervention is not applicable. |
Blast injury | - The experimental setup allows for the exposure of animals to a “pure” blast event without reflected shock fronts from the ground or other surfaces. | - Issues surrounding standardization and implementation are a concern and hindrance for the widespread uptake of blast injury-related models |