Benign Paroxysmal Positional Vertigo (BPPV): This condition is characterized by brief, episodic vertigo spells triggered by specific head movements, which could be exacerbated or caused by an ear injury. The duration of vertigo spells in BPPV can last from seconds to minutes, aligning with the 30-minute spells described, although typically they are much shorter.

Labyrinthine Concussion: An injury to the ear can cause a labyrinthine concussion, leading to vertigo. The symptoms can vary in duration and may include hearing loss or tinnitus.
Perilymphatic Fistula: This condition involves an abnormal connection between the inner and middle ear, which can cause vertigo, hearing loss, and other symptoms. An ear injury could potentially cause or exacerbate this condition.
Vestibular Neuritis or Labyrinthitis: Although typically associated with viral infections, an ear injury could potentially trigger or mimic these conditions, leading to vertigo and other vestibular symptoms.

Stroke or Transient Ischemic Attack (TIA): Although less common, vertigo can be a symptom of a stroke or TIA, especially if accompanied by other neurological deficits. Given the potential severity, it's crucial not to miss this diagnosis.
Post-Traumatic Meningitis: An ear injury could potentially lead to meningitis, especially if there's a breach in the dura mater. While less common, the severity of meningitis makes it a diagnosis that should not be missed.

Superior Semicircular Canal Dehiscence: A rare condition where there's an abnormal opening in the bone overlying the superior semicircular canal, which can cause vertigo and other auditory symptoms. An ear injury might exacerbate or reveal this condition.
Otogenic Sigmoid Sinus Thrombosis or Other Intracranial Complications: Rare but serious complications of ear infections or injuries, which could potentially cause vertigo among other symptoms.