Benign Paroxysmal Vertigo of Childhood: This condition is a common cause of vertigo and nystagmus in children, often presenting with brief episodes of vertigo and vertical nystagmus, and is usually self-limiting.

Vestibular Migraine: Although more commonly associated with horizontal nystagmus, some cases can present with vertical nystagmus. The diagnosis is considered based on the presence of migraine headaches and episodic vertigo.
Inner Ear Infection or Inflammation: Conditions such as labyrinthitis can cause nystagmus due to inflammation of the inner ear structures. The presence of fever, hearing loss, or tinnitus would support this diagnosis.

Brainstem or Cerebellar Tumor: Although rare, tumors in the brainstem or cerebellum can cause vertical nystagmus due to their location affecting the vestibular pathways. Early diagnosis is crucial for treatment and prognosis.
Wernicke's Encephalopathy: This is a medical emergency caused by thiamine deficiency, often seen in malnourished children or those with poor dietary habits. Vertical nystagmus can be a presenting feature, along with confusion and ataxia.
Multiple Sclerosis: Although more common in adults, pediatric multiple sclerosis can present with a wide range of neurological symptoms, including vertical nystagmus, due to demyelinating lesions in the central nervous system.

Congenital Nystagmus: While typically noticed in infancy, some forms of congenital nystagmus may not be diagnosed until later in childhood. It is characterized by involuntary, rhythmic eye movements that can be horizontal, vertical, or rotary.
Chiari Malformation: This structural defect in the cerebellum can cause a range of neurological symptoms, including nystagmus, due to the herniation of cerebellar tonsils into the spinal canal. Vertical nystagmus can occur, especially with types that affect the brainstem or cerebellar pathways.