DIPG is a clinical-radiologic entity and as such typical MRI characteristics in combination with classical clinical symptoms (CN deficits, ataxia, long tract sign) of short duration (less than 6 months) are essential for the diagnosis. Blood chemistry and other lab studies including examination of cerebrospinal fluid are generally not helpful.
As the disease progresses, more cranial nerves and corticospinal tract involvement (positive Babinski sign) become apparent and hemiplegia, dysphagia, hiccups and hoarseness are commonly seen. Personality changes including separation anxiety, clinginess and night laughter are described, and cranial nerve and corticospinal tract involvement become bilateral. Increased intracranial pressure is not an early feature, in fact only a minority of DIPG patients (20%) presents with obstructive hydrocephalus, but direct irritation of the emetic center in the brainstem may cause vomiting.