Origin of positional nystagmus with direction changing towards the upper ear. A case report of head trauma.

Characteristics and utility of combined duplex color-coded ultrasonography in the cervical rotational position with head MRI and MRA in the differential diagnosis of apogeotropic direction-changing positional nystagmus

“…However, it is dangerous to diagnose peripheral or central nystagmus based solely on the nystagmus findings of apogeotropic DCPN, because patients with apogeotropic DCPN may show a variety of nystagmus over time, or it may be transient, as is common in apogeotropic DCPN caused by peripheral disease. Nystagmus findings have been reported to change over time ( Naganuma et al., 1990 ). Another study reported that rotatory components are commonly observed in peripheral diseases ( Iwasaki et al., 1992 ).…”